Water-cooled chillers are typically intended for indoor installation and operation, and are cooled by a separate condenser water loop and connected to outdoor cooling towers to expel heat to the atmosphere.
Air-cooled and evaporatively cooled chillers are intended for outdoor installation and operation. Air-cooled machines are directly cooled by ambient air being mechanically circulated directly through the machine’s condenser coil to expel heat to the atmosphere. Evaporatively cooled machines are similar, except they implement a mist of water over the condenser coil to aid in condenser cooling, making the machine more efficient than a traditional air-cooled machine. No remote cooling tower is typically required with either of these types of packaged air-cooled or evaporatively cooled chillers.
Industrial chillers typically come as complete, packaged, closed-loop systems, including the chiller unit, condenser, and pump station with recirculating pump, expansion valve, no-flow shutdown, internal cold water control. The internal tank helps maintain cold water temperature and prevents temperature spikes from occurring. Closed-loop industrial chillers recirculate a clean coolant or clean water with condition additives at a constant temperature and pressure to increase the stability and reproducibility of water-cooled machines and instruments. The water flows from the chiller to the application’s point of use and back.
If the water temperature differentials between inlet and outlet are high, then a large external water tank would be used to store the cold water. In this case the chilled water is not going directly from the chiller to the application, but goes to the external water tank which acts as a sort of “temperature buffer.” The cold water tank is much larger than the internal water water goes from the external tank to the application and the return hot water from the application goes back to the external tank, not to the chiller.
The less common open loop industrial chillers control the temperature of a liquid in an open tank or sump by constantly recirculatingRDT it. The liquid is drawn from the tank, pumped through the chiller and back to the tank. An adjustable thermostat senses the makeup liquid temperature, cycling the chiller to maintain a constant temperature in the tank.
Most industrial chillers use refrigeration as the media for cooling, but some rely on simpler techniques such as air or water flowing over coils containing the coolant to regulate temperature. Water is the most commonly used coolant within process chillers, although coolant mixtures (mostly water with a coolant additive to enhance heat dissipation) are frequently employed