ASR - Energy Efficient Retrofit of an Unconditioned Bldg

7/23/2019 ASR - Energy Efficient Retrofit of an Unconditioned Bldg

1/15

This article was downloaded by: [York University Libraries]On: 23 September 2014, At: 14:07Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House37-41 Mortimer Street, London W1T 3JH, UK

Architectural Science ReviewPublication details, including instructions for authors and subscription information:

http://www.tandfonline.com/loi/tasr20

Energy-efficient retrofit of an unconditioned institute

buildingAanchal Sharma

a, P. S. Chani

a& S. Y. Kulkarni

a

aDepartment of Architecture and Planning, Indian Institute of Technology, Roorkee 247667

Uttarakhand, India

Published online: 05 Apr 2013.

To cite this article:Aanchal Sharma, P. S. Chani & S. Y. Kulkarni (2014) Energy-efficient retrofit of an unconditioned institut

building, Architectural Science Review, 57:1, 49-62, DOI: 10.1080/00038628.2013.769424

To link to this article: http://dx.doi.org/10.1080/00038628.2013.769424

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the Content) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of thContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon an

should be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions
http://dx.doi.org/10.1080/00038628.2013.769424http://www.tandfonline.com/page/terms-and-conditionshttp://www.tandfonline.com/page/terms-and-conditionshttp://dx.doi.org/10.1080/00038628.2013.769424http://www.tandfonline.com/action/showCitFormats?doi=10.1080/00038628.2013.769424http://www.tandfonline.com/loi/tasr20


2/15

Architectural Science Review, 2014

Vol. 57, No. 1, 4962, http://dx.doi.org/10.1080/00038628.2013.769424

Energy-efficient retrofit of an unconditioned institute building

Aanchal Sharma

, P.S. Chani and S.Y. KulkarniDepartment of Architecture and Planning, Indian Institute of Technology, Roorkee 247667, Uttarakhand, India

(Received 29 February 2012, Accepted 20 January 2013 )

The purpose of this study is to demonstrate the energy-efficient retrofitting of an existing unconditioned academic departmentbuilding in the campus of the Indian Institute of Technology, Roorkee, India. It is achieved with the use of energy simulationmodelling to examine the energy-saving benefits of power-consuming equipments, power generation through renewablesources improving thermal comfort through Energy Conservation and Building Code Indias compliance and motivating thebuildings occupants for energy-responsive behaviours. These strategies, when applied together, lead to an overall reductionof 40.4% in the total energy consumption. It was observed that the energy units saved for an unconditioned building aresignificantly lower than that of a conditioned building, but thepercentage changes are comparable for both the types.The heatgain results from simulation software also show that in such buildings external windows account for most of the heat gainwithin the building, whereas uninsulated walls result in heat loss throughout the year. Changes in the operative temperatureof the order of 0.54.0C are observed by proposing a green roof, false ceiling, wall insulation and high performance glass.

If the same retrofits are applied to all other academic buildings, huge energy savings and cost benefits can be obtained.

Keywords: energy-efficient retrofitting; unconditioned academic institute building; energy simulation modelling; EnergyConservation Building Code India; composite climate

1. Introduction

In India, unconditioned buildings form the largest chunk

of the existing building stock due to a largely favourable

climate and a developing economy; particularly in the gov-

ernment sector. Many of the existing institutional buildings

are more than 50 years old and were not designed keeping

energy efficiency in mind. While new building construction

incorporates state-of-the-art efficient technologies, old con-

struction continues to perform poorly in terms of its energy

efficiency (FORESIGHT 2008). This lacuna needs to be

addressed, particularly in developing countries like India,

which has a significant pool of such buildings.

The Indian Institute of Technology Roorkee (IITR)

is identified as one such campus which is more than

150 years old and has a spread of about 365 acres. It

houses about 18 academic departments, 10 hostels, vari-

ous community and activity centres, sports facilities and

several heritage buildings. The institute has a total con-

nected electrical load of 7.3 MW and a contract demand

of 8.6 MVA. The energy consumption of the institute for

academic session 20092010 was 18,198 MWh approxi-

mately. A meagre reduction of 1% in energy consumptionwill roughly save 182 MWh energy units or 144 MT of car-

bon emissions at a 0.79 tCO2/MWh emission factor for

India (CO2 Baseline Database for the Indian Power Sector

2008). Therefore, energy-efficientretrofittingof the existing

Corresponding author. Email: [email protected] research performed in this article forms a part of the ongoing Doctoral Research of Aanchal Sharma, the first author.

buildings on the campus can lead to a significant reduction

in the total energy consumption, which will not only reduce

the monthly energy costs but also have a positive effect on

the environment.

