Architectural research writing, 6th semester, 2020 - TJPRC

www.tjprc.org [email protected]

EVALUATION OF ENERGY PERFORMANCE OF AN OFFICE BUILDINGCASE

STUDY ON TERI, BENGALURU

HEMA SHREE. V1, ARJUN. N. P2, VINAY. J3 & ANUP KUMAR PRASAD4

1,2,3Student, School of Architecture, REVA University, Bangalore, India

4Professor, School of Architecture, REVA University, Bangalore, India

ABSTRACT

This is an empirical research paper that compares the actual and projected simulation results of TERI. The research

adopts the design methodology and aims to develop logical guidelines for passive design strategies. The formulated

guidelines help to mitigate the energy loads on the building WRT office buildings. These could be replicated in buildings

in similar climatic zone of Bengaluru (temperate climate) aided by computer simulation and climatic study.

KEYWORDS: Simulation, Design Strategies, Thermal Comfort & Visual Comport

Received: May 12, 2020; Accepted: Jun 02, 2020; Published: Jul 17, 2020; Paper Id.: IJCSEIERDAUG20201

INTRODUCTION

Energy efficient buildings are those with building envelopes that mitigate the need for additional energy loads in

order to increase thermal and visual comfort levels.

WRT to building envelope high performance could be achieved through solar protections like sun shades,

understanding the requirements of light in different parts of the building; window orientation, window to wall ratio,

glazing affecting the heat and light entry to the building; design elements that understand light and affecting the

ambience of space; building materials with SHGC corresponding to the environment.

In broader perspective at the site level, a better building performance could be achieved through shape of

the building WRT to the local climate; optimum solar orientation of the building responding to the sun path.

Aim

To analyze if the passive and active design strategies are able to meet the desired comfort level of the end user and

its impact on energy performance of the building.

OBJECTIVE

Identification and analysis of elements of passive and active design strategies in the building.

Impact of passive design strategies on the energy consumption of the building.

Analysis of thermal and visual comfort of the end users through simulation and constructive criticism by

occupants.

Comparison of simulation results and actual performance of the building.

To formulate guidelines for passive design strategies.

Orig

ina

l Article

International Journal of Civil, Structural,

Environmental and Infrastructure Engineering

Research and Development (IJCSEIERD)

ISSN (P): 2249–6866; ISSN (E): 2249–7978

Vol. 10, Issue 4, Aug 2020, 1–18

© TJPRC Pvt. Ltd

2 Hema Shree. V, Arjun. N. P, Vinay. J & Anup Kumar Prasad

Impact Factor (JCC): 9.5582 NAAS Rating: 4.15

Scope

Comfort factors are limited to lighting and ventilation; mechanical ventilation is not a part of study; Study of lighting is

based on natural source of light only; Constructive criticism from occupants only; Design guidelines are limited to passive

design only.

Primary study has not been carried out due to the Covid-19 pandemic lockdown, considering the submission

deadlines. Hence, the subcategories (analysis) coordinating with primary study i.e. constructive criticism, simulations of

plans, complete results on performance of building (actual & projected) have been withheld.

METHODOLOGY

Figure 1: Current Trend and Methodology on Architectural Design.

NEED FOR STUDY

The paper acts as a guideline for designing a climate responsive building for Bangalore and similar climatic region.

The design strategies could be directly applied saving more time.

Easier logical understanding behind the passive design strategies.

Better understanding of landscape in order to choose the type of plantation according to the requirements.

A better understanding on elements of nature and climate before design.

Literature Case Study (PEDA Office)

Day light: On the South Western facade, dome shaped structures with glass fixed in the voids to allow natural light.

The atrium is covered by lightweight shell roofing specifically angled to allow sun in winters and block in

summers.

Light Vaults: The vertical cut outs in the floating slabs are integrated with light vaults to allow day light without

glare and heat.

Evaluation of Energy Performance of an Office Buildingcase Study on Teri, Bengaluru 3


Cavity Walls: The cavity walls (2”) facing South and West are filled with insulation material for efficient thermal

effect.

Solar Power Plant: 25Kwp solar photovoltaic power plant to meet the basic requirement of electricity.

