What is an Evaporative Cooler?

At HVAC.com, we get this question a lot: “What is an evaporative cooler?”  Well, you came to the right place to get the answer!  Read on as we explain the concept of evaporative cooling, when its application makes the most sense, some pros and cons.

The most common form of residential air conditioning system in the United States utilizes refrigerant, a compressor, and an expansion valve (among other components) to remove heat from the indoor environment.  These systems are widely applied in all climates.


So What Are Evaporative Coolers?

Evaporative coolers (also known as a swamp cooler, desert cooler, and wet air cooler) are very different.  In an evaporative cooler, instead of using a refrigerant cycle to remove heat, water is used instead.  When water evaporates, it naturally creates a “cooling effect” as the water molecules are vaporized and “absorbed” into the air.  Evaporative coolers typically pass a flow of water across a “pad” or other media while an electric fan is used to blow air across the water-filled media.  This flow of air across the wet surface accelerates the evaporation of the water.  As the water evaporates, it removes heat from the air so that the air that is blowing into the conditioned space is less hot than it would have been otherwise.



Is There A Specific Climate In Which These Are Primarily Used?

Yes, evaporative coolers are ideal for dry climates where the moisture content in the air is low.  As the humidity level in the air declines, evaporative coolers become more effective and energy-efficient.


Evaporative Coolers vs. Air Conditioners

Evaporative coolers are usually much less expensive than refrigerant-based systems because there are fewer components and less technology involved.  In addition, when applied in the ideal dry climate, evaporative coolers can be more energy-efficient than a refrigerant-based system.  Finally, evaporative coolers provide an added benefit of adding moisture to the air to humidify the conditioned space, which in the correct proportions can make the space more comfortable.


What Is The Maintenance For Evaporative Coolers?

For maintenance, most evaporative cooling units need to be cleaned periodically and the evaporative media needs to be replaced on a regular schedule to ensure optimum performance.

If you have any questions about evaporative coolers, send us an email at [email protected].