Theprimary effort of this research is to apply therelevant

energy-efficient solutions to an unconditioned academic

institute building and to demonstrate any major (or minor)

energy consumption and carbon emission reductions. The

academic building of the Department of Architecture and

Planning (DAP), IITR has been identified as a case study

for this purpose.

2. Literature review

The existing literature show great paucity in energy-

efficient designs for unconditioned buildings. The building

energy codes of various countries like the United States,

India and Canada focus largely on conditioned commer-

cial buildings and are derived from standards produced

by the American Society of Heating, Refrigerating and

Air Conditioning Engineers (ASHRAE) (Evans, Shui, and

Delgado 2009). In India, Energy Conservation BuildingCode (ECBC) sets the standards for the energy-efficient

design and construction of commercial buildings with a

minimum connected load of 500 kW or a conditioned

floor space of 1000 m2 (Energy Conservation Building

2013 Taylor & Francis


3/15

50 A. Sharmaet al.

Code 2007). ECBC intends to improve the energy effi-

ciency of the five building systems, viz. building envelope,

heating ventilation and air-conditioning (HVAC) systems

and equipments service hot water and pumping, interior

and exterior lighting and electrical power. Even though it is

recommended for building types other than commercial as

well, not all other types of buildings have the requirements

of HVAC systems and service hot water and pumping.

A number of authors have also worked on the energy-

efficient retrofitting models for commercial office buildings

and propose multiple energy-efficient strategies. Yiquin,

Rongxin, and Zhizhong (2008) estimated savings of

7545 kWh/month by proposing a design with a combina-

tion of a high-efficiency building envelope, high-efficiency

lighting system and day lighting dimming in the perimeter

area, and a high-efficiency HVAC system for a resource and

development centre in Shanghai, China. In another retrofit

programme, Anne and Neils (2002) predicted substantial

reductions in thermal and electrical energy by using both

passive solar and energy conservation techniques for 10European office projects. It is evident that significant work

has been carried out to improve the energy performance of

centrallyconditioned offices/commercial buildings: and the

results show that cost-effective energy savings in the order

of 2030% can be achieved (Dascalaki and Santamouris

2002). However, very less text has been found for energy-

efficient retrofitting of existing unconditioned buildings.

A research study considering a similar type of uncondi-

tioned academic institute has been demonstrated by Nashib

and Mathur (2009) for the Malaviya National Institute of

Technology Jaipur, India. It discusses the Clean Develop-

ment Mechanism potential through the introduction of the

renewable energy technologies like solar water heaters andsolar steam cooking and energy-efficient technologies in

air conditioning and lighting. However, it does not explore

the possibility of integrating an energy-efficient building

envelope with energy-efficient air conditioning and light-

ing technologies as was done by Yiquin, Rongxin, and

Zhizhong (2008) for a centrally air-conditioned building.

Warren and Peter (2008), in their study, have concluded

that the most effective way to find energy-saving opportuni-

ties in an unconditioned building is to improve the comfort

of its primary users as it prevents them from using energy-

consuming systems. ASHRAE Standard 55 (1992) specify

the combinations of indoor space environment and personal

factors that will produce thermal environmental conditionsacceptable to 80% or more of the occupants within a space.

In 2002, ASHRAE proposed a newAdaptive Comfort Stan-

dard (ACS) to complement the traditional Predicted Mean

Vote-based comfort zone (de Dear and Brager 2002). ACS

is now presented as an optional method for determin-

ing acceptable thermal conditions in naturally conditioned

spaces in ASHRAE Standard 55-2004 (2004).

The European Commission (2006) supported a project

wherein energy savings from behavioural changes of the

occupants have been demonstrated in 70 public sector

buildings. The energy consumption of a building can be sig-

nificantly rationalized by changing the building occupants

behavior, and the use of intelligent metering information is

useful to determine the energy savings.

