solar passive system for buildings

Under the supervision of

Dr. Jaiprakash Bhamu

Associate Professor, DME

Presented by

Garima Sharma

Introduction to Passive Solar

System

What is the meaning of this word “Passive” ?

What is “Passive solar design”?

Passive solar systems rules of

thumb Construction on east-west axis.

Time of receiving sun light during heating season.

Spaces locate on the north.

open floor plan.

shading.

Basic Principles of Passive Solar

Design Passive solar design uses the elements of a building such as

orientation, windows, walls, roof and floors as well as the localizedenvironment to collect, store and distribute solar energy to heat ahome in winter, and block the sun’s heat in summer.

Generally, passive solar design makes use of the following elements:

Orientation

The local environment

Insulation

Energy efficient windows

An absorber

Passive Solar Heating The goal of all passive solar heating systems is to capture the sun's

heat within the building's material and release that heat during

periods when the sun is not shining.

Primary elements of passive solar heating are :

Thermal mass to absorb, store, and distribute heat.

South-facing windows are designed to let the sun's heat in while

insulating against the cold.

Open floor plans allow more sun inside.

There are 3 main methods of passive solar heating:

Direct gain

Indirect gain

Isolated gain

Direct Gain• Living space work as solar collector, heat

absorber and distribution system.

• South-facing windows.

• Use of thermal mass.

(www.azsolarcenter.org)

Indirect Gain Thermal mass place between sun and

space.

Use of flat plat collectors.

(www.azsolarcenter.org)

Isolated Gain

Sunspace

Main functions of sunspaces

Main considerations

Siting

Heat Distribution

Glazing

(www.azsolarcenter.org)

Passive solar cooling Passive cooling systems are least expensive means of cooling a home

which maximizes the efficiency of the building envelope without

any use of mechanical devices.

The primary focus of passive cooling is:

Slow heat transfer into the house.

Remove unwanted heat from the building.

Various passive technologies that can be adopted in the various

climatic zones in India are as follow:

Shading system

Ventilation

Solar chimney

Thermal mass

Wind towers

Evaporative cooling system

2.6.1

Shading system

The most effective method of cooling a building is to shade

windows, walls and roof of building from direct solar radiation.

There are two types of shading system:

External Shading

Internal Shading

External shadingThese method used in external shading:

Eaves

Awnings

Screens and shutters

Louvers

Verandahs

Pergolas

Trees and shrubs

Different kinds of shading

Retractable Awnings

(Maleki,B.A.2011)

Different kinds of shading

(Maleki,B.A.2011)

LouversShade From Pergola

Internal shading•Internal shading can be provided

using curtains and blinds.

Internal shading can be a useful

device when:

• The sun penetrates for only a

short time heat build-up will not

be major problem.

• Windows can he sun be left open

adjacent to them.

• It is required to reduce glare.

(Maleki1, B.A.2011)

Passive solar ventilation

Passive ventilation is when air is exchanged in a building through

openings in the building envelope using the stack and wind

pressures.

These are the passive cooling ventilation strategy:

Cross-Ventilation

Stack Ventilation

Cross-Ventilation

•cross-ventilation

strategies place air inlets

on the windward side and

air outlets on the leeward

side of the home.

(www.level.org.nz)

Stack Ventilation• In stack ventilation cool air

is pulled throughout the home

while warmer air rises above

the cool air to exit through an

opening near the top of the

structure.

(www.level.org.nz)

Thermal Mass A material that has thermal mass is one that has the capacity to

absorb, store and release the sun’s heat energy.

The best way to cool a building is to build with thick stone or

masonry.

Thermal mass is measured in terms of ‘Volumetric heat capacity’.

Thermal mass properties of some material are presented in table

below:

Material Conductivity W/m K

Vol. heat capacity kJ/m3K

Water 1.9 4186

Cast concrete 1.4 2300

Granite 2.1 2154

Brick 0.72 1360

Evaporation cooling• Evaporative cooling lowers indoor air temperature by evaporating

water.

• In evaporative cooling, the sensible heat of air is used to evaporate

water, thereby cooling the air, which, in turn, cools the living space

of the building.

Methods of evaporative cooling include:

• Roof pond systems

• Water spraying

(Guerra, A. 2010)

Solar chimney Improve the ventilation using

convection.

Stack effect,

Black-painted chimney, with a

partly glazed surface area towards

the top.

During the day, solar energy heats

the chimney and the air within it,

creating an updraft of air in the

chimney.

(Pasomarthi)

Wind Towers•In a wind tower, the hot air enters the tower through the openings in

the tower, gets cooled, and thus becomes heavier and sinks down.

(Bahadori, M.N.2006)

Advantage of Passive Solar Design Eliminate heating and cooling costs

Reduce greenhouse gas emissions

Clean process

Eco-friendly

Cost

Attractive living environment

Low maintenance

Unwavering comfort

Disadvantage of Passive Solar Design:- Great deal of work for the engineers to arrange this system.

All systems are not same.

Careful construction required

Improperly designed not work well

Sunshine not available all day

Extra heat and the higher temperatures

Thermal wall loses heat back to the out-of-doors through the glass

Case study of solar passive hostel university of Jodhpur

Wind tower in Jodhpur Hostel to catch favorable cool

wind from south-west for passive cooling

•Glasses

•solid timber shutters

•wind tower

•air gap in the roof

•light colored stone

•South facing windows

Solar Passive Hostel University of Jodhpur(Gupta,V.1992

References Kamal, M.A. (2012), “An Overview of Passive Cooling Techniques in

Buildings: Design Concepts and Architectural Interventions”, Acta

Technica Napocensis: Civil Engineering & Architecture, Vol. 55, No. 1,

pp. 84-97.

Maleki, B.A (2011), “Shading: Passive Cooling And Energy

Conservation In Buildings”, International Journal on “Technical and

Physical Problems of Engineering”(IJTPE), Vol. 3, No. 4,pp, 72-79.

Guerra, A. (2010), “The Roof-Pond or Roof Water A Solar System To

Gain Indirect”.

Bahadori, M.N. (1978); “Passive Cooling System in Iranian

Architecture”, Scientific American, pp.144-154.

Pasumarthi, N., and Sherif, S.A. (2008), “ Experimental And

Theoretical Performance Of A Demonstration Solar Chimney”.

http://www.passivesolar.sustainablesources.com, cited on 12th Jan. 2014.

http://www.azsolarcenter.org, cited on 16th Jan. 2014.

Gupta, V.(1992),“ Solar Passive Hostel University of Jodhpur”,

ARCHITECTURE+DESIGN May-June 1992,pp. 34-35.

Thank You

Questions are Welcome