How Often Should An Evaporative Cooler Dump Water?

You have an evaporative water cooler and want to know if it is working properly. An evaporative cooler can dump water. If there is a problem with your evaporative water cooler, you may need to contact someone for service. You want some assurance that your water cooler is dumping at the appropriate time, so we've done the research for you. Keep reading to get all of your questions answered.

An evaporative cooler should dump water every six to 12 hours if it has a dump-style drain valve. It should also dump when it turns off. The minimum standard for dumping water is once every 24 hours.

There are different kinds of evaporative coolers, including direct and indirect. Direct evaporative coolers may also be referred to as swamp coolers. There are some differences in how these coolers operate and their level of efficiency. You may want to learn more about evaporative coolers, including whether they leak water and how much water they use in a day. This post will give you all the details you are looking for.

An air humidifier placed on the side of the bed, How Often Should An Evaporative Cooler Dump Water?

How Often Should An Evaporative Cooler Dump Water?

The amount of water that an evaporative cooler uses depends on the humidity in the air and the fan's speed. The water that goes into the reservoir will evaporate, so it might not be clear why it is necessary to dump water so frequently. This is actually a strategy to control microbial spread. In order to control microbial spread, your evaporative cooler should dump water every 72 hours. In practice, the recommended minimum is to dump the water once every 24 hours.

There are three different ways that your evaporative cooler can be set to dump water as needed:


This is the best option for saving water. The automatic dump will occur when a preset conductivity level is reached. This will ensure the cooler operates at a high rate of efficiency. The cooler will only dump some of the water in order to reach the preset conductivity level.


This method is found to be wasteful of water. The measured option will dump the water after a certain amount of water has been evaporated through the system. The volume of evaporated water is not an efficient way to dump as it usually dumps too frequently. If you don't use your cooler for a few days, then this dumping strategy will not dump as frequently as it should.


The timed strategy will dump water for a certain period of time after the cooler has turned off. This strategy is also found to be wasteful of water. It is a more effective strategy than the measured dump, however.

Do Evaporative Coolers Leak Water?

There are three possible ways for an evaporative cooler to leak water. The water pad might be the wrong size or installed crookedly, which will cause water to leak through. The water lines connected to the cooler may have a loose valve or break, which would cause a water leak. If you have a metal cooler, then it is expected to rust over time. When the rust gets bad enough, then it will cause water to leak through. This is an indicator that it is time to replace your evaporative cooler.

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How Much Water Does An Evaporative Cooler Use Per Day?

The water consumption of an evaporative cooler varies based on the amount of humidity in the air and the fan speed. Portable coolers use up to a gallon an hour. A central system can use up to seven gallons per hour. You can complete the math equation to determine how many gallons per day based on the number of hours you run your evaporative cooler.

At seven gallons per hour for 24 hours, the cooler would use 168 gallons of water per day. Some people do decide to run their evaporative coolers around the clock, but it is likely that you will not need to run it for 24 hours every day.

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Can You Leave An Evaporative Cooler On Overnight?

Yes, it is possible to leave an evaporative cooler on overnight. It is common for some people to leave the cooler on continuously for a 24-hour period. There is no issue with the system running continuously, but you may wish to consider leaving it on overnight if you live in a humid climate. Direct evaporative coolers, or swamp coolers, will add humidity to the air. For dry climates, leaving the system on overnight will not cause your home to become too humid.

Do Evaporative Coolers Humidify The Air?

Direct evaporative coolers will increase the relative humidity in the air of your home. These coolers are also known as swamp coolers. This does not mean that evaporative coolers cannot be used in high humid areas, but it does mean your home will have increased humidity. It may not be the best choice in high humid areas. Indirect evaporative coolers use another method and are not connected to the outside. These evaporative coolers do not humidify the air.

If you live in a dry area, then adding humidity to the air is a bonus. There are several benefits to having a higher relative humidity in your home. This includes improved air quality along with benefits for your hair and skin. Dry air can have negative effects on the wood in your home, and adding humidity can help prolong the life of your home floors and walls. For more information, check out "Should You Use A Humidifier In The Summer?"

If you live in a humid climate, then you may want to consider an air conditioner unit instead. An air conditioning unit does not add humidity into the air, but it does passively remove humidity from the air. This does not work the same as a dehumidifier because the moisture can return back to the air within your home. For more information, check out "Does Air Conditioning Add Moisture To The Air?"

What Is The Difference Between Direct And Indirect Evaporative Cooling?

Direct evaporative coolers run air through a water-soaked pad, which cools and filters the air. It also adds humidity to the air of the home. An indirect evaporative cooler has a separate heat exchanger that prevents the moisture from entering the air stream that filters into your home.

Homes in dry climates may benefit from the increased humidity that comes from direct evaporative cooling. These units are also known as swamp coolers. They are the preferred choice for dry climates because air conditioners will remove moisture from the air.

Areas with more moisture in the air may decide to use indirect evaporative cooling or an air conditioning unit. The evaporative cooling system will be more energy-efficient for all climates. The indirect evaporative unit will have no effect on the relative humidity of the air the enters your home as opposed to air conditioning units that will remove some of the humidity from the air.

In Closing

Evaporative coolers may dump water automatically, which is considered the most efficient way to cool your home and conserve water. The other two methods are by timer or by measuring the amount of water that has evaporated. Both of these methods are considered inefficient uses of water. Evaporative coolers should dump water every six to 12 hours when set to automatic, but the minimum standard is for the water to be dumped once every 24 hours. In order to prevent microbial spread, the water needs to be dumped every 72 hours.

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