Do Air Conditioners Use Water To Run? (Solved)

You may be thinking about buying an air conditioning unit and are not sure if AC units use water.

Figuring out which air conditioners use water to run is confusing, and you don’t want to be surprised after making a purchase.

This article will break down for you the question, ‘does AC use water’ and show how different cooling appliances use water to run.

Do Air Conditioners Use Water To Run? (Different Types Explained)

Air-cooled AC units do not require water to run because they pull outside air to cool their condenser. However, water-cooled air conditioners do need water to cool the condenser.

Most residential air conditioners are air-cooled and do not use water. These devices produce water as a result of condensation, but water is not added as part of the cooling process.

Industrial air conditioners and some portable units are water-cooled. Instead of using a refrigerant, these systems use water. There are two types of water-cooled systems: chilled water and cooling tower.

GE Window Type Air Conditioner Above a Table with a Tablet and Coffee

Do Window AC Units Use Water To Run?

No, these small residential units do not use water to run. Instead, window units work by pulling cool air into the machine through the intake vent, cooling it inside the unit with coils that contain refrigerant, and blasting the cold air into the room through the exhaust vent. An air filter usually removes small particles from the incoming air before it is blown into a room.

Do Central Air Conditioners Use Water To Run?

No. Central air refers to residential air conditioning with the AC unit kept outdoors with cool air distributed throughout the home. These units use air-cooling. A thermostat controls temperature, and refrigerant flows through copper tubes that absorb heat from the air.

Central air conditioning is considered more efficient than space-cooling units because the system is designed to handle cooling for an entire house. This means that it can condition a large amount of air at one time, so it doesn’t have to run nonstop.

A central air conditioning system has multiple indoor and outdoor components working together to control temperature and humidity levels. For example, an outdoor and indoor unit work together to bring cool air into a building, while a whole-house fan can help circulate that air through each room.

Do Portable Air Conditioners Use Water To Run?

If there is no way to vent hot air from a structure, a water-cooled portable AC unit is the best option. An air-cooled unit is best if a window is available for venting and there is no convenient water source nearby.

Water-cooled units are more efficient because they only use one fan, whereas air-cooled units use two. Also, water-cooled units do not output hot air if venting is blocked.

Do Commercial Air Conditioners Use Water To Run?

Yes, many large-scale commercial and industrial air conditioning systems use water to run. We have available chilled water systems and cooling tower air conditioners.

Chilled water systems use cold water running through metal coils to pull heat from the air. Then, the heated water is pumped outdoors. Chilled water cooling appears in residential applications, but it’s mainly used in commercial settings.

A cooling tower improves system efficiency by delivering smaller amounts of cold water through coils consistently. Only as much water is needed to cool the air, preventing waste. Cooling towers do not have residential applications.

How Much Water Does An Air Conditioner Use?

Air conditioners are much more efficient than units produced decades ago, but heated water is still a byproduct of the cooling process.

Depending on humidity, a residential central air conditioner can drain up to 20 gallons of water a day. A dehumidifier is often coupled with air conditioning to bring indoor humidity to ideal levels in highly humid climates.

Water should only be seen draining outside. If water is collecting indoors, there is a block somewhere in the condensation output.

Window units function the same way on a smaller scale. A condensation tube should drain hot water outside. A window AC can discharge up to two gallons of water daily.

Water-cooled systems have a drip container that must be emptied when it fills with condensation. This will obviously happen more frequently in humid climates.

Air-cooled portable air conditioners vent out of a window, so no internal container is there to worry about.

Commercial systems can account for up to 50% of a facility’s total water use. Depending on the size of the facility, this can be a massive amount of water. Many building managers do not know how much water the HVAC uses, resulting in inefficiencies.

Commercial Central Air Conditioner on Top of Building

Can An AC Run Without Water?

Yes, air-cooled systems can run without water. These systems use a liquid refrigerant instead of water to cool air. Water-cooled systems will not function without water.

People Also Ask (FAQ)

Why is my air conditioner putting out so much water?

Humid conditions will increase water output as the AC unit draws heat from the air. Air with high moisture content will result in increased condensation.

If you’re seeing water collecting indoors, the condensation tube may be blocked. Air conditioning systems generate condensation, so if there is no way for the excess water to drain away, it will drip off the unit and collect wherever it falls.

How do I get water out of my AC unit?

If water is collecting in your AC unit, you likely have a clogged drain line. The line can be cleaned with a small brush, and a wet/dry vacuum can be used to suck out any residue.

Will water damage my AC unit?

If water is drained correctly, it will not damage your air conditioner. However, bacteria can settle and cause mold or mildew growth if the drainage line becomes backed up or blocked.

Rain should not damage an outdoor unit. Problems occur when a unit sits in deep standing water, such as after a flood. The longer the unit sits submerged, the more likely components will be damaged.

How can I reuse my air conditioner water?

Water from air conditioners can be directed to a garden or potted plants. Use the water for a birdbath or outdoor pond. This water can be used to clean floors and windows.

Do not consume this water because the inside of the air conditioner is probably quite dirty.


Air conditioning use will only continue to increase as the planet grows warmer. Water use will also increase as water-cooling becomes more efficient. Determining which AC units use water is a challenge, but hopefully, this article will help you make an informed decision.

Most residential buildings do not use water-cooled air conditioning units, although this is likely to change as more manageable cost structures emerge. As it stands, water-cooling remains the choice for commercial and industrial facilities.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.