Chiller is compressor based equipment which cools as well as controls the temperature of a liquid. It does not act like air conditioners that cool air. Besides compressor, the other components of a chiller include a reservoir, a temperature controller and a recirculating pump.

Chiller is known as significant cooling equipment used in laboratories. The main purpose of a chiller is to remove heat from one area and pass it to sources like ambient air or water.

The Working Principle Of Chiller

A chiller works on the principle of vapor compression or vapor absorption. Chillers provide a continuous flow of coolant to the cold side of a process water system at a desired temperature of about 50°F (10°C). The coolant is then pumped through the process, extracting heat out of one area of a facility (e.g., machinery, process equipment, etc.) as it flows back to the return side of the process water system.

A chiller uses a vapor compression mechanical refrigeration system that connects to the process water system through a device called an evaporator. Refrigerant circulates through an evaporator, compressor, condenser and expansion device of a chiller. A thermodynamic process occurs in each of above components of a chiller. The evaporator functions as a heat exchanger such that heat captured by the process coolant flow transfers to the refrigerant. As the heat-transfer takes place, the refrigerant evaporates, changing from a low-pressure liquid into vapor, while the temperature of the process coolant reduces.

The refrigerant then flows to a compressor, which performs multiple functions. First, it removes refrigerant from the evaporator and ensures that the pressure in the evaporator remains low enough to absorb heat at the correct rate. Second, it raises the pressure in outgoing refrigerant vapor to ensure that its temperature remains high enough to release heat when it reaches the condenser. The refrigerant returns to a liquid state at the condenser. The latent heat given up as the refrigerant changes from vapor to liquid is carried away from the environment by a cooling medium (air or water).

Where Are Chillers Used?

Chillers have several uses and are sometimes preferred over traditional split systems or package units because the water conducts heat better than air. This is also why water-cooled chillers are known for being more consistent and efficient in their performance and for having a longer lifespan than their air-cooled counterparts. Water-cooled chillers are common in medium and larger facilities (so long as they have an adequate water supply), such as airports, hospitals, hotels, shopping malls, commercial buildings, and more.

Air-cooled chillers are more prevalent in small to medium sized facilities where space and water may be limited. The costs to install and maintain these chillers are lower than that of their water-cooled counterparts, but they typically have a shorter lifespan. These chillers are commonly used for restaurants, corporate and sporting events, and temporary structures.

Chillers are also often used for industrial or medical applications. Assembly equipment, construction sites, lasers, MRI machines, and various other high-powered equipment and facilities may require chillers to maintain a workable temperature.