High Performance Commercial Buildings in India: Adopting Low-cost Alternative Passive Strategies 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

Walls 230mm brick wall with 12.5mm plaster on both the sides	Roof 200mm concrete slab with U- value higher than that of the ECBC recommended

Window 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

Conventional Building, Shimla

Existing Building Design Features

Building Envelope

Walls

Roof

Window

Building Lighting

Lighting controls

HVAC system Design

Energy Performance of the Building

Lighting Energy Performance of the Building

• Space Conditioning Energy Performance of the Building