Water Bodies: The water bodies with waterfalls and fountains have been placed in the central for cooling.

Wind Tower coupled with Solar Chimneys: centrally placed wind tower coupled with solar chimneys on the

domical structures for direct & indirect cooling and drafting of used air.

Thermal comfort: Controlled Solar access, Air is cooled by a wind tower, the volume of air is heated by solar

penetration through the roof glazing.

Figure 2: PEDA Office South Elevation.

ANALYSIS - GEOGRAPHY AND CLIMATE

Geography

Location- Bengaluru latitude: +12.97(12°58’12” N)

Longitude: +77.56(77°33’36” E) Time zone: UTC+5:30 hours

Country: India Continent: Asia

Sub-region: Southern Asia Altitude: ~890m

Climatic Study

Figure 3: Temperature and Radiation Change. Figure 4: Detailed Radiation (Lum).

ANALYSIS – CLIMATE

Bengaluru receives breeze with 10-20 km/h speed. The breeze directs from East and West for major period of the year.

Wind with the speed of 25-35 km/h is also majorly observed from North-West and South-West and North-East but for the

very short period of time.



Figure 5: Sun Path Diagram. Figure 6: Wind Speed.

The sun path for this region is tilted towards south from the normal for longer period of time since Bengaluru is

situated in Northern hemisphere.

The sun path for Bengaluru region tilts 10 degrees from normal towards North during the months of June and

July. The sun path tilts 38 degrees from normal towards South during the months of December and Jan and lies in

between these angles during other months.

ANALYSIS-TERI (The Energy Resource Institute)

Figure 7: Optimum Orientation. Figure 8: Building Orientation.

The building plays a vital role in solar architecture, fulfilling the guidelines of optimum orientation.

The optimum orientation refers to the condition in which thermal gain is lowest considering the 3 hottest months

of the year and highest thermal gain during 3 coldest months of the year.

The building is oriented along North West-South East direction

Exposing the shorter sides of the building to East and West helps in the reduction of thermal gain since the

maximum thermal gain is from East and West.



Figure 9: Shadow Range During Different Times of the Year.

The images show a range of shadows during different times of the year helping the window design, shading

device and landscape. The shadow patterns as observed are shading the Northern façade for most part of the year except on

the summer solstice (June 21) meaning, glare free north light could be taken as an advantage for the maximum period of

the year. As the winter approach the shift of sun path towards the South leading to the oblique sun rays helps in easy entry

into the building, therefore natural heating during winter.

Zoning

The office block is placed towards the road, i.e. towards east. The guest house is located on the western end of the site.

Figure 10 Terrace Plan. Figure 11: First Floor Plan.

Openings

Location of windows- most of the windows are located on the North façade. The air entering from East and West into the

landscape in front of North façade circulates in between the trees and cools down and enters the building from the

openings. The wind flow from North direction into the site is east when compared to other directions. The landscaping on

Equinox

Summer

Solstice

Winter

Solstice



the right place managed this in bringing the air into the building from other directions to by stopping the wind with trees,

circulate in between the landscape, cool it down and the air is circulated into the building.

Self-Shading Façade

The façade along the North is designed such that it self-shades and keep the wall cooler preventing from thermal gain. The

small projections acting as a shading device are chamfered and angled in such a way that when the radiations hit one of

them, they cast shadow below and this follows.

Figure 12: Façade Projections for Solar Shading Figure 13 a & b: Skylight 1 & 2

Fenestrations

Figure14: Fenestrations for Entry of Light.

The fenestrations are well designed to utilize the maximum glare less light from North. North light

skylights are provided down seeing the atrium spaces and the interior landscape.

These atrium spaces with sky lights brings the light into the heart of the building. This in turn provides

the light to the plants inside, helping them to filter air and give fresh air into the work spaces.

The office is well lit with abundant day light with East dependency on artificial lighting throughout the

year.

Passive Features

Material: Kadapa stone



Properties of the material: High Heat retention

Wind movement: South to North

Constraints: Foul smell from the drain on the South

Figure 15: Air Flow due to Negative Pressure. Figure 16: Solar Chimney.

Figure 17: Section Representing Wind Movement. Figure 18: Vents in the South Wall.