Since it is evident that the existing unconditioned build-

ing stock constitutes a major portion of building construc-

tion and continues to perform inadequately in its current

energy and carbon efficiency, it becomes imperative to

analyse these for energy efficiency.

3. Methodology

Based on the findings of the literature review, energy-

saving opportunities in an unconditioned academic institute

building have been categorized into four subheads viz:

(a) Energy conservation by upgrading to efficient

energy systems;

(b) Incorporating on-site renewable energy resources;

(c) Improvisation of thermal comfort; and(d) Rationalizing the building occupants behaviour.

To comply with the above-mentioned objectives, Design

Builder simulation software has been identified to pre-

dict the energy consumption, heat gain through building

envelope and indoor ambient conditions of the case study

building. A baseline model is prepared using the case

studys site data, existing characteristics of information,

type of construction, operational practices, occupancy pat-

tern etc. (ECBC Tip Sheet 2009) and then rerun to simulate

the effect of the proposed changes. The baseline data col-

lected to model the case study are elaborated in Section

4.1 and the simulated energy consumption of the buildingand heat gain through the existing building envelope are

discussed in Sections 4.2 and 4.3.

ECBC guidelines for the building envelope and the heat

gain results from simulation softwarehave been used to pro-

pose retrofits for the building envelope so as to improve the

thermal comfort within the building. Since unconditioned

academic institute buildings do not have HVAC and service

hot water and pumping requirements, ECBC guidelines for

the same are not being referred to. Any improvement in the

thermal comfort due to the proposed changes will be anal-

ysed according to ACS as listed in Section 5.3 of ASHRAE

Standard 552004 (2004).

Energy consumption results from simulation modellingbased on end-usage will help in identifying the equipments

and systems to be upgraded. Once the proposed energy con-

sumption is determined, the capacity of onsite electricity

generation through renewable resources will be established.

This will help to reduce not only the power load on the

grid but also the carbon emissions associated with the tra-

ditional power generation methods. To take it a step further,

a close analysis of the behaviour of the occupants will

help to create an awareness among them for more respon-

sible energy-use behaviour. Section 5 elaborates all the


4/15

Architectural Science Review 51

energy-conservation measures proposed for the case study

based on the simulation results and discussions and four

subheads already categorized in this section.

4. Baseline model

To provide an energy-efficient retrofit solution for a build-ing, it is necessary to analyse the existing facilities and

features. The simulation results of the baseline model pro-

vide a key foran effective retrofit alternative as a benchmark

for computing the effect of the changes proposed. The

baseline data for this case study are discussed in further

detail.

4.1. Data collection for development of baseline model

Roorkee is located in the state of Uttarakhand, India, which

is in close proximity to the Himalayas and the river Ganges

and experiences extreme climate conditions, i.e. very hot

summers and very cold winters, often termed as a com-posite climate (or a humid sub-tropical type of climate).

The minimum and maximum temperatures in degree Cel-

sius and total precipitation in millimetres for Roorkee city

are demonstrated in Figure1(Wikipedia 2012).

DAP was built in 1961 witha total floor areaof 4330m2

spread over three floors. It has a rectangular footprint of

55 m 33 m with its longer axis aligned in the east-west

direction, a flat roof, a central green court of 26 m 11 m

and a smaller court of 8 m 6 m with trees planted in them

(Figure2). Rooms are arranged around the big courtyard

with the main entry from the east. Facilities utilized by the

students, i.e. lecture rooms, seminar rooms, design studios

and computer labs are arranged in the northern part and all

other facilities like staff rooms,faculty rooms andtoilets etc.

are located in the southern part of the building (Figure 3).

The building is naturally ventilated and has few window

air conditioners. It has a tarred road in the east and a brick

pavement for parking in the north. It also has a large land-

scaped area with several trees in the north. In the south, the

building has a green area with very few trees, and in the west

it has another department. It has an RCC framed structure,

and the external walls are 1-brick thick, i.e. 340 mm, with

plaster on both sides. The southern wall on the first floor is a

Figure 1. Roorkee climatic chart.

Figure 2. Site plan of DAP, IITR.


