Part 1 - Thermal Comfort

THERMAL COMFORT

HONEYCOMB HOUSINGT H E A F F O R D A B L E A LT E R N AT I V E T O T E R R A C E H O U S I N G

M O H D P E T E R D A V I S

M A Z L I N G H A Z A L I

N O R A Z I A N N O R D I NUNIVERSITI PUTRA MALAYSIA

OUTSIDEAIR TEMPERATURE

TEMPERATUREGRADIENT

SOLAR RADIATIONON HOT DAYS TERRACE HOUSES GROSSLY OVERHEAT

Thermal Comfort Housing is an environmentally friendly solution to the general problem of overheated Malaysian houses which causes misery to millions.

AFFORDABLE HONEYCOMB HOUSINGA Cool Shady EnvironmentA New Urban LifestyleA

FFORDABLE HONEYCOMB AF

FORDABLE HONEYCOMB A Cool Shady Environment

A Cool Shady Environment



The Problem and the Solution…

Neighbours now share a child friendly park, bringing nature back into urban living.

The trademark application for HONEYCOMB was advertised in the Malaysian Government Gazette no. 19847 dated 24th November 2005.Applications for patents in respect of A METHOD OF SUBDIVIDING A PLOT FOR HOUSING AND A HOUSING SUBDIVISION SO FORMED were filed in Australia on the 16th of January 2004 no.

200400191 and in Malaysia on the 30th of July 2004 no. 20043089.Cover illustration by Mohd. Hairi Jamaluddin and Mohd. Erwan Othman. The layout of this book was designed and composed on a Pentium 4 computer system with Windows XP Professional by Anniz Bajunid. The typeface, Arial, was used in Adobe InDesign CS Version 3.0.1.Printed and bound by Uniprints Marketing Sdn. Bhd., 11-15 Jalan 3/148A, Taman Sungai Besi Industrial Park, 57100 Kuala Lumpur, Malaysia.Further information on Thermal Comfort Honeycomb Housing can be obtained online at www.tessellar.com.

Perpustakaan Negara Malaysia Cataloguing in Publication DataMohd Peter Davis Thermal comfort honeycomb housing / Mohd Peter Davis, Mazlin Ghazali,Nor Azian Nordin. Bibliography: p. 188ISBN 983-3455-38-7Key words:1. Architecture, Domestic — Design and plans. 2. Dwellings — Heating and ventilation. 3. Dwellings — Design and construction. 4. Housing — Research. I. Mazlin Ghazali. II.Nor Azian Nordin. III Title. 728First Published 2006 by Institute of Advanced Technology, Universiti Putra Malaysia 43400, Serdang, Selangor Darul Ehsan, MALAYSIA. Copyright © 2006 by Mohd Peter Davis and Mazlin Ghazali. All rights reserved. Except as permit-ted under the Malaysian Copyright Act, no part of this publication may be produced in any form or by any means, now known or hereafter invented, including photocopying and recording, or stored in a data base or retrieval system, without the prior written consent of the publisher.

THERMAL COMFORT

HONEYCOMB HOUSING

THE AFFORDABLE ALTERNATIVE TO TERRACE HOUSING

THERMAL COMFORT

HONEYCOMB HOUSING

MOHD PETER DAVIS

MAZLIN GHAZALI

NOR AZIAN NORDIN

Institute of Advanced Technology (ITMA)UNIVERSITI PUTRA MALAYSIA (UPM)

THE AFFORDABLE ALTERNATIVE TO TERRACE HOUSING

ContentsT H E R M A L C O M F O R T H O N E Y C O M B H O U S I N G

v

Contents .........................................................Preface ...........................................................Message from the Sarawak Minister of Housing ..........................Part 1 - THERMAL COMFORTMOHD PETER DAVISwith NOR AZIAN BIN NORDINChapter 1 Housing Studies At Universiti Putra Malaysia............. Chapter 2 Building A Dream Bungalow (1989-1992) ..............Chapter 3 Housing Problems .....................Chapter 4 Population Density ....................Chapter 5 Thermal Comfort .......................Chapter 6 Thermal Discomfort In Malaysia ....................................Chapter 7 How Houses Heat Up ...............Chapter 8 Kampong Housing ....................Chapter 9 Roof Wind Turbines – Do They Work? ...............................Chapter 10 Computer Simulation Of Houses ......................................Chapter 11 Scientific Architecture ................Chapter 12 Ventilation Strategy For Malaysian Houses .....................Chapter 13 How We Invented ‘Cool Roof’ ...Chapter 14 Designing Thermally Comfortable Housing ................

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39172127334147515357697383

Part 2 - HONEYCOMB HOUSINGMAZLIN GHAZALI

Chapter 1 Honeycomb Housing ...............Chapter 2 The Basic Concept Of Honeycomb Housing ...............Chapter 3 The External Spaces ...............Chapter 4 The Housing Units ...................Chapter 5 Pioneer Project Kuching, Sarawak ...................

Part 3 - BUILDING THE FUTURE MOHD PETER DAVIS ..............

List of Figures ................................................Bibliography ...................................................Acknowledgements .......................................About The Authors .........................................Reviews and What We Think ........................

95111117125135

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171180182183184

PrefaceThermal Comfort Honeycomb Housing

The Affordable Alternative to Terrace Housing

The intention of this book is to demonstrate the feasibility of supplying Malaysian families with environment-friendly homes of high quality at an affordable price, even for young married couples before their babies start arriving. We present the scientific case for achieving this ambitious national goal and invite fellow professionals in the housing industry to collaborate.

Our optimism comes from a long period of research and development beginning in 1989 as recounted in this book, not in a dry academic style but as a real life story. We discovered that sheep in our cool animal sheds at Universiti Putra Malaysia were living more comfortably than humans in overheated terrace houses. On detailed investigation the situation was found to be even more ridiculous. On hot days residents of terrace houses would suffer two to three times less heat stress if they abandoned their houses altogether and lived under trees! Indeed, up to 75% of residents in our random household surveys said their terrace houses were too hot on around half the days of the year. After years of steady progress, designing, building and testing thermal comfort houses on the university campus, we were joined by a real architect, hardened to the harsh commercial realities of low-cost housing, but attracted to

our rather idealistic social housing aims and our scientific approach to architecture. Together we discovered how to provide thermal comfort housing without air-conditioning but at no extra cost to the home buyer. This cool house technology, if fully implemented, could save Malaysia RM 200 billion in electricity over a 30 year period. This story forms the first part of the book.

T H E R M A L C O M F O R T H O N E Y C O M B H O U S I N G

vii

viii

Then in 2003 came the scientific leap. Honeycomb Housing, the subject of the second part of the book written by Mazlin Ghazali, suddenly crystallized and increasingly revealed a practical solution to the social and environmental problems caused by terrace housing. A new way of subdividing land into hexagonal culs-de-sac had been discovered which saved up to 20% of the roads, liberating lands in front of the houses for cosy neighbourhood parks. Now we had the chance to bring nature back into urban areas. A wide variety of rare fruit-bearing rainforest trees could be introduced to attract the birds and shade the roads. Instead of monotonous rows of ‘concrete jungle’ terrace houses, the Honeycomb layout allowed us to design wide frontage bungalows, semi-Ds and triplex houses and clusters of very affordable quadruplexes (4 units of corner lot houses) and very novel sextuplexes (6 units of corner lot houses) and all built around the parks. We have created in Honeycomb housing the physical basis for co-operative neighbourhoods, safe for small children to play outdoors. In short, we have discovered a modern scientific way of bringing the best aspects of Lat’s kampongs into urban developments. Consumers agree. In market surveys, conducted by UPM, 95% of respondents liked our overall concept and 80% would like to buy one of our affordable houses.

Now it’s down to action. Developers are beginning to gear up to build Affordable Thermal Comfort Honeycomb Housing for many families. In the longer term there is potential in every other developing country. The world market for housing is immense. The developing world, if it is to lift itself out of poverty, urgently needs 500 million new dwellings in perhaps 1000 new cities. Malaysia, with a 50-year track record of successfully urbanizing its population, can become a major builder of thermal comfort Honeycomb cities for developing countries.We hope this book will inspire students to take up science and technology and dedicate themselves to ‘Building the Future’, the title of the closing chapter of this book.

Mohd Peter Davis Visiting Scientist, Institute of Advanced Technology,Universiti Putra [email protected]

Message from the Sarawak Minister of Housing

A house, regardless of its pricing, is a home. It is not just a structure for dwelling. It has to be felt and treated as a home where each family may live for generations to come. It is where a family grows to create a healthier community society and living environment and eventually evolving into a better nation. When we look at the previous concept of housing for the lower income group, the answer was always ‘low-cost housing’ without much thought of comfort, suitability and the future it holds. A house, no matter how low its cost, is a future investment, both spiritually and physically. It is part and parcel of the community and the future well-being of the nation. So the concept of ‘Affordable Homes’ demands an extra effort by both the Government and the public to build better homes.In Sarawak, our role in the Housing Development Corporation (HDC)

is to find suitable resources to build such homes at an affordable price for the public to own. These houses may be priced somewhat higher than existing ‘low-cost’ houses, but they are more spacious and surely can be called homes, and an investment for generations to come. So, this branding is to eliminate the social stigma attached to the idea of ‘low-cost houses’ and to develop the community-based housing schemes. From there we will move on to create a new brand of ‘HDC Homes’.


ix

YB Dato Sri Abang Haji Abdul Rahman Zohari bin Tun Abang Haji OpengSarawak Minister of Housing

x

When HDC develops housing projects, HDC does not only build houses. We are building a future community, a new well-equipped township. A new approach to housing development has to be evolved. The basic principle of ‘HDC Homes’ concept is that it must deliver a healthier community and stimulate community bonding. HDC Homes encompass not only affordable homes but any other commercially viable homes within the same surrounding that can help bridge the gap between the lower income and the higher income groups whilst creating a healthy and well bonded community. HDC Homes will accommodate the needs of various type of homebuyer, including the elders and the handicapped, larger families and the need for growing children and youth in the community. Facilities such as internet linkage, library and playground will make HDC Homes, homes for the future, homes to come back to and grow in, be it affordable ones for the lower income or any high-end homes.I am asked ‘Will it be practical to build such ambitious homes especially for the lower income group considering the increase in the prices of raw material?’.The answer is that we have to be more creative and innovative. We must

find ways and means to be cost effective. We are looking into new technologies and designs. There are new methods and technology that can shorten the construction period and with less raw materials. We must learn to adapt and change.The Sarawak government has looked carefully into “Thermal Comfort Honeycomb Housing”, the subject of this book. We have held detailed discussions with the inventors, Mazlin Ghazali, Principal of Arkitek M. Ghazali and Mohd Peter Davis, a Visiting Scientist with Universiti Putra Malaysia. Their new Malaysian concept is very much in line with our requirements. As announced on 3 September 2005, the Sarawak Ministry of Housing will be introducing the Thermal Comfort Honeycomb concept in the Ninth Malaysia Plan.

YB Dato Sri Abang Haji Abdul Rahman Zohari bin Tun Abang Haji OpengSarawak Minister of HousingDecember 2005

PART 1

THERMAL COMFORT

MOHD PETER DAVIS

with

NOR AZIAN BIN NORDIN


PART 1Chapter 1Housing Studies atUniversiti Putra Malaysia Our research at UPM over the last 17 years has concentrated on Thermal Comfort. We did most of our basic climatic studies not with houses but with sheep sheds. After a lot of research we discovered that our experimental sheep at UPM were living far more comfortably than humans in terrace houses!

This is how it happened. The Malaysian Government had imported a large flock of sheep from Australia in 1988

and distributed them to various universities and research institutions with the intention of establishing a sheep industry under rubber trees.

With only three day’s warning, three hundred large Australian sheep were given to Universiti Pertanian Malaysia (UPM). By coincidence, a few weeks later

I (Mohd Peter) came from Australia to take up a two-year contract lecturing in

animal science at UPM. I had worked for

many years as a biochemist in the CSIRO


Division of Animal Production in Sydney, the headquarters of sheep research for the Australian Government. In fact that was where I met my wife Noni (Zainur Alsmi Sharif) who had been sent by MARDI, where she was a research scientist, to tour sheep production laboratories throughout Australia. Between us, we knew a lot about

sheep and it was inevitable that I was assigned to look after UPM’s Australian

sheep under the direction of Dr Ali Rajion, another sheep man. The sheep were a tough breed adapted to the hot and dry Australian outback, but they soon started

dying at the alarming rate of 10% per month. They could not cope with the horrendous disease load in Malaysia, the heat stress of the humid climate and the poor quality pastures. We adopted an emergency rescue strategy and quickly modified the animal

houses to keep them cool and help them

survive.

ExperimentalAustralian Sheep

3

t h e r m a l c o m f o r t

4

UPM Hilton for Sheep

Figure 1.1Sheep in this experimental animal shed at Universiti Putra Malaysia (UPM) are more thermally comfortable than humans in terrace houses.

We would suffer 2 to 3 times less thermal discomfort if we abandoned our overheated houses and lived under trees!

2 million concrete houses in Malaysia, from low cost houses to luxury bungalows. Our rather sad, though inescapable conclusion was that 10 million Malaysians would suffer 2 to 3 times less thermal discomfort if they abandoned their overheated houses and lived under trees!

Something must be terribly wrong, since one basic function of a house is to protect its inhabitants from the extremes of the climate, the wind, the rain, the cold and the heat.

This was very successful and with good care, improved nutrition, better housing and 8 years of basic sheep research, Ali

Rajion and I, with our own animal science diploma students as research assistants, were able to produce lambs ready for the dinner table in only 4 months. It was in the course of these studies that we discovered just how well we were looking after our

animals. We named the sheds the UPM Hilton for Sheep.

It is absurd of course for domestic animals to l ive better than humans. This thought inspired the long series of experiments on low-cost houses, terrace

houses, semi-detached houses, bungalows

and apartments. We recorded temperatures using a new technique we developed with MARDI and discovered that gross overheating is a general problem in all of the

1 . h o u s i n g s t u d i e s i n u p m

5

We also uncovered health problems in overheated houses by conducting scientific

random household surveys. These were carried out by very keen final year project

students from UPM under the supervision of Dr Nurizan Yahaya. The studies concentrated on terrace houses since 70% of the urban population lives in this type of housing.

Half to three quarters of all respondents said that their terrace houses were too hot on about half the days of the year, confirming our objective indoor

temperature studies. When asked how they

felt on hot days inside their terrace houses, a high percentage of owners reported symptoms of heat stress.

The household surveys also consistently revealed two other major problems of terrace houses — the kitchens

are too small and the roofs leak.

3 Major Defects of Terrace HousesKitchen too small

House too hot — on half the days of the yearRoof leaks

Based on UPM Random Household SurveysFigure 1.5 Defects of Terrace Houses

Figure 1.3 UPM students at the

‘Hilton Hotel for Sheep’.

Figure 1.2Sheep grow very fast

when heat stress is prevented.

Figure 1.4 Overheated houses are a community

health problem.

Figure 1.4 Overheated houses are a community

Health Problems inOverheated HousesOn hot days inside their terrace houses62% suffer HEADACHES37% get ANGRY34% get SICK

These are the basic symptoms ofHEAT STRESSBased on UPM Random Household Surveys


6

10 million Malaysians suffer these problems in poorly designed terrace houses. Can we overcome these

problems?

