The 8 Best Evaporative Coolers

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This wiki has been updated 32 times since it was first published in June of 2015. Evaporative coolers are essential to the comfort of millions of people in hot and dry climates. Also known as swamp coolers, these devices consist of a filter that's saturated with water and situated in front of a fan. The water evaporates, cooling and adding humidity to the air in the room. They work best in arid environments, and they're especially helpful alongside air conditioners. When users buy our independently chosen editorial selections, we may earn commissions to help fund the Wiki.

1. Hessaire MC37M

2. Honeywell CO30XE

3. Mason & Deck ME2MOGO

Editor's Notes

January 29, 2021:

For some background on the effectiveness of these, see our most recent editor's note. As an additional tip, we want to strongly advise keeping your swamp cooler as clean as possible. Don't hesitate to give it a full cleaning and/or replacement filter media as soon as you detect even a whiff of an off odor, as mold and mildew can build up pretty easily in these appliances.

With that said, the Honeywell CO30XE is a good choice for large bedrooms and medium-size living rooms, while the Homelabs Portable and Hessaire MC18M are suitable for smaller bedrooms and offices. For outdoor use, the Mason & Deck ME2MOGO is tough to beat for the price, and the Hessaire MC18M performs slightly better, for slightly more money. The Phoenix Manufacturing Brisa is a good choice for semi-permanent installation, and if you need to cool down a covered patio or good-size garage, take a look at the Portacool Cyclone 130.

May 07, 2019:

First of all, if you're looking for one of these, it's important to have realistic expectations. They only work in dry weather, and even then, they don't pump out frigid air. They generally reduce air temperature at their output anywhere from 7 to 15 degrees. But they also add humidity, which can make everything more comfortable. Incidentally, they work great with air conditioners, and don't let anyone tell you otherwise. These things work specifically by evaporating water (hence the name), while water condensation is actually a side effect of using an A/C unit. In fact, using an A/C unit can technically increase the efficiency of a swamp cooler, because the A/C is acting as a dehumidifier.

With that out of the way, you'd be hard pressed to find a more effective unit than one of those from Honeywell. They make great A/Cs and their evaporative coolers are no different. Also, they're available in relatively large models, some of which are powerful enough even for outdoor use. The Hessaire is another dual-purpose model, and though it's pretty costly, it's very effective. Speaking of the outdoors, if you're at a hot and dry job site or film shoot, consider the Portacool. They make some truly massive options which are very high on the price spectrum, and we've highlighted one of their most cost-effective selections.

The DeLonghi comes very close for indoor purposes, though, as does the Frigidaire, and they cost a bit less than Honeywell's products. The same is true of the Whirlpool. If you don't want to spend much, check out CostWay or SunpenTown, just don't expect them to cut temperatures much across entire rooms. And if you're interested in a semi-permanent solution that's more effective but also more expensive than most others, look at Essick's in-window unit, which is great for pole barns, workshops, and other large spaces.

4. Portacool Cyclone 130

5. Homelabs Portable

6. Phoenix Manufacturing Brisa

7. Hessaire MC18M

8. Honeywell CO48PM

The Principles Of Evaporative Cooling

The concept is simple: the more you sweat, the cooler you will be.

The human body regulates its temperature in a variety of ways -- including constriction of blood vessels and the burning of stored fats -- none of which is as common and conspicuous as perspiration. Sweating is the body's primary vehicle of thermoregulation, and can help a person maintain a stable internal body temperature even during intense exercise or in a hot environment.

Sweating works to cool the body down thanks to the effects of evaporative cooling. The average healthy adult can produce between two and four liters of sweat per hour during vigorous exercise, and in the right circumstances this sweat will be able to properly evaporate in order to maintain a healthy internal temperature. The concept is simple: the more you sweat, the cooler you will be. The efficacy of evaporative cooling can be hampered by an extremely humid environment, however, and as we'll see this can have an affect both on human thermoregulation as well as on machinery designed to regulate ambient air temperatures.

