Swamp Coolers vs Evaporative Coolers: What’s the Difference?

Are you looking for an efficient and affordable cooling solution? If so, you’ve probably come across references to both evaporative coolers and swamp coolers. These devices are an air conditioning alternative that can dramatically cool the air with relatively low energy demand.

Is a Swamp Cooler an Evaporative Cooler?

You might be wondering what the difference is between evaporative coolers and swamp coolers. Which one will provide the most effective cooling solution? In truth, they offer the same results because they are the same machine.

There is no true difference between these two terms. “Evaporative cooler” is a technically accurate name that describes how the device functions. “Swamp cooler” is a somewhat derogative slang term that describes what can happen to an evaporative cooler if you don’t take proper care of it.

Evaporative Coolers: It’s How They Work

Evaporative cooler is a term that describes how this type of air conditioning (loosely defined) works. Evaporative coolers take advantage of the fact that evaporating a liquid requires considerable energy. When that energy comes from the air, the air cools down. It’s the same effect that lets your body cool down by sweating.

Evaporative coolers maximize this effect. They create a situation where hot air can evaporate a lot of water. This is accomplished using evaporative media that soaks up water like a high-tech sponge but also lets air pass through. When a fan pushes or pulls air through the evaporative media, a lot of this water evaporates, cooling the air.

With one pass through an evaporative cooler, the air temperature can drop by 30° F. This lets evaporative coolers provide effective climate control even when you can’t trap or concentrate cooled air for multiple passes.

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Swamp Cooler: Where’d the Name Come From?

If evaporative cooler is a technical description of how the devices work, swamp cooler is an evocative one – and what it evokes isn’t always pleasant.

Where did this name come from? As with many slang terms, nobody knows for sure. The common assumption is that the name refers to what happened to old-style evaporative coolers if they weren’t properly cared for.

Wherever there is standing water, there is potential for the growth of algae and mold. An evaporative cooler increases this potential by sucking in air that can be laden with additional resources for these microorganisms to feed on, including pollen, seeds, and other airborne debris.

To make matters worse, early evaporative coolers used evaporative media made of untreated wood wool and aspen wood fibers, also called excelsior. These fibers would degrade and break apart, falling into the reservoir, where they would mold and decay. This led to an evaporative cooler that looked and smelled like a swamp. So they were called swamp coolers.

How to Make Sure Your Evaporative Cooler Isn’t a “Swamp Cooler”

Kuul evaporative mediaThese days, there’s no reason why an evaporative cooler should fit the name “swamp cooler.” With modern materials and design, it takes only minimal maintenance to avoid odors and contamination of your evaporative cooler.

Modern evaporative media like Kuul Comfort® are cellulose pads – like a special form of paper. These are much better at absorbing water without breaking down into debris in your reservoir. In addition, they are treated to inhibit the growth of mold and algae.

To avoid odors in your evaporative cooler, take the time to clean the unit once a week. In most Portacool models, you can start by shutting off the water pump while running the fan. This dries out the evaporative media. Meanwhile, drain the reservoir. Take out the evaporative media and clean out the reservoir with soap and water. Rinse thoroughly and dry fully. Then replace the evaporative media, refill the reservoir, and you’re good to go.

Jetstream Series


Jetstream Series

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Cyclone Series


Cyclone Series

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Hazardous Location Series


Hazardous Location Series

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Discontinued Evaporative Coolers


Discontinued Evaporative Coolers

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Portacool 510


Portacool 510

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Apex Series


Apex Series

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How Efficient Are Swamp Coolers?

Swamp coolers can be very effective, but their effectiveness depends on the local climate and the efficiency of the “swamp cooler pads” (a common slang term for evaporative media).

Local Climate Swamp Cooler Effectiveness

Swamp coolers work by evaporating water into the air. When the water evaporates, it takes energy from the air, which cools the temperature. The effectiveness of this process depends on how hot the air is and how much water (humidity) is already in the air.

When the humidity is relatively low (say 20% relative humidity or less), portable swamp coolers are very effective, dropping the hot air temperature by up to 30 degrees. In this case, “hot” means 90° F or more. At lower temperatures and higher humidity, you will see less of a temperature drop.

At 2% relative humidity, a swamp cooler can drop 125° F air to 83° F. However, at 80% humidity, a swamp cooler can only drop 75° F air to 72° F.

These are, of course, theoretical potentials. The actual effectiveness of portable swamp coolers also depends on the evaporative media and access to fresh air.

Evaporative Media and Swamp Cooler Effectiveness

Evaporative media design can dramatically impact the effectiveness of portable swamp coolers. Ideally, you want a swamp cooler pad that absorbs a lot of water and puts that water into contact with moving air.

The best evaporative media help swamp coolers reach 95% of their theoretical effectiveness. Poorly designed evaporative media might achieve only half that effectiveness.

It’s also important to note that swamp cooler pads can degrade over time. Many evaporative media, such as aspen pads, degrade quite quickly. As they degrade, they lose effectiveness. Even the best evaporative media will lose effectiveness over time as they become clogged with debris. When possible, cleaning the inlet side of evaporative media is a good idea, as long as the media is designed to do this. Check the care instructions from the evaporative media manufacturer.

