Funded by Southern California Edison Company’s Local Government Strategic Plan Strategies Program

under the auspices of the California Public Utilities Commission.

Evaporative Coolers & Whole House Fans

Evaporative coolers cool air by evaporating water and blowing that air throughout the home. When hot, dry air passes over water it cools off. Evaporative coolers work best in arid climates, making them great for the San Gabriel Valley! They are less expensive than central air conditioners, and they have lower operating costs.  They add humidity to the air in your home, which can be a healthy alternative to the dry air produced by central air conditioners.

What can you do about it?

An alternative to an evaporative cooler is a whole house fan. A whole house fan draws cool night air through the fan, which allows the collected outside air to cool the entire house. With the addition of interlocking controls, the fan can also prevent your HVAC unit from working at the same time.

Buy an evaporative cooler.

Be sure to look for an evaporative cooler that comes with its own thermostat—as these models will shut off when the home reaches the desired temperature, making them much more efficient than standard models.

Aspects to consider before buying an evaporative cooler.

Evaporative coolers should not be used in humid climates because they add humidity to the air in your home. Also, they cool your house down to a higher temperature than an air conditioner would, and they require simple maintenance about once a month. If the cooler is installed on the roof, there is some roof deterioration caused by routine maintenance trips. A sunlit rooftop cooler will be about 1°F less effective than a shaded cooler. Rooftop maintenance also requires using a ladder, which may be an inconvenience.