Free-cooling is a cooling system with help of low temperature of outdoor air.
If the system cools the technological equipment or industrial processes, that are operated permanently throughout the year, even at low outdoor temperatures, it is preferable to use cooling systems with a free-cooling unit, in terms of energy consumption. Cold water is– thanks to outdoor air and lower power consumption of fans - almost free!
There are 3 operating modes:
- Machine cooling: at temperatures above 15 °C, the free-cooling unit works the same as the standard cooler. The heat load is covered by the evaporater with help of compressors.
- Mixed cooling: at temperatures between 5 and 15 °C is the outside air able to remove only part of the heat load. When the outside temperature drops to 15 °C, the control system starts the free-cooling pump in case of stacked, or readjusts the three-way valve in case of compact. Water passes through the air/water heat exchangers, placed in series with the evaporator to reduce its thermal load.
- Free-cooling: if the outside temperature is low enough, the air/water heat exchangers can dispense the entire heat load, without having to run the compressors.