 Air Access Is Crucial to Swamp Cooler Effectiveness

Air conditioning units count on being able to recirculate air and cool it stepwise. Swamp coolers, on the other hand, depend on access to fresh, hot air to work. If you have an evaporative cooler that is only taking in already cooled air, its effectiveness will decrease because the air it’s drawing in is both cooler and more humid.

To be effective, a portable swamp cooler should have access to hot air, either by being positioned outside, being next to an open window, or having an external air vent.

What Is Better – A Swamp Cooler or Air Conditioning?

Swamp coolers and air conditioning units utilize entirely different processes to cool the air, and as a result, the right solution for you will depend on your specific application.

How Does Air Conditioning Work?

AC units use chemical coolants to remove heat and moisture from the air. Hot air is drawn into the system, where it is cooled by coils. A fan will then circulate this cooled air throughout the room(s) being cooled to achieve your desired ambient temperature. The heat and moisture that was extracted from the air as part of the chemical cooling process is then released outside through a ducting system.

Due to the way air conditioning works, you need a closed indoor environment to ensure your system operates at optimal efficiency. If you have an open window or door, the chemically cooled air will escape the room, forcing the AC unit to work harder to maintain your desired temperature.

How Do Swamp Coolers Work?

Swamp coolers, on the other hand, operate using an open system that relies on outside air to activate the cooling process. Hot, dry, outside air is drawn into the swamp cooler. When this air comes into contact with the evaporative media, it triggers the evaporation process, causing the air temperature to drop. Without a constant supply of hot, dry, outside air, the evaporation process will become much less efficient, and it will be harder to achieve your desired cooling effect.

So unlike air conditioning which becomes less effective when doors and windows are open, a swamp cooler requires access to an open-air source to maximize its effectiveness. Without the ability to keep a door or window open, swamp coolers aren’t a viable cooling option.

Which Cooling Solution Is Right for Me?

In general, air conditioning will be the better solution in situations where you don’t have access to an outdoor air source. This makes AC an excellent option to cool many homes. If you have access to an outdoor air source, swamp coolers will often deliver the cool, comfortable environment you want at a fraction of the cost.

Large swamp coolers can be installed to cool your entire home, but if you’re using portable swamp coolers, their primary application for residential cooling will be for outdoor patios or home workshops. Suppose you’re trying to cool an auto garage, airplane hangar, or a large industrial space such as a warehouse or factory, swamp coolers will typically be a more effective solution for several reasons:

  • These spaces typically have open doors or windows during working hours, making air conditioning impractical
  • The size of the space being cooled typically makes air conditioning too cost-prohibitive to be a viable solution

In addition, if you’re trying to cool an outdoor space such as a backyard, sports field, outdoor work environment, or a restaurant patio, outdoor swamp coolers will be the more practical option since this open-air source makes air conditioning impractical.

Why Is Air Conditioning More Expensive than a Swamp Cooler?

Swamp coolers are much less expensive to run than air conditioning because they are more energy-efficient. It only takes a small amount of electricity to run the fan drawing air through the swamp cooler. In contrast, AC units require a tremendous amount of electricity to run the compressor used to cool the air, the heat exchanger which pulls heat out of the air, and the fan circulating the chemically cooled air throughout the building.

Powering an AC system can take as much as seven times as many watts of electricity as is required to run a swamp cooler. As a result, your energy bill will be significantly higher. This increased energy cost becomes exponentially greater when you’re trying to cool a very large space, which is why air conditioning is often impractical for large commercial and industrial areas.

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Are Swamp Coolers Better than Fans?

portable standing fanFans are another popular cooling method, and you may be wondering whether this solution will provide more effective results than a swamp cooler. If you’re truly looking to cool the air to provide a more comfortable ambient temperature, there is no comparison. Swamp coolers are by far the more effective option.

Fans use blades to circulate the air in the room. They don’t actually cool the air temperature; instead, they simply push around the hot air. This will provide mild cooling benefits by speeding up the evaporation of sweat on your body. However, sweating is never comfortable, and the cooling benefits from sweat are relatively minimal compared with lowering the temperature of the air in the room.

Because swamp coolers can drop the air temperature by as much as 30° F, they can significantly reduce the ambient temperature in the room. This will not only allow you to maintain a more comfortable body temperature, but it will help you avoid sweating profusely on a hot day.

