How to Choose the Best Swamp Cooler

Mar 27, 2020

While not the most recent invention, swamp coolers have been gaining popularity in the last few years as an effective alternative to air conditioners and electric fans. There are so many options on the market now that it might be hard to choose one that will fit your needs the best.

In this article, you can find all the essential information about swamp (or evaporative as they are also called) coolers and things to consider when buying one. But first, let’s find out what exactly is a swamp cooler.

What Is a Swamp Cooler and How It Works

Swamp Cooler

You’ve probably heard at least one of these terms, and what both of them mean is a cooling device that uses water as a natural cooling agent. The working mechanism is pretty simple:

  • You fill up a container inside the cooler with clean water.
  • Moisture pads inside soak up the water.
  • A fan inside the device evaporates the moisture.
  • As a result, you get air that has been cooled down thanks to the water.

Benefits of using a swamp cooler

evaCHILL Evaporative Air Cooler

Swamp coolers provide a lot of benefits in terms of their efficiency, power consumption, and other properties. They are:

  • Energy-efficient. Unlike an AC (traditional, wall-mounted, or portable), swamp coolers don’t need a lot of energy to service the fan that evaporates water and cools down the temperature around the device. A high-quality evaporative unit can help you save up to a quarter of your monthly energy bill.
  • Effective at cooling down the air. Unlike a fan, swamp coolers lower the temperature in a room by as much as 15 degrees C (27 degrees F). It might be a difficult process to understand if you’re not into physics, but evaporating water cools down the air, of course, if it’s not hot water.
  • Good at humidifying the air. Swamp coolers use an additional source of water, so they don't evaporate water from the air, but from water pads inside the device. Thus, they humidify your space, which makes them so good for a dry climate. Remember that the optimal humidity for the indoors is from 40% to 60%.
  • Free of chemical refrigerants. Chemical refrigerants are only relatively safe and only as long as they are contained within a device. In the case of any leaks, you risk poisoning since refrigerants are odorless. However, evaporative coolers use water as a safe and effective alternative.
  • Easy to plug in and don’t require installation. Residential swamp coolers are portative and work from any place that has a working plug socket. Some models can be plugged into a power bank via a USB port or 12V car adapter, or they can even work on a battery.
  • More affordable than an AC. You can find a good evaporative cooler for under $200, which is easily a third of the price for a ductless mini-split AC system (without taking into account the cost of installation).
  • Eco-friendly:
  1. No heat is exhausted as a result of the evaporation process.
  2. Does not use any Freon-like liquids.
  3. Allows you to highly decrease the energy spent at your home or office.

Types of Swamp Coolers

In this article, we focus mostly on direct and residential swamps coolers, as they are the most mobile and convenient for the vast majority of people living in a dry climate. However, when you are busy choosing the best evaporative cooler for your space and needs, it’s good to know about all the types so you don’t confuse your options and go for the right type straight away.

All swamp coolers can be categorized as follows.

Вy technology:

  • Direct. This type is installation-free and ready to plug in right out of the box. Just add water into your device's water tank, power it, and it will start working a fan that vaporizes moisture to lower the temperature. Direct coolers also humidify the air, but not to the point of dampness, as it’s not the same process you’d get when boiling water.
  • Indirect. Unlike the previous type, this one uses a heat exchanger to evaporate water and almost doesn’t affect the humidity. However, indirect evaporative coolers require installation and work on two fans, thus consuming more energy.
  • Two-stage. This is a hybrid between indirect and direct cooling that uses both a heat exchanger and a water pad to cool down the air passing throughout the device.

By the field of application:

  • Residential. This type is made to service homes and thus is smaller in size with more portable options and can work from a power plug or a portable energy source such as a power bank or battery. Residential coolers can be indoor or an indoor/outdoor hybrid for cooling patios or camping sites.
  • Commercial. These are more powerful constructions meant for use on sports fields, farms, construction sites, hangars, and other large spaces.

The main differences in the types of coolers lie in the type of technology that vaporizes water and the size of the area they’re meant to cool down, but they also vary in the size of the device itself and the set of features it comes with.

Swamp Cooler Features

All residential direct swamp coolers have a water tank, moisture pads, and controls to power the device, but there’s also a set of optional features that some models can have. Here are the most common features intended to enhance your experience as a user of an evaporative cooler.

  • Cooling speeds. This refers to the force with which a fan inside a swamp cooler accelerates air throughout the device. Most models that have this feature offer three speeds.
  • Digital controls. As opposed to mechanical controls, digital ones offer you more control of how your device works. For example, you can set the temperature you want or set a timer, not just turn the device on and off or change speeds.
  • Remote control. Some swamp coolers have a typical remote control like in AC units, but more modern options use a wifi connection to control the device. You just need to download the manufacturer’s app and sync your swamp cooler to your phone.
  • Fill design. This refers to the water tank — some devices, especially the smaller ones, have a removable tank. In others the water can be poured in, and some models can be hooked to a direct source of water via a hose.
  • Timer. This is  also an optional feature and a handy one if you go to sleep with your cooler on and want it to switch off automatically or if you want it to switch on while you’re out so you can come back to a fresher home.
  • Air filtration. Some devices have additional filters that stop a portion of dust, smoke, and other particles from escaping back into the air, thus making it cleaner.

Things to Consider When Buying a Swamp Cooler

Which Swamp Cooler to Choose?

Aside from the availability of features you might need in a particular device, there are also some things up for consideration, defined by your room capacity and personal preferences. Let’s dive deeper into the topic and see what you should decide for yourself before buying an evaporative cooler.


