Evaporative Cooling: How It Works


Evaporative coolers are available in a variety of models and sizes today. However, did you know that they have been used since ancient Rome? If you are wondering why an ancient cooling system can work in today’s time, it is best to understand how evaporative cooling works and whether it suits your needs.

What is Evaporative Cooling?

You have probably observed feeling the chill after swimming on a hot, dry day and then getting out of the water and feeling the wind hitting your wet skin. This happens because of evaporative cooling.

Evaporative coolers like those from Aspen Air recreate this occurrence and offer a constant flow of cool, refreshing air into a hot, uncomfortable environment. The early versions of evaporative units were called swamp coolers due to the high moisture content released into the air from the old technology. The latest generation of evaporative coolers are made to achieve maximum cooling in exchange for minimal moisture content, but some people still call them swamp coolers.

How Evaporative Units Work

Evaporative cooling units circulate water through saturated cooling media while drawing air across the media’s surface. Moisture is absorbed by hot air from media, decreasing the air temperature discharged from the cooler.

The media is the unit’s heart, usually called pad. It is where the water evaporates and the air passes through them is cooled. A special water distribution system spreads water over the pad’s surface. This makes sure there is a uniform supply of water to thoroughly soak the entire air contact surface. The unit also comes with fans to create a negative pressure to draw the air through the pads. When water comes in contact with air, evaporation occurs.

Is Evaporative Cooling Good for the Environment?

Refrigerated cooling makes the air dry and makes use of chemicals that can be harmful to the environment when released into the atmosphere. But, evaporative cooling is based on a natural process of air cooled by water. Thus, it will not dry out the air, impact the environment, and affect human health. Evaporative cooling is a healthy way to cool as it replaces stale air with clean, fresh air several times per hour. It is just important to keep the doors and windows open.

Is it Cost-Effective?

An evaporative cooling unit is cheaper than other cooling systems. Also, it requires lower to no installation costs. In fact, the unit is cheaper to operate than refrigerated cooling. But, the costs vary depending on local utility costs and ambient climate conditions.

Author Bio – Sharon Pulbrook writes for Aspen Air. The family has been involved in the heating and cooling industry for 30+ years. She writes regularly about her industry insights on their blog.