Virtually every terrace house owner in the surveys claimed that their original kitchen was too small. This explains the

main renovation owners make, often

hacking into their new terrace houses even

before they move in the furniture. Build and renovate. What a crazy way to build a house! Why not design terrace houses with bigger kitchens in the first place and keep

everybody happy? There is no land space to do so. This is another absurdity. It is against the building code to build up to the back lane

but once the certificate of fitness has been

issued the local authorities seem to turn a blind eye.

Our studies at UPM, in collaboration with the Technical University of Denmark,

also revealed that Kuala Lumpur, like many

other growing cities in the world, is becoming hotter and hotter. It appears that whole cities,

not just individual houses, can overheat. This phenomenon is termed the ‘Heat Island Effect’. Unfortunately for its residents, the average temperature in Kuala Lumpur increased by 1.2 0C over the last 20 years, a world record. Indeed, long term residents of KL say it is now becoming impossible to survive without air-conditioning.

It is very easy for the long suffering consumer to become demoralized with the problems of urban housing. A house or apartment is the most expensive and most important item we ever buy and we spend most of our working lives paying it off.

Defects in dwellings and neighbourhoods are a source of great dissatisfaction and irritation, which appear constantly in the newspapers.

Heat Island Effect

Figure 1.6 Kuala Lumpur got hotter and

hotter from 1975 to 1995.

This temperature monitoring of KL and other

cities deserves to be updated every 10 years

and the public informed.

FiFigure 1 1.6.6 K Kualala L Lumpur got hohotter andnd

‘Heat Island Effect’Many cities are getting hotterby 0.1 to 0.60C (per decade) Baltimore, USA 0.1 0C Shanghai, China 0.1 0C Oakland, USA 0.2 0C Tokyo, Japan 0.3 0C Los Angeles, USA 0.4 0C Kuala Lumpur, Malaysia 0.6 0CConclusion : Malaysia holds the World Record!

1 . h o u s i n g s t u d i e s i n u p m

7

Figure 1.7UPM Students with

Dr Ahmad Hariza Hashim (left),

conducted random household surveys

and discovered that terrace houses are

too hot on about half the days of the

year.

Figure 1.8How can we stop

Kuala Lumpur from overheating?

Our motivation as scientists has always been to unearth and understand the basic problems. Once we do that, history has proven that the technological

solutions are not far away. This is because we humans are very inventive creatures!

Conclusion : The outdoor temperature in Kuala Lumpur has increased 1.2ºC in 20 years.

Slope = 0.06 ºC/yrR2 = 0.75

25.5

28.027.527.026.526.0

1975 1980 199519901985

Average

Annual Te

mperatur

e ºC

Year

21 YEARS (1975-1995) SUBANG METEOROLOGICAL STATION, MALAYSIA(Gregers Reimann, Nor Azian Nordin, Mohd Peter Davis, December 1999)

Chapter 2Building A Dream Bungalow (1989-1992)D esigning and bui lding a

thermally comfortable bungalow for my family was not a sudden decision. Instead it was a long process, in which our other plans collapsed one after the other. My wife had a perfectly good 22’ x 80’ double storey terrace house in Subang Jaya, which she had bought whilst single and had devotedly decorated and equipped, with cabinets, elegant light fittings in every room and a

modern kitchen. She was in love with this dream house in the city, a far cry from a childhood spent studying by the light of a kerosene lamp in a wooden kampong house in Rembau, Negeri Sembilan (Figure 2.1).The only trouble was that I could not live in the modern terrace house, no matter how hard I tried after we got married in 1984. It was simply too hot. What made it worse was that the sweaty work I was doing decorating the house and improving the electrical wiring and plumbing happened to be in March. We


now know March is the hottest month of the year (at least in Kuala Lumpur). I could not sleep, I could not think and I could not wait for the weekends. I just wanted to get back to the beautifully cool and restful nights in my mother-in-law’s classic kampong house.

This house was designed by my wife’s grandfather in the 1930s and combined traditional architectural elements from various Malayan States into an elegant family home shared by three generations and by the whole community on religious occasions.

I went back to work in Sydney, as a biochemist with CSIRO, the Australian Government research organization, and my wife soon followed to do a PhD for 4 years at Sydney University. I carried with me the dream of one day living in the tranquillity of the Rembau foothills with their wonderful kampong architecture: a long, long way from the concrete and, even then, the mind-

9

My Kampong House


10

Home Handyman

boggling traffic of KL. I reasoned that it

was possible to combine the best of both worlds: city jobs and kampong living, connected by fast cars and Malaysia’s rapidly emerging North South Highway.

Being a home handyman I wanted to revive the pre-war glory of the classic kampong house and tastefully install all the modern comforts, such as the Australian kitchen, bathroom, workshop and garage. At that time Malays were in love with the city and joyfully left their kampongs for work and study. I saw things differently. The real history of Malaysia lies not just in the British Colonial buildings of the cities, but goes back to the kampong

architecture imported from much earlier thriving civilizations in South-East Asia. This is fai thful ly recreated in ‘Mini Malaysia’ at Ayer Keroh, Melacca, but the

real thing exists in thousands of beautiful, now partly abandoned kampongs around Malaysia.

However, kampong houses are biodegradable and if not cared for can be taken over by insects and secondary jungle in two years. They deserve a better fate and could be safeguarded for many generations to come, using the modern preservation technology employed in old bui ldings and museums and by archaeologists. It is not too late.

Figure 2.1 Kampong houses are beautifully cool at night (Chembong, Rembau). See Chapter 8 for a complete discussion of this house and kampong houses in general.

2 . b u i l d i n g a d r e a m b u n g a l o w

11

I had witnessed in the early 1970s the attempted destruction of Sydney’s historic houses in ‘The Rocks’ for the planned erection of office blocks. Thanks

to the noble and spirited opposition by concerned citizens and the trade unions, The Rocks, near the Opera House, is now a major tourist attraction for overseas and local visitors alike and an essential historical outing for all Australian school kids.

We returned in 1988 to l ive permanently in Malaysia and raise a family. I was armed with all the home handyman books, videos, tools and machines we could afford. Australia is the land of do-it-yourself and I had readily acquired some of the skills and knowledge needed for house renovation (building on my interest in woodwork whilst I was growing up and working in England). I reasoned that my chances of renewing my two-year contract as a lecturer with Universiti Pertanian Malaysia were not good, given the limited work permits at that time. If Malaysia did not want my brains then I would earn my living with my hands, fixing

houses, making kitchens, operating from home. Meanwhile, my wife generously gave in to my only condition for living permanently in Malaysia. Instead of remaining in Subang Jaya we moved to Rembau to my dream kampong house, completing the urgent renovations whilst planning the longer term innovations. This arrangement, however, soon turned into an ordeal. I was travelling two hours every day, whizzing back and forth

to Serdang with a heavily pregnant wife and we were both suffering from the heat and humidity.

At weekends I was stuck in the kampong house for much of the time preparing new lectures, being just one page ahead of my veterinary students.

I could not think on hot afternoons. The temperature inside a kampong house, I now know, follows within half an hour the outdoor temperature, which can be hopelessly above the upper thermal comfort level during the day time. Do not worship the kampong house, beautifully comfortable at night, but a torture chamber by day. You can survive under a fan but you cannot think. You get a headache and become lethargic and irritable — the general symptoms of mild long term heat stress.

The other problem was social. There was almost no one of our generation left in the kampongs; they are really old peoples’ homes. So we began looking all around Seremban for a cool bungalow to buy and renovate. We hunted for nearly a year, but they were all too hot. It slowly dawned on me that if we wanted a naturally cool bungalow we would have to design and build our own.

That is what we did. We bought PKNS land at RM 6.50psf, on ready-to-build

land, in Bandar Baru Bangi, Selangor and I put my head together with my colleague in animal housing, Dr Shanmugavellu from MARDI. Since we had no model cool house

The temperature inside a kampong house follows within half an hour the outdoor temperature.


12

to follow we started from basic physical principles (Figure 2.2). We agreed that we needed to orientate the house to keep out the sun and we needed an insulated roof, shaded walls and plenty of natural ventilation.

I wanted to build a wooden house on stilts, based on kampong architecture, but Bomba (the Fire Brigade) advised me of the fire risks and the bureaucratic hurdles

I would need to jump to get approval in an urban area. So I reluctantly settled on concrete. This was a lucky accident because, as we discovered much later, thermal mass is essential for keeping a house cool in Malaysia during the day. Also, I

Figure 2.2 Mohd Peter’s Cool Bungalow

Figure 2.3 Large Veranda and Awnings

Risks and Hurdles of a Wooden House


13

Figure 2.4 Mohd Peter’s

thermal comfort bungalow was

designed to stay cool without

air-conditioning (Bandar Baru

Bangi, Selangor).

was lucky that I was not an architect so I did not follow their mistakes. I just jumbled up three architectural styles I liked — kampong architecture (with maximum door and window openings for natural ventilation), a British colonial wrap round 8-foot veranda (Figure 2.3) from Queensland, Australia (to keep the sun off the walls) and an insulated American farmhouse roof with six dormer windows (to let out the hot air). I spent 400 hours at night and at weekends designing the house, building scale models and incorporating the interior design required by my wife. Only at the end did we try to make the bungalow attractive from all angles (Figure 2.4 and 2.5).

Form followed function, unlike much of modern Malaysian architecture where looks come first. We got a draftsman to

make the final drawings, an architect to

check and stamp them and an established house builder, Steven Tan from Kajang, to

build our dream bungalow for RM 282 000. I had beginner’s luck as an amateur

architect and the house worked! It was thermally comfortable and became my most successful experiment in a long career as a researcher. Perhaps this was because we were spending our own money for once, instead of the Government’s. To this day, 14 years later, we are still living comfortably in this house without any air-conditioning,

Jumbled up three architectural styles


14

bungalow of the same size, that is 4000 sf internal area. It follows that the electricity saved will pay for the construction of the house in 23 years. It seems too good to be true, but it is true — free housing, funded by practical, energy-efficient technology, is clearly

possible.‘Thermal Discomfort’ is our measure

of human heat stress. One unit is defined as

one degree Celsius above the upper thermal comfort level for one hour whilst sitting and wearing light clothing. The aim of house design is to reduce thermal discomfort units to zero or below. Thermal comfort is almost achieved, even during the hottest month of the year, in the downstairs rooms and first floor bedrooms

of the house pictured in Figure 2.6, but not in the living room and especially the loft.

continuously testing and improving the ventilation system. We have not done any alterations to the bungalow, except for the roof, which is now made of beautiful glazed blue tiles kindly sponsored by Golden Clay Tiles, in return for a series of experiments to determine if clay tiles make a house cooler than do concrete tiles. The one big mistake I made was not putting enough insulation in the roof : at that time we did not have computer simulation.

However, I avoided an even bigger mistake. I did not follow the crowd and build a conventional bungalow with air-cons throughout. In the long run this move saved us a great deal of money. I estimate, conservatively, that it would cost RM 1000 per month for electricity to air-condition a normal

Electricity saved on air-conditioning pays for the construction of the house in 23 years!

Thermal Discomfort

Figure 2.5 Family living positioned on the ground !oor, where we spent most time during the day.


15

Our dream bungalow, designed to suit our family needs, has served a wider purpose; it is the first scientific demonstration that energy efficient

thermally comfortable houses can be built in Malaysia without using air-

conditioning. If you ever get the chance, have fun and design your own

dream house.

Figure 2.6 Experiments prove

that cool houses can be designed for the

Malaysian humid tropics without heart-stopping electricity bills.

THERMAL COMFORT HOUSE - BANGI 2 1/2 STOREY BUNGALOW WITH PASSIVE VENTILATION AND NO AIR-CONDITIONINGIN UNITS OF THERMAL DISCOMFORT* CONCLUSION:-Indoor environment stays acceptably cool for an electricity cost of RM 25 per month to run the ceiling fans

41 units ofThermalDiscomfort OUTDOORS IN SHADE*Values indicate units of Thermal Discomfort per 12 daylight hours (5-9 March 2000)Values under fans (at moderate speed) show reduced Thermal Discomfort (see Chapter 6)

Loft

Bedroom 1 Living

Bedroom 2 Bedroom 3

Chapter 3Housing ProblemsBefore we discuss in more detail

some of the mistakes made in urban housing, we should first put Malaysian housing into

a proper perspective. The United Nations’

2003 report on Human Settlements found

that almost half the world’s urban population

lives in slums (characterized by lack of

basic services or clean water, poorly built

housing and overcrowding). However,

this serious social problem was largely

avoided in Malaysia. The Malaysian housing

industry since Independence has been

outstandingly successful. The construction

of reasonable quality urban housing, built

to Government regulations, kept pace with

the large population increase and the mass

migration from the rural areas. Malaysia’s

housing success has become a role model for developing countries and high on the

agenda of visiting dignitaries, such as South

Africa’s Nelson Mandela.

Figure 3.1Nelson Mandela wants Malaysia’s

help in designing and building houses

for Africa.


17

Housing Affordability

A major problem with Malaysian

houses today is the price. Houses are

just too expensive for the large majority

of families. How do we assess housing

affordability? The international rule of

thumb is that a house or an apartment

should not cost more than 3 years of

gross family income. For instance, if the

average gross family income is RM 2000

per month, as reported in the Malaysian

census, affordable housing for the average family is therefore RM 72 000

(that is RM 2000 x 12 months x 3 years).

We can now determine the type of house,

apartment or flat a family can safely afford

based on their gross family income per

month. The 3-year affordability rule may

seem too strict, but in fact is perfectly

sensible. It leaves sufficient income for

other essential family expenditure such

as food, clothing, transport, household

expenditures, health, schooling and

entertainment. Housing loans are usually

over periods of 20 to 30 years, so you

have to think long term. If a family breaks

this rule its monthly housing repayments

will be too high and it will not be able to make ends meet. A family member will

have to look for a second job, which often

undermines the welfare of the children.


Figure 3.2House prices have become ridiculous: 80% of Malaysian families cannot af-ford to buy a house.

18

From the housing affordability

table (Figure 3.2) it can be seen that the cheapest double storey terrace house

(say RM 150 000) will require a family

income of RM 4170 per month to sustain

the house repayments. In reality perhaps

only 20% of families actually earn this

amount or more per month. Therefore,

80% of Malaysian families cannot really

afford to buy a house. Apartments, and

‘pigeon hole’ flats are therefore the only

hope of home ownership for most families.

Over the last 20 years Universiti Putra

Malaysia’s Associate Professor Nurizan

Yahaya has documented serious social

problems with low cost houses, flats and

apartments. The Malaysian squatters’

organizations highlighted one of the

problems at a national forum, reported in

The New Straits Times of 6 October 2003.

They said to the Government, in effect,

‘We don’t mind shifting from squatter

housing but when you move us, please

give us bigger flats and apartments’.

‘Affordable Quality Housing’ is a concept introduced by Universiti Putra Malaysia at a Government/Industry seminar in 1997, and formally adopted by the Government

of Sarawak in 2005.

3 . h o u s i n g p r o b l e m s

19

Chapter 4Population Density

T he Malaysian populat ion in 2003 reached 23 million. The United Nations forecasts that it will increase by 60% to 37 million by the year 2050.

