Also called “swamp coolers” Evaporative Coolers operate by passing air over water-saturated material, evaporating the water. The act of evaporation reduces the air temperature by 15° – 30° before it is directed to an area you need to be cooled.
Evaporative coolers are most often used in place of air conditioners in climate zones that aren’t very humid. But for outdoor spaces, you can pick up a portable unit that can be effective for cooling the air temperature quickly and efficiently for hundreds of feet depending on the unit size.
Before purchasing a unit, you may want to know how these things work and what kind of cost they entail. I’ll explain things in greater detail below.
How Do Evaporative Coolers Work?
Evaporative coolers rely on a steady stream of circulation from the device to the area they are needed. The basic principle is that hot air is passed over water-saturated pads (kept saturated by pumps), forced to evaporate, cooling the air. The air is then forced by fans to the area it is needed while hot air is displaced out of the area.
In an enclosed space, cool air from the machine should be allowed to push the hotter air out of that area. So if your space is enclosed, there still needs to be an opening available for hotter air to escape.
Where and How Are Evaporative Coolers Installed?
For coolers used in an enclosed space, there are two possible scenarios, here. The cooler can be installed using ductwork that can move the cool air to multiple locations. Or, the cooler can simply be installed in a central location and the cool air is blown outward.
In an outdoor living space, the portable version of these evaporative coolers can be moved to where you want the air to be cooled and focused. No installation is needed at all because these things are usually on wheels. Access to outdoor air (warm to hot) actually makes the cooler more effective. Because this works to condition the ambient temperature, the effect can be felt hundreds of feet away.
These things are welcoming additions for pavilions, covered patios, and especially event tents.
How Much Do Evaporative Coolers Cost?
According to energy.gov, evaporative coolers are quite energy-efficient. Evaporative coolers cost about one-half as much to install as central air conditioners and use about one-quarter as much energy. Of course, we’re talking about outdoor living spaces here, so you probably won’t be installing a unit so much as choosing a portable unit to be used.
Portable units can be purchased at big-box stores for a little at $130 each. You can go up from there, but the portables are going to be cheaper for the most part. I’ve seen some units reach up to $1500. If you have a system installed internally that can obviously cost a lot more. But we’re discussing our outdoor living spaces here, not indoor.
What Are the Benefits & Drawbacks of Using Evaporative Coolers?
Evaporative coolers are not a good choice for very humid climates. Why? Because they actually add humidity to the air. The airflow needs to be increased for cooling in humid conditions. Because I live in the South East United States, these kinds of cooling systems really aren’t recommended.
However, these machines use very little water compared to other activities that use water. If you live somewhere that has water restrictions, it may not always be an efficient choice of cooling.
Thanks to a lot of sediment build-up, you’ll need to drain and clean your cooler regularly. The pads and the cooler itself can suffer from a build-up of salts and minerals if your area has hard water. Pads and filters both need to be changed regularly, especially if the unit is being run continuously.
They also need a more detailed cleaning at least once per season, if not more depending upon how often they are used. This is especially true when you use outdoor coolers that may get insects caught up inside of them that could grow mold.
The whirring sound tells you it’s working right, anything else means, you may need repairs. The motor creates noise when it runs and so does the pump. There are also multiple fans that push the air out of the unit. All of this together can make for some noise, but it’s not anywhere near as loud as standard air conditioning units. Therefore this may be a benefit.
I’ve also been told that swamp coolers are mosquito deterrents. Why? Flying insects aren’t keen on moving air that’s not the natural airflow they are accustomed to.
It’s Up to You
So, what do you think? Is this the type of cooling you want for your outdoor living space? I know I’m curious to try these things. I’ve seen plenty of concerts and restaurants with outdoor seating use them. Swamp coolers are energy efficient, less expensive than misting and turbo cooling systems, more portable, and according to even federal standards, seem to do the trick.