The South facade has a cavity wall with the outer layer of Black Kadapa stone.

This Kadapa stone has high heat retention.

The South wall has no openings in the lower level and only has ventilators on the top.

The stone wall heats up due to sun rays and there is an increase in the temperature.

The increase in temperature leads to air heating up. This hot air rises and escapes from the top vents.

This escape of air creates a negative pressure inside the building which in-turn sucks in air from the Northern side

of the campus.

This Northern side has extensive landscape, thus leading to cool air entering the building.

Earth Berm

The earth having low embodied energy, the fluctuations in temperature within the earth are least when compared to the

atmosphere outside. Fluctuations in temperature within the soil reduces as the depth increases, the temperature reaches to

constant, the same as annual mean temperature of the location at the depth of 4m below the ground level. TERI is designed

to use this concept in a part of building,

Solar Energy

The roof is integrated with solar panels. A part of energy requirement for the workstations has been fulfilled by



these photo voltaic cells.

Solar energy is further utilized for the water heating requirement in the guest house.

Figure 19: Solar Panel. Figure 20: Solar Water Heater.

Rainwater Collection

The central court in between houses an open air amphitheater as an informal gathering space, the pond collects all the

storm water run-off from the pavement and also the run-off water from all roof tops. The collected water is used to

maintain landscape.

Figure 21: Water Body. Figure 22: Rainwater Pipeline.

OBSERVATION

Integrated Design Approach

Cost Analysis

Active Design Strategies

Cost analysis and

payback

calculations

Passive Design Strategies Comfort systems

for passive and

active design

strategies

Comfort Analysis Building Forms Lighting

Climate

Analysis Thermal comfort Orientation Electrical systems

Macro

climate

analysis

Visual comfort Building Envelope Renewable energy systems

Micro

climate analysis

Natural ventilation Shading and Day lighting



DESIGN GUIDELINES

Targets

EPI (Energy Performance Index) to be achieved for moderate climate for day time occupancy (5 days a week) for

a commercial/institutional/academic building is 75kWh/sq.m./year, 225kWh/sq.m./year for a 24/7 occupied

building of a similar typology.

EPI to be achieved for a moderate climate in a residential building is 50kWh/Sqm/year (considering 24/7

occupied)

Artificial lighting efficiency to demonstrate luminous efficiency of at least 75 lumens/ unit.

Usage of BEE star rated fans.

Peak heat gain through building envelope for each A/C building to meet 30 W/Sqm.

Site design strategies which assists the decrease of UHIE (urban heat island effect).

Design strategies in which natural site features could be protected or incorporated into project and reduce the

impact on environment through site planning strategies and passive design.

Usage of low flow fixtures- usage of BIS recommended wastes 9flyash, blast furnace slag) having properties

similar to conventional construction materials and these being materials with low embodied energy.

DESIGN GUIDELINES

Adaptive Thermal Comfort Factors

Standards based on adaptive thermal comfort model can be operated at more moderate temperatures and can play a major

role in reducing energy use whilst maintaining the comfort, productivity and well-being of occupants

For naturally ventilated buildings

Indoor operative temperature (°C) = 0.54 x outdoor temperature + 12.83, the 90% acceptability range for the

adaptive models for conditioned buildings is ±2.38 °C

For mixed mode buildings



For A/C buildings (Below equations are not applicable for outdoor running mean temperature below 15°C)

Air temperature-based approach

Indoor air temperature (°C) = 0.078 x outdoor temperature + 23.25, the 90% acceptability range for the adaptive

models for conditioned buildings is ±1.5 °C

Standard effective temperature-based approach





Where the indoor operative temperature (°C) is neutral temperature and outdoor temperature is the 30-day outdoor

running mean air temperature (°C)

DESIGN GUIDELINES

Design Guideline Matrix for Temperate Climate Zone

Thermal Factors

Table 1

Vertical Fenestration

(Without External Shading Window to Wall Ration <40%

VLT <0.27

U-Factor (W/m2.K) <3

SHGC – Non North 0.27

SHGC – North for latitude ≥15ºN 0.50

SHGC – North for latitude <15ºN 0.27

Skylights SRR <5%

U-Factor (W/m2.K) <4.25

SHGC 0.35

IL luminance Range

Table 2

S. No. Type of Interior or Activity Range of Service Illuminance (lux)

1 General Offices 300-500-750

2 Computer Workstations 300-500-750

3 Conference Rooms 300-500-750

4 Print Rooms 200-300-500

DESIGN GUIDELINES

Passive Design Strategies ( Psychrometric Analysis) – Climate Consultant

The psychometric chart plotted for temperature and humidity shows the weather condition of Bangalore throughout the

year.

