Looking for an evaporative swamp cooler?
You've come to the right place.
If you want to cool a room, you have two options: a conventional air conditioner such as portable AC or a window unit, or an evaporative swamp cooler.
Conventional air conditioner systems use a chemical – called a refrigerant – to suck heat from the air in the room. An evaporative swamp cooler uses water and a fan to provide evaporative cooling.
The fan draws warm air over the water, causing it to evaporate, which cools the air and humidifies it as well.
A swamp cooler doesn't cool as much or as quickly as an AC – usually only by a few degrees. Because of its humidifying effect, an evaporative swamp cooler is best for a dry and hot climate such as California, Nevada, and Texas.
A swamp cooler is also a great choice if you want to save energy, as it consumes much less electricity compared to an air conditioner.
What's In This Guide?
In this in-depth buying guide, we review the best evaporative swamp coolers you can buy online. We also explain when to use a swamp cooler, how it works, and how to choose the right one for your cooling needs.
If you prefer conventional air conditioners (e.g., if you live in a humid climate), see our reviews of the best portable AC.
We've also reviewed the best small portable air conditioners for smaller rooms, boats, and RVs.
When Do You Need an Evaporative Swamp Cooler?
A swamp cooler is not appropriate for all types of weather and climates. Because it humidifies the room as it cools it, only use it when it is dry and hot.
The swamp cooler works best when humidity levels are low (that is, the air is dry), as it allows water to evaporate more efficiently and thus cool the room quicker.
That's why swamp coolers are best for residents of dry and hot states such as those in the southwest US.
You can still use a swamp cooler in locations that are more humid like Florida and Louisiana but keep the windows open to prevent a build-up of moisture in the room. It'll take longer to cool the room.
But if humidity is too high, the room can feel clammy and uncomfortable even with the windows open. In that case, switch to a conventional portable or window AC and wait to use your swamp cooler when it's less humid.
Know What to Expect
We see many negative Amazon reviews on otherwise excellent swamp coolers. The reviews are from customers who should have bought a portable or window air conditioner instead of a swamp cooler.
We'd like to emphasize two things, so you don't waste money on an appliance that's not right for your cooling needs.
1. Swamp coolers are not for humid areas
Take a look at this map by Luma, makers of the Luma Comfort swamp cooler. It shows the best places to use a swamp cooler.
If you live on the right-hand side of the map, do not get a swamp cooler. Not only will it make the room muggy, damp, and plain uncomfortable, it won't provide much cooling.
An evaporative cooler needs a hot and dry environment to cool properly.
2. Expect a cool, not chilly, room
A swamp cooler can cool the room to a point where it feels comfortable, but don't expect it to make the space feel chilly. Only an air conditioner can do that.
Typically, an evaporative cooler will bring the room temperature 10-30 degrees down from the outdoor ambient temperature.
This does not apply if you have an extra-powerful swamp cooler. A powerful unit like the Cool-Space AVALANCHE-36-VD (reviewed below), can get the room too cold.
Best Evaporative/Swamp Air Conditioners
Disclamer: All links below go to Amazon.com
- Editor's Top Pick
950 sq. Ft.
- 25" x 17" x 37"
- Best for medium size rooms
320 sq. Ft.
- 18" x 13.9" x 33.7"
- Best for small rooms
- 13.6" x 12.2" x 29.5"
- Best outdoor swamp cooler
460 sq. Ft.
- 22.4" x 17" x 44.5"
- Best value
500 sq. Ft.
- 20" x 10" x 28"
- Best compact
425 sq. Ft.
- 16.5" x 13.4" x 31.5"
- Most stylish
250 sq. Ft.
- 12.8" x 11.2" x 34.5"
- Best for garage or workshop
6400 - 9700 CFM
3600 sq. Ft.
- 62" x 30" x 70"
Phoenix Manufacturing BW3004
- Best window swamp cooler
600 sq. Ft.
Capacity not listed
- 40" x 30" x 28"
- Best personal swamp cooler
45 sq. Ft.
- 6.69" x 6.7" x 6.87"
Top 10 Swamp Coolers: Reviews
1. Editor's Pick: Hessaire MC37M Portable Evaporative Air Cooler
The Hessaire MC37M is our top recommendation for most homes. It has a powerful 3,100 CFM airflow that cools rooms up to 950 sq. Ft.
With its compact size and caster wheels, the Hessaire MC37M's portability is not a problem – and not just within your home, but outdoors as well.
