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Air conditioners have become indispensable to modern life, a revolutionary invention, as one might say. It provides respite from scorching summers and creates comfortable indoor environments. After years of using ACs, have you ever asked yourself, does an air conditioner use water?
In this post, we will delve into the inner workings of AC units to understand if and how water is involved in the cooling process.
Before exploring the water-related aspects, it’s essential to have a basic understanding of how an air conditioner works. Air conditioning units operate on the principles of thermodynamics, specifically the process of refrigeration. The primary components of an air conditioner system include a compressor, condenser, expansion valve, and evaporator.
Do air conditioners produce water? Yes, it happens because of the condensation process, converting water vapor in the air into liquid water, commonly referred to as condensate water. Condensate water occurs when warm air contacts cold surfaces below the dew point temperature, thus producing those water droplets.
Now that we understand the basic process of how air conditioners work, let’s address whether they use water in this process. The answer is that it depends on the type of air conditioner.
There are two primary categories of ACs: air-based and water-based ACs. Most ACs, commonly found in homes and buildings, fall under the air-based category. These systems do not utilize water for cool air. Instead, they employ a refrigerant gas or ‘freon’ that follows a cycle of compression and expansion. This cycle enables warmth removal from indoor air, subsequently releasing it outside.
In contrast, water-based ACs incorporate water as a central component of their cooling mechanism. These systems use water as a medium to facilitate the cooling process. It’s essential to recognize that not all ACs involve water, and it primarily applies to the water-based AC variant.
When choosing an air conditioner unit, it’s crucial to consider the type of cooling system that best suits your needs. Two popular options are air and water-cooled ACs. Let’s compare these systems based on key factors:
Choosing between air-based and water-cooled AC units depends on efficiency, space requirements, maintenance, and environmental impact. The water-cooled air conditioner is more suitable in large buildings as commercial air conditioners, while air-based units are commonly used in residential homes as residential air conditioners.
Now that we understand how air conditioners work and the difference between water-cooled and air-cooled AC units, let’s address what kind of AC units use water and how they use it in this process.
Typically, residential air conditioners (split units, window units, and portable air conditioners) do not use water to refresh the air. These residential air conditioners chill the air by removing the warm draft and moisture from the indoor environment through the air filter, and the condensed moisture is usually drained outside through a large tube or collected in a drip pan.
Now, there are four types of water-based AC:
An evaporative cooler uses water to refresh outdoor air through evaporation. Warm, dry outdoor air is drawn through water-saturated pads. As the air passes through the wet pads, the water becomes water vapor, absorbing warmth from the air and cooling it down.
The cooled air is then circulated indoors. Evaporative coolers are most effective in dry and arid climates where low humidity allows for efficient evaporation. They are usually an outdoor unit type of AC that evaporates the warm draft inside below the dew point temperature.
A water-cooled package AC unit is a self-contained air conditioning system that incorporates cooling components within a single package. These units typically include the compressor, condenser, evaporator coils, and a water-cooled condenser. Water removes warmth from the condenser coils, and a water pump circulates the water to aid in warmth dissipation. These units are used when air-cooled systems are not efficient enough due to extremely hot air loads.
A water-cooled VRF system is a type of air conditioning system that uses a water-cooled condenser in conjunction with a variable refrigerant flow system. The system uses freons to transfer heat between indoor and outdoor units, and water is used to freeze the freon in the condenser coils. These systems provide efficient and flexible cooling solutions for large commercial buildings.
A chilled water system is a central cooling system used in commercial and industrial buildings. It utilizes chilled water as a heat transfer medium to cool indoor spaces. The cold water produced is circulated through pipes to air handlers, which absorb heat from the air. The warmed water is then sent into cooling outdoor unit towers where heat is evaporated. The water produced now returns to the system to repeat the process.
Water plays a crucial role in all these systems, but how it is used differs:
The choice between these systems depends on climate, cooling requirements, efficiency goals, and the specific demands of the cooled building or space.
The amount of water an air conditioner uses can vary widely depending on several factors, including the type of air conditioner, its cooling capacity, operating conditions, and climate.
Every HVAC system possesses distinct water consumption, regardless of its classification as a water-based AC. Here are some general guidelines:
Most residential and commercial air conditioners have a closed-loop freon system and do not consume water regularly. These systems rely on the refrigerant cycle to transfer heat without water involvement. As a result, they don’t consume water for cooling purposes.
These systems can consume significant water, especially in arid climates with high evaporation rates. The exact water usage will depend on factors such as the size of the cooler, humidity levels, and the desired indoor temperature.
A portable device could consume around 4 liters of water in an hour, while a centralized system might utilize up to 25 liters within the same timeframe.
The water consumption of water-cooled package units and VRF systems is contingent on their capacity and the cooling load they are designed to manage.
About 1.8 gallons of water evaporation are necessary for each tower ton (equivalent to 15,000 BTU/hr), equal to roughly 0.03 gallons per minute per ton.
Chilled water systems function as entirely enclosed circuits. Thus, it consumes no water when functioning correctly and without any water leaks. However, if cooling towers facilitate the refrigeration cycle, each ton of cooling necessitates approximately 2.0 gallons of water evaporation per hour for the tower’s operation.
If you’re concerned about water usage, it’s a good idea to check the specific type of air conditioning system you are considering and consult manufacturers or experts to get accurate information about water consumption.
While not every aircon employs water in its process, all aircon units generate water as a byproduct. As aircon cools the air, they eventually reach the dew point, forming water byproducts. The following are the typical processes through which they drain this water:
It’s important to ensure that the drainage system is functioning correctly to prevent leaks, which can lead to potential damage to the AC system. Regularly check your indoor unit ACs drain line.
Ensure your AC does not leak water, as it may cause problems in the copper tubing, condensate line, drain pipe, and more. Also, note that the water produced by an AC is not drinkable.
Regular maintenance and periodic drainage system inspection are necessary to ensure the proper functioning of water-cooled ACs and optimize their cooling performance.
Most air conditioners use the principles of refrigeration and do not use water as part of their cooling process. On the other hand, evaporative coolers rely on water’s evaporation for cool air. While portable ACs do not use water for cooling, they generate water as a byproduct, which needs to be managed through drainage or collection.
Knowing the type of air conditioner you have can help you understand its mechanism better and ensure proper maintenance. Regardless of the type, air conditioners have revolutionized modern living by providing a comfortable escape from the sweltering sun, making life more enjoyable during the year’s hottest months.