However, one hundred years ago when Malaya was a patchwork of British colonies and protectorates and an agricultural society, the population was

Figure 4.1 Malaysia is a young

growing nation and will need a good

supply of houses for the next

two generations.


only 3 million. Independence was followed by a rapid transition from agriculture to an industrial society and this created the national wealth to support an expanding population. By 2050 when Malaysia is expected to be fully developed, and hopefully far wealthier, the population will be 10 times its 1900 level.

Malaysia will be 10 times its 1900 population by 2050.

21

Year

Million

0

40302010

1900 1925 200019751950 20502025

IndustrializationPopulation : 10 FOLD INCREASE in 150 YEARSAgriculture

Projected Population : UNITED NATIONS

Developed Nation23 Million

2003

37 Million2050

MALAYSIAN POPULATION


22

Such a ‘population explosion’ terrified my generation in the 1960s and

1970s with the dire predictions from ‘The Club of Rome’ and the sprouting environmental movement that the food, oil and mineral resources on ‘spaceship earth’ were about to run out. The fear, orchestrated notoriously by American Secretary of State Henry Kissinger in ‘Agenda 200’, was that the population growth in underdeveloped countries threatened to use up all the mineral resources of our (American owned!) planet.

This did not happen and will not happen provided that we develop our brains and thereby the discoveries, inventions and

creations to enhance the productivity and natural bounty of nature. This after all is precisely the intellectual path of civilization that humans have always followed. It has allowed the human population to expand tremendously by orders of magnitude beyond the capabilities of any ape-like animal, particularly over the last 50 000 years. The latest genetic analysis of mitochondrial and Y-chromosomal DNA from all races on earth proves convincingly that we all descended extremely recently from a small group of humans in Africa.

Our common ancestors quite literally walked and sailed out of Africa and spread throughout the world to form the six

Figure 4.2 Malaysia has plenty of room to grow when compared to other Asian countries.

Population Explosion

Asia : Population Density(person per square kilometre)Laos 24 Myanmar 62Malaysia 69 112 by year 2050? Cambodia 71 Indonesia 119 Thailand 121 China 134 Vietnam 246 Philippines 281 Japan 336

4 . p o p u l a t i o n d e n s i t y

23

Figure 4.3 Malaysia has a very satisfying

rate of growth but needs a balanced

distribution of population densities

between states.

billion population we have today (Reference ‘The Journey of Man’ 2002 by Spencer Wells). This means that in reality there is only one race on earth — the human race. This should come as no surprise; it is exactly in accordance with the teachings of all the major religions. We are all related. We all have the same basic needs. We should all settle our differences and strive to live up to our common heritage and be one big happy family!

Since Independence from the British, multiracial Malaysia has tried very hard to do exactly this and has won the respect of other developing nations for its relatively successful efforts so far. Malaysia’s population has

increased three fold since independence, yet it is far better fed, housed and educated than during colonial days and not in any way at the expense of other countries. Even so, Malaysia’s population density (people per square kilometre of land) is still low compared to the neighbouring countries and especially the developed countries. When we look into more detail it is clear that Malaysia’s population is not evenly distributed around the states. Selangor has 526 people per square kilometre whilst Sarawak has only 17. The population density map indicates where we should be planning new cities to uplift the living standards of the present generation, our children and grandchildren.

Population Density

Malaysia 69Indonesia 119Philippines 281

Kuala Lumpur5676Selangor526

Perak98Penang1274

Kedah175Perlis257

Pahang36

Kelantan87 Terengganu69

Negeri Sembilan129Melacca385 Johor144

SINGAPORE6428

THAILAND121

Sarawak17

Sabah35

POPULATION DENSITY — YEAR 2000(persons per km2)


24

Malaysia is a young multicultural nation with a very young population : half of its people are under 23 years of age. They will soon come on to the housing market and be joined in due time by their children and grandchildren. With present advances in labour-saving building technology, home ownership for every Malaysian family is fast becoming a realizable dream.

With residential building and urban renewal (to replace sub-standard housing with new houses, community parks and public amenities) the prospect emerges of a very healthy housing market for the next 50 years, in other words for the next two generations.

Figure 4.4We have to plan now for the housing needs of these children… and their children! According to leading world economist and American statesman, Lyndon LaRouche, two generations (25 to 50 years) of forward planning are needed for a nation to be successful.(see www.larouchepub.com)

This is how far ahead we have to think when we talk about housing and basic infrastructure like roads, railways, water, and electricity as well as food production for a growing population. The problem is that such long term national planning does not come naturally to people. Indeed Malaysia is a youthful, energetic nation and just wants to get on with the job as fast as possible. We have developed what newspaper reporters, investigating the uncoordinated public transport in Kuala Lumpur, have termed the ‘Build now… think later!’ culture.

The Future of the Housing Industry

Half of Malaysia’s population is under 23 years of age and will soon come on to the housing market.

4 . p o p u l a t i o n d e n s i t y

25

Malaysia’s population is set to increase by 60% by 2050, which is within the lifespan of half the present population. The current map of population density indicates where new Malaysian cities need to be built. This offers a great opportunity to correct the mistakes of the

last 50 years and design tropical urban environments more suitable for this hot and humid climate.

Chapter 5Thermal ComfortThermal comfort is subjective. It

is said to exist where 80% of those persons exposed to an environment indicate that it is ‘comfortable’ on the scale:-

cold, cool, comfortable, warm, and hotIndoor thermal comfort can be

determined by a quite simple experiment. Students attending a lecture of mine in a large hall at UPM were asked to vote on how they felt on the cool to hot scale. Each student was allowed one vote. Figure 5.1shows the results:-

Figure 5.1 Indoor Thermal

Comfort

27


COLD 0COOL 41COMFORTABLE 260 f 82%WARM 15HOT 1NUMBER OF STUDENTS 317HALL TEMPERATURE 26 0C

Eighty-two per cent were comfortable with the hall temperature at 260C, meaning that the air-conditioning was set just right for this size of class. Of course you can never satisfy everyone. One student felt hot, but he gave a good reason — he had a fever. From simple experiments of this type we have concluded that the thermal comfort zone for Malaysia is within 240C to 280C. Grander versions of these experiments conducted by researchers using climate chambers have confirmed this conclusion.

Indoor Thermal Comfort

There is a popular belief that Asians and Africans can withstand the heat better than Europeans. Indeed it is a common view, even in Malaysia, that Indians can take the heat and are said to be biologically better suited than Malays for working in plantations and on the roads. However, these beliefs are not true. Professor Fanger from Denmark, the foremost expert on human thermal comfort, concludes that there is no significant difference between

the various ethnic groups in the world. This simple conclusion, without any ifs or buts, comes from his own extensive studies with Danish and American college students. Prof. Fanger in his book Thermal Comfort

Racial Differencesalso quotes other researchers who have developed the same conclusion :

‘This applies to various studies including by Ellis among Asian and European residents in Singapore; a study by Angus among students of many different races in London and the investigation by Wyon in British operating rooms comprising subjects of different ethnic groups’. On biological grounds these findings are not surprising.

All 6 billion humans on earth today come from the same human ancestors who lived in Africa just 60 000 years ago. We all belong to the same family. The genetic diversity that has occurred during man’s 50 000 year colonization of the world (representing just

Figure 5.2The genetic di!erences between the people of the world are extremely small. We all experience and su!er from heat in the same way. Skin colour makes no di!erence.

No significant

difference between

various ethnic

groups in the world.


28

Figure 5.3Cooling E!ect of

Fans

Contrary to popular opinion, a ceiling fan does not cool

a room. But it certainly makes

us feel about 20C cooler.

Blaming the climate

is partly correct.

When various ethnic groups are tested in rigorous experiments in climate chambers, scientists can find no significant differences in thermal comfort

conditions for the different groups. As we have seen, there is only one race

on earth, the human race. We all suffer from heat in the same way.

2000 generations) has been quite minor in this very short time. The minor, indeed superficial differences between various

When Malaysians feel hot they generally blame the climate. However, this is only partly correct. The source of our thermal discomfort is not only the climate, but the heat generated by our own bodies as a waste product of cellular metabolism and muscular work. Think about it. The Malaysian outdoor environment rarely exceeds 350C, yet our normal body

Why We Feel Hot

ethnic groups (in skin,eye and hair colour for example), are insufficient to cause any

differences in basic human physiology.

temperature is always hotter, at the normal 370C. It is difficult for humans (of any ethnic

group) to lose body heat to the outside environment during daylight hours. Under Malaysia’s rainforest climatic conditions the humidity is generally high (50% to 95% humidity on most days of the year) and the average wind speed is very low (less than 1.6 km per hour).

Thermal ComfortFan creates artificial wind which removes

hot humid air from skin, replacing it with

cooler, slightly drier ambient air.

Heat StressedInvisible envelope of hot humid air acts

as insulation and prevents heat exchange

with environment.


29


30

These factors combined make it very difficult to lose heat from our bodies by evaporating sweat from our skin, a biological cooling process that humans do very well in hot dry climates such as Australia and the Arab countries. There is nothing much that we can do

Malaysia is a major producer of ceiling fans and fans in general, for good reasons. Survival in our hot homes is unthinkable without fans. An electricity blackout causes misery. Our surveys by UPM students reveal an average of 5 fans per terrace house. Ceiling fans create an artificial wind which

makes us feel 20C cooler. A fan allows us to tolerate a 300C indoor environment rather than one at 280C. The popular belief that a fan cools a room is not correct. In fact the heat generated by the electric motor of the fan actually makes the room around 0.10C hotter. To lose heat from our bodies we need a temperature gradient. We lose heat from our bodies (at 370C) through our skin (at 340C) to the cooler air in a room, say at 320C. However, in still air we have a problem. An invisible layer of hot air at 34-350C builds up and covers our skin and acts as an insulator. This barrier of hot air prevents heat loss from the skin to the environmental air, which makes us feel uncomfortable. The wind generated by a fan rips away this

Why Fans Are So Useful

about the Malaysian humidity, short of demolishing our national treasure, the rainforest. However, if we could increase the wind speed to even 6 km per hour, the Malaysian outdoor climate would become quite toleratable and far more acceptable to tourists from cold climates.

layer of hot air, replacing it with the cooler air inside the room and provides us with instant relief from the heat. Of course this physical cooling effect can only occur if we are sitting almost directly under the fan, in

Figure 5.4Before electricity a ceiling fan (called a punkah) required a man at the end of a rope. What a boring job!

It would be nice if we

could increase the

wind speed to 6km per hour!

To lose heat from our bodies we need a

temperature gradient.

5 . t h e r m a l c o m f o r t

31

Liquid sweat alone

provides no cooling

effect at all.

the pathway of the artificial wind. This is

the big limitation of a ceiling fan in a room. The fan is fixed; it needs to be movable

— a problem in search of an inventor! As the house heats up the fan becomes less and less effective. As the room temperature approaches the 340C skin temperature, the ceiling fan provides no physical cooling at all. We are merely replacing the hot air surrounding our skin with the equally hot air in the room. We respond to this wretched situation by sweating. Nonetheless, the fan is still useful by assisting biological evaporative cooling of sweat. As the environmental air temperature reaches

The ceiling fan exploits these biological and physical cooling

principles yet only consumes 40 watts or one cent’s worth of

electricity per hour. The humble fan is therefore one of mankind’s

truly useful inventions. The poor ‘coolie’ of a century ago, obliged

to spend the best years of his life fanning the British colonials at

Singapore’s Raffles Hotel, would certainly have agreed...

had he known.

300C in Malaysia we begin to sweat slightly; by 340C in still air many of us are sweating profusely. We feel and look miserable, often with sweat dripping off our ears. Liquid sweat provides no cooling effect at all. It is only when the water in sweat evaporates on our skin that our bodies are cooled down. A fan helps this evaporative cooling, again by replacing the layer of hot air surrounding the sweaty skin with equally hot but slightly drier environmental air. A fan replaces the air covering sweaty skin, which is almost 100% saturated with water, with air at around 60% relative humidity, that can still take up water from the sweating skin.

Chapter 6Thermal Discomfort in MalaysiaThe Malaysian outdoor climate

is only thermally uncomfortable for 10 hours per day. Once the sun goes down the outdoor environment is well within the thermal comfort zone for 14 hours, even during a heat wave (Figure 6.1).

‘Thermal Discomfort’ is a very useful concept since it quantifies and characterizes both the indoor and outdoor environments in human terms. We have

Figure 6.1 Daily Temperature

Cycle

The outdoor temperature in Malaysia is hot

for sure. However, for 14 hours out

of every 24 hours the temperature is within the human

thermal comfort zone.


defined one unit of thermal discomfort as

being the dissatisfaction experienced by a person wearing light clothing and resting, inside a building, or outdoors in the shade, when subjected to a temperature 10C above the upper thermal comfort level (280C). The units, in 0C per hour, are cumulated. Thus, a person exposed to an average environmental temperature of 290C for 1 hour followed by a temperature of 310C

33

Thermal Discomfort

Tempera

ture ºC

Time

24

3432302826

6am 10am 10pm6pm2pm 2am22

OUTDOOR TEMPERATURE30 units of Thermal Discomfort

Thermal Comfort Zone24ºC - 28ºC

DAILY TEMPERATURE CYCLE


34

direct solar radiation since Malaysians do everything possible to stay out of the sun, including the use of umbrellas. Malaysia is also the land of no wind, except for brief periods of strong winds, often associated with rain. Likewise, we also disregard the effect of humidity since in the Malaysian climate (but certainly not in other, drier climates) the humidity is determined solely by the air temperature. My collaborator, Dr Shanmugavelu from MARDI (the Malaysian Agricultural Research Institute) has proven this and indeed has written the non-linear formula from 15 000 pairs of outdoor temperatures with corresponding relative humidity values, as kindly supplied by the Kuala Lumpur Meteorological Office. As the

Figure 6.2Humidity Prediction Equation

As the temperature goes up the humidity comes down.

for the next hour, suffers 1+3 = 4 units of thermal discomfort over the two hour period. Likewise, in the daily temperature graph (Figure 6.1), the outdoor environment imposed 30 units of thermal discomfort in 24 hours. This is a measure, admittedly crude, of the 24-hour heat stress a person experiences outdoors in the shade. For the Malaysian humid tropics (i.e. the lowlands of the Peninsula) we have taken the liberty of disregarding the effect of sunshine, wind and humidity, which greatly affect the feeling of warmth in other climates.

This sometimes offends our scientific colleagues, but we have adopted a

practical rather than an academic approach to human thermal comfort. We disregard

A practical rather than an academic approach to human thermal comfort.

Dr Shanmugavelu’s Humidity Prediction Equation for Malaysiay + a+ bx + cx2

The humidity can be accurately calculated (±4%) knowing only the ambient temperature. Temperature Humidityy = Relative Humidity 24 0C 95 %x = Temperature 28 0C 79%a = 231.04 30 0C 72%b = -7.106 33 0C 62%c = 0.0598 35 0C 56%

6 . t h e r m a l d i s c o m f o r t i n m a l a y s i a

35

temperature goes up the humidity comes down in a predictable way.