5/15

52 A. Sharmaet al.

Figure 3. Zoning plan of DAP, IITR.

cavitywall construction in brick. Internal wall partitions are

also in brick and plaster. Windows are in steel frame with

a single pane clear glass of 6-mm thickness. The building

roof and floor were originally done in cast-in situ cement

concrete but later the flooring was topped with carpet and

vinyl sheets in various rooms.

In the design builder model (Figure4), DAP is dividedinto a total of 30 zones (Figure3) based on its occupancy

and usage.

4.2. Simulated results of energy consumption for

baseline model

The electricity data of DAP for the past 3 years reveal an

average consumption of 49,493 kWh/annum. The annual

energy consumption of DAP as per the simulation results is

50,496 kWh, which, when compared with the actual energy

Figure 4. Design builder model of DAP.

consumption (Figure5), proves the accuracy of the created

simulation model and hence can be considered as the base-

line model and re-simulated to provide the energy-efficient

retrofit solutions.

From Figure 5, it is evident that the energy consumption

is not uniform throughout the year and varies significantlyeach month. It was less than 3000 kWh for the months

of February, June and November, whereas it was more

than 5000 kWh for the months of January, April, August,

September and October. Here, it is worth noting that the

monthly energy consumption varies for the same weather

conditions too. For example, in the month of December,

energy consumption was less than 4000 kWh, but for the

month of January, it was more than 5000 kWh. Similarly,

in May and July, it was more than 4000 kWh, but for June

it was about 2000 kWh. The reason for this monthly fluc-

tuation of energy consumption is the occupancy pattern of

the students, staff and faculty of the academic institute. The

actualoccupancy pattern of thestudentsand staff is shown in

Figures 6 and7, respectively. Since thestudentsare on vaca-

tion during the months of March, May, June, July, October

and December, these months energy consumption shows a

dip as compared with the months following or preceding

them (even if falling in the same season). Therefore, in this

paper, importance is given to the analysis of energy sav-

ings based on typical daily energy consumption (Figure8)

because it follows a much regular pattern and is easier to

analyse.

The consumption pattern of electricity load based on

the end usage (Figure 9) shows that lighting consumes 29%

of total energy, whereas computer and equipments con-sume 24% electricity and other miscellaneous items (fans,

coolers, heaters, ACs etc.) consume 47% of total energy

use.

4.3. Heat gain through the existing building envelope

In order to improve the thermal comfort in the building,

heat gain through the existing building envelope is anal-

ysed for four zones, viz south-east (SE), south (S), west

(W) and north-east (NE), on all three floors of the building.


6/15


Figure 5. Annual energy consumption.

Figure 6. Student occupancy pattern.

Figure 7. Staff occupancy pattern.

Heat gain values are not discussed for the SE and W zones

on the ground floor as they are unoccupied. The findings

from this section will help to identify the building envelope

configurations to be retrofitted.

4.3.1. Roofs

The simulated heat gain values through the roof for the

four zones show high heat gain/loss in summers/winters

(Figure10), which is highly undesirable for composite cli-

mates. Heat gain/loss can be reduced by insulating the roof

appropriately (Nayak and Prajapati 2006). Heat gain pro-

files follow a regular pattern in all the four zones and it is

evident that the S and NE zones follow a similar profile

and show higher values of heat gain in summers and lower

values of heat loss in winters as compared with the W and

SE zones which show lower values of heat gain in summers

and higher heat loss in winters.

4.3.2. WallsFigure 11demonstrates the simulated monthly heat gain

values through walls. Uninsulated walls result in heat loss

throughout the year, which is an advantage in summers but

not desirablein winters ASHRAE Standard55-2004 (2004).

Net heat loss is highest in the S zone of the second floor and

varies between 3.27 and 7.24 kWh/m2, whereas heat loss

is less in the rest of the zones and lies in the range of 2.68

1.66 kWh/m2. Since the southern walls on the first floor

have a cavity wall construction, the heat loss is quite low

as compared with the southern walls on the second floor.


7/15

54 A. Sharmaet al.

Figure 8. Comparison of energy savings based on daily usage.

Figure 9. Distribution of electricity load based on end-use.