Figure 23: Comfort Zone 9.7% (852 hrs). Figure 24: Dehumidification only 30.3% (2646hrs).



Figure 25: Sun Shading of Windows 30.6% (2683 hrs). Figure 26: Natural Ventilation 39.3% (3446 hrs).

Figure 27: Direct Evaporative Cooling 14.2% (1243 hrs). Figure 28: Internal Heat Gain 16.8% (1473 hrs).

Figure 29: High Thermal Mass 33.4% (3921 hrs). Figure 30: Two Stage Evaporative Cooling 17.7% (1550 hrs).



Figure 31: Fan Forced Ventilation Cooling 41.4% (362 hrs). Figure 32: Dehumidification + Cooling 45.8% (5562

hrs).

DESIGN GUIDELINES-PASSIVE DESIGN STRATEGIES

Window Overhangs

Window overhangs (designed for this latitude) understanding the requirement of heat and light or operable sun shades

(awnings that extend in summer) that reduce or eliminate air conditioning.

Figure 33: Roof Extension and Window Overhangs.

Porches

This is one of the more comfortable climates, hence shade to prevent overheating, open to breezes in summer, and use of

passive solar gain in winter.

Shaded outdoor buffer zones (porch, patio, lanai) oriented to the prevailing breezes can extend living and working

areas during hot days. Meshed or screened porches and patios can provide comfort cooling by ventilation during warm

days.

Figure 34: Porch. Figure 35: Landscape Placement.

Vegetation

Use plant materials (bushes, trees, ivy-covered walls) especially on the West to minimize heat gain (plantations to be

chosen supporting summer rains)



Roof

Low pitched roof with wide overhangs works well in temperate climates

Figure 36: Pitched Roof.

Orientation

Figure 37a: Orientation Along NS.

Figure 37b: Orientation Along EW.

Ventilation

Good natural ventilation can reduce or eliminate air conditioning in warm weather, if windows are well shaded and

oriented to prevailing breezes. Low narrow building floor plan can help maximize cross ventilation in temperate climates.

On hot days, ceiling fans inducing indoor air movement can drop it to 2.8°C cooler; A whole house natural ventilation can

store the coolth within high mass interior surfaces (night flushing); to induce stack ventilation even with low wind speed,

maximize vertical height between air inlet and outlet (double heights, open well staircase) thus less air conditioning is

needed.

Figure 38: Ventilation.

Passive Solar Heating



For passive solar heating, most of the glass area to be placed facing towards South to maximize winter sun exposure, but

overhangs required for summer shading is a must for this strategy.

Orient broad building surfaces away from hot Western sun exposure, but design overhangs to fully shade in

summer.

Figure 39: Openings on South Direction.

Figure 40: Landscape Design for South.

Landscape Design

Trees other than conifer or deciduous should not be planted in front of passive solar windows on South in order to not

violate solar access and to take full advantage of this strategy, but are fine beyond 45 degree from each corner, or this

strategy could also be customized according to light requirement.

Roof Design

Use light colored building materials and cool roofs (with high emissivity) to minimize conduct heat gain. Use materials

with high SRI (Solar Reflectance Index) to minimize amount of heat absorbed.

Figure 41: Roof Panel.



Figure 42: Building Massing.

Building Massing

The main strategy in moderate climate is about protection from the sun and good ventilation, larger surface areas

supporting enough number of openings for ventilation and heat emission during the night. However, the building should

not have a large surface to volume (S/V) ratio to minimize heat gains. The buildings will perform better if arranged in row

houses, group arrangements or with adjoining houses to create a volumetric effect.