As an examp le , when t he temperature is 240C the humidity is 95%; when the temperature is 280C the humidity is 79%; and on a hot afternoon when the temperature is 340C the humidity is only 55% (Figure 6.2). Humidity in Malaysia can nearly always be predicted from the temperature. In practice, we can therefore greatly simplify matters and relate thermal discomfort in Malaysia to just one measurement, the environmental air temperature.

For this to be useful we really need to know the thermal discomfort for every day of a typical Malaysian year. This may

sound easy but it first involves analysis

of the outdoor temperature data for every hour of the day… over the last 20 years! Fortunately, this enormous amount of precious data was generously supplied to UPM (for Subang Airport) by the Malaysian Meteorological Office in Kuala Lumpur. We

were able to create the first approximation

of a typical Malaysian ‘temperature year’ where each day is expressed in units of thermal discomfort. This work was carried out during a 4-month study at UPM by a very smart Danish postgraduate student, Gregers Reimann, who has a close affinity for Malaysia since his father, Lesse

Reimann was Ambassador to Malaysia from 1997 to 2003.

Figure 6.3Three ‘cool’

researchers: Mohd Peter, Gregers

Reimann and Nor Azian Nordin.

Environmental Air Temperature


36

Thermal discomfort provides an alternative method of representing the weather. The weather forecast appearing on TV every night is very misleading. It states the expected maximum and minimum temperatures for different parts of Malaysia. However, this information gives the impression that Malaysia has an extremely even climate throughout the year (Figure 6.4). This is not really true. When we analysed not just the peak daily temperatures, but the thermal discomfort caused by the hourly temperatures throughout the year, we discovered a quite different situation. When hourly outdoor temperatures were converted to units of thermal discomfort, the true seasonality of Malaysia was revealed

Figure 6.4Maximum and Minimum Temperatures in Kuala Lumpur During the Year

The data are misleading : they simply imply that each month is more or less the same (see text).

The UPM Thermal Discomfort Forecast

(Figure 6.5). We showed two regular heat wave periods for peninsular Malaysia, in early March and late May. The regular heat wave in early March always catches everyone by surprise since the last week of February is quite cool. Figure 6.6 shows the same data as Figure 6.5 but in more detail, in blocks of 3 days.

Figure 6.5Malaysian Reference Weather Year

Every day in Malaysia is hot but some days are hotter than others. The heat pattern in Malaysia is best visualized by dividing each month into 10 day periods. This reveals the regular heat waves at the beginning of March and the end of May. These hot months cause two to three times more thermal discomfort than the ‘cool’ months (September, November and December).

MALAYSIAN REFERENCE WEATHER YEAR

Tempera

ture ºC

5

30252015100

454035 ‘Hot’ Days

March Heatwave May Heatwave

‘Average’ Days

‘Cold’ Days

MonthJan Feb MayAprMar Jun Jul Aug Sep Oct Nov Dec


37

Clearly, the Malaysian climate is not just one hot day followed by another as suggested by the maximum temperatures. Instead there is great variation throughout the year; the hottest days (4th to 6th March)cause 16 times more heat stress than the coolest days (16th to 18th December). The first six months of the year are considerably

hotter than the last six months. The average thermal discomfort during the hottest two months (March and May) is 32 units per day compared to only 14 units during the 4 cool months (September to December). We now have the prospect of a far more sensible TV weather report :- ‘Tomorrow is expected to be another

hot day in Kuala Lumpur causing 41 units of thermal discomfort, but next week is expected to be cooler, in the range of 20 to 25 units. The TV map gives tomorrow’s expected thermal discomfort in each State.’

Figure 6.6 is therefore a forecast of thermal discomfort throughout the year, providing very useful knowledge for planning a wedding or an outdoor activity. Who, for instance would enjoy a midday wedding under a tent during early March or late May? Just look at the Figure 6.5 to see the heat stress you are likely to impose on your guests. Figure 6.6 will also help agricultural enterprises

Figure 6.6 Malaysian

Weather Year : Thermal Discomfort Units (every 3 days)

Planning a wedding? Check out this table. It

forecasts how much your guests will

su!er on di!erent days of the year.

Malaysian Climate


38

The 20 year temperature study we conducted at UPM also revealed an exceptionally severe heat wave between January and June 1998 caused by the El Nino effect (thought to be related to periodic flare ups on the sun). The thermal discomfort

in Kuala Lumpur was 75% higher than in the same months of the previous nine years (Figure 6.7) and caused a great deal of

to take precautions, especially chicken farmers who can lose half their birds on a hot day. The thermal discomfort forecast will also greatly assist Tenaga National

El Nino Effect

in estimating the widely fluctuating daily electricity demand for air-conditioning and ensure sufficient electricity production during hot periods.

suffering in Malaysia. The insides of concrete houses

were well above the upper thermal comfort level every minute of the night and day for months on end and sleep was difficult. This

turned the urban population into zombies — too tired to think straight. We suspect this exceptional heat wave caused (and that possibly the March and May heat waves

Figure 6.7Thermal Discomfort (1989-1998) Petaling Jaya Meteorological Station, Selangor

A spectacular heat wave occurred in Malaysia in 1998 (January to May). It was part of the worldwide ‘El Nino’ e!ect.

Exceptional Heat WaveJan-May 1998Thermal Discomfort75% more than same months in previous 9 yearsJan-May 1998 : Mean 45.4 ± 1.37 s.e.Jan-May 1989-1997 : Mean 25.9 ± 0.32 s.e.

5

4540353025201510

5055

1989 1990 1997199619951994199319921991 1998 1999

Thermal

Discomfo

rt per 24

hours (m

onthly av

erage)

Year

THERMAL DISCOMFORT (1989-1998)


39

which occur every year, may be causing) an increase in accident rates at home, on the roads and at work, particularly for the urban population living in overheated concrete houses. A statistical study to test this

When you are outdoors in Malaysia, almost all of the thermal discomforts you experience occur whilst the sun is high in the sky between about 10am and 5pm. People generally do not choose to be outdoors during these hot times. Indeed, the noonday sun is reserved, according to Indian tradition, for ‘mad dogs and Englishmen’. Agricultural Malays, a generation or two ago, were culturally adapted to the harsh climate and chosed to

Living with Thermal Discomfort

hypothesis, comparing accident rates during hot and cooler times of the year, would be very worthwhile. We will be delighted to give our 20-year thermal discomfort data to any serious students undertaking this project.

leave the rice fields at 11am, rested under

the house and only returned at 3pm. The early mornings, late afternoons and all the hours of darkness are quite comfortable in spite of the 60% to 90% humidity. People voluntarily move outdoors to wash cars, take care of the garden, play sports and engage in Malaysia’s favourite pastime, outdoor eating. The Malaysian climate is therefore pleasantly comfortable for 14 hours per day.

However, if the Arabs had colonized Malaya instead of the British, we would probably have ended up with a far more sensible lifestyle

in Malaysia. We might work and socialize outdoors during the cooler night and sleep through the hot part of the day. Turning night into day

and building houses under floodlights, instead of the blazing sun,

would certainly make a lot of sense, improving productivity as well as the long term health of building workers.

Chapter 7How Houses Heat Up

The very best way to find out

how houses heat up is to repeat our original

experiments in your own house. This is quite

cheap to do and very suitable for amateur

scientists, especially science students

looking for worthwhile projects. Please be

warned before you leap into action, that it

requires a bit of dedication (like crawling out

of bed every one or two hours to measure

temperatures!). Once you have discovered

for yourself how your house heats up and

cools down, you will never forget. More

importantly the experiment will get you

thinking, especially on hot days when you

and your family are sweating and suffering

inside your house. You will start inventing

ways to make your house cooler, first in

your mind and then putting your ideas into

practice and testing the results. This process


of discovery, thinking and inventing is what

distinguishes man from animals. All humans

are born with this unique capability; which

cannot be acquired by a single animal of

any species, no matter how hard we train

monkeys in the laboratory or dolphins

in the pool. Only humans, through their

technology, can change the natural world

to their advantage.

This is why the human population on

earth has been able to increase, especially

over the last 50 000 years, to over 6 thousand

million whereas dogs, apes, monkeys or

elephants cannot expand naturally beyond

a few million (www.larouchepub.com ). Do the following experiment in your

house. While you are doing it, observe your

cat. It is able to find the coolest spot in your

hot house to sleep. However, this is all it can

The process of discovery, thinking and inventing is what distinguishes man from animals.

41

Our Early Experiments

do, its highest pinnacle of achievement, its

genetically determined career limit. Don’t

expect your cat to contribute anything more

to your experiment. Buy your equipments.

Red alcohol thermometers for house and

garden use can be purchased at some

large supermarkets for RM 10 to RM 20.

With careful reading they can give the

temperature to 0.20C accuracy.

Check the temperature of all the

thermometers on the shelf. Buy only those

that read the same temperature in the

controlled environment of the store. Don’t

be the sucker to buy the last thermometer in

the store: it could be very inaccurate. Armed

with just five to ten alcohol thermometers,

the world is at your feet!

Hang the thermometers in different

rooms of your house at about 4 feet from

the floor and at least 2 inches from the

wall (since you want to measure the air

temperature not the wall temperature, which

can be several degrees different). Place a

thermometer in the roof space. Hang one

or two thermometers outdoors under a tree

or a large bush. As often as you can, or

preferably every hour, go round the house

and garden and record all the temperatures

for a few days. Plot graphs of temperature

against time of day to discover for yourself

how different rooms of your house heat up

and cool down throughout the day compared

with the outdoor environment. Repeat the

experiment on different days of the year.

Figure 7.2 (left)Internal view of a Digital Temperature Data Logger

We routinely set the sensor to record the temperature every 24 minutes for 2 weeks. At the end of the experiment, the data are downloaded into a computer for analysis.

Figure 7.1 (far left)Digital Temperature Data Logger

The size of a match box.


42

Figure 7.3 Temperature Inside

a Concrete House

For most of the time the temperature inside a concrete

house is much hotter than

outdoors. This is the

fundamental design fault of 2 million urban houses in

Malaysia.

Why is your house always hotter?

If you want to know how your house

performs thermally compared to your friend’s

house, you will need to co-operate and

both do the experiment on the same days

under the same climatic conditions. Why is

your house always hotter? Your house is

single storey; your friend’s house is double

storey with the same built-up area, but his

roof is only half the area. You hypothesise

that the overhead sun is the source of the

overheating in Malaysian houses. A larger

roof lets in more solar heat. Can we shade

the roof with a big tree? If your hypothesis

is true this action should then make your

single storey house much cooler, indeed

even cooler than a double storey house. If it

is as simple as that, why didn’t our Malaysian

ancestors build houses under trees?

Perhaps they knew that this was dangerous;

that a storm could bring down the tree,

destroy the house and kill the occupants of

the house. Instead of shading the roof, can

we insulate it against the heat of the sun?

So, whilst your cat can do little more than

sleep and catch mice, you and potentially

any other human in the world are now on the

road to inventing a solution to overheated

houses which will benefit not just you and

your family but every family in Malaysia and

future generations. This represents human

progress. It does not take the rare gifted

person to discover and invent. All humans

are born with this capacity and become very

happy when allowed to express this gift. In

this regard, humans are unique amongst the

living creatures on earth.

7 . h o w h o u s e s h e a t u p

43

Tempera

ture ºC

Time

24

3432302826

6am 9am 6pm3pm12pm 9pm22

Temperature inside Single Storey Terrace House94 units of Thermal Discomfort

Thermal Comfort Zone24ºC - 28ºC

TEMPERATURE INSIDE A CONCRETE HOUSEFebruary 1998 Heatwave

12pm 3pm

Temperature outside 30 units of Thermal Discomfort


44

Our early experiments were done

with alcohol thermometers, but we needed

an automatic method for measuring indoor

temperatures which was less laborious

and more civilized than crawling out of

bed every few hours. We first tried a

thermo hygrograph, a clockwork drum

which graphically records the temperatures

and humidities for 24 hours or one week,

depending on the gearing. However, this

method is a long way from the cutting

edge of technology. In fact, Charles

Darwin took a thermo hygrograph on his

voyage round the world in the Beagle in

the 1830s. The instrument has earned its

rightful place in science museums, but it

proved unsatisfactory for our purposes,

being extremely difficult to calibrate and

not sufficiently accurate.My colleague, the

highly inventive Dr Shanmugavelu from

MARDI, came up with the technical solution

whilst studying in Scotland at the Institute

for Rural Buildings. The Institute was asked

to evaluate a prototype miniature electronic

temperature sensor and it proved ideal

for our housing studies. Even though it

is the size of a matchbox, it has its own

battery and sensor and is able to record

on its microchip the air temperature on

1800 occasions together with the time and

date. Before the experiment we plugged

the gadget into a computer and specified

Temperature Data-logging

the temperature intervals. Generally we

recorded the temperature every 24 minutes

for 28 days.

Since the sensors are wireless and

so small, we could place many of them

inside a house (usually around 20 sensors

per house) such as in the living room,

each bedroom and especially the roof

space. After the experiment we plugged

the sensors back into the computer and

downloaded the data stored in the sensor’s

memory microchip. We then crunched up

the data using Excel spreadsheets and

constructed the time versus temperature

graphs as seen in this book.

Armed with these electronic

temperature sensors, two of us were

able to do in a quite leisurely fashion, as

much as perhaps 50 assistants working

round the clock using the primitive alcohol

thermometers. We were not worn out

collecting the data, a trap many young

researchers fall into. We had plenty of time

to think. This is the power of technology.

ElectronicTemperature Sensors

Figure 7.4 Alcohol Thermometer

7 . h o w h o u s e s h e a t u p

45

Figure 7.5 Traditional Wooden

Kampong House

The temperature inside traditional

wooden kampong houses closely

follows the outdoor temperature.

Wooden kampong houses closely follow outdoor temperatures at all times with a lag of only half an hour.

It is a popular belief that hot houses

are a natural consequence of the hot and

humid Malaysian climate. Nonetheless, this

belief is a myth. We have proved at UPM

that the outdoor temperature, even during

the hottest month of the year (March) is

within the human thermal comfort zone for

14 hours per day. However, when we data-

logged the temperatures inside a terrace house we discovered a completely different

environment (Figure 7.3). The house did

not cool down at night like the outdoor

environment. Instead it heated up during

Clearly, the overheating in modern concrete terrace houses is caused not so much by the hot tropical climate but more by poor architectural design.

It is far easier to re-educate our architects than to change the climate.

Indoor Climatethe day and remained hot throughout the

night; it became an oven. Step outside the

house at night time and the temperature

can be 50C to 70C cooler. In contrast

to concrete houses, traditional wooden

kampong houses do not retain heat at

night: they do not exhibit the oven effect. In

fact their designs ensured that they closely

follow the outdoor temperature at all times

of the day and night with a lag of only half an

hour. If kampong architecture overcomes

the oven effect why can’t modern Malaysian

architecture?

Tempera

ture ºC

Time

OUTDOOR TEMPERATURE

INDOOR TEMPERATURE

23

3130292827262524

32

8am 11am 5am2am11pm8pm5pm2pm

TEMPERATURE OF KAMPONG HOUSE

Chapter 8Kampong Housing


T here is a strong belief in Malaysia, reinforced by architects, that natural cross flow ventilation in houses is

ideal for achieving thermal comfort. This

belief comes from kampong architecture.

