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Best portable swamp coolers: don't wither in the dry heat

Best portable swamp coolers: don't wither in the dry heat
(Image credit: Luma)

The best portable swamp coolers will add moisture to dry air, while cooling down a room. Evaporative coolers work best when lowering the temperature in dry, arid climates. This means, despite the name, swamp coolers aren't good for lower temperatures in places with high humidity, like swamps. If you are looking to inject some moisture into a dry climate, however, an evaporative cooler is the best way to go. This is mainly because they use less energy than air conditioners, saving you money in the long run. 

We've evaluated portable evaporative coolers for more than four years, spending over 75 hours researching the top brands. During our research, we looked at several types of portable evaporative coolers from brands such as Luma Comfort, Honeywell and Hessaire. Of the models we considered, we ranked the Luma Comfort EC110S the best because it’s affordable and performs well in medium-sized rooms.    

1. Luma Comfort EC110S: Best overall 

Luma Comfort EC110S - Best swamp cooler

Luma Comfort EC110S

The best swamp cooler for mid-sized rooms and portability.

Fan Speeds: 3 | Water Tank Size: 1.76 Gallons | Noise Level: 66 dB | Weight: 16.20 lb | Coverage Area: 250 Sq.Ft | Air Flow: 500 CFM

Good for most small and medium rooms
Good airflow
Can't cool large spaces
High running cost
Small water tank

The Luma Comfort EC110S strikes a balance between affordability and power. This portable swamp cooler’s airflow rating is 500 cubic feet per minute (CFM), which is good enough to cool medium-size bedrooms up to 250 square feet.

However, it may not be powerful enough for large family rooms. At around $150, this isn’t the cheapest unit we looked at, but its price is still competitive with budget models.

The EC110S’s water tank can hold 1.76 gallons, which is good but smaller than those that come with most units we evaluated. That said, the water tank weighs around 14 pounds when full, which is as heavy as the swamp cooler itself. Although the cooler is lightweight and only slightly larger than a tower fan, it helps that there are wheels on the bottom to move it around the house.

As with most evaporative coolers, the EC110S doesn’t cool as well in humid environments or when the outside temperature gets too warm. You also have to occasionally clean it out, though using purified water can help prevent mineral deposit buildup inside the cooler and make it easier to care for over time. Because this is a fairly powerful machine, it uses more energy than smaller units, though the cost difference isn’t enough to affect your power bill that much.

2. Luma Comfort EC45S: Best value 

Luma Comfort EC45S - best swamp cooler

Luma Comfort EC45S

A small and inexpensive swamp cooler that is ideal for tight spaces

Fan Speeds: 3 | Water Tank Size: 1.6 Gallons | Noise Level: 64 dB | Weight: 12.80 lb | Coverage Area: 100 Sq.Ft | Air Flow: 250 CFM

Same size as a tower fan
Good for small rooms
Difficult to access water tank
Only for small rooms
Low airflow

The Luma Comfort EC45S indoor portable evaporative air cooler is one of the least expensive units we looked at.

We like that it's about the size a of a tower fan – it is more compact and easier to move than most other portable evaporative coolers. However, its size means the unit’s water tank is on the small side. This portable swamp cooler is ideal for small rooms up to 100 square feet, though we don't recommend it for medium or large rooms based on many of the online reviews we read. The EC45S is energy-efficient, using around 45 watts of power as it runs.

As we researched this model, we found that many customers had trouble accessing the water tank on the bottom of the machine because it fits in the spot so tightly. Additionally, this unit's low airflow rating of 250 CFM means it doesn’t circulate air as well as our top pick, the Luma Comfort EC110S. However, the EC45S can sweep from side to side like a normal fan, which helps make up for its lower airflow.

The Luma Comfort EC45S has other convenient features such as a shutoff timer, a digital control panel, a remote control and dust filters. While this unit may not be as effective as our top pick, it's a good evaporative cooler for the price.

3. Hessaire MC18M: Best for large spaces 

Hessaire MC18M - Best swamp cooler

Hessaire MC18M

A powerful swamp cooler that is excellent at cooling tight spaces

Fan Speeds: 2 | Water Tank Size: 5 Gallons | Noise Level: 53 dB | Weight: 16 lb | Coverage Area: 500 Sq.Ft | Air Flow: 1300 CFM

High airflow
Large water tank
Small spaces only 
Too large for most bedrooms
One year warranty

The Hessaire MC18M is a good evaporative cooler for large workshops and patios. It can cool areas up to 500 square feet, which is substantially more space than most portable evaporative coolers we looked at can handle.

