Portable Evaporative Cooler Guide: How It Works!

A portable evaporative cooler or swamp cooler can be used just about anywhere, but it’s most effective in climates where there is low humidity and the air is hot. There are different types of coolers, but they do the same thing, and that is combine a cool, steady breeze with water’s cooling properties to reduce the indoor temperature.

While the general functions of an evaporative air conditioner are the same, there are differences in the way these products work and you must account for this. By knowing how these coolers operate you’ll have a better idea of what to look for.

How Portable Evaporative Cooler Works

Portable Evaporative CoolerA cooler reduces the indoor temperature by fusing together water’s cooling properties with an effective air moving system, and this combination can lower indoor temperature by up to 30 F. That in short is how these devices work, but the more advanced models  increase moisture to prevent wood and fabrics from getting dry. Evaporative cooler pads also perform a specific function, and that’s to act as a filter and remove allergens and dust in the air.

The last point is worth stressing out: when people shop for these coolers the first and often only thing they check is its cooling capability. However you must not overlook their ability to remove dust and allergens in the atmosphere especially if you or someone in the household has a respiratory condition.

If you’re still not convinced that you need a cooler, consider the following benefits:

  • The breeze can reduce room temperature by up to 6 degrees
  • These coolers purify the air and remove smoke, pollution and contaminants
  • Does not damage the ozone layer
  • Energy efficient

Comparisons with Air Conditioners

These coolers do not compete against air conditioners and can actually be used to complement them. You don’t need an AC to use these however, as they can be your only cooling system. But you must not use a cooler and AC at the same time because one reduces humidity and the other adds to it.

Optimizing Coolers

Every ducted evaporative cooler comes with a user manual that explains how to maximize its output. In general they are most potent in places where the temperature is high and humidity is low. Because of the way coolers are built, they’re not as effective during the rainy season or in cold climates. The amount of humidity these coolers provide depends on the design and manufacturer so it’s something you need to research.

Types of Coolers

There are several kinds of coolers available:

  • Portable Coolers: these are the focus of this guide simply because they are very convenient. Unlike other coolers, they can be moved from room to room without any fuss, and yet they can cool a room up to 300 square feet.
  • Down Discharge Coolers: these coolers are installed on a roof and release the cooled air down in your home. These are usually large enough to cool down an entire house.
  • Mobile Coolers: these are bigger than the portable types and are often used in garages, warehouses, job sites, patios and generally any outdoor setting.

Cooler Pads

Cooler PadsThere are many types of evaporative cooler motors, but coolers are ore distinguished by the kind of pad they use. There are basically two types: those made fiber (different materials) and rigid media.

Fiber pads are affordable but more maintenance is required and replacements are necessary. Rigid media pads cost more but they don’t need as much maintenance, and if properly kept will last for years.

Fiber pads:

  • Made up of either cellulose fiber, synthetic fiber or Aspen wood shavings
  • Aspen wood is the most durable
  • 1 to 2” thick
  • Economical

Rigid Media Pads

  • About 8 to 12” thick
  • Needs lower maintenance
  • Has a long lifespan if properly maintained

Sizes and Shapes

These coolers come in different shapes and sizes, but the one thing you’ll notice is that the portable units are the most compact compared to the rest. While a small footprint is nice, you should also check the capacity of the unit, meaning the space (in square feet) that it can cool down.

What are the CFM Ratings?

The CFM ratings (cubic feet per minute) are used to determine how much airflow a cooler can move. To find out the CFM for your home, do the following:

  1. Calculate the square footage of the room you want to cool
  2. Multiply the sq. ft. by the ceiling’s height.
  3. Divide the figure by 2. The result is the CFM for the cooler you require.

Maintenance Issues

Maintenance IssuesThe best thing about a portable unit is the fact that they’re easy to maintain, provided of course, that the unit is made of sturdy material and corrosion resistant. The majority of portable coolers sold today are built to last, but read the manual for directions on maintenance and how frequent the inspection has to be.

The rule of thumb is you should inspect the unit once a month. The maintenance process varies, but usually all you need to do is drain the water and get rid of any minerals that might have accumulated. If you’re not going to use the cooler for a few days, it’s a good time to perform a thorough cleaning and prevent bacteria from building up.


There are many accessories you can add to a cooler such as a purge pump so water is purged automatically every 6 or 8 hours. Or you can add ceiling cents to allow the exhaust to pass through the attic and into the roof vents. This is a good option if an open window is a security worry for you.


Buying a portable evaporative cooler is no longer as difficult as it used to be thanks to the advent of online shopping. However the fact that you have several options can make the process more challenging especially if you’ve never purchased one before. But if you follow the guidelines above you’ll be better informed.

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