In any commercial building, approximately 50-60% of power usage is for air conditioning. This is a great opportunity for owners to reduce operating power and cost and, at the same time, save money. To seize the potential energy savings by reducing air-conditioning power consumption, it is crucial to consider the entire building energy loads as well as the systems and technologies for meeting these loads.

Normal load estimation procedures evaluate the heat gain of a space and to assume that the air conditioning equipment will remove the heat at this rate. Air conditioning equipment selected on this basis is oversized and capable of maintaining much lower room conditions than the original design. Considering this the actual cooling load is generally below the peak heat gain.

A study of an office building demonstrates this fact. An oversized air conditioner would be installed to ensure adequate air conditioning in the hottest summer day but in reality the air conditioning system never works at full capacity.