Adopting Low-cost Alternative for Energy Saving
Case Study

General Information:

City: Shimla
Climate: Cold
Operational schedule – 24 hours, 7 working days in a week
Area of the building: 10000m² (out of which 8000 m² - conditioned area, 2000 m² - non-conditioned area)

Function: Hotel

Existing Building Design Features

Building Envelope


230mm brick wall with 12.5mm plaster on both the sides


200mm concrete slab with U- value higher than that of the ECBC recommended


6mm clear single glazed window in thermally unbroken aluminium frames

(SC – 0.89,
U-value of Glass –4.3 W/m2K)
WWR – 28%

Clear single glazed window increases the solar heat gain which is an advantage in cold climate. WWR is in the limits of ECBC recommended (max 40%)

Building Lighting

Lighting controls

  • 8.7% of the total energy consumption
  • Fixtures: 50W halogen lamps, Incandescent lamps of 25W, 40W and 60W, and fluorescent tube lights of 40W with magnetic ballasts
  • The LPD of 12.4W/m2 is higher than that of max ECBC recommended (10.8 W/m2) which has high energy saving potential
HVAC system Design

  • 2 boilers of 600kg/hr
  • 2 air cooled chillers of 30TR and 1 air cooled chiller with 60TR
  • The COP of the chillers is 3.5 (rated) / ECBC recommended is 2.90
  • Rated Sqft/TR – 717
Energy Performance of the Building

Lighting Energy Performance of the Building

  • Annual Consumption (lighting) – 13% of the total
  • Lighting Performance Index – 32 KWh/Sqmt/annum

• Space Conditioning Energy Performance of the Building

  • Annual Consumption (A/C) – 86% of the total
  • HVAC Performance Index – 206 KWh/Sqmt/annum

Annual energy consumption due to lighting & air conditioning (kWh): 2373928

Energy Performance Index of the building (KWh/Sq.mts of built up area/annum): 237

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