When used properly, "whole-house" fans can be energy savers. However, EPA does not label these fans because all of the products perform about the same. Whole-house fans are mounted in the attic floor and pull cooler air from outside into the house through windows to lower the temperature of the house. Whole-house fans work well in climates where the days are hot but the evenings cool off quickly and there is low humidity (such as in the desert). In certain situations, whole-house fans can be used instead of air conditioning to cool off a house after a hot day. For example, when the temperature inside the house is 80-85 degrees and the temperature outside is 60-70 degrees after the sun goes down, the fan can be used to pull the cool, dry outdoor air in through the windows to quickly cool off the house instead of using the air conditioner. In a few minutes the house cools down and the fan can be turned off. The fan works quickly and uses much less energy than air conditioning.