The powerful airflow of the Hessaire MC37M makes it ideal for use in any room, including large open-style living rooms.
You can also use it in your porch, garage, or gazebo, though cooling performance is reduced when in an open space.
When humidity is low, and it's hot outside, the Hessaire MC37M cools a room almost as fast as an AC. Users say the temperature difference between the outside and inside can be as large as 25 degrees.
One reason the Hessaire MC37M cools so well is its multiple air intake panels. Instead of the usual one panel like in most swamp coolers, the Hessaire MC37M sucks air from three sides.
This allows it to cool a large amount of air faster and more efficiently.
Another reason for its high cooling performance is the type of media it uses. A pump carries water to the hi-density XeL50 rigid media, which has a much wider evaporation surface area compared to other types of media.
The wide surface area increases the amount and speed of evaporation, which enhances cooling performance.
For its power, the Hessaire MC37M is surprisingly compact. It doesn't take up much floor space.
It's also easily portable thanks to heavy-duty casters. You can push it from room to room or even take it outside.
Like all evaporative coolers, you have to regularly fill the Hessaire MC37M's tank with water. A full tank lasts about 12 hours. If you don't want to keep filling the tank, connect a hose to provide a constant supply of water.
Issues & Limitations
Several customers have actually complained that the Hessaire MC37M is too powerful. This is usually a good thing but can be a problem on a cooler day when you need less cooling.
The Hessaire MC37M has adjustable fan speeds, but the lowest speed is not low enough. A much lower fan setting would have been great.
Other missing features we would have liked include remote control, a built-in timer, and auto shut-off when the water level gets low.
Despite a few missing features, the Hessaire MC37M is still a great choice for most homes thanks to its powerful cooling performance, easy portability, and a bargain price.
2. Best Swamp Cooler for Medium Size Rooms: Honeywell 525-729CFM Indoor Outdoor Portable Evaporative Cooler
For medium-sized rooms, we recommend the Honeywell 525-729CFM evaporative cooler. It has an airflow of 525-729 CFM, enough for rooms up to 320 square feet.
The Honeywell 525-729 CFM evaporative cooler is perfect for most rooms. It's not overly large but has enough airflow to cool a 320 square foot or smaller bedroom, living room, or home office.
You can also use it outside on the porch, in your backyard, or on the deck. It has a weather-resistant design.
Despite its size, the Honeywell evaporative cooler has one of the largest water tanks among our picks. The 7.9-gallon tank can last several hours before you need to refill it.
If you don't want to keep adding water, there's an option to connect a hose for constant water supply.
The water tank is detachable to make it easy to fill it with water.
For the days when it's hotter than usual, there's a dedicated ice compartment you can fill with ice. The cooler will blow cooler air through the ice melts pretty quickly. It's ideal only for temporary relief.
The Honeywell cooler also comes with a carbon filter to remove dust and allergens from the air. You also get a remote control with which you can set a timer, adjust fun speed, swing the vents, and turn the unit on or off.
Size-wise, the Honeywell cooler has a tall and narrow design. It'll easily fit in small spaces since vertical space is not an issue in most homes.
Issues & Limitations
Even with the fan set at the lowest speed, the Honeywell evaporative cooler is loud. If you are using it in a small enclosed space, it's even louder.
If you are looking for a powerful but affordable evaporative cooler for a medium-size room, the Honeywell evaporative cooler is a great choice.
3. Best Swamp Cooler for Small Rooms: DeLonghi America Portable Evaporative Cooler
For rooms smaller than 250 sq. Ft. even the compact Honeywell cooler above is overkill. Instead, we recommend the DeLonghi EV250WH.
It's cheaper and has just the right amount of power to cool and humidify a small space.
If you need a cooler for your small bedroom or home office, the DeLonghi EV250WH works great. It's not very powerful but cools spaces smaller than 250 sq. Ft. quickly and efficiently. It's also quieter than most evaporative coolers.
The 1.1-gallon tank needs refilling every five or so hours. Unfortunately, there isn't an option to connect a hose.
The DeLonghi EV250WH includes a washable filter and built-in ionizer to make sure you receive cool and clean air. It also comes with remote control with which you can select different modes, set a timer, and swing the vents.
The control panel on the unit has additional functions, including sleep mode, ionizer, and natural mode.
Another feature we love is the ice pack that's included with the cooler. Put it in the freezer and then pop it into the cooler when you need faster cooling.
The DeLonghi EV250WH is compact and easily portable. It has casters that make it easy to move it from room to room.