Swamp coolers vary in size and weight, and those two characteristics don’t always coincide with how powerful a device is. Some lightweight options can effectively cool down a small room or your personal space, while some of the bigger models are just wasting space.

This point comes down to how portable you need your device to be. So if you want something you can carry around from one room to another or bring in a car to work or camping, go for a smaller size. In this case, be mindful of a device’s power (how much space it can cool down) or look into other points to help narrow down your choice.

Maintenance Level

Swamp coolers are fairly easy to maintain, but you do have to be diligent about it. So when you’re choosing a model, look at the instructions manual and the product details to decide:

How easy it is to clean

Most devices are prone to a buildup of bacteria, so you need to clean them regularly with a mild soap solution and sometimes even opt for an antimicrobial spray. Some models are made of high-quality materials that don’t cause bacteria buildup, so rinsing them with just water every time you refill the water container is enough.

What kind of filters it uses

Swamp coolers commonly use cellulose, fiber, or carbon filters. Cellulose filters are the least effective in filtering the air and need frequent changing, as they are organic and can get moldy if you don’t replace them on time. Fiberglass filters are a better option for trapping particles like dust that can cause allergies and affect the quality of the air. They can be washed but still require regular replacements.

Last but not least, some evaporative coolers use carbon filters meant to trap unpleasant odors in the air. As with the previous type, they need to be cleaned often and replaced regularly to maintain a good quality of air.

As you can see, most swamp coolers need to be washed quite often and need regular filter replacements. That’s why we have developed and patented evaBreeze — a non-organic material that offers a better surface for evaporation and doesn't allow for a buildup of mold or bacteria. Thus, it is easier to clean and can provide a better quality of air for a longer time.

Space That Needs Cooling

Small Space For Cooling

The next thing you need to consider is the space you want to cool down. All direct residential swamp coolers can be roughly split into three categories, by their intended placement.

  • Indoor: personal, living space, bedroom, den, etc.
  • Outdoor: patio, sunroom, garage
  • Other: car, camping

So if you want a device that will cool down just your personal space and one that you can carry around anywhere, a personal evaporative cooler that works from a power bank is fit for practically any situation. But if you want one for your garden, there are also options created specifically for the outdoors that you can leave in the open for extended periods.

Cooler Sizing

Finally, you need to properly size the unit to your needs. Sizing refers to the power and cooling capacity of a device. You might have heard of BTU rating, which is a means of measuring an AC’s efficiency. However, swamp coolers use CFM value for that.

How to calculate CFM

CFM stands for cubic feet per minute. To measure it, you need your room’s square footage, ceiling height in feet, and cubic feet.

Cubic feet = square footage * ceiling height

CFM = cubic feet / 2

So if your square footage is 50 feet and your ceiling height is 9 feet, you need a CFM value of 225.

Swamp cooler capacity

Here, we mean the cooler’s water capacity, which you would need to know if the manufacturer didn't specify CFM. Residential coolers rarely can be hooked up to a water source, so you can choose by capacity and space that needs cooling.

  • For small to medium spaces you need 3 to 7 gallons
  • For large spaces — 7 to 12
  • For outdoors — 12 to 16

Coolers that have 16+ gallon water capacity are usually used for commercial purposes and aren’t intended for homes.

Best Swamp Coolers

Now that you know about the essential criteria for choosing a swamp cooler, here are a few examples of the top options.

Evapolar portable swamp cooler

Evapolar Portable Swamp Cooler


  • Perfect for cooling personal spaces (home, office, car, etc.) up to 33 ft² or 4 m²
  • Decreases the temperature by 15 degrees C
  • Purifies and humidifies the air
  • Has a cartridge with a better surface area for evaporation, which makes it more effective than the alternative personal coolers
  • Patented evaBreeze® material for filters doesn’t build up mold or bacteria

And also:

  • It is made from high-quality plastic and doesn't smell.
  • It has a high cooling power considering it’s a personal cooler.
  • It has a cool lightweight design that fits any interior design and allows you to carry it around anywhere you wish.
  • It is reasonably priced (starting from $99).
Learn more about Evapolar

Bonair Durano window-mounted swamp cooler

Bonair Durano Swamp Cooler


  • Meant to cool big spaces (1900 feet²)
  • Has 3 speed settings
  • A good option for a garage or sunroom
  • Easy to install
  • Works from a remote control

But also some cons:

  • Has to be connected to a water source
  • Costs more than a lot of swamps coolers ($598)
  • More suitable for houses rather than apartments
  • Requires all doors to be open for the cooled down air to circulate further

Portacool outdoor swamp cooler

Portacool Swamp Cooler


  • Manufactured for outdoors
  • Meant for cooling 300 feet²
  • Has a water tank or can be connected to a water source

But also some cons:

  • Costs more than a lot of swamp coolers ($399)
  • Quite bulky (weighs 50 pounds)

Wrap Up

Evaporative coolers are an effective alternative to other cooling appliances if you live in a dry hot climate (or if you have dry summers) and a good option for the outdoors if you reside in a more humid climate. They purify, humidify, and effectively cool down any space while using a safer alternative to chemical refrigerants — water. It all comes down to your preferences in size, capacity needs, and features that will make your experience as a user exceptional.

If you’re looking for a portable option you can transfer from one room to another, you don’t even need to calculate each room’s CFM and decide which of the values to look for — an optimal choice would be to cool down just your personal space, and Evapolar is up for that job. With Evapolar evaporative devices you can effectively cool down the space around you without growing mold, and you can easily carry them around to find relief anywhere you go.