How Do Air-cooled Chillers Work?

In this article we will be looking at how air cooled chillers work. Air cooled chillers are very common, especially in small to medium size commercial and office type buildings. They are usually located externally, either up on the roof or at ground level. This is because Air Cooled Chillers do not use cooling towers, instead they dump their heat into the ambient air and therefore need access to a lot of fresh air, in order to reject the unwanted heat from the building.

An industrial air-cooled chiller is a refrigeration system that cools fluids and works in concert with a facility's air handling system. Chillers have four main components: evaporator, compressor, condenser and expansion valve.

 Air Cooled Screw Chiller   

The Air Cooled Chiller has 4 main components.

• Evaporator – This is where the chilled water is produced and the heat from the warm return “chilled water” is extracted, to be sent to the condenser.

• The compressor – typically screw, scroll or reciprocating.

• The condenser – a bundle of horizontal pipes which contain the hot refrigerant, these are surrounded by a number of thin sheets of metal in the vertical axis. These help distribute heat away from the tubes and into the air which is blown across the tubes and thin sheets of metal.

• Expansion Valve – This expands the refrigerant before it enters the evaporator.

 Air Cooled Scroll Chiller

How do air-cooled chillers work? 

Air cooled chillers work by absorbing heat from treated water. Once the water in the air handling system is used, it becomes hot and is sent back to the chiller. The heat is transferred out of the water using the evaporator of the chiller. The liquid refrigerant evaporates as it moves up the evaporator tube, producing a low pressure gas. Next, the evaporated refrigerant enters the compressor where the low-pressure gas is compressed into a high-pressure gas. The gas then leaves and enters the air-cooled condenser.

In the condenser, the heat is removed from the chiller by a fan on the side of the condenser. Since the heat is blown to the outside of the chiller, it is ideal to place the chiller outside or in a large indoor location where it will not be affected by the excess heat. After the gas leaves the condenser, the refrigerant becomes a high-pressure liquid. 

The high-pressure liquid passes through the expansion valve into the evaporator. In the process, the refrigerant changes from a high-pressure liquid to a low-pressure liquid. Because industrial chillers operate in a continuous cycle, this low-pressure liquid is then transferred back to the evaporator, where the entire cycle will be repeated.

Industrial chillers are typically used in large buildings such as hotels, indoor shopping malls, hospitals and large industrial buildings, as well as in locations where there may be multiple buildings to cool, such as outdoor malls and theme parks. Portable air-cooled chillers can also be used for large events or emergencies.

For more information about the principles of air-cooled chiller, welcome to contact us at +86 15262310939 or write to us at j.li@szhuateng.com. We will be happy to help you out!