How to Use a Swamp Cooler

Portable swamp coolers are easy to use. The following steps will have your swamp cooler up and running in no time:

  • Fill the tank with cold water – The first thing you’ll need to do is fill the reservoir with cold water. Whether you’re using an outdoor swamp cooler to stay comfortable on your patio or cooling a large indoor space, an abundant supply of water is crucial to ensure your swamp cooler works properly. A water temperature of approximately 50° F will maximize your cooling efficiency.
  • Give the media time to soak up the water – Before turning on your cooler, the swamp cooler pads will need time to soak up the water. If you start running the cooler’s fan before the evaporative media has become saturated, no evaporation will occur, and you’ll just blow hot air around the room. To avoid this issue, make sure the pads soak for about 5-15 minutes before turning on the swamp cooler.
  • Prime the pads – While you’ll need to soak the media prior to running the fan, it’s also a good idea to prime the pads before using the cooler. To do this, simply pour water directly over the pads to moisten them up. This initial infusion of water will ensure evaporation will occur once you start running the fan, even if you haven’t allowed for a long enough soaking time to ensure the pads are completely saturated.
  • Point the fan at the desired cooling area – Make sure your swamp cooler is pointed at the exact location you’re trying to cool. This will ensure this area receives the maximum amount of cold air possible. Once you’ve positioned the portable swamp cooler properly, turn it on and enjoy the cooling benefits.

How Well Does a Swamp Cooler Work? Tips to Achieve Optimal Cooling

The secret to getting the most out of your swamp cooler is knowing how to use it properly. While the instructions above will help you get the evaporative cooler running, the following tricks will ensure it operates at peak efficiency to maximize the cooling benefits you receive:

  • Open the windows – If you’re used to running air conditioning, this tip will seem counterintuitive, but it goes to show the difference in the way air conditioning units and swamp coolers work. Air conditioning is most effective in an enclosed space without access to outdoor air. Swamp coolers, on the other hand, require a steady stream of fresh air to operate at optimal efficiency. This is because the evaporation process introduces additional moisture into the cold air being circulated from the swamp cooler. Over time, this will make the room being cooled more humid, which will reduce the effectiveness of the swamp cooler. You can avoid this problem by opening the windows to draw in dry outside air that will be more effective for the evaporation process. If you’re using your swamp cooler in a large garage, workshop, or industrial space, make sure the door is open to provide access to the hot, dry air your cooler needs.
  • Use a dehumidifier – If you live in a very humid environment, are experiencing unusually high levels of humidity in an arid climate, or simply feel it’s too hot to keep the doors and windows open, you can improve the efficiency of your swamp cooler by using a dehumidifier in the room. Dehumidifiers pull moisture out of the air, lowering the humidity in the room. For best results, point the dehumidifier directly at the swamp cooler intake grill. This will ensure the driest air is being used to cool your space.
  • Don’t use ice – Because cold water provides for more effective cooling than hot water, many people think that adding ice to the reservoir will improve cooling efficiency. However, this will actually make your swamp cooler less efficient since the ice will have to melt before it can evaporate.
  • Add plants to the room – You can augment the benefits of your dehumidifier by adding plants to the room. Houseplants will absorb moisture in the air, keeping the room a little drier. This will help your swamp cooler operate at maximum efficiency.
  • Purchase the right-sized swamp cooler for the room – Portable swamp coolers come in a wide range of sizes. Make sure you do your research and choose the right size cooler for the space you’re cooling. A swamp cooler that is too small won’t cool the room effectively, and one that is too large may make the room too cold. Portacool evaporative coolers come in a wide range of sizes to ensure we can address your specific needs. Use our tool to find the right Portacool for your application.
  • Experiment with the position of your swamp cooler – One of the benefits of portable swamp coolers is that you can easily move them around to deliver cooling in the precise area you need it. Experiment with placing the cooler in different locations around the room to maximize the cooling efficiency for your specific needs.

Can I Run My Swamp Cooler All Day?

You can run your swamp cooler all day as long as there is a consistent flow of water running through the cooler. Depending on the specific evaporative cooler you’re using, this may require you to monitor the cooler and refill the reservoir whenever it runs low. However, certain swamp coolers allow you to hook it up to a water supply, ensuring it will never run out of water.

All Portacool evaporative coolers come with hose hookups to allow for continuous water flow. In addition, all of our models have an automatic shutoff when the water level in the reservoir drops below a certain threshold, ensuring you won’t damage your evaporative cooler. These features allow you to run your cooler all day without concern.

One of the benefits of swamp coolers is that they are extremely energy efficient. As a result, it costs significantly less money to run your swamp cooler all day than it would to run air conditioning all day. This will help keep your energy bills down during the peak heat of summer.

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Portacool Evaporative Coolers Maximize Effectiveness

If you are looking for a way to keep cool in poorly insulated spaces, near heat sources, or outdoors, Portacool evaporative coolers are a great option. Well-designed to supply fresh air with only minimal maintenance, you will never have to describe them as “swamp coolers.”

Portacool uses Kuul Comfort evaporative media, which are highly engineered and utilize the best materials. This lets Portacool units achieve close to the total theoretical potential of our evaporative coolers. The media is very durable and does not lose effectiveness quickly so that you don’t have to replace it very often. In addition, Kuul evaporative media is specifically designed to be used with Portacool evaporative coolers, ensuring the best possible results.

Portacool evaporative coolers have powerful fans that can suck in a high amount of outside air to cool vast spaces.

In addition, Portacool evaporative coolers have been made in the US since 1990. We offer best-in-class warranties and customer service to help all Portacool owners be happy and satisfied with the effectiveness of their evaporative coolers.

Visit a local or online retailer for Portacool evaporative coolers to learn which style might be most effective for your application.


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