Textbooks on tropical housing agree:-

‘As movement of air is the only

available relief from climatic stress…

the buildings will have to be opened

up to breezes and orientated to catch

whatever air movement there is…Door and

window openings…should be as large as

possible, allowing for a free passage of air.’

(Koenigsberger, 1973) However, this advice conflicts with

my own experience of houses with natural

cross flow ventilation, particularly my mother-

in-law’s beautiful wooden kampong house

in Rembau, Negeri Sembilan. This house

was built in the early 1930s by my wife’s

grandfather, who used the skills of the Orang

Asli to select two giant termite resistant trees

from the virgin jungle. The logs were hauled

to the Rembau sawmills where they were

rough cut into columns, beams and planks.

The house stands proudly today surrounded

by mature rambutan trees, giant mangosteen

trees and coconut palms, testimony to the

craftsmanship of the Malays and a highly

appropriate social housing type that we

are trying to recapture in contemporary

architecture. Cool Honeycomb housing is

our attempt to create a comfortable, modern

form of kampong housing in urban areas,

with a sense of community and closeness

to nature.

We have already seen the graphs of

the indoor temperature of a kampong house

compared to that of the outdoor environment.

The inside temperature follows the outdoor

temperature within half an hour. This is

due to the lightweight wooden construction

and the natural cross flow ventilation. This

makes kampong houses beautifully cool at

UnderstandingNatural Cross Ventilation

47


48

hot. I thought long and hard about this problem

and the practicalities of making the upstairs

of our kampong house thermally comfortable

during the daytime. Why not block the cross flow ventilation by closing all the windows and

sealing all the openings above the windows

and even the gaps in the floorboards, the very

ventilation features that made the house cool

at night, and then install air conditioning. Our

electrician said that this would put too big a

strain on the old electrical wiring.

We would have to rewire the

whole house and also replace the 2-phase

electricity supply with 3-phase, as required

by law when installing more than two air-

cons, but this was only the beginning. To

avoid an otherwise horrendous electricity

Figure 8.1A Kampong House

Kampong houses, unfortunately, cannot be renovated to make them cool all day without destroying their character.

night, but the penalty is paid during the day

when temperatures are well above the upper

thermal comfort level.

In fact, the first floor of kampong

houses is not actually occupied during the

daytime; it is too hot. In kampong houses (built

on stilts), the large downstairs kitchen serves

as the informal social centre, and provides

a more comfortable environment during the

hotter part of the day. The kitchens rely on the

almost constant ground temperature (around

280C) in Malaysia to moderate the daytime

air temperature (which can reach 350C), not the cross flow ventilation. Despite what the

textbooks say, it is not possible to keep a

house cool in Malaysia during the daytime by

natural ventilation; the outdoor air is simply too

Kampong kitchens rely on constant ground temperature to moderate the day-time air temperature, not the cross ventilation.

8 . k a m p o n g h o u s i n g

49

Figure 8.2A Typical Concrete

House

A concrete house can be kept cool by

air-conditioning it throughout, but the

electricity bill over 40 years may exceed

the cost of the house.

bill, the bare wooden walls would need to

be insulated with glass wool or rock wool

and subsequently lined with plasterboard.

We also desired an upstairs bathroom and

especially a small modern kitchen where

the fridge, sink and stove formed a compact

triangle to minimize walking. We had grown

weary of the old downstairs ‘ten mile per day’

kitchen. At this stage we stopped to think.

Perhaps we were trying to convert an old

wooden ship into a modern ocean liner. Our

plan to renovate our kampong house began

to crumble. Renovating a modern concrete

house seemed a more sensible strategy. All

the bungalows we looked at in our first year

after returning to Malaysia were also too

hot. In order to achieve thermal comfort they

would require whole house air conditioning.

Are we against air-cons? Of course not. For

those of us sweating it out in the tropics, the

modern air-conditioner wins the vote as one

of the world’s truly great inventions!

Extensive research and development

has created quiet, environment-friendly and

highly efficient air-cons. Malaysia is now the

world’s number one producer. Whilst some

people object to air-cons on health grounds,

our objection was purely financial. I had

calculated that to purchase all the air cons

needed for a bungalow, to replace them

every 10 years and to pay the probable

electricity bills over the next 30 years, could

easily require a sum of money exceeding the

initial cost of an old bungalow. This is crazy

economics!

The price of all the air-cons for a bungalow, replacing them every ten years, and the electricity bill over 30 years together exceed the initial cost of an old bungalow!

Saturating a house with air-conditioners is a hopelessly inefficient way of

cooling it. First design a passively cool house and only then install a single air-con in the living room to provide your perfect indoor environment when

outdoor is particularly hot or when you have a house full of guests.

Chapter 9Roof Wind Turbines - Do They Work?O ur most frequently asked

question, as specialists in cooling down houses is, ‘Do roof wind turbines work?’ This is no idle question. Almost every street in Malaysia has one house and sometimes many houses with the distinctive aluminium wind turbines sitting on their roofs. With 2 million overheated urban houses accommodating some 10 million heat stressed people, they find

a ready market, particularly during the hotter months from January to June. Wind turbines are big business : Malaysian consumers

51


have spent perhaps RM 200 million on them. Most are sold from attractive supermarket displays. The spinning wind turbines are flanked with impressive ventilation diagrams

and convincing salesmen who are armed with the absolute certainty that for well under RM 1000, including installation, you can cool down your house and immediately notice the difference. They don’t cost a cent to run… the wind is free. What a great solution! A made-in-Malaysia environment-friendly product, with a 10 year guarantee against defects and leaks.

Figure 9.1E�ect of Roof Wind

Turbines on the Indoor Environment

of a Double Storey Terrace House,

Subang Jaya

The question on everyone’s lips : Do

wind turbines work? Our experiment

shows they have no e�ect.


52

‘Look around : everyone is buying them. Our company has sold 500 in the last two weeks. What better proof do you need?’ Obviously, the public believes that wind turbines cool down houses.

However, public opinion is often wrong; 200 years ago popular opinion believed that the earth was flat. Indeed, the

convicts being transported from England to the Australian penal colony believed and greatly feared that the ship would eventually fall off the edge of the ocean.

I have been talking to the wind turbine salespeople for the last 15 years. I like to ask them this straightforward question: What is the temperature reduction in the roof space, the bedrooms and the living room when you install wind turbines, compared to the house next door? I am still waiting for a straight answer. Meanwhile we have conducted three detailed temperature data-logging experiments to answer this question. Figures 9.1 and 9.2

show the results of one of the experiments. Should you buy wind turbines for your

house? Study the scientific evidence. Take

note of our conclusions, based admittedly on only three experiments, but decide for yourself based on the loca l conditions and the location of your house. Wind turbines are certa in ly effective in hot windy climates such as Texas where they were invented over 100 years ago, and they are standard components of outback houses in Australia. The trouble with Malaysia is the very low average wind speed (1.6 kph.)Check out wind turbines in your area over a year. See how often they are turning. Wind turbines need to be spinning quite fast to be effective.

To get a good ventilation rate in the roof space, sufficient to cool down the house

noticeably, requires a wind speed of 6kph

or more. The Malaysian salesmen’s claim is generally true...for Australia.

Figure 9.2 Wind Turbine Experiment

Two neighbouring terrace houses in Subang Jaya. Temperature taken at 2pm on 13 October 2000. Wind turbine salesmen claim wonderful bene!ts. We disagree. Check our evidence.

Normal House Wind Turbine HouseAttic Average Temperature

WIND TURBINE EXPERIMENT43.1ºC

CONCLUSION : ROOF WIND TURBINES HAVE NO COOLING EFFECT ON HOUSE

43.8ºC49.0ºC41.3ºC39.0ºC37.2ºC32.6ºCB/R 1

36.5ºC33.2ºCB/R 2

35.0ºC32.3ºCB/R 3

31.3ºCLiving

30.2ºCKitchen

31.3ºCStore

31.1ºCDining

46.9ºC42.9ºC41.7ºCNA

32.5ºCB/R 1

36.1ºC33.1ºCB/R 2

36.5ºC32.5ºCB/R 3

30.2ºCLiving

33.2ºCKitchen

31.3ºCStore

30.2ºCDining

Chapter 10Computer Simulation of HousesComputer simulation technology

has dramatically improved our ability to predict the indoor environment of Malaysian houses. Denmark is the world leader in its application to the design of energy-efficient housing. The transfer of computer

simulation technology from Denmark to Malaysia through four-month visits to UPM by Danish postgraduate students has proved very successful and beneficial to

both countries. This joint effort is greatly accelerating

our social objective of designing thermally

comfortable housing for tropical countries, without the expense and high electricity bills for air-conditioning. The computer simulation

software created over 30 years from original research findings by the Danish Building

Research Institute has been perfected for designing thermally comfortable houses and commercial buildings in cold Denmark. However, the software is not much use for


53

hot Malaysia. The problem was realized and

solved in 2000 by Energy Engineer, Gregers

Reimann, a Danish postgraduate student and son of the previous Danish ambassador to Malaysia, Mr. Lasse Reimann. The

Ambassador and his wife Karin, a medical

researcher at UPM, helped open the doors for Gregers to create, for the first time, a

Malaysian ‘Weather Year’ (Reimann 2000).

This was compiled from 21 years

of hourly meteorological data collected at the Kuala Lumpur weather station. The

massive amount of raw data including hourly air temperatures, rainfalls, wind speeds and directions, direct radiations and cloud covers were all crunched down to give the best statistical estimate of the climate for a typical Malaysian year. For this fine project,

Gregers was awarded the highest student

assessment ever recorded by the Technical

University of Denmark. The Malaysian

weather year married to the Danish software

A Malaysian ‘Weather Year’

BSim (which stands for Building Simulation)

gave remarkably accurate predictions of the indoor climate when compared with our data on UPM experimental houses and single and double storey terrace houses, which had been laboriously compiled over the years by our temperature data logging technique. This successful validation was

carried out at UPM by three other Danish postgraduate students, Kaspar Lynge

Jensen, Kenneth Andersen and Tryggvi

Nielsen, who were all co-supervised by

Gregers.

It was a great moment for us all when the results came out of the computers

(Figure 10.3). For the first time ever in a

developing country, we were able to predict the indoor environment of a house accurately throughout the year. Now we will be able to

answer all the ‘what if’ questions at the early

design stage of a house, before actually building it. These questions are easy to

ask but exceedingly difficult and expensive

to answer by classical experiments. For

instance, what happens to the indoor temperature if we change a white roof to a red roof? The experiment looks deceptively

simple. Just build two identical houses, one with a white roof and the other with a red roof and temperature data-log both houses during the same two-week period.

Figure 10.1The website for Bsim, the Danish indoor climate software.

For the first time ever in a developing nation, we were able to predict the indoor environment of a house accurately throughout the year.


54

However, in practice, identical houses do not exist. No two houses

are exactly alike. They may be similar,

like sisters, but they are not identical twins. Neither can two houses occupy

the same piece of ground. However, this is a legitimate requirement since the sun, the shade or the wind is different even for side-by-side houses. The social

use of the test house and the control house may also be quite di fferent; e.g. in regard to opening windows and doors for instance, different cooking times, use of different electrical goods which generate heat and so on. These

social effects can be control led in

unoccup ied exper imenta l houses . However, the whole point is to determine the thermal performance of the test and control houses under real life family conditions. The accuracy of our temperature

data logging technique is also limited to +0.20C. We have too many confounding var iab les and cannot prove which variable is causing the observed change in thermal performance, unless the change is large, in the region of 10C. The

beauty of the computer simulation is that we are comparing the altered house with itself on the same piece of land, at the same time under identical conditions of

1 0 . c o m p u t e r s i m u l a t i o n o f h o u s e s

Figure 10.2Gregers Reimann,

a post-graduate student from the

Technical University of Denmark, created

the Malaysian Weather Year. He won the highest

award ever given by his university for this !ne piece of

work.

Accuracy of the data-logging was +0.20C.

55


56

Share our excitement. We have developed a brand new Malaysian

architectural tool. Now the fun begins! With computer simulation

we can accomplish in a few months and without laying a

brick what would take us perhaps five years and a RM20 million

research grant to do using our previous, build-first-test-later,

classical scientific approach.

Figure 10.3 Validation of BSim 2002

Success! The Malaysian version of Bsim software agrees with our actual temperature experiments.

climate and family occupation. At last we

have absolute control of the variables. In computer simulation the test and the control houses are physically identical, the outdoor environment affecting both houses is identical, the social use of both houses is identical. Indeed, all that we are looking at is the variable of interest, which in this example was the effect of a white versus a red roof.

Using computer simulation we can simultaneously change as many features of the house as we like and determine the combined effects on thermal performance.

25.5

30.529.528.527.526.5

7am 12pm 3am10pm5pm

Tem

pera

ture

ºC

Hour

ACTUALTEMPERATURE

SIMULATED TEMPERATURE

LIVING ROOM, UPM THERMAL COMFORT HOUSEMARCH HEATWAVE

VALIDATION OF BSIM 2002

Chapter 11Scientific Architecture

We can now use the Malaysian version of the Danish software as a powerful building design tool. This will help make houses passively cooler in the humid tropical climate. Its usefulness to architects and engineers is illustrated in the following case study involving computer simulations of our UPM experimental house assuming normal family occupation. Together with our Danish postgraduate students we simulated a series of ‘what if’ design changes.


57

(1) Concrete TilesWhat if we change the normal concrete tiles to highly insulated Cool Roof; how will the indoor temperature change during a heat wave?Result: The indoor temperature is reduced by 3.50C (Figure 11.1.a)

Explanation:In a normal house the concrete tiles exposed to bright sunlight get hot (up to 500C) and the heat is transmitted into the house. Changing the concrete tiles to a highly insulated ‘Cool Roof’ completely blocks solar heat gain, making the inside of the house much cooler.

(2) Roof Colour

What if we change the Cool Roof colour from red to white; how much cooler will the living room become? Result: The peak afternoon temperature is reduced by 0.30C (Figure 11.1.b)

Explanation:The answer lies in simple physics; dark colours absorb heat whereas white reflects

heat. An experiment showed that the surface temperature of a white metal roof in bright sunlight was 420C compared with 490C for a red metal roof, a 70C difference.

Figure 11.1 BSim Tests and Results

Computer simulation can be used to design cool houses for Malaysia before they are built.


58

25

Insulated Red Metal Roof3.5ºC

Concrete Tiles3533312927

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

SIMULATE CHANGE FROM CONCRETE TILES (a)

26

Red Roof0.3ºC

White Roof

3130292827

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

SIMULATE CHANGE IN ROOF COLOUR (b)

26

3 Air changes / hour0.4ºC

0.5 Air changes / hour

3130292827

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

SIMULATE LOWER NATURAL VENTILATION (c)

25

No Ventilation

Night Time Ventilation

3130292827

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

SIMULATE MECHANICAL VENTILATION (d)

261ºC

26

Lightweight wall0.3ºC

Concrete wall

3130292827

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

SIMULATE HIGHER THERMAL MASS (e)

26

Normal windows0.1ºC

Double glazed windows30292827

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

SIMULATE DOUBLE GLAZED WINDOWS (f)

Living RoomUPM Thermal Comfort HouseMarch Heatwave

Explanation:Night-time mechanical ventilation at a high rate is very effective in cooling down a house at night. The reason again is very simple; the outdoor night air can be 5 to 100C cooler than the inside of the house. The coolness of the night gets stored in the concrete structure of the house and helps to keep the house cooler the following day. Natural ventilation is insufficient for night cooling and

only provides about 3 air changes per hour. UPM’s mechanical ventilation system is very efficient and provides about 28 air changes per

hour for 1 cent for electricity per room per hour.

