Best Evaporative Coolers

Buying guide for best evaporative coolers

If you’re looking for a cost-effective, more environmentally friendly way to cool your home, an evaporative cooler is a great option. Also known as “swamp coolers,” evaporative coolers are designed not for humid conditions but rather for arid, dry, hot climates such as those found in the American Southwest and West.

Evaporative coolers fill a unique niche among climate-controlling appliances, offering efficient cooling in a package that is easier to install and less expensive overall. However, they do not work in every climate and may require you to refill the water tank frequently.

Not everyone is familiar with the benefits of the evaporative cooler and how it can save money on electricity while freshening and humidifying the air in your home, so you might be unsure how to find the right unit for your needs. Thus, before you go shopping, it helps to read a comprehensive buying guide about the best evaporative coolers to learn about size, type, and other important aspects of the appliance.

The humidity created by an evaporative cooler can be beneficial for fabrics and wood in arid climates.

Finding the best evaporative cooler for you

Your region can determine evaporative cooling effectiveness

Unfortunately, evaporative coolers don’t work well in climates with more than 60% humidity, so they’re not a good choice east of the Mississippi or in parts of the Northwest, but they excel in dry climates. The lower the humidity level of the air in your space, the more effective an evaporative cooler will be. The past few years have seen a big increase in the number and types of evaporative coolers available. In short, there is an evaporative cooler to suit your needs and the space you want to cool.

Evaporative coolers vs. air conditioners

Evaporative coolers are very effective at refreshing dry, stale air through their circulation process, which draws in dry air, passes it over moistened padding inside the unit, and then blows out slightly humidified, fresher air. It can lower the air temperature in a room or house by 5°F or more.

An evaporative cooler costs less to purchase than a traditional window unit or portable air conditioner. It also requires less energy to complete the cooling process since there’s no refrigerant compressor — just a fan and pump to circulate water. That means owners will pay less over the life of an evaporative cooling unit than they would for an air conditioner of similar size and power rating. In some cases, the savings can be as much as 50%, and some brands claim as high as 75%.

Air conditioners cool the air inside the home by drawing in warm air and passing it over an evaporator coil that has been cooled using a refrigerant (usually a hydrochlorofluorocarbon like R-22 or R-410A). This also removes some of the humidity from the air in the form of condensation. The drier, cooler air is then circulated back into the home. While it’s effective and popular, air conditioning uses more energy than evaporative cooling. The price of an air conditioner, particularly at a higher cubic feet per minute (CFM) rating, is often significantly more than an evaporative cooler, and it costs more in electricity to run over the long term.

Low environmental impact

Evaporative coolers are better for the environment than air conditioners in a handful of ways:

• No refrigerants: These greenhouse gasses cause tremendous damage to the ozone layer due to their ubiquity—they are found in refrigerators as well as home and vehicle air conditioning systems.
• Low heat generation: Traditional air conditioners work by moving hot air out of a space to the outside, warming the immediate environment. This effect is particularly noticeable in heavily populated areas. Evaporative coolers generate very little heat and don’t shuttle warm air outside.
• Low energy usage: The energy efficiency of evaporative coolers means they use far less electricity, thereby costing far less to run as well.

An evaporative cooler works best in arid and hot climates. In the right situation, it can cool the air by up to 20 degrees.

What features to look for in an evaporative cooler

As with air conditioners, evaporative coolers vary in features such as fan speed, installation method, and extras such as oscillation and outdoor functionality.

Types of evaporative coolers

There are two primary types of evaporative coolers: direct and indirect.

Direct: The most common and affordable evaporative cooling type, direct coolers pass air directly over or through water-saturated padding, returning cooler, humidified air to the room or house.

Indirect (or two-stage): A newer type of evaporative cooling, indirect cooling uses a secondary air stream that is pre-cooled, helping to cool down the primary air stream (the air that will circulate into the house) even more efficiently. This is a pricier unit, but it works very well in areas where daytime temperatures climb above 100°F.

Airflow

There are two ways for an evaporative cooler to deliver cooled air: down flow and horizontal flow.

Down-flow coolers: The original evaporative coolers, down-flow (or down-discharge) coolers are mounted either on the roof or the side of a home. Air is drawn into the unit, cooled and moisturized, and then discharged downward into the living space.

Horizontal-flow coolers: These evaporative coolers blow cooled air horizontally into a home or room. The most common horizontal-flow coolers are portable units and window models, but ground-installed horizontal-flow coolers are becoming popular because they’re easier to access for maintenance.

Either way, make note of the cubic feet per minute (CFM) of evaporative coolers as you compare models, as this is the biggest factor in determining how much space a unit can effectively cool. One way to think of it is that the higher the CFM, the more frequently all of the air in a room is cycled through the cooler. This number usually falls between 500 and 20,000 CFM, but the easiest way to gauge efficiency is to check what square footage the manufacturer recommends for their cooler.

Evaporative cooler installation

There are five common ways to use or install evaporative coolers: portable, window mounted, roof mounted, side mounted, and ground installed.