REFERENCES

1. Case study on Energy Efficient Building, Date of access: 03/04/2020.

2. http://peda.gov.in/main/case_study_15.12.2016.pdf

3. The Energy and Resources Institute (TERI) Building, Date of access: 03/04/2020.

4. http://fairconditioning.org/showcase/the-energy-and-resources-institute-teri-building-bangalore/

5. Techniques and Practices in Green Building in India, Date of access: 03/04/2020.

https://www.krishisanskriti.org/vol_image/07Jul201512074256%20%20%20%20%20%20Rupa%20T%20%20Ganguly%20%

20%20%20%20%20%20%20%20%20%20%20665-670.pdf

6. Green Building Construction for Sustainable Future, Date of access: 03/04/2020.

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.884.2750&rep=rep1&type=pdf

7. Kiran Kumar, D E V S. (2014). Ecological Concepts in Buildings- Case study of TERI office in Bangalore.

8. Hassan, Mohammad Ul, and Sudarshan Singh. "Fabrication, Experimentation, Performance Evaluation of Two Stage Air

Cooler and Comparison with Conventional Air Cooler." International Journal of Mechanical Engineering (IJME) 5.4 (2016):

75-84.

9. Sari-Ali, I., B. Chikh-Bled, and B. Benyoucef. "Effect of shading on the performance on solar photovoltaic." Int J Appl Eng Res

Dev (IJAERD) 4.2 (2014): 41-8p.

10. Mechouet, A. B. D. E. L. A. Z. I. Z., et al. "Evaluating the impact of air infiltrations on the thermal and energy performances

for different types of dwellings in casablanca city." International Journal of Mechanical and Production Engineering

Research and Development (IJMPERD) 8 (2018): 793-800.

11. Senthil, R., and A. P. Nishanth. "Optical and thermal performance analysis of solar parabolic concentrator." International

Journal of Mechanical and Production Engineering Research and Development 7.5 (2017): 367-374.

12. Green Building Case Study on TERI,Bangalore; Date of access: 22/05/2020.

https://www.slideshare.net/vinaymandaloju/green-building-case-study-on-teribangalore

13. TERI; Date of access: 22/05/2020. https://www.slideshare.net/thincdesign/teri-13480414

http://peda.gov.in/main/case_study_15.12.2016.pdf

http://fairconditioning.org/showcase/the-energy-and-resources-institute-teri-building-bangalore/

https://www.krishisanskriti.org/vol_image/07Jul201512074256%20%20%20%20%20%20Rupa%20T%20%20Ganguly%20%20%20%20%20%20%20%20%20%20%20%20665-670.pdf

https://www.krishisanskriti.org/vol_image/07Jul201512074256%20%20%20%20%20%20Rupa%20T%20%20Ganguly%20%20%20%20%20%20%20%20%20%20%20%20665-670.pdf

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.884.2750&rep=rep1&type=pdf


https://www.slideshare.net/thincdesign/teri-13480414



14. GRIHA Version 2015, Date of access: 22/05/2020. https://www.grihaindia.org/files/GRIHA_V2015_May2016.pdf

15. ECBC 2017 Design Guide, Date of access: 22/05/2020 https://beeindia.gov.in/sites/default/files/DesignGuideline_Draft.pdf

16. Figure 1: Abid, N., 2015, current trends and methodology on architectural design.

17. Figure 2: PEDA Office South Elevation, 2016, Date of access: 22/05/2020.

https://www.google.co.in/url?sa=i&url=https%3A%2F%2Fwww.slideshare.net%2FSIDDIQSALIM1%2Fpunjab-energy-

development-agency-building-

chandigarh&psig=AOvVaw16OZsDsUcPRXRyIQCiA_P6&ust=1590755202885000&source=images&cd=vfe&ved=0CAIQj