Without proper insulation a metal roof of any colour will make the house dramatically hotter and uninhabitable on hot afternoons. However, the insulation in Cool Roof greatly moderates this temperature difference and the living room is then only 0.30C hotter with a red roof. In practice; this means that the consumer is not restricted to a white Cool Roof but can choose any colour and pay only a small temperature penalty.

(3) Natural Ventilation

What if we reduce the natural ventilation from 3 to only 0.5 air-changes per hour by closing doors and windows and other openings?Result: The peak daytime temperature is reduced by 0.40C whilst the night-time temperature is increased by 0.50C (Figure11.1.c).

Explanation:Contrary to popular belief, natural ventilation during the day increases the indoor temperature. The reason is elementary. The outdoor air is hotter, reaching 350C on a hot afternoon. Why bring hot air into the house? Blocking natural ventilation reduces the indoor temperature during the day. However, blocking the cool natural ventilation at night (outside air temperature 250C) prevents the house from cooling down.

(4) Mechanical Ventilation

What if we mechanically ventilate the house at night only at the rate of 28 air-changes

per hour?Result: The night-time temperature in the living room is reduced by 1.00C and the peak daytime temperature is also reduced by 0.20C (Figure 11.1.d).

1 1 . s c i e n t i f i c a r c h i t e c t u r e

59


60

This ventilation system can be as simple as an exhaust fan sucking the cool night air into the living room and each bedroom. You must provide vents (holes) in each room so that the hot air can escape, eventually to the outdoors. The tricky bit with ventilation is to keep the rain out. This requires ingenuity.

(5) Concrete WallsWhat if we replace the lightweight gypsum walls in the UPM experimental house with concrete walls? Result: The daytime temperature is reduced by 0.30C (Figure 11.1.e).

Explanation:Concrete walls have high thermal mass which takes a long time to heat up and cool down. Inside the house there is a three hour lag period before the outdoor temperature is reached. A wooden kampong house has low thermal mass and thus responds much more quickly to the outdoor environment, reaching ambient temperature within half an hour. Therefore, a wooden house cools down beautifully at night, whilst a concrete house is cooler than a wooden house during the day.

(6) Double Glazed Windows

What if we double glaze the windows; does it cool the house?Result: The daytime temperature is reduced by only 0.10C (Figure 11.1.f).

Explanation:Normal glass windows readily transmit outdoor heat or cold into the house. Double glazed windows (two sheets of glass separated by a layer of air or inert gas) act as see-through insulation and are very effective when the difference between indoor and outdoor temperature is more than 200C. However, in Malaysia this difference is only 50C, even on a hot afternoon. Therefore, normal houses with ordinary-sized windows do not justify the high expense of double glazing.


61

Figure 11.2Sensible design using computer

simulation dramatically

improves the indoor climate.

The Malaysian version of the Danish computer simulation of the indoor environment, recently developed at Universiti Putra Malaysia, is a very powerful tool for assisting architects to scientifically design thermally comfortable and energy efficient houses. Architects working

alongside scientists and engineers at the drawing board stage can now accurately test and fine tune the thermal performance of house designs during any time of the year. These

high technology procedures replace the problematic and expensive process of building experimental houses and tediously live testing their thermal performance against control houses under different climatic conditions.

(7) Combining the Cooling Features

What if we combine all of the above six features. Will the cooling effect be increased?Result: The combined effect makes the improved house 5.60C cooler than the normally constructed house with concrete tiles (Figure 11.2).

Explanation:Adding up all the six individual cooling features should only make the house 4.80C cooler during the day. So the whole system is greater than the sum of its parts. This is because the various cooling features interact; for instance the night-time ventilation combined with concrete stores more coolness than lightweight walls.

Conclusion

24

Concrete Tiled HouseUPM Experimental House

LIVING ROOM TEMPERATURE28ºC

30ºC

33.6ºC

Future ImprovementUpper Thermal Comfort Level

3432302826

7am 12pm 3am10pm5pm

Tempera

ture ºC

Hour

36COMBINING THE 6 COOL DESIGN FEATURES


62

We have been successful at UPM, using the Malaysian version of the Danish BSim software, in determining the design principles for energy efficient, thermal comfort housing

for the Malaysian humid tropics. These design principles, in order of importance, are briefly

summarized:-

Instead of the current Malaysian practice, perceptively characterized by journalists as ‘build first, think later’, computer simulation allows

us to build houses the other way round. Welcome, professionals in the

Malaysian building industry to the discipline of ‘scientific architecture’…

think first build later!

Design Principles for Cool Malaysian Houses

1. Highly Insulated Roof

Up to 80% of the heat gain in a

house comes through the roof. The reason is simple; the sun is the source of solar radiation. Malaysia being almost on the equator has the sun overhead most of the day. The Cool Roof we invented at UPM consists of a white metal roof, a small air space, aluminium foil and ‘Roxul’- a brand of Rockwool insulation. These elements were optimized by computer simulation to completely block solar

heat gain, which was the aim of the design. Experiments on renovated terrace houses proved the theory was correct. On a hot day, Cool Roof reduced the temperature in the attic (where the water tank lives) from 480C to 350C, the outdoor ambient air temperature. In the future other ways may be found to do it, but the design principle remains the same: the heat gain through the roof must be completely blocked.

2. Night Time Mechanical Ventilation

At night time the outside air slowly cools down, usually to around 25 0C. When introduced into the house by mechanical ventilation, the cool air cools us down and also the concrete structure of the house. A ventilation rate of 1 per hour means all the air in a

room is replaced by outdoor air in one hour. A ventilation rate of 2 means all the air is replaced every 30 minutes and so on. The higher the ventilation rate the cooler the room becomes until the walls, floors and furnitures reach the same temperature as the

80% of heat gain in a house comes through the roof.


63

3. Low Natural Ventilation

Outside air naturally enters the house through open doors and windows and when these are closed some outside air still enters through gaps around the door and window frames. Louver windows are quite leaky. Older houses often have ventilation bricks in the walls below the ceiling. However, contrary to popular belief, daytime ventilation is undesirable and heats up the house. The best strategy is to seal off most of the natural ventilation to reduce the daytime ventilation rate from the usual 3 or more air changes per hour to the minimum value 0.5, which is required to keep the air in a room sufficiently fresh for human breathing. Cooking creates both heat

outdoor air. However, this would require massive fans and create gale-force-wind inside the room! Computer simulation demonstrates the most practical and cost effective solution. The most cost

effective is a ventilation rate between 14 to 28 air changes per hour. The design

aim is to change the air in the whole house every 2 to 4 minutes throughout the night, between 6pm and 7am.

in the kitchen and smells throughout the house. Both can be overcome by switching on an exhaust fan in the fume hood over the stove.

At night time the mechanical ventilation system flushes the house

continuously, which removes not only heat stored in the walls, floor and household objects, but also the industrial pollutants in manufactured materials, especially the solvents used in furniture making. American studies have shown that the indoor air can be 10 times more polluted than the outdoor air. The design principle is therefore, to minimize natural ventilation during the day and to maximize mechanical ventilation at night.

4. Wall Shading

If you are unlucky your bedroom faces the afternoon sun and you will notice that the wall heats up and stays hot for most of the night, often making the bedroom too hot for sleeping. The heat is also coming through your roof and heating up the internal walls and the bedroom floor. So you are being

cooked from all directions, like a barbecued chicken. Shading the walls from direct sunlight is very effective in reducing some of this heat buildup. A 5- foot (1.5m) awning will protect a single storey wall from around 95% of the

direct sunlight. This is the secret of the 5-foot walkways in front of old Chinese

Most cost effective ventilation rate is between 14 to 28 air changes per hour.

Minimize natural ventilation during the day and maximize mechanical ventilation at night.


64

5. High Thermal Mass Walls and Floor

The concrete walls, floors and roof

tiles turn two million urban houses into sweat boxes on hot days in Malaysia and they remain hot for most of the night. Concrete has high thermal mass, meaning that it can store a lot of heat, far more than low thermal mass materials, such as the wood used to construct kampong houses. For this reason the textbooks on tropical housing recommend low thermal mass materials. We followed their advice in building 35 experimental thermal comfort houses on the UPM campus by using commercial ly avai lable

to great effect. However, this was an expensive solution, since it doubled the footprint of the house. In any particular building, our computer simulation will give not only the optimum but also the most cost effective overhang to shade the walls. We have designed 5-storey low-medium cost apartments with minimal wrap-around veranda on each floor to save costs ; they still give a good

cooling effect inside the apartments. Wall shading, no matter how it is achieved, is an essential element for designing passive thermal comfort houses and apartments in Malaysia. Look around you. It is a simple principle ignored in most cases.

shop houses. The sun still hits the east and west walls, but only in the early morning or late afternoon when there is less heat in the sun. Together with bamboo shop blinds lowered during these times, the sun is completely prevented from reaching the walls of old shop houses.

The method for shading the walls which I like most, uses verandas. These were borrowed by British colonial architecture from India and customized in the other territories throughout their empire. I borrowed the Australian ‘Queenslander’ 8-foot wrap-around

veranda concept when I designed my own bungalow in Bandar Baru Bangi,

lightweight ‘BT Drywall’ or lightweight insulated ‘Rapidwal l ’ . However, we now know through computer simulation that a concrete house can be considerably cooler if every design measure is taken to prevent solar heat gain through the roof and walls and provided the house is mechanically ventilated at night. Concrete stores heat, but it just as effectively stores coolness. The design principle is that high thermal mass, suitably protected from solar heat gain, now works in our favour to keep the house or apartment cool.

Minimal wrap-around veranda give good cooling effect.

Concrete stores heat but it just as effectively stores coolness.


65

Water has four times more thermal mass than concrete. Can we make

even cooler houses with water filled walls and floors? Yes, why not? The

temperature of heavy rain is quite cool, 230C (a fact much appreciated by

trees in Malaysia). Let us learn from nature by collecting the rainwater from

the roof and circulating the cool water through the hollow walls and floor.

To achieve a cool rainwater house, all we need are a few bright hydraulic

engineers… and a good plumber.

6. OrientationKeeping the sun and the rain out

are the top objectives of designing for Malaysian architects. We do not disagree. The rain spoils the carpets and furniture whilst the sun coming through the windows dramatically heats up the house. However, we put orientation to the sun at almost the

bottom of our design list. In practice, the architect must make use of whatever land is provided by the developer or individual land owner and he has little say about orientation. We have come to the view that a house designed to be built in any orientation to the sun is the answer to this problem.

Unlike straight rows of terrace houses, our ‘Honeycomb’ houses are built round a circle. For economic reasons and ease of construction we need standard house designs. Therefore, we need to test and modify the house design by computer simulation against all orientations to the sun. We cannot completely overcome the effect of orientation but we can minimize it. For instance in the UPM thermal comfort bungalow we prevented nearly all the sun from entering the house by designing a

roof with a large overhang and with awnings above the ground floor walls. The front master bedroom heats up by an extra 0.40C if the bedroom’s French windows face the morning or afternoon sun. This modest overheating can be minimized by drawing the curtains, or planting tall trees, to prevent the sun from entering the bedroom. The principle is therefore to design houses and apartments, which can be built in any orientation to the sun by minimizing the heating effect.

Houses and apartments can be built in any orientation to the sun by minimizing the heating effect.


66

Figure 11.3Three postgraduate students (Tryggvi in blue, Kenneth in black and Kasper in white came from freezing Denmark to help Mohd Peter & Nor Azian (centre) design cool houses for hot Malaysia. This team perfected ‘Cool House Technology’ using computer simulation and the Malaysian Weather Year developed earlier by Gregers Reimann. The experimental house in the background incorporated the older technology such as low-pitched roof, louver windows and wind turbines.

7. Double Glazing

This is the least important design element for Malaysian houses. Double glazing does have a cooling effect of around 0.10C in our computer simulation case study. This is almost negligible and does not warrant its high cost, and the even higher cost of energy-saving windows filled with

inert gas. These products are for much colder or much hotter climates where the year round maximum and minimum temperature range can be 400C rather than Malaysia’s modest 100C. However, there will be occasions in Malaysia when computer

simulation will show double glazing to be beneficial in saving air-con electricity consumption, such as in office buildings and luxury bungalows

with feature windows facing the view and the sun.

The design principle concerning double glazing and other products on the market, such as wind turbines, heat-reflecting paint and clay tiles is

that they must be justified at the early

design stage by computer simulation. All of these examples have some effects on thermal comfort but is the benefit cost effective?

Cooling effect by double glazing is almost negligible in our tropical climate.


67

Computer simulation is a powerful tool that has revealed the general principles for designing energy-efficient thermal comfort dwellings for Malaysia, but it needs to be intelligently applied by architects and engineers. The same general approach can be used for other climates, especially developing countries where the actual raw climatic data have not been collected. We have plugged the Danish BSim program into climatic data generated by Swiss software for Shanghai,

Science and technology have this great power to improve the general

welfare of billions of people.

Beij ing and Bahrain, and optimized Malaysian quarter-detached houses to these quite different climates. We are, therefore, on the road to formulating the design principles for energy-efficient thermal comfort for other developing countries. Postgraduate students from these countries can study with us in Malaysia and go back home a few years later with detailed plans for implementing national housing programmes, customized to their country’s climate and culture.

Computer simulation is a powerful tool but needs to be intelligently applied by architects and engineers.

Chapter 12Ventilation Strategy for Malaysian HousesW hen Malaysians feel hot

during the day inside their modern houses they follow the traditional kampong culture by opening windows and doors to the outdoor breeze. At night time windows and doors are closed to keep out burglars and, hopefully, mosquitoes. This natural cross-flow ventilation strategy was adopted

throughout South-East Asia long before the electricity era and is quite sensible for wooden kampong houses with their extensive openings above the windows

and in the roof space. The brilliant feature of kampong architecture is that it keeps out the sun and the rain without restricting the free flow of outdoor air. Before electricity

and ceiling fans were invented, the breeze

coming into the house acted as a natural fan providing the only relief in the hot and

humid climate. This is the primary reason why kampong houses are built on stilts; air movement is stronger 10 feet off the ground

and is less obstructed by vegetation.


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However, this perfectly sensible

ventilation strategy for kampong houses

is quite the wrong strategy for modern Malaysian houses, and only makes them hotter. A careful study of the daily outdoor temperature cycle reveals why (Figure 12.1). Opening windows during the day allows hotter outdoor air to enter the house and heat up the concrete walls and floor. Closing

windows at night prevents the cool outdoor

air from cooling down the structure of the house. The correct ventilation strategy

which I have applied for the last 14 years in

my own thermal comfort concrete bungalow in Bangi is the exact opposite:-

Keep doors and windows closed all day long to prevent natural ventilation

Open as many windows and doors as possible all night long to encourage naturalventilation. (We protect open doors and

windows from burglars with grills and motion alarms).