This evaporative cooler has a large, 4.8-gallon water tank, which means you don't need to refill it very often. You can also hook it to a garden hose to keep it running, which is particularly helpful. This Hessaire model has an airflow rating of up to 1,300 CFM, which is another reason it cools large areas so well.

While it can be used to cool your home’s interior, the MC18M is poorly suited to this purpose compared to a rooftop swamp cooler or a smaller unit that won't take up much space in your bedroom. However, the cooler has wheels to help you move it around. When you find the right spot, you can lock the wheels to keep the cooler from rolling on its own.

The MC18M isn't the largest model Hessaire makes, but it's one of the more expensive evaporative coolers we reviewed, costing around $175. Even though it’s more expensive than average, it may be worth the price if you spend a lot of time working in a large workshop or garage. The warranty only lasts one year, like that of every other portable evaporative cooler we reviewed, and it's disappointing to see such short warranties.

4. Honeywell CS10XE: Best for small spaces 

Honeywell CS10XE - best swamp coolers

Honeywell CS10XE

Best swamp cooler for cooling small and tight spaces

Fan Speeds: 4 | Water Tank Size: 3 Gallons | Noise Level: 50 dB | Weight: 18.50 lb | Coverage Area: 175 Sq.Ft | Air Flow: 300 CFM

Great for tight space
Low running cost
Great features

At a little over two feet tall and with a six-foot-long power cord, the Honeywell CS10XE is the perfect size for dorm rooms and small apartments.

The maximum air flow is 300 cubic feet per minute (CFM) which will quickly cool a 175 square foot space by up to 30 degrees in optimal conditions. It’s also pretty inexpensive to run, costing about $9 over the course of the summer.

The only real downside is that this unit can be heavy. The water tank holds 2.6 gallons and weighs almost 20 pounds when it’s full, making this harder to tote around from room to room than other options. Also, a quick search of Amazon reviews indicates that this swamp cooler is fairly loud. The air flow on the highest setting produces a lot of noise, and the water tank makes gulping noises as the water level drops. However, both of these issues are not uncommon for even standard swamp coolers.

The Honeywell CS10XE’s features make it a nice choice for dorm rooms and office spaces. It has a small remote and a large LED screen that is easy to read even in low light. You can also pre-program the unit to turn off automatically after a certain amount of time, and. there’s a low-water alert and a reservoir for ice. The ice reservoir is kind of small and can only hold a handful of ice, but this little bit of extra cold gives the cooling a nice boost. You can use the CS10XE to spot cool when your current air conditioner doesn’t quite cut it or to cool a smaller office or bedroom space.

5. NewAir AF-310: Most versatile 

NewAir AF-310 - best swamp cooler

NewAir AF-310

A portable swamp cooler that is ideal for using in multiple rooms and spaces

Fan Speeds: 3 | Water Tank Size: 1 Gallon | Weight: 11.60 lb | Coverage Area: 100 Sq.Ft | Air Flow: 312 CFM

Tower fan functions
Air purifier functions
Light-weight spot cleaner 
Small water tank
Cools small areas

When it comes to versatility, the NewAir AF-310 delivers. This unit works not only as a portable evaporative cooler, but also as a tower fan, a humidifier and an air purifier. This multi-faceted unit even comes with a slew of other convenient features such as a remote and a sleep mode.

One major complaint is that the water tank is smaller than normal, at only a gallon in size. However, it is easy to remove and fill. This also means that the AF-310 is lightweight and easy to move around a room to spot cool as needed. Additionally, the ice bin is unique in that it holds a reusable gel ice pack; most other portable swamp coolers require that you pour ice cubes into a reservoir.

In optimal conditions, this unit can cool a 100-square foot space by about 20 degrees. That’s not a lot of space, but if your air conditioning is underperforming or you work in a small shed in the backyard, you can use this evaporative cooler to take the edge off. The remote works from up to 15 feet away and it also has a timer, so you can set it, forget it or adjust it. The unit will even let you know when it runs out of water.

Why trust us on swamp coolers?

We've been testing heating, ventilation, and air conditioning for more than four years at Top Ten Reviews. We apply exacting standards to each product we test, primarily focusing on performance and user-friendliness. We design our tests to simulate typical consumer experiences rather than focusing on numbers you need an engineering degree to understand.

When, as in the case of portable evaporative coolers, we aren't able to test the physical products, we apply the same due diligence to make sure our information and conclusions reflect the mission of Top Ten Reviews.

