Do Evaporative Coolers Need Water? How Much Water Do They Use?

Evaporative coolers are one of the most popular air conditioning appliances that provide the kind of cooling that people need in the summer. Due to their special cooling mechanism, they are best suited for dry regions.

This is because they add humidity to indoor air and can make things more comfortable in dry regions.

Evaporative coolers are portable, efficient and easy to use. They are also more affordable and cheaper to run than air conditioners, and this explains why they are popular.

If you’re considering getting an evaporative cooler, you may also be wondering why they are “evaporative” and if they need water to work, we’ll answer these questions and more in a bit.

Do Evaporative Coolers Need Water?

Yes, evaporative coolers need water. Let’s be clear about one fact; evaporative coolers need water for cooling, but it doesn’t mean they cannot function without water.

To understand this properly, we need to explore how an evaporative cooler works and why water is important. Evaporative coolers work on the basis of evaporation.

A typical unit will consist of a water reservoir, a fan, and a thick pad, among other elements and controls. The thick pads absorb water from the unit’s reservoir which the fan pulls in hot, dry air from the room and sends it across the pads.

This causes the soaked-up pads to evaporate. Basic evaporation is automated in this case and water vapor goes into the air along with air, adding moisture to the air and cooling it in the process.

This is why water is needed. The reservoir of the unit should contain water that is absorbed by the thick pad and then blown into the room as vapor for cooling. However, the unit can work as a mere fan without water; it just won’t provide the cooling that water offers.

How Much Water Do Evaporative Coolers Use?

You must, therefore, be ready to use up a lot of water if you decide to buy an evaporative cooler. It is more likely that you won’t be running the unit for 24 hours and that could also reduce how much water it uses.

Note that the water tank of each evaporative has its own size and to ensure the unit keeps providing cool air, you need to feel the tank as it empties out. As earlier said, there’s no one-size-fits-all in these situations.

The amount of water your unit depends on the size of the unit and its tank, the fan power and speed, as well as the room’s relative humidity.

How Long Does the Water Last in An Evaporative Cooler?

How long the water lasts in an evaporative cooler depends on how much water the tank can hold and how much water the unit uses. It is best to have units with large tanks, so you do not have to refill too frequently.

Imagine you have an evaporative cooler with a 3-gallon tank that uses about 2 gallons of water per hour. It means the water would last for about 90 minutes and you’d need to fill the reservoir after every 1½ hour.

If you have a larger tank, say about 6 gallons, that would give you up to 3 hours of use before a refill is required.

That’s how you know how long the water in your evaporative cooler would last. Get the size of the tank and how much water is used up per hour.

How Often Does an Evaporative Cooler Dump Water?

The average evaporative cooler dumps water every 6 to 12 hours. Whatever the case, the standard is a minimum of once every 24 hours. You may wonder why the appliance needs to dump water; it is mostly a mechanism to keep the water quality high.

Although the water is supposed to evaporate and be used, dumping will ensure microbial organisms and dirt are removed and the tank is refilled with clean water.

Sometimes too, some units dump the water after they are turned off, so you have to refill the tank when you turn them back on.

Here’s the logic. Imagine you use your evaporative cooler for only 1 hour after the last refill and then embark on a 6-day trip.

When you return, you’d get home to an evaporative cooler with 6-day old stake water which may have become contaminated by germs and bacteria. Turning on your unit that way would mean spreading the germs in the air and inhaling them.

But, when this water is dumped, you’d only need to refill with clean water and enjoy fresher air. This is common with units that feature a dump-style drain valve.

Can You Use an Evaporative Cooler Without Water?

Yes, you can but it’s just as good as using a fan. Without water, the unit will simply blow out warm air but will not provide cooling that your room needs.

But the most appropriate question would be whether it’s advisable to use an evaporative cooler without water. That would be No.

Without water, your room will be warm, and if you already live in a hot region, things can get really uncomfortable. It is better to use a regular fan than use an evaporative cooler without water.

Also, using an evaporative cooler without water can cause the unit’s motor to burn out, damaging your appliance in the process.

What Happens When an Evaporative Cooler Runs Out Of Water?

When an evaporative cooler runs out of water, it stops producing cool air and the room becomes warm.

Also, your motor may be affected over time because its operation is altered. When this happens, it is advisable to refill the unit immediately. You should turn off the evaporative cooler, remove the attached reservoir and fill it up as instructed.

Final Words

In conclusion, your evaporative coolers need water to work effectively and provide the cooling effect you desire in the summer.

The amount of water your unit needs to function properly and how long it lasts depend on a number of factors, including the size of the unit, relative humidity, as well as the fan power of the unit.

Note that an evaporative cooler can be the companion you need in the summer and can ensure you’re comfortable all day long at a very low operating cost.