Sensible ventilation strategy for kampong houses is quite wrong for modern Malaysian homes.


70

The principle is simple; wait for the outdoor air to cool down before inviting it into

your house. No matter how much we explain the elementary theory that it is impossible to cool down a house with hot air, Malaysians still want to open all the doors and windows during the day and close them at night. Of course the outdoor breeze, if any, gives a

temporary relief from heat stress but at the expense of heating up the house structure. The solution to daytime heat is to close the windows and sit under a fan to let the indoor air at about 300C cool your body, rather than using the outdoor breeze at about 330Ccoming through the window.But old habits

die hard. Malaysians, and in particular architects, still believe that designing houses

with openings and allowing daytime cross flow ventilation is the best way to cool a

house naturally. Rational argument is not enough.

What to do? When all else fails adopt the scientist’s motto: prove it by doing an experiment! We spent two months at the computer doing just that.

The problem in Malaysia is that we cannot design for natural ventilation due to

the unpredictable direction of the wind and its very low average speed throughout the year

(less than 1 mile per hour). Instead of relying

on natural ‘cross ventilation’ as advocated

by many Malaysian architects (without any

evidence that it works!) we tested three

mechanical ventilation strategies. We used

computer simulation at the design stage of our UPM thermal comfort bungalows.

The aim of the experiment was to determine the ventilation conditions for

achieving thermal comfort (i.e. zero units of

thermal discomfort for 24 hours) on the hottest

day of the year. Three ventilation strategies

were tested by computer simulation.

It is impossible to cool down a house with hot air.

Tempera

ture ºC

Time

THERMAL COMFORT ZONE

OUTSIDE TEMPERATURE30 Units of Thermal Discomfort

22

3032

282624

34

6am 10am 2am10pm6pm2pm

DAILY TEMPERATURE CYCLE

1 2 . v e n t i l a t i o n s t r a t e g y f o r m a l a y s i a n h o u s e s

71

1. Daytime ventilation (7am to 6pm) was the very worst possible strategy. The more

the house was ventilated during the day, the more uncomfortable it became, until

at 56 air changes per hour it became almost the same as living outdoors.

Instead of protecting us from the hot environment, we had made our thermal comfort

bungalow uninhabitable on hot afternoons. With the flick of a switch, the daytime ventilation system transformed our thermal

comfort bungalow into a hot and unlivable kampong house. Architects, and other stubborn believers in daytime cross-flow ventilation, please take note!

2. The second strategy, 24-hour mechanical ventilation, was better than daytime

ventilation but overall had no beneficial effect. Running the electric ventilation fans

continuously, night and day, is therefore a waste of money.3. The third strategy, night time mechanical ventilation (6pm to 7am), was outstandingly

successful. The more we ventilated with cool night air the cooler the house became

throughout the whole 24 hours.

With these experiments we have scientifically proved what we have always insisted

to disbelieving architects and consultants:Ventilating with hot outdoor daytime air (either naturally or mechanically) only

makes the house hotter

To make the house cooler simply ventilate with cool night air.

‘Elementary!’ Sherlock Holmes might have said.

We have spent the last 50 years excluding Cool Night Air from our modern Malaysian homes. It is time we welcomed it back.

*Units of Thermal Discomfort in UPM ‘Cool Bungalow’(on hottest day of the year)

*

Chapter 13How We Invented ‘COOL ROOF’

On a hot afternoon in Malaysia, the outdoor air temperature rarely exceeds a rather modest 350C (compared with extreme temperatures of 450C or even 500C in hot dry climates such as Australia and the Arab countries). However, on a hot afternoon the air inside the roof space (the attic) of a Malaysian terrace house reaches extreme temperatures. In a temperature data-logging experiment the attic air temperature reached 490C just under the peak of the roof and gradually decreased to 310C in the downstairs living room (Figure 13.1). This180C temperature gradient inside the house causes great problems for the occupants. As we have said, humans are only thermally comfortable in a much lower air temperature range of 240C -280C. The use of ceiling fans makes us feel 20C cooler. Thus an indoor air temperature of 300C is the practical upper thermal comfort level when resting under


73

a ceiling fan. The ground floor in a terrace

house on a hot afternoon is a bit warm at 310C, but just about tolerable under a ceiling fan. However, the bedrooms at 330C are very uncomfortable and the ceiling fan provides hardly any relief. The roof space above the ceiling is dangerously hot and could cause death from heat stroke. On hot days therefore, only the ground floor of a double

storey house is fit for human habitation. This

is rather unjust since house buyers paid for the whole house but can only use around 42% of its volume with any reasonable degree of thermal comfort.

Single storey terraces are even worse; they are a social disaster. On hot days there is no cool place anywhere in the house. An estimated 7 million long-suffering Malaysians, nearly 30% of the total population, live in overheated terrace houses.

The attic air temperature reaches 490C compared to outside air temperature of 350C!

Identifying the Problem

lowered the roof pitch of urban houses (to save materials and money).

extended the party wall beyond the roof in terrace houses (to prevent fire

spreading via the roof to the whole row of houses).

Removed all the natural ventilation spaces (to keep out birds and rain).

However, the unintended effect of these quite sensible changes is a completely sealed roof space that reaches the same high temperature as the sun exposed concrete tiles. This excessive heat in the roof space generates the experimentally observed temperature gradient in modern houses …and misery for millions.

It is worth reflecting on this sad situation, since this could prevent similar mistakes in other developing counties as they modernize their societies and urbanize their rural populations. For 50 years Malaysian architects have been flying

The radiation from the sun is the original source of the heat, but the bad physical design of modern houses is the real reason for these social problems. The sun heats up the concrete roof tiles (to 490C in this example) which in turn heats up the air in the roof space to the same extreme —temperature way above the 350C maximum outdoor temperature. This hot air cannot escape since architects have increasingly

turned the roof space into a sealed, almost air-tight compartment. They have unwittingly created a furnace in the roof. The heat has to go somewhere and is transferred through the ceiling and into the concrete walls and floor. The house becomes an oven and remains hot throughout the day and for most of the night. The bad architectural design has turned modern houses into human sweat boxes.

Kampong Houses Are DifferentWhen we measure the temperature

in kampong roofs the situation is altogether different. The roof space in kampong houses hardly heats up at all; the air temperature is only 10C to 20C hotter than the outside air. This is proof that the grossly overheated roof of modern houses is man-made. It is the modern architects who should be held responsible, not the climate. Sorry Architects, but that’s the harsh truth!

The kampong roof is a brilliant design. The high pitch and the generous ventilation openings at the gable ends and eaves, allow the hot air to escape. This design prevents a temperature build-up whilst almost completely keeping out the rain. However, kampong roofs are rather luxurious and expensive and often become homes for rats, birds and other wildlife.

Malaysian architects for very sound reasons have, over the last two generations, done the following:-


74

Hot air cannot escape the attic, thusturning the house into an oven.

Kampong houses are only about 10C-20C hotter than the outside air.

blind, preoccupied with the economics and aesthetics of housing. The long-suffering consumer has been ignored. Computer simulation of the indoor environment at the design stage is the answer. This is good news for computer-savvy young architects. Develop your skills, the architectural firms

need them!Architects need to work side by

side with scientists using analytical tools to measure the consequences of their designs before they are built. Architects can become the champions of a new Malaysian culture: Think first, build later! Computer simulation is the ideal tool and can be the basis for new building legislation. However, bureaucratic

enforcement of new laws can be agonizingly slow. A more human approach is needed.Insulating the roof space above the ceiling became popular in western countries over 40 years ago to keep houses cool in the summer and warm in the winter. It was very effective. Roof insulation material includes glass wool, rockwool and polystyrene. It is not the insulation material itself, but the air it traps which provides the insulation effect. A cheap way of insulating roofs, common in Australia, uses fluffed-up old newspaper

(treated with boric acid to make it fireproof)

which is pumped from a tanker on the street and into the roof by simply removing a few tiles. Considering that Malaysia has 2

1 3 . h o w w e i n v e n t e d ‘ c o o l r o o f ’

75

Computer simulation is the ideal tool and can be the basis for new building legislation.

18ºC Temperature gradi-ent in a Terrace house, Subang Jaya.(2pm, 13 October 2000)

18ºCTEMPERATURE GRADIENT

31ºC

SOLAR RADIATIONOUTSIDEAIR TEMPERATURE 35ºC

33ºC36ºC39ºC41ºC49ºC


76

million overheated houses this would be an attractive strategy for solving the problem and would cost less than RM 500 per house. A Malaysian company imported 30 bags of the lightweight material and we lined up the co-operative owner of a terrace house for a temperature data-logging experiment. However, just before doing the experiment we suddenly stopped. We noticed a water stain on the ceiling and realized a leaking roof would be a disaster.

The insulation would become water logged and possibly cause the ceiling to collapse. A little later the results of a large random consumer housing survey, conducted by our groups of UPM final year

Developing the Solutionstudents, started coming in. All groups revealed the same three defects of terrace houses (as mentioned earlier):-

Number 1 defect - The kitchen is too small.Number 2 defect - The house is too hot on about half the days of the year

Number 3 defect - The roof leaksThe very high incidence of leaking

roofs was a surprise. The reason is a peculiarity of the Malaysian climate. Strong winds often accompany heavy rain. Sooner or later the rain, driven by a gale-force wind, will be coming in the right direction to find the gaps in the concrete roof tiles.

Houses leak more as they get older. The

Random consumer surveys highlighted roof leakages as one of three most common house defect.


77

C

roof timbers dry out and the roof sags a little, causing the gap in the roof tiles to open still further. House owners and roofing

contractors know that fixing a leaking roof

is a never-ending job. In view of these results we had to

abandon newspaper insulation. The only cheap solution to overheated houses was

Perhaps to get the ball rolling, and in the best traditions of science and innovation, architects should take responsibility for their new designs and actually live in the houses they create for a three month trial, with

their families. This could work wonders in creating both a new generation of scientific architects and a good atmosphere for introducing practical

legislation for comfortable homes…with encouragement and support from a grateful public.

defeated by Malaysia’s special climate. What bad luck it was for millions of heat stressed Malaysians! So it was back to the drawing board, back to the laboratory…


78

Tempera

ture ºC

Normal RoofCool Roof

ROOF SPACE TEMPERATURES ON A VERY HOT DAY(1 June 2001, Serdang, Selangor)Single-storey terrace house

35ºC

48ºC

30ºC UPPER THERMAL COMFORT LEVEL

UPM COOL ROOF

White Metal Roof

Aluminium Foil

Rockwool

25

4045

3530

50

7am Time11am 3am11pm7pm3pm


79

Metal roofs, correctly installed according to manufacturer’s instructions, are 100% leak proof. Unfortunately, metal roofs are very noisy in heavy rain and also heat up the attic. Placing insulation materials underneath the metal roof, rather than on top of the ceiling, would prevent the attic getting hot and solve the temperature gradient problem.

This was our thinking behind Cool Roof. At this time a new ‘Lysaght®’ metal roofing product ‘Clean Colorbond®’

from Bluescope Steel (Malaysia) became commercially available, which successfully repelled the dirt and prevented tropical staining in 5-year trials in Singapore. For the first time a white roof became a practical

possibility. Every physics student knows that white surfaces reflect solar heat whist dark

colours absorb heat. A white roof had been installed earlier in KL and looked spectacular for a month or two, but then began to look awful due to unsightly dirt and stains. The brave pioneer, a bungalow owner, had to completely change his near white clay tiles for a darker colour.

Would Bluescope Steel sponsor a white metal roof (and donate their expertise and a roofing contractor) for UPM

experiments to cool down terrace houses? Yes they would for mutual benefit. They

eventually went on to sponsor this book.

Linking up with IndustryThis was a welcome change…a Malaysian company interested in opening up a possible new market rather than merely hunting for immediate profits. We tested small metal

samples coated in different Clean Colorbond colours in bright sunlight with a temperature gun (see page 65).

We obtained good results. A white metal roof had a surface temperature of 420C; over a range of darker colours the temperature increased gradually to 530Cfor a black roof. Other factors than colour are involved: metal roofing has half the specific heat and weighs ten times less than

concrete tiles. In bright Malaysian sunlight a red concrete tile roof therefore stores 30 times more heat than a white metal roof. No wonder the roof space heats up in 2 million modern houses.

Roof InsulationA white metal roof still needs

cons iderable insu la t ion and other components, such as aluminium foil with an air space, to completely block solar heat gain in the attic. Insulation for houses needs to be fireproof, shrink-proof and must

not give off any toxic gases. This limits the choice to either rockwool or glass wool. Both have the same insulation value. How to design an economical cool roof for the Malaysian climate?

In bright Malaysian sunlight, a red concrete tile roof stores 30 times more heat than a white metal roof.


80

To find out directly by experimenting on houses is almost impossible, but the problem was solved elegantly using ‘Therm’ computer simulation (freely avai lab le on the in ternet) and the temperature data on the white metal roof surface. Our theoretical roof design was put to the test and was fully validated in two detailed roof renovation experiments with exist ing terrace houses, using neighbouring houses as controls. We first made sure the that thermal performances of the test house and the control house were similar by conducting two-week temperature data-logging experiments.

In both experiments we removed and discarded the concrete tiles and replaced them with UPM ‘Cool Roof’. The white roof is very striking and looks just like concrete tiles. The roof renovation

of the double storey terrace house in Subang Jaya, owned by Dr and Mrs Lam (Figure 13.10) used glass wool insulation, kindly supplied by Poly Glass Fibre (M) Bhd. In the second experiment we used a new form of rockwool donated by Roxul Asia Sdn Bhd. to renovate the roof of a single storey terrace in Sri Serdang.

The results were very convincing. UPM ‘Cool Roof’ reduced the thermal discomfort by 80% in the double storey ter race house and by 70% in the single storey terrace, without using air-conditioning. The owners of the houses are very happy with their cooler houses and of course the free renovat ion. Indeed, almost everyone we talk to wants to volunteer their house for the next experiment!

‘Therm’ Computer Simulation

Consumer ReactionUPM Cool Roof‘The temperature in my house is now cool at all times without air-cons.’

UPM Cool Roof(2 years tested)100% Leak proof

Buglar proof


81

We have proposed ‘A National P lan For Renova t ing Two Mi l l i on Overheated Houses’ (Bui ld ing and

Investment, April 2002). Every urban house could be renovated with Cool Roof over a 10-year period for a total cost of RM 22 billion. Admittedly, this is a lot of money. However, to achieve the same cooling effect, whole house air-conditioning would cost 10 times more. This is when the colossal electricity cost over a 30-year period is taken into account. The electricity saved could be put to much better use by industries to help create national wealth.

‘Cool Roof’, despite its economic and social merits and proven performance, cannot get off the ground commercially. A fa i r contractor ’s pr ice is around RM 12 per square foot or RM 10,000 to

renovate a terrace house. Seemingly, everyone wants Cool Roof, but there is a general feeling that the Government should encourage house owners to be energy-efficient with a ringgit for ringgit subsidy. This is a common practice in other countries. For a new terrace house the Cool Roof mater ia ls add around RM 5000 to the building cost and therefore the selling price. Developers welcome the new technology, but they are reluctant to spend another ringgit on materials. They correctly point out that terrace houses are already too expensive. It seems that everyone wants ‘Cool Roof’ but nobody wants to pay for it. This is often the fate of new inventions...good but too expensive.