4.3.3. External windows

Monthly heat gain through exterior windows is shown in

Figure12and it is evident that most of the heat gain in

DAP is happening through exterior windows. However, it

is quite less in the NE zone as compared with the W and SE

zones of the building. Heat gain through exterior windows

in the S zone is quite less in summers because of the louvred

windows, as shown in Figure4.Heat gain through exterior

windows is much less on theground floor as compared to the

first and second floors. Heat gain profiles through exterior

windows for different zones show no correlation with each

other. For the W zone, it is maximum in the month of June

(11.48 kWh/m2

) and decreases gradually to 5.6 kWh/m2

inwinters.

5. Energy conservation measures

5.1. Upgrading the systems

If old fans (90 W) are replaced with the new energy-

efficient fans (50 W) and traditional fluorescent tube lights

(36 W) with new low-energy T5 light fittings (14 W), the

annual energy consumption will reduce by 24.13%, i.e.

14,719 kWh/annum over the baseline model (Figure13).

The change in daily energy consumption after

retrofitting the fans and lighting systems (Figure8) shows

that the energy consumption of a typical summer workingday will dip from 264 to 183 kWh/day and that of a typ-

ical winter working day from 222 to 181 kWh/day. It is a

30.68% improvement in the daily consumption for a typi-

cal summer day and an 18.47% improvement for a typical

winter day.

5.2. Renewable energy system

Solar photovoltaic (SPV) systems in the range of 1

100 kW are ideal for a wide range of applications (Bakosa


8/15


Figure 10. Simulated heat gain through roof.

Figure 11. Simulated heat gain through walls.


9/15

56 A. Sharmaet al.

Figure 12. Simulated heat gain through windows.

and Soursos 2002). As per the Planning & Maintenance

Guidelines for Solar Photovoltaic Power Supply (April

2004), systems for day loads up to 30 kWh are easily

manageable. Therefore, a grid-connected rooftop SPV sys-

tem of 26 kW is proposed to support the daily demand of

25.99kWh for indoor lighting of the building. After sup-

porting the 5651 kWh annual power demand for interior

lighting on SPV systems, the annual electricity bill will

further reduce to 30,126 kWh, which is a total 40.39%

reduction on the grid supply (Figure 13). A typical PV mod-

ule of 3036 crystalline silicon solar cells of surface area

100 cm2, connected in series, gives a peak power of approx-

imately 50 W (Sick and Thomas 1996), i.e. a 1-kW system

needs about 20 such modules and a surface area of about

8 m2. Inorderto install anSPV systemof 26kW, a roofarea

of about 210m2 will be required (Figure14).

5.3. Thermal comfort

As per the heat gain analysis, retrofits are proposed for the

roof and wall assemblies of the southern faade on the sec-

ond floor, and for the external windows of the SE faade on

the second floor and western faade. Here, guidelines fromECBC for the Building Envelope have been considered in

deciding the proposed U values of different assemblies.

Figure 15 shows the actual and the proposed envelope

configurations of the case study.

5.3.1. Roofs

The actual U-factor forroof configuraion is 3.375 W/m2-K,

while ECBC recommends aU-factor of 0.409 W/m2-K for

the roofs. Since the heat gain in summers through the roof is

high for the S and NEzones,a green roof is proposed, which


10/15


Figure 13. Comparison of energy savings based on end-use.

Figure 14. Proposed roof area for solar photovoltaic modules installation.

will make the overall U-factor 0.404 W/m2-K and hence

reduce the heat gain/loss in summers/winters (Castletona

et al.2010). In theSE zone, to reducethe heat loss in winters,

a false ceiling is proposed, which will make the U-factor

1.267 W/m2-K.

5.3.2. WallsFor the southern wall on the second floor, the actual

U-factor is 1.242 W/m2-K, whereas ECBC recommends

a U-factor of 0.440 W/m2-K. Therefore, a 50-mm-thick

polystyrene insulation is proposed on the outer surface,

making the overallU-factor 0.423W/m2-K.

5.3.3. External windows

As per ECBC, theU-factor for external windows should be

3.3W/m2-K, whereas the actual U-factor provided in the

building is 6.121 W/m2-K. After analysingthe performance

of various glazing assemblies, a 6-mm clear pewter-coated

glazing with a U-factor of 4.945 and solar heat gain coef-

ficient of 0.218 is proposed for the southern windows on

the second floor and the W zone windows on the first and

second floors.

