Energy conservation in Building

A huge amount of energy is spent by building. Lighting, motors, electronic equipment, etc are needed and found in building. Moreover HVAC system is the highest energy consumption for commercial building. Energy conservation in building becomes great interest and causes energy audit needed especially for old building.

There are several actions which can be applied to conserve energy for building. Building envelope, Electrical System, and HVAC System are the most common part of it.

Building envelope

Building envelope is related to cooling or heating system because when cooling or heating system is being designed, one of the important thing is material selection for wall, roof, windows, etc. When outdoor and inside temperature are different, heat transfer will occur and add heat gain for the building. Therefore building envelope material selection is very important.

If the building is already built, several actions to improve thermal performance are:

• Thermal insulation attachment for building surface without thermal insulation
• Replace windows with more efficient windows which has high R value, low emisivity glazing, etc
• Reduction of air leakage. Air leakage causes outdoor air enter the inside the building and add heat gain which has sensible and latent heat.

Electrical System

Electrical system involves Lighting, office equipment and motors. In Lighting, the conservation energy actions which can be applied are use energy efficient lamp and ballast. Now, LED technology has begun to replace conventional lighting such incandescent. Besides that, optimize day light is also can be applied.

Office equipment includes computer, printer, fax, copier, etc. Motors can be found in many equipments such as fan, washing machine, etc. For office equipments and motors, the actions which can be applied are choose the energy efficient equipment. Set computers automatically switch to low power also can be applied for it

HVAC

HVAC is the highest energy consumption in building. About 40% of the total energy is consumed in commercial building for HVAC system. Some actions for this are:

•         Set the temperature set point in thermal comfort zone. Turn on the HVAC system only when it is needed.
•        Retrofit of constant air volume system
•              Heat recovery system installation
•              Central cooling plants retrofit.

Source: Hand Book of Thermal Engineering.