View of ENERGY PERFORMANCE OF VARIOUS SHAPES OF GROUP HOUSING BUILDINGS

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Vol.03, Issue 09, Conference (IC-RASEM) Special Issue 01, September 2018 Available Online: www.ajeee.co.in/index.php/AJEEE

ENERGY PERFORMANCE OF VARIOUS SHAPES OF GROUP HOUSING BUILDINGS Ritu Singh^1,Dr. Madhura Yadav²

1PhD. Scholar, school of architecture , Manipal University, Jai

2PhD. Guide, Director, school of architecture, Manipal University, Jaipur

Abstract:- The present study focuses on the total energy consumption of the various shapes of group housing buildings in hot & dry climate of Jaipur, India. Several methods can be adapted to improve the indoor thermal environment thereby reducing the energy consumption loads like material, reflective glazing systems, shading devices etc. However, before using any of these methods it is important to find out an optimize shape to cut down solar radiation absorption which leads to an overheated indoor environment and an increase in cooling energy loads. This paper discusses & analyzes the total energy consumption of various shapes of these multistoried group housing building blocks in order to conclude the most efficient shape with respect to energy consumption. A computerized simulation tool is used to carry out the investigation. eQuest is building energy analysis software designed and developed by DOE2 (Copyright James J. Hirsch). First the temperature of a building’s envelope was calculated, and then the results were exported to e-Quest, where the building energy consumption was calculated. All simulations were performed for 8760 operating hours. The possible shapes analyzed are Linear, E-shape, U- shape, L-shape, star shape, enclosed cluster type & Regular shape (concentrated stair & lift lobby with 4-6 flats on each floor). The results indicate the Regular shape has a significant impact on decreasing discomfort hours when compared with other shapes.

Key Words: building shapes, energy consumption, non-conditioned buildings, hot & dry climate

1.INTRODUCTION

Group housing projects are an unclaimed answer to the present housing shortage especially in the urban areas. However the use of various energy efficient design strategies like material, glass, shading devices etc. seems tough with respect to economical & practical aspect in these multistoried constructions. In recent years, the concept of sustainability has attracted increasing attention within building science, for energetic, ecologic and economic reasons. The decreasing fossil fuel reserves warrant a minimized consumption of energy and maximized application of renewable energy sources.

Possible ways to use passive energy efficient techniques may cut down the energy loads. Mutual shading, reflection, earth cooling, proper ventilation, orientation & size of building etc. are such means of passive techniques which are effective in terms of buildings energy consumption (1). However the effectiveness of the shape of a group housing building may also effect the overall cooling loads in the hot & dry climate. A potential method to fulfill these requirements for dwellings is innovation in design of buildings wherein natural cooling methods can be utilized to reduce

method. The research will focus on analyzing the proper orientation and shape of buildings for Evaporative cooling technique. Building energy simulations will be done for Jaipur climate conditions.. This study analyzes the energy performance of various group housing blocks shapes viz. L- shape, U- shape, E- shape, Star shape, Linear shape, cluster shape & Regular shape buildings. Under this research work the best orientation for the proposed building is to be analyzed. The results of all orientations will be then compared to the baseline orientation. Simulations will be done for Jaipur climate conditions. All the zones are naturally cooled using evaporative cooling technique and the internal design temperatures have been considered under best green building practices. As expected, the simulation results will indicate that the best possible orientation for the proposed building.

2. BUILDINGS & PROJECT DESCRIPTION

The analyzed building is G+10 Residential Building. Buildings have different floor area as per the shapes. Building height is considered as 10 ft. The building has a

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Wall Ratio (WWR) glazing area will be around 14.38%. All the floors are typical.

Detailed material specifications will be presented in final report. Simulations of energy performance will be done for Orientations varying by 90 deg each.

2.1 Climate

Energy simulations will be done for Jaipur( Rajasthan, India) climatic conditions.

2.2 Interior Conditions

The Internal Cooling Conditions has been considered around 91^oF which is less than 33^oC as followed for naturally ventilated buildings as per best green building practices. No heating has been considered.

2.3 Numerical Model & Software Description:

As most building energy simulation models do not allow to incorporate soil cover accurately, an integrated strategy will be used to calculate soil heat transfer and building energy consumption will be calculated with e-Quest software. First the temperature of a building’s envelope will be calculated, and then the results will be exported to e-Quest, where the building energy consumption will be calculated. All simulations will be performed for 8760 operating hours.