‘A National Plan for Renovating Two Million Overheated Houses’

IS UPM COOL ROOF NOISY DURING HEAVY RAIN?Concrete Tiles

52 db 52 db67 db

Cool Roof


82

UNITS OF THERMAL DISCOMFORT(per 24 hours)

80% reduction in Thermal Discomfort

Concrete Tile Roof

5

Lysaght COOL ROOF

2

1313 2376

0 1

41 510

‘Cool Roof’ reduces the thermal discomfort by 80% but at RM10,000 the renovation is considered too expensive by consumers. So it’s back to the

drawing board!

Chapter 14Designing Thermally Comfortable HousingIt became clear to us that Cool

Roof was not commercially viable as a stand alone product. It needed to be incorporated into new house designs, but at no extra cost. Our computer simulation studies showed that to make a passively cool house we also needed to incorporate

My co-author Mazlin Ghazali (of the firm Arkitek M. Ghazali) had long been

interested in designing and building cluster houses (four houses under one roof) as

a possible alternative to terrace houses. Together we perfected this design and incorporated our Cool House technology. As we simulated the effects of these

changes on the indoor temperature we became puzzled by the computer results. The attic temperature was too cool and was below outdoor temperature. This was


83

our night time ventilation system and wall shading devices. Similarly, we wanted

to achieve this at no extra cost. How do we pay for all this expensive Cool House technology? We needed to recover the costs somehow by designing more economical houses.

impossible! Cool Roof only blocks solar heat gain in the attic; it cannot make the attic cooler than outside. After repeating

the simulations several times, our Danish students finally rebelled and said that there

was nothing wrong with their conclusions. Together we worked out the reasons.

‘Quarter-detached’ Houses

Cool House Technology

Figure 14.2 Conclusion : Thermal Comfort 21/

2 storey house

costs the same per square foot as hot double storey terrace house.

Figure 14.1 Computer simulated performance of Quarter-D houses during the hottest month of the year.


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SIMULATED THERMAL PERFORMANCE of QUARTER-D HOUSES1Designed by Mazlin Ghazali and Mohd Peter Davis, UPM4 Houses under 1 Cool Roof

Footnote1. Using Malaysian Version BSIM 2002 2. Mean maximum and minimum temperatures during hottest month of the year (March)3. Occupied by family of 5

CONCLUSIONThermal Comfort (i.e. below 30ºC with ceil-ing fans) can be achieved all year round in Malaysia without air-conditioning.

26.1ºCLarge eavesfor shading

Night time mechanical ventilation30 air changes/hour

UPM Cool Roof(Red) March HeatwaveOutdoors33.6ºC Maximum24.1ºC MinimumDouble glazed windows

Pergolashading25.6ºC26.1ºC

30.9ºC30.1ºC30.1ºC

NIGHTMinimum Temperature2 DayMaximum Temperature2

750 sf

Double StoreyTerrace House2 1/2 StoreyThermal Comfort House

750 sf

350 sf575 sf

575 sfLiveable AreaBuilding Cost

1500 sfRM 50 x 1500 sf = RM 75 000

1500 sfRM 50 x 1150 sf = RM 57 500

EXTRA COSTS FOR ATTIC RMCool Roof / Awning 5 500Attic Ceiling 1 840Attic Floor 2 300Floor Finish 2 870Gable Wall 600Gable Window 600Staircase 2 000House Ventilation 2 000Sub total 17 710TOTAL CONSTRUCTION COST RM 75 210

Figure 14.3Model of ‘Quarter-

Detached’ house (4 corner lot houses under one roof ).

Our Quarter-D houses are a very compact block with a small common roof compared to the large amount of concrete (Figure 14.1). The concrete was acting as a heat sink, cooling down the attic air temperature. We reasoned that replacing the lightweight cei l ing with a concrete ceiling would further cool down the attic and the rest of the house. It did exactly as we expected and made the attic 1.20C cooler. The normally uninhabitable attic was cool enough for human occupation at any time of the day

or night (Figure 14.1). We could do the

unthinkable and turn Malaysian attics into bedrooms. All we had to do was provide a

bathroom, wall partitions, an attic window and a staircase. The cost of the attic bedrooms per square foot was much lower

than the rest of the house. We were getting extra

hab i tab le space for minimal cost

by making use of the useless roof

space. This cost saving completely covered the extra cost of

materials for the Cool House technology, as shown in Figure 14.2.

Overall, our quantity surveyor found that the cost per square foot of habitable area for our cool house was the same as for a normal hot house. The Cool House technology was now free of charge. This gave great scope to Arkitek M. Ghazali.

Architects could now make 11/2 and 21/2storey houses with attic bedrooms and smaller footprints, liberating land for extra garden. To save costs the houses could be offered with a bare attic and easily renovated without building approval to meet the needs of a growing family. At last teenagers could

have their own private space, away from the madding crowd, up in the roof! (Figure14.3).

Now we have an attractive alternative to overheated terrace

houses. We have created brand new Cool Quarter-detached houses for the medium-cost housing market.

They will stay cool without air-cons but cost no more than equivalent terrace houses. Developers are

showing keen interest in building them. For the first time in Malaysia,

we have introduced a ‘Liveable Attic’... great news for teenagers

who want some privacy!

1 4 . d e s i g n i n g t h e r m a l l y c o m f o r t a b l e h o u s i n g

85

We could turn attics into bedrooms.

The Cool House Technology is now free of charge.


86

Figure 14.4Expected performance of a UPM Cool bungalow on the hottest day of the year compared to the same bungalow without UPM Cool House technology.

Figure 14.5The aim of the design is to reduce thermal discomfort to zero units per 24 hours.

OUTDOORS35.6ºC

HOTTEST DAY OF THE YEAR (MARCH)MAXIMUM TEMPERATURE

30.8ºCUPM COOL BUNGALOWNORMAL BUNGALOW

29.8ºC29.6ºC

32.8ºC34.2ºC39.4ºC

OUTDOORS45 UNITS

HOTTEST DAY OF THE YEAR (MARCH)UNITS OF THERMAL DISCOMFORT

3 UNITS

UPM COOL BUNGALOWNORMAL BUNGALOW

1 UNIT

1 UNIT

25 UNITS

48 UNITS

58 UNITS


87

Figure 14.7Even during the

coolest month the UPM Bungalow will

be much cooler.

Figure 14.6On the hottest day

of the year the master bedroom of the UPM Cool

Bungalow is expected to be 4.70C

cooler (daytime) and 2.60C cooler

(night-time) than in a conventional

bungalow.

Tempera

ture ºC

Time

4.7ºCNormal Bungalow

34

31302928272625

35

32


MASTER BEDROOM DURING HOTTEST DAY (MARCH)

33

2.6ºCUPM Cool Bungalow

Tempera

ture ºC

Time

3ºC

Normal Bungalow

24

302928272625

31


MASTER BEDROOM DURING COOLEST DAY (NOVEMBER)

1.6ºCUPM Cool Bungalow


88

per hour at night time for our new designs of thermal comfort houses, although 14 air-changes per hour is almost enough. This rate of night ventilation combined with our other Cool House features makes the house thermally comfortable without air-conditioning, even on the hottest day of the year. To be useful, our scientific findings

need to be taken out of the University,

adopted by architects and developers and finally written into the Malaysian Building

Code. Based on our experiments and

people’s desire for energy efficiency, we recommend a minimum night time mechanical ventilation rate of 14 air-changes per hour for residential houses in Malaysia. The extra electricity bill is only 50 cents

Thermal Comfort Bungalows Four Thermal Comfort 21/2 storey bungalows are under construction on the UPM Campus. The design has been

optimized with computer simulation, giving excellent results. The attic will be the coolest instead of the hottest part of the house and it provides 700 sf of extra liveable space, but the thermal comfort bungalow costs no more per square foot of liveable area than a normal overheated bungalow. When the construction of the bungalows is completed, they will be tested using our temperature data logging technique during heat waves and cooler times of the year. The critical test will be the comparison with the above results from our computer simulation studies.

We have adopted 28 air-changes

Figure 14.8UPM Thermal Comfort Bungalows nearing completion.

Minimum night time mechanical ventilation rate of 14-air changes per hour is needed.


89

per night to run a whole house ventilation system. Every home should have one.

Low-medium Cost Apartments As we saw in Chapter 3, many

(probably most) Malaysian families have

been priced out of the terrace house market in the towns and are forced to buy ‘pigeon-hole’ flats as the only affordable housing

available. No wonder families rush back

to their kampongs, to the space, trees and the community at every opportunity. Surely

Malaysia, aspiring to be a developed nation by 2020, can do better than pigeon-hole flats!

Mazlin Ghazali has built a successful practice designing low to medium cost apartments using space efficient and

Figure 14.9 Pigeon-hole Flats

structurally efficient architecture developed

and perfected in housing projects over the last 10 years. Six thousand apartments

have been built to these designs, notably for teacher housing, as student accommodation at a UTM branch campus in Nilai, and for the

Selangor State University, currently under

construction.We have modified a successful

design using Cool House technology and computer simulations, economically optimizing the indoor temperatures of an apartment block (Figure 14.10). The results are striking, a 30C reduction of the maximum temperature and 100% reduction in thermal discomfort. Only ceiling fans are required for thermal comfort even on the hottest day of the year.

Pigeon-hole Flats


90

Figure 14.10UPM Cool House technology applied to !ats and apartments looks highly promising.

Our thermal comfort apartments, suitable for the low-medium income groups, have been designed to overcome the many social problems of low-cost apartments, long identified by UPM’s housing sociologists. Our

economical 5-storey hexagonal design has six 3-bedroom triangular apartments on each

floor with wrap-around garden verandas and

a central 800 sf social area for parents and children.

There is a lift, especially for young families, the handicapped and the over 50s. The design aim is to provide a modern, high density, healthy lifestyle and encourage social interaction amongst three generations. There is good privacy for each family and separate

bedrooms for boys and girls. With only minor modifications, the

housing designs for Malaysia can also serve the needs of many other developing countries. By choosing appropriate building materials,

our computer simulations have shown that our standard houses and apartment blocks can be customized to any climate on earth, thereby minimizing energy consumption for heating or cooling. Indeed, the energy savings over the lifetime of the building can equal the original construction cost, neatly achieving an important element of ‘sustainable’ development.

Energy savings over the lifetime of the building can equal the original construction costs.

OUTDOORS24.1ºC MIN35.6ºC MAX

SIMULATED PERFORMANCE HOTTEST DAY OF THE YEARCOOL APARTMENTSNORMAL APARTMENTS

25.5ºC27.9ºC Wall Shading

NightVentilation

Cool Roof

MIN MAX MIN MAX32.7ºC28.1ºC 32.7ºC28.1ºC 32.7ºC28.0ºC 32.7ºC27.8ºC 32.0ºC

UPM TECHNOLOGY

3ºC reduction in maximum temperature100ºC reduction in Thermal Discomfort

29.8ºC25.5ºC 29.2ºC25.5ºC 29.2ºC25.5ºC 29.3ºC25.6ºC 29.4ºC


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Despite the fact that scientists are underpaid (and while we’re at it, overworked!),

Research and Development is expensive and risky. The torturous path from invention to profit puts off even large companies, which,

with their accountants’ mentality, regard R&D as a ‘Black Hole’ where millions can

be pumped in, but nothing comes out. So

Malaysian companies have grown up relying heavily on imported technology and have not developed a research culture. This is where the Government steps in by funding long term R&D through the universities and research institutions. Only the Government can tolerate the high cost and the uncertain payback. What Malaysian company would have been willing to invest the RM 10 million it has cost in real terms (salaries, buildings, services, support staff, etc.) to fund this

Thermal Comfort Technology over the last 17 years? It has only been in the last year or

two that the potential ‘return on investment’ has became visible to the accountants. The prospect of an energy efficient

house with a cool attic but costing no more than existing houses delights the home buyer. It is now up to architects, developers and builders to follow our design principles and start building new thermally comfortable housing and renovating the existing two million overheated urban houses. These companies will make a lot of money by adopting this technology which, although novel, cannot be patented since it is an application of existing insulation and ventilation technology. Seemingly, the

Government (meaning you the taxpayer!) is

now providing free technology for companies to get rich. The Government, however, is not quite the sucker it seems. Consider the Government’s potential return on its RM 10 million investment.

Figure14.11Energy E"cient

House According to Our Computer

Simulations

This Thermal Comfort cluster

house (see Figure 14.1) will stay

cool without air-conditioning,

saving RM228 per month on

electricity compared to an existing

terrace house. The electricity savings over 30 years pay

for the house!

The Bottom Line

Electricity Savings(Computer Simulations)Thermal Comfort Quarter-detached House Terrace House

No air-con requiredElectricity Cost -Night Ventilation RM 16 per monthWhole house air-conditionedElectricity Cost - RM 244 per month

Electricity Saved - RM 228 per month - RM 2736 per yearSaving RM 82 080 in 30 years!


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This Government funded Cool House technology developed at Universiti Putra Malaysia can make a house 15 times more energy efficient than houses now

on the market. The technology cost you, the taxpayer, an estimated RM 10

million over the last 17 years. If fully implemented this R&D could potentially

save Malaysia RM 200 BILLION in electricity over the next 30 years!

This potential RM 200 bill ion return for a RM 10 million investment (a 20 thousand fold increase!) illustrates the

‘magic’ wealth creating ability of R&D. It benefits the whole society and pays for the

more fundamental scientific research, which

may take 25 to 100 years to mature. We need about 10% of our school children to take up science, engineering and technology as a profession to generate the wealth and infrastructure needed for the country’s future children and grandchildren. This is the path of human progress that Malaysia and other developing countries must willingly follow.

The fainthearted suggest that our Thermal Comfort Technology will send Tenaga Nasional, the national electricity

company bankrupt. We argue that the electricity saved in energy-efficient houses

and apartments can be put to better use to meet the growing demand for electricity by commerce and industry, creating wealth and better paid jobs… and good income for the Government from personal and company taxes.

Many people suppose that our technology is bad news for Malaysia’s air-con manufacturers. We don’t think so. In

fact, we recommend a 1 1/2 to 2 HP air-con

in the living room of every Thermal Comfort House, to provide just the right temperature, even on the hottest days of the year. We are not against air-cons. They are the greatest invention ever for the tropics; every home needs one. We are against the air-con electricity bill. Energy efficient housing makes air-conditioning accessible to the whole population. Consider this analogy: A new energy

efficient car comes on the market capable

of getting you around for just RM 20 per month in petrol, compared to the RM 300

(15 times more) for the petrol guzzling car

you are now driving. Imagine how this could boost car sales.

Cool House Technology is clearly no threat to the air conditioning industry. Malaysia is already the world’s largest producer of super efficient air-cons, which

are designed to cool down air. However, they are being piled into existing houses (I have counted 9 air-cons in a new corner lot terrace house!) in a hopelessly inefficient

attempt to cool down its concrete structure. Prevent the concrete from heating up and

a single air-con can do a marvellous job.

Part 1 - Thermal Comfort

Documents

thermal comfort housing

affordable honeycomb

housing studies

housing subdivision

comfortable housing

housing research

housing units

housing problems