Evaporative air coolers are a type of air conditioner that employs evaporation. A fan inside the machine pulls hot, dry air in through a wet media pad. The hot air quickly warms the top layer of moisture on the pad, causing the water to evaporate and dropping the temperature within the air cooler by up to 20 degrees. This cool, moist air is then expelled from the unit by the same fan that draws the hot, dry air in, creating a constant airflow through the wet pad and into the immediate area.
These devices don’t consume as much energy as a traditional air conditioner because they only operate a fan. The water for the pad is provided by an internal tank that needs to be refilled when the level gets too low to properly cool the air. If an evaporative air cooler seems like a smart, money-saving solution for your home, read on for important shopping considerations and to check out some of the best models on the market.
- BEST OVERALL: HESSAIRE MC18M Portable Evaporative Cooler
- RUNNER UP: HESSAIRE Indoor/Outdoor Portable Evaporative Cooler
- BEST PERSONAL COOLER: iBaste Portable Air Conditioner
- BEST FOR SMALL ROOMS: COMFYHOME 3-IN-1 Portable Air Conditioner
- BEST FOR LARGE ROOMS: HESSAIRE MC61M Evaporative Cooler, 5,300 CFM
- ALSO CONSIDER: TaoTronics 3-in-1 Evaporative Air Cooler
What to Consider When Buying the Best Evaporative Air Cooler
Before choosing an evaporative air cooler for the home, consider the various types available as well as the space that needs cooling, the tank capacity, and features such as wheels, a timer, and an air swing delivery system.
Types of Evaporative Coolers
Evaporative coolers differ based on size, mounting location, and the angle at which the cool air is released. The types include portable, window, down discharge, side discharge, and swamp coolers.
- Portable evaporative air coolers are the most common option for cooling the home. These units stand on a set of wheels and typically have top and side handles to help move the unit around.
- Window evaporative air coolers are designed to sit in an open window. They pull hot, dry air directly from the outside, rapidly cooling the inside of the home. Though these coolers are more effective than portable ones, they are pricier and less popular.
- Down discharge evaporative air coolers are usually mounted on the roof, with air being blown down to cool the entire house. These units can make the home susceptible to roof leaks if they aren’t properly installed and sealed.
- Side discharge evaporative air coolers are the most common type. They come as both portable and window coolers that push air out horizontally. While they aren’t as effective as a whole-home solution, side discharge coolers are easier to access and maintain and can prevent water damage from leaks that might go unnoticed with down discharge models.
- Swamp cooler is a term often used interchangeably with evaporative air cooler. However, some manufacturers specifically reference large, whole-home units as swamp coolers, while smaller units are more commonly called evaporative air coolers. Regardless of the term used, be sure to check the product information to ascertain that you’re getting a product with the capacity you want.
Cooling Area and CFM
The size of the cooling area is an essential consideration when deciding on the best evaporative air cooler for your home. You’ll want to ensure that the unit you buy has appropriate air output to cool the intended room.
Typically, the cooling area of an evaporative air cooler is measured in cubic feet per minute or CFM. Calculate the necessary CFM for the target room by multiplying the length, width, and height of the room to find the volume, then dividing the total by 2: CFM = (L x W x H) ÷ 2.
However, the cooling method evaporative air coolers use can affect these numbers—and the effectiveness of the machine. More humid locations won’t see the same cooling benefits as arid climates, which is why these coolers are more popular in the American Southwest, in such states as Arizona, than in hot, moist climates.
Water Tank Capacity
Evaporative air coolers operate by pulling hot, dry air through a wet media pad. The hot air causes the top layer of moisture on the pad to evaporate, which can lower the air temperature within the cooler by up to 20 degrees. This cool air is then pushed out by the fan to cool the room. However, without a water source to keep the media pad wet, evaporative air coolers are nothing more than bulky fans.
