Helpful Swamp Cooler Features for Outdoor Use

swamp cooler refreshes an outdoor market

Swamp coolers, also know as "air coolers" or "desert coolers," are a kind of evaporative cooler — simple devices that combine air and water to provide lots of cooling in hot, dry conditions. There are a number of swamp cooler features that make them more portable — great for outdoor cooling, more efficient, easier and safer to use.

Simply being aware these options are available puts you in a position to make a better decision about your purchase.


Some swamp coolers connect to a hose for a continuous source of water. Some have an optional hose / tank set-up. If you'll be where a hose cannot reach, these can attach to a portable tank, instead, making them more portable. You will still need a source of electricity, though. Using a generator would make a tank-fed swamp cooler usable almost anywhere.

Portable swamp coolers are mounted on casters so they can be wheeled from place to place. Heavier units will have wider casters. The wider the caster the easier it will be to move the unit over uneven ground, such as dirt or grass. Look for casters with locking wheels. You might want to use a separate wheeled frame or dolly to move smaller units across uneven ground.

Tanks generally hold enough water to last for a few hours of mild weather. Keep in mind that hotter, drier weather will use more water per hour. Be prepared to refill the tank as necessary. You may need to consider having an extra supply of water. Separate, portable tanks of up to 50 gallons / 190 litres and more are easily available and come with wheeled frames for portability and water lines that you can hook up to your evaporative cooler.


There are a variety of air filters available to fit most swamp coolers. Carbon filters help eliminate odors. HEPA filtershelp filter out particles from the air such as dust, pollen, and pet dander (these can be especially helpful for asthma and allergy sufferers). Filters can also extend the life of the pads by reducing the amount of particles that can clog or damage them. Look for sizes that will fit in your unit.

Inspect your unit's filters from time to time. Clean or replace them when they start to get clogged since clogged filters can lower the cooling capacity of your unit.

Fan Only Option

This allows you turn off the evaporative part of the cooler and just use the fan. This swamp cooler feature can be great to provide a cooling breeze when the weather is too humid for evaporative cooling. The fan without evaporative cooling can cool an area by 4 - 8°F / 2 - 4.5°C.


This setting lets the water run before the fan turns on. If the fan starts at the same time as the water pump, the fan will start blowing hot air before the pads have a chance to fill with water. But with this setting, the pads fill with water first. Then when the fan starts, the air from the unit will immediately be cool.

Thermostat / Timer

A thermostat control can turn the cooler on when the area you want to cool reaches a certain temperature. It can also be set to turn off when the area cools down to a certain temperature. Similar to this is a timer control which turns the unit on and off automatically at certain times rather than at certain temperatures. Both the thermostat and timer can save energy by limiting your cooler's use to when you need it most.

Water Level Sensor

This swamp cooler feature senses when the water level is low and alerts you with a sound or light. This is especially helpful if you need to refill the tank manually.

Water Purge or Flush

An automatic "water purge" or "flush" control works together with a drain valve to periodically remove the recirculating water from the system and replace it with fresh water. This valuable swamp cooler feature can prolong the life of your cooler and help keep it clean.

Bottom threshold of human hearing 10dB
Recording studio 20dB
Quiet living room 30dB
Quiet office or library, refrigerator 40dB
Quiet conversation 50dB
Average office noise, clothes dryer 60dB
Average conversation, dishwasher 70dB
Average factory 80dB
Typical home stereo volume 90dB
Heavy truck 100dB

Noise Level

Most swamp coolers run fairly quietly. Their pumps and motors aren't very large and they don't use a lot of electricity. But some are built to run more quietly than others. And if you need yours to be especially quiet -- if you'll be running it when people are sleeping, for example -- the noise level may be important to you.

Some manufacturers use a decibel rating (dB) to give you an idea of the amount of noise you can expect from their cooler. But there are a lot of variables involved with how a cooler makes noise.

The noise from a cooler can be made by many things: the motor spinning, the motor's own cooling fan inside the enclosure, the fan blades moving, the pump operating, the water trickling through the unit. Running a cooler on a low setting or fan only will be quieter than the same fan running on high with evaporation.

Even the way it's installed can make it louder or quieter, which is something a manufacturer cannot predict. A unit installed on packed earth or solid rock may make less noise than a unit installed on a raised metal platform.

Consider the quality of the cooler's sound as well as its volume. Different frequencies produce different tones, even at the same decibel level. A loud, low rumbling sound may not be as noticeable as a quiet, high whistling sound.

So just use dB ratings to get a general idea of the fan's noise level.

Here's a chart of decibel ratings and the typical sound to which they compare.

Air Flow - Direction

Being able to adjust the direction of the air flow can help you place the cool air exactly where you need it. If people tend to gather around a certain part of the area you are cooling, perhaps a table or seating area, adjustable louvres can help you direct the main flow of cool air toward that are without moving the cooler.

Ducting adapters can be installed onto some units for the same purpose.

Some swamp coolers have an oscillating feature, which means they swivel back and forth to cool a larger area. This changes the direction of the air flow. Even though the amount of air flow doesn't change, it moves, intermittently covering more area than if it were still.


Multiple speed can help you fine tune your cooling and energy use. Low speeds are great for days with milder weather or at night. Low speeds use less electricity and water than high speeds, sometimes saving over 50%. Low speeds are also quieter -- better for sleeping and other activities that may require especially quiet environments.

Use high speeds during the hottest hours of the day or when you need to quickly lower the temperature, such as when the unit has been off for several hours.

Cabinet Color Options

Swamp coolers can get really large -- 3 feet / 1 meter vertically and horizontally is not unusual. After all, they contain the workings to move a lot of air and hold many gallons of water. A simple thing like color options can help it blend in with its environment or emphasize its technical and functional appearance.

Interested in learning even more?

  • To learn more about other outdoor cooling solutions that use evaporation, see our page on evaporative coolers.
  • Visit our other pages on swamp coolers.
  • To compare swamp coolers with other outdoor cooling solutions, visit our

    comparison page.

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