Associated Air Product Chillers
What is a an Industrial Chiller?
In a chiller, heat is removed from a liquid via a vapor-compression or absorption refrigeration cycle. The liquid could be water that passes through pipes in a building and coils in air handlers or through fan-coil units, which help dehumidify the air. Or it could also be refrigerants or brine water, like ice rink chillers.
Generally, chillers are air and water cooled. Air cooled chillers are located externally to a facility and have condenser coils cooled by fan-driven air. Water cooled chillers are usually located internally and water is recycled to a heat sink or external cooling method. The external cooling method can include a cooling tower or in some cases, a water fed cooling system, which is more efficient at heat rejection.
What Are the Types of Industrial Chillers?
There are four types: Reciprocating, centrifugal, screw-driven, and absorption. The first three are powered by electrical motors, steam, or gas turbines. Absorption is powered by a heat source, such as steam or hot water.
Chillers can also have compressors that use oil or there are oil free chillers.
There are almost as many different types of chillers as there are applications to use them. Chillers can be standard or heat recovery with free cooling coils to take advantage of operating in colder weather. Chillers can even be simultaneous heating and cooling. Modular chillers can create great redundancy in a system and can make for smoother chiller replacements. We have both oil free and standard style chillers. We also have great flexibility in design for specific applications.
What Are the Uses of Commercial Chillers?
Large commercial buildings that require a substantial amount of cooling often use water chillers because they are cost effective and there is a reduced hazard by not having refrigerant piped all over the building.
These systems work by pumping cool water throughout the building. Cool air is then transferred to the occupied spaces by terminal devices located within the building or by using coils located in air handling units. Automatic valves at these terminal devices or cooling coils provide the air temperature control. In a large commercial building the heat absorbed by the water may be transferred to the outside air through a cooling tower.
Fundamentally, the function of the chilled water system is to transport the cooling fluid from the chillers, to the load terminals and back to the chillers to maintain space comfort. Because a chilled water system uses water as its secondary refrigerant, a chiller is used to remove heat from the water which is then circulated through other components to absorb the heat from the space.
Chilled water systems include both supply and return piping in a closed circuit, which means they are sealed from the atmosphere and do not need extensive chemical treatment to control contamination and corrosion. The water is cooled by the chiller and supplied to cooling coils or heat exchangers where it cools the air by absorbing energy. Once warmed, the water is returned to the chiller to start the process all over again. As the water cools in the chiller, absorbed energy is transferred through a refrigeration cycle to water circulating in the condenser system and is subsequently transferred to the outside of the building.
A distinct advantage of using water is the fact that it is non-corrosive, has specific heat value, it is non-toxic and inexpensive. This makes it an excellent choice when compared to other secondary refrigerants such as sodium chloride brines, propylene glycols, ethylene, methanol or glycerin. Another advantage to using a chilled water system to provide climate control is that water cooled chillers typically last longer than air cooled chillers. This is due to the fact that the air cooled chiller is installed outdoors, whereas the water cooled chiller is installed indoors. Additionally, if it is well insulated, there’s no practical distance limitation to the length of a chilled water pipe.