The water for these machines is held in an internal tank, which range in size from as little as 0.1 gallon, for small, personal units to more than 10 gallons for whole-home models. The larger the tank, the longer the cooler can operate, so opt for a product with at least a 5-gallon tank if you want to run the cooler through the night.
Air Swing Delivery System
An air swing delivery system refers to the oscillation feature present on some evaporative air coolers and most fans. Oscillation louvers in the cooler control how far the cooler can oscillate, typically ranging from a fixed position (0 degrees) up to an arc of 120 degrees. Other common oscillation settings include 40 degrees and 70 degrees, allowing users to set the ideal range of motion for the cooler.
Adjustable vents are another convenient control feature. Changing the angle of the vent will alter the direction of the cool air flowing from the unit. This allows the user to direct air to the ground, up into the air, or to the left or right, depending on where people are gathered.
Wheels make an evaporative air cooler easy to move from room to room and also lessens the risk of water in the tank shifting and spilling. Typically these models have four wheels attached to the base and may have two locking wheels to keep the cooler stationary once it’s in place. Just keep in mind that even with a set of wheels, the water in the tank can still spill if the cooler is quickly jerked or pushed across the floor.
Timer functions let the user set the cooler to operate based on personal preference and the water level in the tank. The unit can stay on until the appointed time without the risk of running out of water.
Typically, timers can be set for up to 15 hours of continuous runtime. Use 1-hour, 2-hour, 3-hour, and 4-hour switches to quickly set the cooler for the indicated duration instead of having to change a dial or select a custom amount of time. When time runs out, the unit shuts off automatically—an especially efficient function at night when household members are sleeping. The cooler will operate for a few hours, then stop after the scheduled time has elapsed.
Evaporative air coolers may have several additional features for improved quality and versatility. These include:
- Garden hose adapters allow the cooler to be connected directly to a garden hose and obtain a constant supply of water. With this connection, the evaporative air cooler can be run continuously without stopping to refill the water tank.
- Water level indicators help ensure that the tank has the appropriate amount of water for cooling the room. If the level gets too low, an audible alarm and a flashing or solid light will alert the user to add water.
- Fan speed control is a common feature that usually includes a low, medium, and high fan-speed setting.
- Air filtration can keep such allergens as pollen and dust from being pulled into the home. These coolers pull air through a filter before it hits the media pads, removing airborne irritants. Some products also offer activated carbon filters and odor-blocking filters.
Our Top Picks
This list of top products was selected based on the important criteria mentioned above, including cooler type, water tank capacity, cooling area, CFM, and overall quality to help you find the right device to keep the home cool in hot weather.
This compact HESSAIRE evaporative air cooler has a water tank capacity of 4.8 gallons and an airflow output of about 1,300 CFM, making it an excellent option for rooms up to about 500 square feet. The evaporative air cooler sits on four wheels, two locking and two nonlocking, allowing it to be moved with ease and stay put when in place.
Change the direction of the airflow output with the adjustable vents, and decide whether to use the fan on low or high. There’s also an internal water pump to move water from the tank to the top of the cooler, ensuring that the pad remains soaked through until the tank requires refilling. This evaporative air cooler operates for up to 4 hours with a full tank. Alternatively, it can be connected to a garden hose for continuous use.
Connect this reasonably priced evaporative air cooler directly to the garden hose with the included hose adapter for a continuous supply of water. This feature allows the cooler to run nonstop without the risk of running out of water. Yet even without connecting it to the hose, the ample 4.8-gallon water tank can operate for up to 4 hours before needing to be refilled.
This HESSAIRE evaporative air cooler has four wheels on the base and a handle on the top for easy portability. There’s also a narrow window in the front of the water tank, allowing users to see the water level without opening the cooler. With a CFM of 1,300, it can keep an area of up to 500 square feet nice and cool during hot weather.