Based on theabove building envelope retrofits,the base-

line model was modified and resimulated to analyse theeffect on thermal comfort. Figures1618show a compara-

tive analysis of thechanges in operativetemperatures forthe

S, SE and W zones, respectively. It is evident that because

of the above retrofits, operative temperatures drop by 0.5C

to 4.0C. The maximum benefit of proposed retrofits is

visible on the second floor of W zones. The change in oper-

ative temperatures of this scale, however, did not fall in

the acceptable range of ACS as described in Section 5.3 of

ASHRAE Standard 55-2004 (2004). But the authors believe

that it will help in the reduction of energy use during a


11/15

58 A. Sharmaet al.

Figure 15. Actual and proposed building envelope configuration.

seasonal change because it will postpone the dependency

on fans and air conditioners by 23 weeks from winters to

summers and alsopushback the use ofheaters atthe onset of

winters. The effect of these retrofits on energy consumption

in case of unconditioned buildings can only be analysed

using intelligent metering.

5.4. Behavioural changes

It is a commonbelief that human behaviourtowards energy-

consuming devices is guided by the thermal conditions of

the environment. But a project report on intelligent meter-

ing and behaviour changes (European Commission 2006)

has concluded that training the buildings occupants in


12/15


Figure 16. Thermal comfort analysis of south zone.

responsible energy use can significantly reduce the energy

consumption. As a step forward in the same direction, a

walkthrough visit to the case study building was performed;

it was observed that the ceiling fans and lights of the studios

and lecture hallswere connected to their respectiveswitches

in an irregular pattern. Owing to this, users switched onall the fixtures when moving in but were not motivated to

turn off the switches before leaving the room. However, if

these had been connected in a regular pattern, as shown in

Figure 19, users would have been prompted to switchon/off

the required number of lights and fans only. It would thus

decrease energy consumption to a certain extent which can

be monitored through intelligent metering. A little effort

in redoing the connections at no extra cost may result in

substantial energy savings. As an alternative, occupancy

sensors can also be installed at a nominal cost, and Nathan

(2010) shows an average potential savings of 40% per year

in energy used for lighting of unoccupied space.

6. Conclusion

In an unconditioned academic institute building situated ina composite climate, apart from computers and its acces-

sories, general lighting and thermal control equipments are

the biggest energy consumers. The results clearly show that

it is possible to significantly reduce the energy demand

of such buildings by applying simple cost-effective retrofit

measures like energy-efficient lighting and fans.

The key findings of this research are listed below:

(1) For an unconditioned building, the energy-saving

opportunities are four-fold. The energy efficiency


13/15

60 A. Sharmaet al.

Figure 17. Thermal comfort analysis of south-east zone.

canbe improved by (i)directly upgradingto energy-

efficient systems, (ii) by providing on-site renew-

able energy systems, (iii) upgrading to an efficient

building envelope to improve thermal comfort,

and (iv) by motivating building occupants for an

energy-responsive user behaviour.(2) The energy units saved for an unconditioned build-

ing are significantly lower than those for a con-

ditioned building, but the percentage change is

comparable for both types and is about 20%.

(3) Apart from concentrating on energy-efficient sys-

tems or renewable energy systems, thrust should

be given on improving the thermal comfort of

an unconditioned building because it reduces the

reliability on window air conditioners, desert cool-

ers and heaters.

(4) The heat gain results from simulation software

shows that in such buildings external windows

account for most of the heat gain within the

building, whereas uninsulated walls result in heat

loss throughout the year.

(5) The thermal comfort of unconditioned buildingscanbe improvedby providinga green roof to reduce

heat gain in summers or by installing a false ceiling

to reduce heat loss in winters. The only limitation

here is that any change in the internal heat gain or

operative temperatures does not affect the cooling

or heating system loads; as there is no central air

conditioning. Hence, the energy saving cannot be

quantified usingsimulation software. However, one

can quantify the change in operative temperatures

within the building, which it improves by 0.5C


14/15


Figure 18. Thermal comfort analysis of west zone.

Figure 19. Proposed connection of ceiling fans and lights with the switchboard.


15/15

Documents

ASR - Energy Efficient Retrofit of an Unconditioned Bldg