Quest is building energy analysis software designed and developed by DOE2 (Copyright James J. Hirsch). eQuest uses the DOE 2.1 Building energy simulation engine. It has the ability to explicitly model all of the following:

 8,760 hours per year

 Hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat set- points, and HVAC system

operation, defined separately for each day of the week and holidays

 Thermal mass effects

 Part-load performance curves for mechanical Equipment

 Capacity and efficiency correction curves for mechanical heating and cooling equipment

Quest was designed to perform detailed analysis of today’s state-of-the-art building design technologies using today’s most sophisticated building energy use simulation techniques.

2.4 Input Parameters

Table 1: Conventional Building Input Parameters

Building Parameters Base Case Values Wall U Value (btu/h sqft

°F) 0.373

Roof U Value (btu/h sqft

°F) 0.575

WWR 14.38%

Clear Glass SHGC 0.75 Clear Glass U Value (Btu/h-ft²-^oF) 1.31

LPD (W/sqft) 1.0

Equipment Load (W/sqft) 0.85

HVAC System Direct Evaporative Cooling

Fan Control Constant Flow Ventilation 33 cfm/person

3. ANALYSIS PROGRESS

As the first step, zoning was done as per the architectural plans. The interior layout has been modeled as per below zoning pattern. For 3D energy simulation model for the building has been developed in eQuest to calculate the energy performance of the building. Figures provided below shows the layouts, outlines & 3D structure developed in eQuest. It accurately resembles the actual building.

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LINEAR SHAPE (outline) LINEAR SHAPE (layout)

POINT BLOCK (outline) POINT BLOCK (layout) 3-D Views of the Building in eQuest

STAR SHAP (outline) STAR SHAP (layout) 3-D Views of the Building in eQuest

L- SHAP (outline) L- SHAP (layout)

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U- SHAP (outline) U- SHAP (layout)

CLUSTER- SHAP (outline) CLUSTER- SHAP (layout) SOURCE: ASHADEEP GROUP OF BUILDERS, JAIPUR, RAJASTHAN

4. PRELIMINARY RESULTS

The table below shows the preliminary results of the energy simulation of all building blocks. These results provide the trend of the energy consumption of the building as per the input mentioned in table-1. The final results may defer and depend upon the refinement of input

parameters and analysis work. The base case was modeled on the ground keeping all façade exposed to the surrounding.

The proposed cases were modeled by rotating the baseline model by 90 deg.

Table below show the simulation results of all the different shapes models in four orientations. (total 28 cases)

BUILDIN

G SHAPE YEARLY ELECTRICITY CONSUMPTION

( KWH ) BLDG.

SLAB AREA (SQFT

ELEC.

CONSU M- TION / SQFT.

YEAR (KWH)

% OF HRS OUT- SIDE OF THRO- TTLIN G RANGE

UN- MET HRS LIGHT

S MISC.

EQUIP- MENTS

SPACE

COOLING VENT

FANS DOMESCTIC

HOT WATER EXT.

USAGE TOTAL

LINEAR (BASE CASE)

26369

1 51522

0 20666 100299 101355 33475 1034687 12119

0 8.547 15.83 1312

LINEAR

(90° TILT) 26369

1 51522

0 22825 110776 101345 33475 1047313 12119

0 8.651 18.49 1550 LINEAR 26369 51522 20737 100644 101353 33475 1035102 12119 8.551 16.06 1331

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Vol.03, Issue 09, Conference (IC-RASEM) Special Issue 01, September 2018 Available Online: www.ajeee.co.in/index.php/AJEEE L-SHAPE

(BASE

CASE) 32144

7 63283

1 22878 111035

149220 21866 4

1456073 16454 0

9867 15.19 829

L-SHAPE

(90° TILT) 32144

7 63283

1 24258 117736 149082 21866

4 1464016 16454

0 9.921 15.98 872 L-SHAPE

(180°

TILT)

32144

7 63283

1 22902 111152 149045 21866

4 1456039 16454

0 9.867 14.68 801

L-SHAPE (270°

TILT)

32144

7 63283

1 24093 116935 149192 21866

4 1463160 16454

0 9.915 15.63 853

E-SHAP (BASE CASE)

25734

6 50876

8 16291 79135 108553 31339

1 1283486 10746

5 12.07 34.86 1902

E-SHAPE (90° TILT)

25734

6 50876

8 17199 83549 108583 31339

1 1288838 10746

5 12.121 34.79 1898

E-SHAPE (180°

TILT)