Issues & Limitations
Don't attempt to use the DeLonghi EV250WH cooler in a room larger than 250 sq. ft. It'll be no better than a fan.
We also don't recommend it for outdoor use unless you place it very close to you.
The DeLonghi EV250WH is not just good for small rooms; it's also a great choice for other small spaces such as RVs, boats, apartments, and tiny homes.
4. Best Outdoor Swamp Cooler: Honeywell CO301PC Outdoor Portable Evaporative Cooler
Need a swamp cooler you can use on your deck, backyard, or porch? We recommend the Honeywell CO301PC evaporative cooler.
It is designed specifically to cool outdoor spaces and large open rooms. A high-pressure blower ensures the cool air travels far and wide.
Evaporative cooling works great outdoors. Unlike portable ACs, swamp coolers don't use more energy when they have to cool a large or unlimited space. They are just as energy efficient outdoors as they are indoors.
But most swamp coolers work best if it's very close to you. If you need to cool the entire porch or outdoor dining area, you need something more powerful.
The Honeywell CO301PC's airflow is rated at 830-1000 CFM. That's powerful.
Combined with the high-pressure blower, the cool air easily covers a large deck or garden.
The Honeywell CO301PC is also perfect for large indoor spaces up to 460 square feet. It's especially ideal for large open style rooms.
One reason the Honeywell CO301PC is perfect for outdoors and large rooms is the double honeycomb pad. The thicker soak pad holds more water, which allows faster and more efficient cooling.
The Honeywell CO301PC is a bit heavy, which is not surprising. But thanks to the casters, you should have no trouble wheeling it outside.
It comes with a 5.3-gallon tank that you need to refill regularly. A low water alarm will let you know when it's time to add more water to the tank. Alternatively, you can connect a hose to provide a constant supply of water.
You can control the cooler using the control panel on the unit or using the included remote control. Using the remote control, you can set an auto-off timer.
To keep it safe outdoors, the Honeywell CO301PC has a rugged weatherproof design. It can withstand moderate exposure to the elements.
Issues & Limitations
The only limitation of the Honeywell CO301PC evaporative cooler is the price. But considering the cooling power and durable design, it's worth it.
You can use the Honeywell CO301PC on your porch, near your hammock, or for a BBQ party. No more stuffy and dry outdoor air – just wheel the cooler outside, connect a garden hose (or fill the tank), and enjoy the cool, humid air.And since you are outside, you don't have to worry about the humidity build-up.
5. Best Value: Hessaire MC18M Evaporative Cooler
Looking for a good quality portable swamp cooler with powerful airflow at an affordable price? We recommend the Hessaire MC18M.
It cools up to 500 sq. Ft. and yet is cheaper than most swamp coolers that can cover a smaller area.
The Hessaire MC18M is the best bargain on an evaporative cooler we found. It's cheap but cools a bigger space than pricier coolers.
The reason it costs less is build quality. It's not that bad, but we recommend care when assembling and handling the unit.
Other than that, it works like a charm. The oscillating vents blow plenty of air - 1300 CFM to be specific. That's enough to quickly cool a 500 sq. Ft. or smaller room.
The honeycomb style media increases the density of the media, allowing it to hold more water. This results in faster cooling.
The downside is that the cooler runs through the water quickly. If the fan speed is set high, you'll need to refill the tank every three hours. On low, the tank lasts about eight hours.
The 4.8-gallon tank is easy to refill, and you can add water while the cooler is running. The cooler has a garden hose adapter, so you can connect a hose instead of constantly refilling the tank.
The Hessaire evaporative cooler does not come with a remote control; all functions are available only on the control panel. You can set two modes: fan-only and cooling. Each mode has two fan speeds: Hi and Low.
Issues & Limitations
We already mentioned the build quality issue. But don't let it stop you from buying the Hessaire MC18M cooler. With care, it'll last just as long as other swamp coolers. For peace of mind, it comes with a 1-year warranty.
Another issue mentioned by customers is the speed at which the cooler burns through the water. But you can solve this by connecting a garden hose, so you don't need to refill the tank.
We should also mention that the Hessaire MC18M does not come with remote control – a small inconvenience but an inconvenience nonetheless, especially for us lazy types who don't want to get up from the couch.
If you want to save money on a powerful swamp cooler, the Hessaire MC18M is the best deal you'll find.
