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 purposes.

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.

Energy Audit:

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 applicable.

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 visible transmission.
• 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 units.
• 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.