Solar Passive Design Building, Transport Corporation of India Ltd (TCIL), Gurgaon
General Information:
Client: Transport Corporation of India Ltd (TCIL)
City: Gurgaon
Climate: Composite
Operational schedule – 6 days and 12 hours
Area of the building: 3058m² (out of which 2607 m² - conditioned
area, 451 m² - Non- conditioned area)
Green Building Design Features:
Building Design
Orientation
Orientation: NE, SW
This helps in receiving less radiation which results in lesser heat
gains and reduced the overall air-conditioning requirement and hence
saves energy. Proper orientation also helps in receiving natural light
and ventilation
Building Height
Minimum height above the ground level to limit exposure to external
conditions. Recessed windows to reduce external solar heat gains.
Water Body
Fountain to flow over extensive surfaces to maximize evaporation. Water evaporation has a cooling effect in the surroundings.
Building Envelope
Walls
Insulation helps retain cool in summer and heat in winter, and acts as sound proof. This can create a major impact on indoor thermal comfort of the building.
Compact floor plan with external walls
Window
Single glaze recessed windows
- Single glazed unit helps in integrating optimum daylight
- Recessed windows and optimum WWR (Window Wall Ratio) which is less than ECBC standard (40%) helps in reducing external solar heat gain
(SC – 0.52, U-value of Glass – 5.7 W/m2K)
Roof
35 mm thickness insulation with reflective glazed tile paving
U-value = 1.01 W/m2K
The glazed tile reflects heat off the surface because of the high solar reflectivity and infrared emittance which prevents heat gain and thus helps in reducing the cooling load from the building envelope.
Building Lighting
Day light integration
Window area minimized to 14% of the external wall area, small peep windows
at seating height and large windows at ceiling level
Small windows at the seating areas can reduce thermal discomfort.
The reduced percentage of window area to wall area helps in reducing the external heat gain into the building.
Lighting system
9% (18.10 KW of indoor lighting) of the total connected load for the
building.
Luminaires used – down lighter recessed type CFLs, electronic ballasts used mostly.
LPD – 5.9 W/m2
- The percentage of the lighting load to the total load shows that there is very less percentage of artificial lighting used in the building
- The electronic ballasts save approx 20-30% in energy consumption over the standard ballasts.
- The LPD (5.9 W/m2) is less than the max allowed LPD of ECBC (10.8 W/m2) which is very good.
HVAC system Design
- Central plant with 2 vapour chillers
- Total cooling capacity is 125 TR
- Co-efficient of performance – 4.21
- operating Sqmt/TR-39
Energy Efficiency controls
No energy efficient controls
Energy Performance of the Building
Lighting Energy Performance of the Building
- Annual consumption (lighting) – 69232 kWh
- Total built space – 3058
- Lighting performance index – 23 kWh/sqmt/annum
Space Conditioning Energy Performance of the Building
- Annual consumption (A/C) – 376102 kWh
- HVAC performance index – 144 kWh/sqmt/annum
- Operating cooling demand – 39 sqt/TR
Annual energy consumption due to lighting & air conditioning (kWh): 445335
Energy Performance Index of the building (KWh/sq.mts of built up area/annum):
147
Comparison of various parameters for solar passive building (TCIL) with conventional case
| Parameters | Solar passive Case (Existing Building) features | Conventional Case (Building features) |
| Building orientation | Building orientation : Longer facades of the building
facing 45 deg to the North |
Building orientation: Longer facades of the building facing East-West |
| Windows, Walls and Roof are not shaded | Windows, Walls and Roof are not shaded | |
| Building Envelope | Insulation on roof with air gap
for walls |
No insulation on wall and roof. |
| Window glazing : U value of glass - 6.17 W/m2/K and Shading coefficient- 0.52 WWR : 11% |
U- Value of Glass – 6.17W/m2K and Shading coefficient
– 0.61 WWR – 11% |
|
| Building Lighting Power density | Lighting power density is 6.3 W/m2 |
Lighting power density 20 W/m2 |
| Controls | Occupancy sensors | No controls or sensors |
| Building Chiller | 2 * 62.5 TR Water cooled vapor absorption chiller
|
PTAC units having EER of 8.4 and Fan power as 0.000134 bhp/cfm |
| Energy performance Index (KWh/m2/yr) | 147 | 170 |
Energy Saving Potential
The conventional case defined above was selected to run different energy saving options and to finally quantify the energy saving potential which can be realized in composite climate by incorporating the low design strategies, ECBC envelope, and the best case (incorporating both low energy strategies and ECBC measures)
Impact of ECBC, Low energy strategies, and ECBC + low energy strategies on conventional case for TCIL building, Composite climate
The above graph shows the variation in the Electrical load (kW), Coil
load (TR) and EPI (energy performance index) for all the cases.
| Parameter comparison | Existing case | Conventional case | Low energy strategy | ECBC case | ECBC+Low energy strategy |
| Electrical load | 18% less than the conventional case | Base case | 25% less than the conventional case | 41% less than the conventional case | 50% less than the conventional case |
| Coil Load | 18% less than the conventional case | Base case | 24% less than the conventional case | 46% less than the conventional case | 57% less than the conventional case |
| EPI | 14% less than the conventional case | Base case | 33% less than the conventional case | 17% less than the conventional vase | 35% less than the conventional case |
Developed by TERI, supported by US Department of State and Bureau of Energy Efficiency, under the aegis of Asia Pacific Partnership