6. Best Compact Swamp Cooler: Whirlpool WPEC12GW Indoor Evaporative Air Cooler
If you are short on space, the Whirlpool WPEC12GW is one of the smallest coolers we found that can cool a fairly large room.
The Whirlpool WPEC12GW is one of the smallest swamp coolers among our picks, making it a good choice if you don't have much floor space to spare. It measures 16.5 x 13.4 x 31.5 inches. It's tall and narrow.
The airflow rating of the Whirlpool WPEC12GW is 214 CFM. The manufacturer says it can cool rooms up to 425 sq. Ft. but we highly doubt that.
A 214 CFM swamp cooler is ideal for small spaces under 150 sq. Ft. This matches with what customers’ report in their reviews. Most who used it in a medium-size or large room got a very small temperature decrease – usually just two degrees.
So even though the manufacturer says the Whirlpool WPEC12GW is good for rooms up to 425 sq. Ft., we recommend it for much smaller spaces or as a personal cooler.
The Whirlpool WPEC12GW doesn't come with remote control, but the control panel has all the functions you need, including a timer, wind modes (natural, normal, and sleep), and fan speeds.
The 1.59-gallon water tank is a bit small, so you'll need to refill it frequently. The cooler doesn't have a garden hose adapter.
Issues and Limitations
The main limitation of the Whirlpool WPEC12GW is its cooling power. It's less than the manufacturer would have you think.
214 CFM is too low an airflow to handle any space larger than 150 sq. Ft.
Another downside of the Whirlpool WPEC12GW is the lack of remote control. You have to stand up and walk to the unit every time you want to change a setting.
Cooling area overstatement aside, the Whirlpool WPEC12GW is a great choice for space-limited rooms as well as RVs and boats.
7. Most Stylish Swamp Cooler: Luma Comfort Portable Evaporative Air Cooler
Most swamp coolers are usually boring boxes that don't really add much to your home décor. If you need something more stylish, we recommend the Luma Comfort Portable Evaporative Air Cooler.
The Luma Comfort Portable Evaporative Air Cooler is one of the few swamp coolers that's not a big grey or black box.
It still has a boxy design at the bottom but with a rounded top where the fan and vents are. The all-black finish also looks pretty awesome and blends well with just about any décor.
The cooler is slim and tall, making it a good choice for space-limited rooms. The rollers at the bottom make it easy to wheel it from room to room.
Luma Comfort has 500 CFM of airflow. The manufacturer recommends it for rooms measuring 250 square feet or smaller.
It comes with a handy remote control and a digital display on the unit.
With the remote control, you can set a timer, adjust fan speed or change cooling mode.
The tank is a bit small, so you'll need to refill it frequently. A full tank lasts about 6-7 hours, depending on fan speed.
For faster cooling, the cooler comes with an ice pack. Put the pack in the freezer and use it in the cooler when it is extra hot. You can also add your own ice cubes to the cooler.
Issues & Limitations
Considering the small tank capacity, a garden hose adapter would have been a nice addition. As it is, you have to refill the tank every 6-7 hours.
That means you cannot leave it on through the night (considering an 8-hour sleep period).
Alternatively, they should have made the tank large enough to last at least 8-9 hours.
Bottom LineIf you care a lot about the aesthetics of your appliances as you do their functionality, you'll love both aspects of the Luma Comfort evaporative cooler: it works great and looks great.
8. Best for a Garage or Workshop: Cool-Space AVALANCHE-36-VD Swamp Cooler
Garages and workshops are typically large spaces that need lots of cooling.
If you spend a lot of time tinkering in your workshop or garage, we recommend the Cool-Space AVALANCHE-36-VD to keep you cool.
It is an industrial-grade cooler with powerful airflow between 6400 and 9700 CFM. It can cool a space as big as 3,600 square feet.
The Cool-Space AVALANCHE-36-VD is meant for industrial/commercial use in warehouses, restaurants, and factories.
But the reason it's great for industrial use also makes it great for cooling your large workshop or garage at home.
It's also perfect if you have a commercial workshop or venue.
As expected, the AVALANCHE-36-VD is big and heavy. It weighs 295lbs and measures 62 x 30 x 70 inches. The heavy-duty lockable casters do make it easier to move it, but you'll want to find the best place for it and keep it there.
The tank is huge – 46 gallons. It lasts for hours, so you don't need to connect a garden hose.
To cool a large space, the AVALANCHE-36-VD uses a 36" direct drive fan to drive a lot of air through the cooling media. It has an airflow of 6400-9700 CFM, ideal for spaces up to 3,600 sq. Ft.