Simply stated, evaporative cooling is the process of lowering body or air temperature by releasing water vapor. The process of evaporation absorbs and holds onto latent heat, effectively reducing temperatures. For the athlete who has just finished a race, the body is cooled as the heat is carried away from his or her body. When it comes to cooling the air temperature itself, the heat removed from the air and transferred into the water vapor reduces the ambient temperature.

Evaporative cooling has been used as a form of air conditioning for thousands of years. Ancient civilizations variously employed fountains, tunnels cut down into underground water sources, and "windcatchers" to help keep themselves cool. Today, the same principles employed by the ancients and by your own body can be found in play in the form of the evaporative cooler, an energy efficient air conditioning system that is highly effective under the right circumstances.

Where And When To Use An Evaporative Cooler

If you live in an area prone to high humidity, then an evaporative cooler is probably not the right air conditioning solution for your needs. The cooling created by these units depends on the water stored in their reservoirs or fed in by a water line to efficiently evaporate in order for them to create cool air that can be circulated down into a residence or place of business.

If you think your area is suitable for evaporative cooling, then take the time to consider which unit is right for your needs and preference.

As many evaporative coolers much have access to exterior air, these units might also be a poor choice for anyone who lives in a region with exceedingly poor air quality.

If, however, you live in a relatively temperate zone, an evaporative cooler might be a fine choice for your air conditioning needs. And if you live in an exceedingly arid and hot area, such as in an actual desert climate, then an evaporative cooler might just be the best solution to your HVAC demands. Using one of these units during the long, hot days of summer in a dry region can mean the difference between marked discomfort and a pleasant interior. As evaporative coolers tend to add a bit of moisture to the air they cool, they can be especially well appreciated in those driest areas.

Some evaporative coolers are portable, suitable for setup in a garage, a single large room, or in a smaller office. Others are much larger, able to cool many rooms of a home from a single fixed location. If you think your area is suitable for evaporative cooling, then take the time to consider which unit is right for your needs and preference.

Choosing The Right Evaporative Cooler

Once you have established that your home or workplace is a good candidate for an evaporative cooler based on the average ambient humidity levels and temperature, you must next decide how large a unit you will need. This decision is of course predicated on the size of the area you need cooled.

This decision is of course predicated on the size of the area you need cooled.

If you just need to cool down a single bedroom, an office, a garage or workshop, or another single, contained space, there are compact evaporative coolers that cost relatively litte, use only a couple dozen pints of water per fill, and, over the course of their lifetime, will afford you significant energy savings as opposed to using a traditional vapor compression or absorption-style air conditioning unit. Remember, an evaporative cooler is not just an effective way to keep cool in a dry area, but is also a cost effective approach, too.

On the other end of the spectrum are portable evaporative coolers that cost closer to a grand, but that can lower interior temperatures by as much as thirty degrees Fahrenheit (or more under the right circumstances, should you even want a temperature that cold) and which can cool hundreds of square feet of interior space.

With a large, powerful evaporative cooler, you can even bring the ambient temperature of outdoor areas lower as well. The units blow cold air around, which helps, but also fill the air with cooling moisture, which can help maintain a cooler, more pleasant temperature even outside on a hot, sunny, dry day. Thus the purchase of a high end portable evaporative cooler could help you be more comfortable inside your home, in the back yard, working in an office, or making sure the customers at your shop or restaurant are offered a pleasant and safe environment.

Christopher Thomas
Last updated by Christopher Thomas

Building PCs, remodeling, and cooking since he was young, quasi-renowned trumpeter Christopher Thomas traveled the USA performing at and organizing shows from an early age. His work experiences led him to open a catering company, eventually becoming a sous chef in several fine LA restaurants. He enjoys all sorts of barely necessary gadgets, specialty computing, cutting-edge video games, and modern social policy. He has given talks on debunking pseudoscience, the Dunning-Kruger effect, culinary technique, and traveling. After two decades of product and market research, Chris has a keen sense of what people want to know and how to explain it clearly. He delights in parsing complex subjects for anyone who will listen -- because teaching is the best way to ensure that you understand things yourself.

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