Everything You Need to Know About Water-Cooled Air Conditioners

Harness the power of water to stay cool

Portable A/C unit sitting in living room
Photo: Mr.Whiskey/Shutterstock
Portable A/C unit sitting in living room
Photo: Mr.Whiskey/Shutterstock
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When you think of air conditioning, you probably think of a residential HVAC setup with cooling coils that use either geothermal energy or refrigerant such as R-22 or R-410a to chill air and send it back outside. But some systems, especially those on a larger industrial level and portable air conditioners, use water to improve efficiency and cool the condensers. 

Here is what you need to know about water-cooled air conditioners and whether one is right for you.

What Is a Water-Cooled Air Conditioner?

Though it might sound vastly different from the units you’re used to and even a little intimidating, a water-cooled air conditioner is fairly common in medium to large facilities. Hospitals, schools, and corporate buildings often utilize these water systems to keep them cool.

Chilled water systems are similar to expansion systems, only instead of using a refrigerant in the refrigeration cycle, this system uses water.  These air conditioners cool water to somewhere in the 40 degrees Fahrenheit to 45 degrees Fahrenheit range (that’s 4.4 degrees Celsius to 7.2 degrees Celsius).

On top of that, there are two types of water-cooled systems that you can choose from: the chilled water system and the cooling tower technology.

Chilled Water System

The chilled water system is installed either on the roof of your building or on the side, where it cools the heat from the water before sending the chilled water throughout the facility. This option is especially useful for longer buildings with extensive layouts, as the chilled water system allows for the system to cool over a long distance.

Cooling Tower Technology

True to its name, cooling tower technology involves a cooling tower that runs cool water across the heat that is in the condenser coils. Though a cooling tower is also efficient at cooling buildings, you do have to make sure that the water levels in the tower aren’t low by adding water routinely.

How Do Chilled Water Systems Work?

To help put all of this into perspective, here’s a breakdown of how chilled water systems work:

  1. First, a centralized chiller plant absorbs the heat out of the building through the use of a compressor.

  2. Then, the heat travels to the condenser, where it is then either taken to the condenser water or sent outside the building to prevent excess heat.

  3. From there, heat that is sent to the condenser water moves to the chiller and then the evaporative cooler, where the heat can evaporate and cool. The heat that is sent outside is cooled through a condenser coil.

  4. Once the heat evaporates, cool condenser water is then able to flow back to the chiller.

  5. This process repeats itself, keeping the building cool through a series of terminals or cooling coils.

What Are the Benefits of Having a Water-Cooled Air Conditioner?

Water-cooled air conditioners are extremely beneficial to larger buildings that would generate a lot of heat when using a standard AC unit. 

Another big benefit is that a water-cooled air conditioner can cool multiple buildings or elaborate layouts without the need for additional units. Your air conditioner will be in one location, making it easy to access and regularly service your AC unit.

In addition, chilled water systems potentially save on energy costs, even if they are more expensive upfront. In fact, you can save as much as 20% on water usage and 20% to 50% on your HVAC energy by switching to a chilled water system. They also have a good ROI due to their energy efficiency. An AC installation company near you can help to go over the best options for your situation.

When to Use a Water-Based Air Conditioner

Are you wondering where you can use a water-based air conditioner? In short, it depends on the type of building.

Large Buildings and Facilities

Many buildings that are larger than a residential space can benefit from a water-based air conditioner. For example, you can cool a large building even with a small unit due to the efficiency of the heat transfer rate, saving you money in the long run.

For Single-Family Residences

You might be wondering if you can use a water-cooled air conditioner in a smaller residence. Admittedly, the benefits of a water-based unit tend to diminish when installed in a smaller space. For this reason, they are rarely installed in residential homes. A couple of problems can also arise from using water-cooled condensers in small homes.

  • Water Usage: For one, it uses a lot of water, which might not be practical for a home in a dryer climate.

  • Maintenance: Condensers can scale, which requires you to clean off the deposits or invest in expensive demineralized water.

Water-Based AC Units for Residential Spaces

At the same time, there are a few exceptions to having a chilled-water AC unit in your home:

Portable Air Conditioners

For instance, portable water-cooled air conditioners use water cooling. Not to mention, these AC units are quieter, produce minimal air pressure, and require no exhaust. 

However, if you’re interested in weighing the cost of portable air conditioners, they have the same drawbacks as other portable AC units; they can only cool a small area.

Swamp Coolers and Evaporative Coolers

Although they aren’t true air conditioners in the technical sense, evaporative coolers, also known as swamp coolers, can effectively cool air in dry climates using water.

The downside of a swamp cooler is that it increases the humidity in a home since it sends the water directly into the air. People who live in very dry climates, such as Arizona, tend to install evaporative coolers most often.

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