If you are cooling a larger space than that, consider getting two or three of them.
The cooling media consists of a cross-corrugated, 8" thick pad with resin to make it stronger and keep away algae.
With the large cooling media and powerful fan, the AVALANCHE-36-VD cools large spaces well, sometimes too well. It can get chilly if you leave the fan on high for too long. Unless it's very hot, let the cooler run at a lower fan speed.
It can also get too humid. As with any other swamp cooler, make sure to leave several windows and doors open to keep fresh air flowing in and prevent humidity build-up.
Issues & Limitations
The AVALANCHE-36-VD is expensive. But considering it's an industrial-grade swamp cooler, the high price tag makes sense.
If you are on a budget, consider a residential evaporative cooler instead.
Another issue is weight. The AVALANCHE-36-VD is not meant to be moved around often. Though it has wheels, you'll find it more convenient to keep it in one location.
Large workspaces can get hot, dry, and uncomfortable. The AVALANCHE-36-VD keeps your working environment cool and perfectly humid. It's not just good for your comfort; it ensures safety as well.
The AVALANCHE-36-VD is made in America so you can be sure of the quality. It also comes with a 5-year warranty to guarantee reliability and durability.
9. Best Window Swamp Cooler: Phoenix Manufacturing BW3004 Evaporative Window Cooling Unit
If you love the look and practicality of window air conditioners, but prefer a swamp cooler, go with BW3004 swamp cooler from Phoenix Manufacturing.
The window cooler can cool rooms up to 600 square feet.
Window ACs are quiet, powerful, and don't take up a lot of space. Window swamp coolers are the same.
The Phoenix Manufacturing BW3004 swamp cooler sits neatly on your windowsill and directs most of the motor and fan noise outside.
As a result, it's much quieter than floor swamp coolers.
With 3000 CFM airflow, the BW3004 cooler can handle spaces as large as 600 square feet. If you have a large bedroom or open style living room, this cooler is perfect.
It plugs into a standard AC outlet – no need to hardwire it.
Issues & Limitations
The main limitation of the BW3004 cooler is portability. Unlike a wheeled floor swamp cooler, you cannot easily move it from room to room.
We recommend getting this window unit for cooling a specific room. If you want the ability to move with a cooler as you go from the living room to the bedroom and other rooms, get a conventional floor swamp cooler instead.
The Phoenix Manufacturing BW3004 swamp cooler is a good replacement for a window AC unit. It's quieter and uses way less power. It's also more environmentally friendly.
10. Best Personal Swamp Cooler: Evapolar evaLIGHT Personal Evaporative Air Cooler and Humidifier
A personal swamp cooler like Evapolar is perfect for your desk or bedside. You can also place it on the coffee table as you watch TV or read a book.
Evapolar evaLIGHT is like a small desk or bedside fan, but with decent cooling capability. Instead of just moving air around, it actually cools it by 5-10 degrees from the ambient temperature.
Evapolar is USB-powered, so you can easily use it on your work desk or your bedside. It's also perfect for camping – just plug it into a power bank or solar generator.
Note that this is a personal space cooler, so check your expectations. You need to be within a few feet of it to feel the cool breeze. It cools an area of approximately 45 sq. Ft.
The tank holds only 35 oz. of water. A full tank lasts 4-5 hours. If you want to leave it on through the night, you'll have to wake up in the middle of the night to refill it.
We love the integrated LED lighting. It's handy as a night light or for mood lighting. Of course, you can turn it off if it bothers you.
Issues & Limitations
The small tank is inconvenient since you have to refill it often. But it's understandable. A bigger tank would have made the cooler bigger and less than ideal for desk or bedside use.
Another issue with the tank is how easily it leaks. If the cooler is not on a completely flat surface or if you disturb it a little bit, some of the water leaks out.
There are also several complaints regarding the LED light. It burns out within days.
The Evapolar evaLIGHT provides a convenient and energy-saving way to keep yourself cool without having to buy an expensive room swamp cooler.
It's especially ideal if you don't want to affect the climate of those around you, such as in an office. You can cool just your personal area.
Evapolar evaLIGHT is super quiet, so the noise is not an issue.
How Does An Evaporative/Swamp Cooler Work?
Ever sat by a lake on a hot day and experienced a cool breeze blowing towards you? A swamp cooler works roughly the same way.
