Evaporative Cooler Tips



Water Use

Evaporative coolers use a lot of water. This should be a consideration if you live in an area where water conservation is important.

To prevent the water reservoir from becoming saturated with minerals, evaporative coolers use more water to flush them out. A bleed-off system drains a small amount of water from the cooler whenever it is running. A "sump dump" system evacuates the water from the reservoir every half-hour or so. Sump dump systems are more effective than bleed-off systems because they discharge not only brackish water but also some of the enormous amount of filtered dirt that collects in the reservoir.


Summer wet-bulb temperatures in the United States can show where evaporative coolers are most effective. The lines mark areas where the wet-bulb temperature is below the indicated number 99% of the time. An evaporative cooler is most appropriate for areas with wet-bulb temperatures below 70°F, where they can meet all or most of a house's cooling needs. They are also effective for much of the summer in areas with wet bulbs between 70°F and 75°F.


Excerpted from No-Regrets Remodeling by Home Energy (1997)