This iBaste portable evaporative air cooler is a solid option for personal use. It’s small enough to be carried by its handle and sit on a desk or night table, and its 0.1-gallon water tank can also be filled with ice for even colder air output. Despite the compact size, the tank can deliver up to 5 hours of use before requiring a refill.
The evaporative air cooler has a CFM of about 200, suitable for home office or bedside use. The device can be plugged into an electrical connection or run on its built-in rechargeable battery. It has three speeds and, just for fun, a light on the top offering seven color options.
This evaporative air cooler comes with a remote and a 12-hour timer, so it can be set to turn off automatically. It has an output of 455 CFM, allowing it to cool a space of about 170 square feet, such as a bedroom, office, or den. Choose between low, medium, and high airspeeds, and take advantage of the built-in wheels to easily move the cooler around the home.
The COMFYHOME evaporative air cooler has an easy-to-fill top-load water tank, a boon to those users who have difficulty bending over. A second tank in the bottom of the cooler allows it to hold up to 1 gallon of water, for up to 12 hours of operation. There are also ice packs included to cool the room faster.
The popularity of residential open plans calls for a heavy-duty evaporative air cooler like this HESSAIRE model. It boasts a high airflow output of 5,300 CFM to cool up to 1,650 square feet. Alternatively, the cooler can be set up outside on a hot day to keep the patio or deck cooler—a big boon to folks using the grill!
The evaporative air cooler sits on four locking wheels, making it easy to move around, and it can be set to oscillate up to 40 degrees. It features three fan speeds and an internal pump that can be turned off for fan-only cooling. The 14.6-gallon water tank only lasts for up to 4 hours, and the cooler can be connected directly to a garden hose for continuous use.
The TaoTronics evaporative air cooler has a 500 CFM airflow output that’s suitable for bedrooms, offices, dens, and other small living spaces. It’s designed to oscillate up to 60 degrees to direct the airflow throughout the room. Turn the oscillation function on or off with the included remote, or use the touch control panel on the front of the cooler.
Users can set the timer for automatic operation ranging from 30 minutes to 10 hours. There’s a 1.85-gallon water tank and two included ice packs to further reduce the temperature of the output airflow. A four-wheeled base lets users move the cooler with ease.
FAQs About Your New Evaporative Air Cooler
These high-efficiency devices are a great option to keep the home cool in warm weather while using less energy than a standard air conditioner. If you’d like more info on how to shop for, use, and maintain these machines, read on for answers to commonly asked questions.
Q: Do I live in the right climate for an evaporative air cooler?
Evaporative air coolers pull dry, warm air through a wet media pad causing the top layer of water to evaporate and lower the temperature within the cooler by 10 to 20 degrees. This process of evaporative cooling works best in hot, dry climates common in the American Southwest, including Arizona, New Mexico, Utah, the California desert, and parts of Texas and Colorado. These coolers can function outside of these regions, but the higher the ambient humidity, the less effective the coolers will be at producing cold air.
Q: Do I need to change the media pads for an evaporative air cooler often?
The frequency with which the media pads need to be changed depends on the individual product and the frequency of use. Typically, the more often the cooler is used, the more frequently the media pads will need to be replaced. However, some media pads can be removed, cleaned with a mild detergent, and reinstalled.
Q: Do I need to close all doors and windows when using an evaporative air cooler?
No—in fact, evaporative air coolers actually benefit from access to outdoor air because they require warm, dry air to produce cool, moist air. It’s advised to have a nearby window or door opened to provide a constant source of warm, dry air to flow through the cooler.
Q: How do I maintain my evaporative air cooler?
Evaporative air coolers are relatively low maintenance. During operation throughout the hotter months, regularly replace the water and clean the media pad with water and a mild detergent to help avoid mold growth. Also, wipe down the outer housing of the cooler to remove dust and dirt.
When the temperatures get colder, drain the water tank and water line, and then run the fan-only feature for 30 minutes to an hour to dry out the machine and the pads. Then store the cooler in a protected place, like a garage, shed, or basement.