Adopting Low-cost Alternative for Energy Saving
Case Study

Transport Corporation of India Ltd (TCIL)





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, 541 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

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 18% 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% (181.12 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
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) – 37610 kWh
  • HVAC performance index – 144 kWh/sqmt/annum
  • Operating cooling demand – 449 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

Energy Saving Potential

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. The below table gives the comparison of the impact of ECBC, Low energy strategies, and ECBC + low energy strategies on conventional case for TCIL building for a composite climate–

 

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



Comparison of various parameters for solar passive building (TCIL) with conventional case


Comparison of various parameters in different scenarios
Parameter Solar Passive Case Conventional Case
Building envelope Insulated walls
Insulated roof
Recessed windows
No insulated walls
No insulated roof
No recessed windows
Energy-efficient controls No lighting controls No lighting controls
Building chiller Central vapor absorption chillers having a co-efficient performance of 4.21 Central carrier reciprocating chillers with co-efficient of performance of 4.01
Energy performance of the building LPD 5.9 W/mm² < ECBC (10.8 W/mm²) LPD 24 W/mm² > ECBC (10.8 W/mm²)
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