25734

6 50876

8 16591 80594 108585 31339

1 1285277 10746

5 12.088 32.62 1780

E-SHAPE (270°

TILT)

25734

6 50876

8 17355 84301 108561 31339

1 1289723 10746

5 12.130 35.81 1954

POINT BLOCK (BASE CASE)

15646

6 30704

4 5347 38059 60885 19045 586847 71831 8.170 13.14 717

POINT BLOCK (90° TILT)

15646

6 30704

4 4820 35018 60954 19045 583447 71831 8.122 9.93 542

POINT BLOCK (180°

TILT)

15646

6 30704

4 5351 38089 60671 19045 586668 71831 8.167 15.45 843

POINT BLOCK (270°

TILT)

15646

6 30704

4 4975 35410 60659 19045 583598 71831 8.125 11.68 637

STAR SHAP (BASE CASE)

17632

3 34605

0 13510 65538 69189 23608

5 906692 80956 11.20 8.69 703

STAR SHAP (90° TILT)

17632

3 34605

0 14051 68165 69166 23608

5 909839 80956 11.239 9.42 763

STAR SHAP (180°

TILT)

17632

3 34605

0 13643 66185 69189 23608

5 907474 80956 11.210 9.19 743

STAR SHAP (270°

TILT)

17632

3 34605

0 14052 68169 69203 23608

5 909880 80956 11.239 9.42 766

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Vol.03, Issue 09, Conference (IC-RASEM) Special Issue 01, September 2018 Available Online: www.ajeee.co.in/index.php/AJEEE LIGHT

S MISC.

EQUIP- MENTS

SPACE

COOLING VENT

FANS DOMESCTIC

HOT WATER EXT.

USAGE TOTAL (SQFT TION / SQFT.

YEAR (KWH)

SIDE OF THRO- TTLIN G RANGE

U-SHAP (BASE CASE)

38176

5 74897

0 26645 129309 187831 23747

9 171200

1 19451

6 9.768 11.88 648

U-SHAPE (90° TILT)

38176 5

74897 0

27114 131580 187746 23747 9

171465 4

19451 6

9.783 12.63 689

U-SHAPE (180°

TILT)

38176 5

74897 0

26222 127252 187641 23747 9

170933 0

19451 6

9.753 11.95 652

U-SHAPE (270°

TILT)

38176

5 74897

0 27411 133027 187683 23747

9 171633

7 19451

6 9.793 13.82 754

CLUSTER (BASE CASE)

48851

8 95850

5 35744 173502 240385 32752

5 222417

7 22427

1 9.917 9.9 540

CLUSTER

(90° TILT) 48851

8 95850

5 37498 182016 239916 32752

5 223397

7 22427

1 9.961 9.68 528 CLUSTER

(180°

TILT)

48851

8 95850

5 35526 172444 239524 32752

5 222204

1 22427

1 9.908 10.01 546

CLUSTER (270°

TILT)

48851

8 95850

5 37638 182696 239901 32752

5 223478

1 22427

1 9.965 9.66 527

5. EPI CALCULATIONS:

Energy Performance Index (EPI) value is also a measure to evaluate energy consumption of buildings. It is defined as the energy consumption of a building per unit area per year.

BUILDING SHAPE

EPI:annual energy consumption (kWh/Sq.mt/Year) BASE

LINE TILT 90° TILT

180° TILT 270°

LINEAR SHAPE 34.2 35.3 34.2 35.3 L-SHAPE 33.2 33.8 33.2 33.7 U-SHAPE 33.0 33.2 32.9 33.3 E-SHAPE 35.3 35.9 35.5 35.9 STAR SHAPE 33.9 34.4 34.0 34.4 CLUSTER TYPE 33.5 33.4 34.0 34.0 POINT BLOCK 29.9 29.4 29.9 29.5

Note: Only Lighting consumption , ventilation fan & Cooling consumption

7. SIMULATION RESULTS :

• As per initial runs, All the different shapes models were simulated in four orientations.

(total 28 cases)

• The building ht. was kept G +10 floors with floor to floor ht. as 10’- 0”.

• As per initial study it was found

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• However, unmet hours (yearly) out side the throttling range, the total energy consumption of the building block as a whole and the EPI were the main governing factors for the best case n shape selection.

• Graphical presentation of the energy consumption per sqmt. of each shape suggested the point block shape building utilizing energy most efficiently.

Hence, the regular shape block will be analyzed to find the best situation for energy efficient housing clusters.