Chiller image courtesy of Cold Shot Chillers.

Chillers can be found in many aspects of your life, even if you do not realize it. Anything that you may like cooled or to maintain a specific temperature most likely uses a chiller to accomplish that. The big, old brick house I grew up in did not have air conditioning. Most summer nights were bearable with open windows and a fan. About three nights a year, however, it wasn’t bearable, it was awful. I tossed and turned, hoping and praying for an air conditioner. I now realize I was hoping and praying for a chiller.

Chillers are used in plastics, injection and blow molding, welding equipment, machine tooling, chemical and cement processing, food and beverage, pharmaceutical formulation, central air-conditioning units, die-casting, cutting oils, vacuum systems, power supplies, semi-conductors and compressed air and gas cooling. Chillers can be found in many industrial, hospitality, university and medical settings.

For the most part, chillers are electrically powered, with the exception of absorption chillers. These types of chillers function with the use of a heat source. The heat source is normally carried to the chiller system through hot water, steam or combustion.

Chillers can be centralized, meaning one chiller serves multiple applications for cooling, or decentralized where each machine or application has its own chiller. Air-cooled and water-cooled chillers are the main types of chillers. Air-cooled chillers use the surrounding air and mechanically circulate it through the condenser coil. No separate cooling tower is required. Water-cooled chillers depend on a remote water tower to function. Water-cooled chillers are normally used for large, indoor facilities such as world headquarter buildings, commercial buildings, hospitals, universities and large governmental buildings where the cost of energy to cool it exceeds 50 tons. This type of cooling is too expensive to do with air-cooled units.

Many different types of refrigerants are used in chillers including Freon, chlorine, fluorine and sulfur dioxide to name a few. Some are environmentally sound, while other can be damaging. When considering chillers one must keep in mind the ozone depletion potential and global warming potential of the refrigerant as part of the purchasing process.