Does An Air Conditioner Use Water?

By Nick Evans •  Last Updated: 08/10/21 •  5 min read

Does a home air conditioner use water? What about commercial units?

If you’re wondering how air conditioners work, you’re in the right place! In this article, we’ll discuss:

  • Does an air conditioner use water?
  • Are air conditioners connected to water?
  • How much water does an air conditioner use?
  • Why do air conditioners go through water?
  • Do refrigerated air conditioners use water?
  • Why do air conditioners throw water?
  • Can you reuse water from an air conditioner?
  • Do commercial air conditioners use water?
Does An Air Conditioner Use Water

Does an Air Conditioner Use Water?

Your average home air conditioning unit does not use water, but instead uses an air-cooling system. Hot air passes through coils in the machine and is cooled using refrigerant.

Air conditioners that use water are difficult and expensive to maintain, therefore not suited to your average household. However, they are more efficient than your regular home unit, and thus great for business or industrial use.

For this reason, many commercial units do use water. If you own or work at a business, you might be maintaining an AC unit that uses water.

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Are Air Conditioners Connected to Water?

Home air conditioners are not connected to water, though commercial units might be. If your home AC unit is leaking water, it’s likely due to technical problems.

Home air conditioners will produce water due to condensation as they cool the air. This is typically drained outside of your home or into your plumping, depending on the type of air conditioner you have.

Leakage inside of your home is abnormal and means your unit needs to be repaired. This may occur for any of the following reasons:

Window units are typically exposed to the elements. A window unit exposed to rain or snow may have water dripping off of it for that reason as well.

How much Water Does an Air Conditioner Use?

The amount of water an air conditioner uses will depend on the type of AC unit you own.

You can expect a home air unit to produce between 5 and 20 gallons of water through condensation, which will drain outside of your home.

Luckily, air conditioners have become much more efficient over time. AC units today are up to 50% more efficient than those in the 1970’s.

Why do Air Conditioners go Through Water?

Home air conditioners don’t go through water, though it may seem like it due to the cooling process producing condensation inside of the machine.

This condensation then drains through the AC unit and outside of your home. Sometimes, technical issues such as blockages in the drainage system can cause the unit to leak water into your home as well.

Do Refrigerated Air Conditioners Use Water?

Refrigerated air conditioners do not use water. Instead, refrigerant is used to cool hot air that enters the machine. Once the air has been cooled, it’s dispensed back into your home. This is how the typical home unit works.

These machines can also do something known as reverse cycle air conditioning, which is when the same unit is used to heat the air in your home as well as to cool it.

Why do Air Conditioners Throw Water?

While home window units don’t use water, they do create condensation which typically drains from the air conditioner on the outside.

If this is leaking inside of your home, it’s likely due to a blockage in the drainage system. The unit should be repaired or replaced.

Other causes for an air conditioner throwing water include:

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Can You Reuse Water from an Air Conditioner?

Thrifty or environmentally-conscious people may wonder if you can reuse water from an air conditioner. Is it safe to drink?

Humans and pets should not consume water from AC units due to possible contaminants such as mold or bacteria. You can use it to water your plants so long as it hasn’t been treated chemically in the past few weeks.

Do Commercial Air Conditioners Use Water?

As discussed above, many commercial air conditioners do use water. AC units that use water can be:

The tube-within-a-tube units are typically least expensive, while shell and tube units tend to be most expensive.

These designs are fairly self-explanatory, but below we’ll talk about exactly how they each work.


In this design, the interior tube contains water while the exterior tube contains refrigerant. As the refrigerant and water flow through the tubes, the refrigerant is cooled by the water.

Shell and Coil

These units contain a copper coil within a “shell.” As with the tube-within-a-tube, there is water flowing within the coil and refrigerant flows through the shell from top to bottom. The water then cools the refrigerant.

Shell and Tube

Many copper tubes sit inside of one shell in these units. This makes them expensive to run, but better at cooling very large spaces.

As with the other designs, water runs through each of these tubes. Refrigerant flows through the shell from top to bottom, with the water in the tubes cooling it as it reaches the bottom of the shell.

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