RxqFwoTCICssInH1ukCFQAAAAAdAAAAABAD

18. Figure 3: Temperature and Radiation Change, 2020, Source: Author using Climate Consultant

19. Figure 4: Detailed Radiation (LUM), 2020, Source: Author using Climate Consultant

20. Figure 5: Sun Path, 2020, Source: Author using Weather Tool

21. Figure 6: Wind Speed, 2020, Source: Author using Weather Tool

22. Figure 7: Optimum Orientation, 2020, Source: Author using Weather Tool

23. Figure 8: Building Orientation, 2020, Source: Author using Weather Tool

24. Figure 9: Shadow Range during different times of the year, 2020, Source: Author using Weather Tool

25. Figure 10: Terrace Plan, 2012, Date of access: 22/05/2020.https://www.slideshare.net/rupeshchaurasia39/teri-bangalore-

solar-passive-techniquesrupesh?next_slideshow=1

26. Figure 11: Terrace Plan, 2012, Date of access: 22/05/2020. https://www.slideshare.net/rupeshchaurasia39/teri-bangalore-

solar-passive-techniquesrupesh?next_slideshow=1

27. Figure 12: Façade Projections for Solar Shading, 2012, Date of access: 22/05/2020.


28. Figure 13a & b: Skylight, 2014, Date of access: 22/05/2020. https://www.slideshare.net/vinaymandaloju/green-building-case-

study-on-teribangalore

29. Figure 14: Fenestrations for entry of light, 2020, Source: Author using Autocad

30. Figure 15: Air Flow due to negative pressure, 2020, Source: Author using Autocad

31. Figure 16: Solar Chimney, 2020, Source; Author using Autocad

32. Figure 17: Section Representing Wind Movement, 2020, Source: Author using Autocad

33. Figure 18: Vents in the South Wall, 2020, Source: Author using Autocad

34. Figure 19: Solar Panel, 2014, Date of access: 22/05/2020. https://www.slideshare.net/vinaymandaloju/green-building-case-

study-on-teribangalore

35. Figure 20: Solar Water Heater, 2014, Date of access: 22/05/2020. https://www.slideshare.net/vinaymandaloju/green-building-

case-study-on-teribangalore

36. Figure 21: Water Body, 2012, Date of access: 22/05/2020. https://www.slideshare.net/thincdesign/teri-13480414

37. Figure 22: Rainwater Pipeline, 2012, Date of access: 22/05/2020.https://www.slideshare.net/thincdesign/teri-13480414

https://www.grihaindia.org/files/GRIHA_V2015_May2016.pdf

https://beeindia.gov.in/sites/default/files/DesignGuideline_Draft.pdf

https://www.slideshare.net/rupeshchaurasia39/teri-bangalore-solar-passive-techniquesrupesh?next_slideshow=1

















38. Figure 23: Comfort zone 9.7% (852 hrs), 2020, Source: Author using Climate Consultant

39. Figure 24: Dehumidification only 30.3% (2646hrs), 2020, Source: Author using Climate Consultant

40. Figure 25: Sun shading of windows 30.6% (2683 hrs), 2020, Source: Author using Climate Consultant

41. Figure 26: Natural ventilation 39.3% (3446 hrs), 2020, Source: Author using Climate Consultant

42. Figure 27: Direct evaporative cooling 14.2% (1243 hrs), 2020, Source: Author using Climate Consultant

43. Figure 28: Internal heat gain 16.8% (1473 hrs), 2020, Source: Author using Climate Consultant

44. Figure 429 High thermal mass 33.4% (3921 hrs), 2020, Source: Author using Climate Consultant

45. Figure 30: Two Stage Evaporative cooling 1.17% (1550hrs), 2020, Source: Author using Climate Consultant

46. Figure 31: Fan forced ventilation cooling 41.4% (362 hrs), 2020, Source: Author using Climate Consultant

47. Figure 32: Dehumidification + cooling 45.8% (5562 hrs), 2020, Source: Author using Climate Consultant

48. Figure 33: Roof Extension, 2020, Source: Author

49. Figure 34: Porch, 2020, Source: Author

50. Figure 35: Landscape Positioning, 2020, Source: Author

51. Figure 36: Pitched roof, 2020, Source: Author

52. Figure 37a & b: Optimum Orientation, 2020, Source: Author

53. Figure 38: Ventilation, 2020, Source: Author

54. Figure 39: Openings on south direction, 2020, Source: Author

55. Figure 40: Landscape design for South, 2020, Source: Author

56. Figure 41: Roof Panel, 2020, Source: Author

57. Figure 42: Building Massing, 2020, Source: ECBC

Architectural research writing, 6th semester, 2020 - TJPRC

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