There are four essential components of an evaporative cooler:
The pump soaks the cooling pad/media with water. The fan then blows warm air over the soaked pad, the same way wind blows over the lake.
The warm air causes water on the media to evaporate. In the process, the air gets cooler.
The air that comes out of the vents is cooler and more humid. The fan distributes it around the room for even cooling.
How much the unit cools, air depends on ambient temperature and relative humidity. Swamp coolers are most effective when it is hot and dry.
Types of Swamp/Evaporative Coolers
Portable swamp coolers: These are the most common types of evaporative coolers. They are large enough to cool an entire room, but are still portable for easy room to room mobility.
Window swamp coolers: These are like window ACs, but they use evaporative cooling instead of a compressor. Like a window AC, a window-mounted swamp cooler provides good cooling performance with minimal noise.
Personal swamp coolers: These are mini ultra-portable evaporative coolers designed to cool the area immediately around the unit. A personal swamp cooler is perfect for your work desk, coffee table or bedside.
Outdoor swamp coolers: Outdoor evaporative coolers work the same way as indoor ones. However, outdoor swamp coolers tend to be bigger, have more powerful motors and large fans to blow cool air across a wider area, and are designed to withstand the elements. Most also have a garden hose connection to save you the trouble of constantly refilling the tank.
Industrial swamp coolers: Industrial evaporative coolers are huge units that blow out massive amounts of cool air. They are designed for large open areas such as a factory floor or warehouse. They are also great for garages and workshops.
Air Conditioner Vs. Swamp Cooler
An air conditioner, whether it's a central AC, a portable AC, or a window AC, uses a compressor and a refrigerant to cool the air.
A swamp cooler, on the other hand, relies on water and a fan to cool air.
This creates significant differences between ACs and swamp coolers.
Most have a programmable thermostat – you can select a specific temperature
You cannot select a temperature – cooling depends on relative humidity and ambient temperature
Works in any climate
They work best in hot and low-humidity climates
Most cool and dehumidify
All swamp coolers cool and humidify
Other than replacing/washing filters, they don’t require any ongoing maintenance
Swamp coolers need to be refilled with water every few hours
They use quite a bit of energy
Swamp coolers provide up to 75% energy savings compared to conventional ACs
ACs can cool to a very low temperature
Swamp coolers can cool a room but not to the same degree as ACs – don’t expect to feel chilly
Pros and Cons of A Swamp Cooler
Buying Guide: What To Look For in A Swamp Cooler
1. Size (CFM)
Sizing is essential when buying an evaporative swamp cooler. If you buy a cooler that's too large for the room, it'll make the air muggy and uncomfortable.
If the cooler is too small for the room, it will be nothing more than a fan.
Unlike air conditioners that are sized in BTUs, evaporative coolers are sized in CFM or cubic feet per minute. This refers to the volume of air they process.
A high CFM cooler passes more air through it, meaning it cools the room faster and can handle a large room.
There's actually a calculation for determining the right CFM depending on room size. Take the room's square footage, multiply it by the ceiling height, and then divide by two. That's the right CFM for the room.
Square Feet x Ceiling height / 2 = CFM
If you have a 300 sq. ft. room and standard 8ft ceilings, the right cooler size is 300 x 8 / 2 = 1,200 CFM.
Unlike BTUs, you don't have to be very strict with CFM. You can get away with a 500-800 CFM swamp cooler for a 300 sq. Ft. room. Just know that it will cool the room slower. But once the room gets cool enough, it'll easily maintain it at that temperature.
If you are not sure what size of cooler you should get, check the manufacturer recommendations. They'll usually list the maximum square footage the cooler can cool.
2. Indoor or Outdoor Use
If you want a swamp cooler you can use outdoors, look for one that's powerful enough to cool a large open space. It should have an airflow of at least 1,000 CFM.
Also, make sure it is designed to withstand the elements. It should be water and UV resistant.
3. Tank Size
The size of the water tank tells you how often you need to refill it.
If you want a swamp cooler that can last all night or all day, make sure the tank has a capacity of at least 5 gallons. Smaller 1-3 gallon tanks typically last 4-7 hours, depending on CFM.
4. Garden Hose Adapter
If the thought of refilling the tank every few hours doesn't sound fun, look for a swamp cooler with a garden hose adapter.
This allows you to connect a hose to provide a constant water supply.
Other Features to Consider:
A swamp cooler is not for everyone, but where it works well, it has many advantages over an air conditioner.
It cools a space to a comfortable level while using much less energy and making less noise.