During our research, we found helpful guides on evaporative cooling from the U.S. Department of Energy as well as the International Association of Certified Home Inspectors. While these guides focus mainly on rooftop models, we recommend you take a look if you want more information on how evaporative cooling works.

How we evaluated swamp coolers

While writing this guide, we researched eight portable evaporative cooler manufacturers and evaluated the specifications and energy efficiency of 10 models. Our research to date has taken over 75 hours.

We aren't able to test portable evaporative coolers in-house at Top Ten Reviews due to installation requirements and uncontrollable environmental conditions in our lab. Instead, we researched each product’s performance, features and warranties as reflected in manufacturer specifications and online customer reviews. Our final decisions and suggestions, as well as how we interpreted the coolers’ specifications, are informed by years of experience with general product testing and evaluations.

How much does a portable evaporative cooler cost?

The cost of a portable evaporative cooler varies depending on your cooling needs. You can easily spend $70 on a small unit for a dorm room or small office or pay up to $300 to $400 on a much larger one to cool garages, warehouses and even outdoor spaces. Keep in mind, though, that these are basically portable swamp coolers, so they are only effective in hot, dry climates. If you live in a humid environment then you may still use a swamp cooler for the hottest and driest part of the day and then switch on the air conditioner in the more humid mornings and evenings. Evaporative coolers cost much less to run than AC so if you want to save on your power bill then this is an option. 

As most portable swamp cleaners need pads to work, it is also important to consider the ongoing cost of the pads. Prices for these start at around $20 and you'll need to change them annually or every 3-5 years depending on the model. 

Why use a swamp cooler?

Portable evaporative coolers cost significantly less to install and operate than central air conditioning systems, although they have much less cooling power. They’re lightweight and require only water and electricity to function, which means you can put them to use in your home or office. Since these units cool by adding moisture to the air, you should never use one alongside a traditional air conditioner, which cools by removing moisture. In shared spaces, these different types of coolers cancel each other out and waste energy. However you can turn one off and use the other, just don't use them at the same time.

How does a swamp cooler work?

A swamp cooler works by taking dry, hot air and cooling it by adding moisture to it by evaporating water stored in an attached tank. The dry air is filtered through a wet swamp cooler pad to add moisture. This air is then spread through the room using a fan or motor. This process is known as evaporative cooling.

How to choose a portable evaporative cooler

When looking to buy a portable swamp cooler, always consider the following:

Climate and swamp coolers 

Evaporative cooling technology is most effective in hot, dry environments such as the Western U.S., and it doesn’t effectively lower temperatures in places with high humidity.

How energy efficient are evaporative coolers? 

Since evaporative coolers don’t have compressors, their power consumption is significantly lower than that of a central air conditioner. On average, evaporative coolers can make the ambient temperature anywhere from 20 to 30 degrees cooler than outside air. These limitations mean evaporative coolers don’t offer the same comfort as portable air conditioners.

Weight and portability

Since portable swamp coolers are intended to cool one room at a time, you may need to purchase a unit that’s light enough to move around your house. More sizable units cool larger areas, but they can be much harder to move than their lightweight cousins. The best-designed heavyweight units have caster wheels that make them easy to reposition. 

Size and effectiveness

For portable evaporative coolers, bigger isn’t necessarily better. At the same time, choosing a unit that’s not big enough can leave you overheated. Evaporative coolers’ cooling efficiency is rated in cubic feet per minute (CFM). All portable swamp coolers have CFM ratings, which makes it easy to figure out if a unit is powerful enough to cool a given area.

To pick the right size cooler for your room, you must first determine how many cubic feet you need to cool. This is done by multiplying an area’s square footage by the ceiling height. For example, a 250-square-foot room with an 8-foot ceiling has a cubic area of 2,000 feet (250 x 8 = 2,000). You then simply divide the cubic area in half (2,000 / 2 = 1,000) to find out how many cubic feet your evaporative cooler needs to be able to cool per minute. So, in this example, you would need a unit with a CFM rating of 1,000.

Additional features

The best portable swamp coolers often come with extra features that make them more convenient and easy to use. Some models have timers, remote controls and automatic thermostats that turn the unit on or off depending on the room’s temperature. Others include oscillating fans to evenly distribute air, alarms that notify you if the unit is running low on water, and adjustable speeds for gradual or rapid cooling. Some portable evaporative coolers also double as ionizers that remove pollutant particles from the air.

Swamp coolers and poor warranty support

One of the most unfortunate things about portable evaporative coolers is the poor warranty support across every brand we evaluated. We did not find a single product that offers more than one year of warranty coverage.

