Evaporative Air Cooler: How It Works and What to Expect

A fan pulls air through a wet pad or other damp medium. Some water evaporates into the airflow, absorbing heat, and the fan distributes that cooler, more humid air.

A portable air cooler contains a fan and a water reservoir, often with a cooling pad. It passes room air over the damp surface and blows the resulting airflow back into the space.

It can affect the comfort of a space, but results depend on room size, airflow, humidity and ventilation. These units do not operate like air conditioners that recirculate air through a refrigerant cooling cycle.

Some fresh-air exchange helps prevent moisture from building up indoors. Follow the unit's instructions and provide suitable ventilation for the room.

No. An evaporative air cooler uses water evaporation and adds moisture to its airflow; an air conditioner uses a refrigeration system to transfer heat out of the space.