In India, Building and Commercial Sector consumes about 15 % of the total electricity
usage of the country and major portion is utilized in buildings. Energy audit studies
conducted in several office buildings, hotels and hospitals indicate an energy saving
potential of 20-30 per cent, which is largely untapped today.
Provision in the Energy Conservation Act for commercial building
The provisions in the Energy Conservation Act regarding energy Efficiency in Buildings
and Establishments provides for the following:
Definition of Building:
Defining building as any structure or a part of a structure having connected load
of 500KW or contract demand of 600KVa and above and intended to be used for commercial
Buildings are Designated Consumers:
Directing owners or occupiers or buildings or building complexes, being designated
consumers, to comply with the provisions of energy conservation building codes.
Directing designed consumers to get energy audit of the building conducted by an
accredited energy auditor in the specified manner and intervals of time.
Commercial Buildings & Establishments are included in the list of energy intensive
industries and other establishments specified as designated consumers in the schedule
to the Act. Hence, all mandatory requirements for designated consumers would be
Some of the measures to increase efficiency of the commercial buildings:
- Use of efficient insulation and heat reflective glasses to reduce the solar gain
through windows and doors, In hot climate like ours glass with low shading co-efficient
and high visible transmittance should be selected to reduce solar and increase high
- Proper ventilation of roof ceiling
- Use of automatic switches
- Use of condenser waste heat for space heating
- Use of variable speed drives at AHU fan motors, at cooling tower fan motors and
secondary chilled water pumps.
- Recovery of hot water from condenser
- Use of centralized cooling system
- Use of thermostat control system
- Maintained uniform “Air Conditioning” green building can be done by adopting appropriate
passive solar design strategies e.g. orientation, fenestration sizing and shading,
landscaping, day-lighting; and by using appropriate building material e.g. insulating
glass units, heat reflecting paints etc.
- Use of underground earth air tunnel (EAT) to supply pre-cooled air to the air handling
- Use of cavity wall construction with insulating infill.
- Use of double glazed windows with selective spectral coating.
- Use of low leakage dampers, enthalpy controller and dry bulb economizer are some
of the energy efficient techniques for HVAC system.