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August 20, 2022  |  Home

What is an evaporative air cooler, and do you need one?

Hot weather can be miserable. However, the extraordinarily high energy bills you get from running an air conditioner all summer long can be even more unpleasant than the temperature. Fortunately, there are other options that are more merciful on your wallet and kinder to the earth as well.

An evaporative air cooler is one alternative. Running this device costs about as much as running a fan, yet it is far better at keeping you cool, especially if you live in an arid climate.

How an evaporative air cooler works

When you get hot, you sweat. As the sweat evaporates from your skin, you feel cooler. Sweating is your body’s way of maintaining your core temperature. It works very well.

An evaporative cooler employs the same basic science as your body. It is a simple machine that only needs three basic parts to work: a fan (driven by a motor), water and an absorbent filter. As the fan moves the dry air through the damp filter, the water in the filter evaporates. This cools the air the same way that evaporating sweat cools your body and lowers the room's temperature.

Why evaporation makes things cooler

Every action has a cost. The cost is energy. If you want to move a boulder, you must exert energy to do this. When water changes states, like turning from liquid to vapor, it also requires energy. The energy this reaction requires is heat. When water evaporates, it removes heat from the air, making the temperature drop.

How much heat can an evaporative cooler remove from the air?

If you live in a hot, arid climate — somewhere that is around 90 degrees with low humidity — using an evaporative cooler may drop the air temperature by as much as 20 degrees. This can change an uncomfortable environment into one that is very pleasant. However, the change won’t be as drastic if you live in an area with excessive temperatures or humidity.

Benefits of an evaporative air cooler

Lower cost

An evaporative air cooler costs less than an air conditioner. However, the bigger benefit comes when you look at your energy bill. Since an evaporative cooler does not have a compressor but a fan, it requires much less energy to operate. The average model uses about one-quarter of the energy of a comparable air conditioner.

Reduces your carbon footprint

While any appliance that uses energy leaves behind a carbon footprint, an evaporative air cooler leaves a much smaller one than air conditioning. In short, it doesn’t waste natural resources or directly emit any greenhouse gasses while operating. However, most electricity that powers your home is still generated by natural gas, nuclear energy and coal.

Easy to maintain

It doesn’t take much effort to maintain an evaporative air cooler. For the most part, you need to wipe down the outside to keep it clean and clean the water tank and filter according to the manufacturer’s recommendations.

Drawbacks of an evaporative cooler

It’s not the best for people with seasonal allergies

For an evaporative air cooler to be the most efficient, you should open a window to allow new air into your home. If someone in your home has seasonal allergies, this invites allergens in and might increase their discomfort.

Not as effective in humid climates

If you live in a damp or humid region, the air may be too moist to evaporate the water in the machine efficiently. This means you won’t notice as much of a temperature drop in these areas.

It can make your home feel sticky

Running an evaporative air cooler adds moisture to the air. In the regions where this type of cooling is the most effective, that moisture will be most beneficial. However, it may leave your home feeling a little sticky and damp.


Q. Doesn’t humidity raise the temperature?

A. No, humidity doesn’t raise the temperature. The only reason you feel like a humid environment is less comfortable is that the air is already full of moisture, so evaporation is inhibited and your body’s natural cooling mechanism becomes less effective.

Q. Is an evaporative cooler worth it?

A. If you live in a hot, arid climate, an evaporative air cooler is effective and can save you a great deal of money. It is definitely worth it. If you live in a humid climate, an evaporative air cooler will still work, but the minimum temperature reduction might not make the appliance your best option for staying cool.

Best evaporative coolers

Honeywell Indoor/Outdoor Portable Evaporative Cooler

This indoor/outdoor model is weather-resistant and has a low 235-watt power consumption while offering a powerful airflow of 500 cubic feet per minute, making it suitable for small to medium indoor spaces, such as a living room. It features a low-water alarm and comes with remote control for convenience. 

Where to buy: Sold by Amazon

NewAir Portable Evaporative Cooler

The oscillating technology on this uniquely designed model helps circulate cool air through the entire space. It features a contemporary design, is lightweight and has a removable water tank to make refills easy. 

Where to buy: Sold by Home Depot

Hessaire Portable Evaporative Cooler

This powerful little model delivers 1,300 CFM of cool airflow. It comes with a 4.8-gallon water tank that provides up to four hours of cooling, but the built-in garden hose adapter can provide continuous water without overflowing the tank. 

Where to buy: Sold by Amazon

Evapolar Personal Evaporative Air Cooler

The Evapolar is designed for personal use. It only cools the air in the space directly in front of the unit. It is small enough to be powered by a laptop and has a built-in light that can serve as a night light. 

Where to buy: Sold by Amazon

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Allen Foster writes for BestReviews. BestReviews has helped millions of consumers simplify their purchasing decisions, saving them time and money.

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