We suspect poor warranties come mostly from the design of these units and the water they use for cooling. For example, although the design uses four simple components – a water pump, a fan, a cooling pad and a water tank – using these components causes a lot of wear and tear. Furthermore, dissolved minerals from your water supply will remain in the unit after the water itself evaporates, which makes it difficult to keep the unit clean and functioning properly in the long term.

You may still get multiple seasons of use from a portable evaporative cooler, but you may need to double down on maintenance tasks, such as replacing the cooling pad and occasionally removing hard-water deposits. Check the unit’s manual for additional maintenance instructions.

Do evaporative coolers need to be vented?

Yes, but not to the same extent as a portable air conditioner. While evaporative coolers don’t produce any waste heat that would warm up an unvented room, they can raise humidity to a point where the cooling effect is not as strong. This is the same reason why evaporative coolers aren’t effective outside of dry climates. As such, you should consider cracking one or two windows in your home to create a cross breeze so humidity levels don’t get too high.

At what humidity do evaporative coolers become ineffective?

The effectiveness of evaporative coolers depends on two factors: relative humidity levels and air temperature. In general, you can expect a temperature drop of 10 to 12 degrees as long as there isn’t more than 50 percent humidity in the air. That said, lower levels of humidity will give you much better performance. With an average humidity of 20 percent, for example, you can expect a temperature drop between 16 and 22 degrees. With regards to temperature, hot air can hold more moisture than cold air, allowing for greater cooling effectiveness, though this applies mainly to dry climates in places like the Western U.S., particularly Arizona, Nevada and Utah, where the hot air isn’t already saturated with moisture.

How to make my evaporative cooler colder?

There are several things you can do to help your portable evaporative cooler produce colder air:

  • Soak the cooling pads before using the fan. It’s important to run the pump by itself for at least 10 minutes before using the fan, especially on hot days when the warm air might dry out the pads faster.
  • Use cold water, but not too cold. The temperature of the water has some effect on how much cool, moist air an evaporative cooler produces. That said, if the water is too cold, it won’t evaporate as quickly, which can waste energy. On the other end of the spectrum, hot water might evaporate too quickly and could introduce some heat into the air. Because of this, you should use cold tap water in your portable swamp cooler, which is usually between 50 and 75 degrees.
  • Use ice cubes for a temporary boost– While it’s true that you don’t want water that’s too cold, it can be useful to put some ice cubes in the water tank to help chill water that’s warmed up over time. However, avoid using ice water in your evaporative cooler otherwise.
  • Use a dehumidifier. You can place a dehumidifier near the intake of a swamp cooler when it’s too hot to open the windows. This will help provide drier air to the swamp cooler and prevent humidity levels in the room from getting too high, although the extra energy cost might mean you'll be better off with an air conditioner instead.

Every swamp cooler we reviewed

ProductPriceOverall RatingPricePerformanceEfficiencyDesignPrice Compared to AverageMax Room SizeMax AirflowPower Consumption (Overall)Power Consumption (Per CFM)Estimated Summer Energy CostWater Tank CapacityWeightWarrantyRemote ControlWidth (inches)Depth (inches)Height (inches)
Luma Comfort EC110SView Deal4.5/ sq. ft.500 CFM110W0.22W$9.631.76 gallons16.2 lbs.1 Year12.7511.2534.5
Hessaire MC18MView Deal4.5/58.59.7107.3More Expensive500 sq. ft.1,300 CFM82W0.06W$7.204.8 gallons16 lbs.1 Year-201028
Luma Comfort EC45SView Deal4.5/51088.98.2Less Expensive100 sq. ft.250 CFM45W0.18W$3.931.6 gallons12.8 lbs.1 Year11.711.737.2
NewAir AF-310View Deal4.5/5108.38.38.1Less Expensive100 sq. ft.320 CFM80W0.25W$7.021 gallon11.6 lbs.1 Year12.6311.3834.5
Arctic Cove EVC350View Deal4.5/ Expensive175 sq. ft.350 CFM63W0.18W$5.523 gallons17 lbs.1 Year181834
Honeywell CS10XEView Deal4.5/ sq. ft.300 CFM63W0.34W$8.942.6 gallons23 lbs.1 Year13.515.731.5
Honeywell CO60PMView Deal4/56.5109.38.1More Expensive850 sq. ft.1,540 CFM220W0.14W$19.2615.9 gallons52 lbs.1 Year-27.5618.3540.04