• Portable: Portable evaporative air coolers are mounted on casters and easy to shift from room to room, so you don’t have to decide whether to install it in your bedroom or your home office. A portable evaporative cooler is an affordable way to freshen the air in small rooms and even apartments. However, the cooling effect is limited compared to a whole-home unit.
• Window: These horizontal-flow evaporative coolers are most effective in regions with moderate heat and low humidity. The cooling effect isn’t as noticeable in regions with very high heat, but for the most part one can drop the temperature in a single room by 5°F to 15°F, according to the Department of Energy.
• Roof: This is the oldest type of evaporative cooler, using downward flow to deliver cooled air to a home’s interior. Direct discharge, which blows air into a central part of the house, and ducted discharge, which blows the air through ducts to various parts of the house, are both possible with roof- or side-mount coolers. The biggest drawbacks are that this type of cooler is more difficult to access for maintenance, and it can cause roof leaks over time.
• Side: Also a type of down-flow evaporative cooler, this type is mounted onto the side of a home so that cooled air blows into the attic space. While it’s highly efficient, side-mounted evaporative coolers suffer from many of the same drawbacks as roof-mounted coolers, including difficult access and potential damage to the home where it’s mounted.
• Ground: This type of evaporative cooler is installed in a similar location and manner as whole-house air conditioning and provides ducted horizontal-flow cooling throughout the home. These are heavy-duty units that work best for large homes and businesses.

Outdoor evaporative coolers

Some evaporative coolers are rated for outdoor use (often in addition to indoor use). Most of the time, they work best in semi-enclosed spaces such as garages, workshops, or screened-in porches. However, they can be effective in open spaces like patios if people are sitting close enough, and they work best on days with low humidity.

Additional evaporative cooler features

• Oscillation: An oscillating fan makes an evaporative cooler more efficient by dispersing cool air evenly throughout a room. It also improves air circulation, allowing the cooler to draw in dry air rather than humidified air and increasing the cooling area of the unit.
• Water supply system: Evaporative coolers either have a tank or connect to your water line for a steady supply. For water tank models, the larger the tank, the longer the cooler can run without being refilled. Most coolers have between 2- and 10-gallon water tanks. Water tank capacity should be considered with the CFM rating to determine the power of a cooler.
• Fan speed settings: This allows you to adjust the air speed of your cooler as you would with a normal fan. Not only does this help you tweak the intensity of the cooler, but it also can control its noise level.
• Remote control: On a hot, muggy day, crossing the room to change the temperature may be the last thing you want to do. Look for evaporative coolers with remote controls to save yourself the effort.
• Timers and schedules: Coolers with a built-in interface may let you set timers or even program a schedule to save energy and cool your home just before you return.
• Included motor: For large ground-installed units, the manufacturer does not always include a motor. Keep this in mind when comparing prices, but also note that you can increase the CFM of a cooler with a more powerful motor.

How much do evaporative coolers cost?

While evaporative air coolers are usually less expensive than air conditioners, they still range greatly in price depending on their efficiency and design.

Inexpensive

For $100 to $500 are portable evaporative coolers for small spaces. While their air cooling power may not match that of mid-range models, many budget options are worth their price and may have extras like sleek bladeless designs or rechargeable batteries.

Mid-range

More powerful portable coolers and window-installed designs range in price from $500 to $750 and are usually sufficiently powerful to cool most homes. These can often output up to 3,500 CFM and have high water tank capacities.

Expensive

Heavy-duty window and portable evaporative coolers, as well as permanent ground-installed coolers, cost from $750 to $3,000. Side and roof units fall into this range as well.

Note that using an evaporative cooler adds moisture to the air. For this reason, the technology is best used in dry climates rather than humid ones.

Tips

• Always keep a window slightly open when using an evaporative cooler. This maximizes the cooling effect and helps the cooler work efficiently.
• Experiment with airflow for optimal cooling. Large evaporative coolers (installed in roof, side, or ground) can be maximized by controlling the way air flows through the house. This takes a bit of experimentation by opening and closing different windows throughout the house and adjusting how much each one is open.
• Coolers should have at least two speeds and a vent-only option. On roof-, side-, or ground-installed coolers, the vent-only setting turns the unit into a whole-house fan during milder weather.
• Consider purchasing rigid filter media pads rather than fiber pads. These are much more expensive but don’t need to be replaced as frequently. If your cooler can fit them, these thicker cooling pads provide more humidity and better cooling.

Air filters are an optional accessory rather than a standard feature on many evaporative coolers.

FAQ

Q. How do I choose the right size evaporative cooler for my home?

A. When shopping, pay attention to the cubic feet per minute (CFM) rating for the cooler, the airflow that a cooler can move. It’s important when figuring out whether a particular unit would cool your entire living space or just a room. Most brands list the estimated square footage that a specific unit will be able to cool, but you can also figure out what you need. Measure the length and width of the room(s) to get the square footage of the area you want to cool, and multiply that by the height of the ceiling. Divide that number by two. The result is the cubic feet per minute you’ll need to cool the area.

Q. I’ve found that an evaporative cooler works well in the hottest part of the day but not so well at night or early in the morning. Is there a way to improve its cooling during these times?

A. In some areas, the humidity in the air varies, and it might be higher from late night through early morning. The effects of the evaporative cooler may not be as noticeable at these times. Some homeowners run an air conditioner when the humidity is higher.

Q. Is it better to use ice or water in an evaporative cooler?

A. You should always follow the manufacturer’s instructions, as ice can damage some coolers. The right amount of ice can lead to more efficient cooling, but too much ice could cause the water to evaporate more slowly. This is because warm water generally evaporates faster. Whether you opt for ice or water, you will still get cold air as long as water is able to evaporate.

Q. Can I run a dehumidifier in more humid environments to make use of an evaporative cooler?

A. Yes. Unless you live in a severely dry climate, a dehumidifier will almost always boost the performance of your evaporative cooler.