A free cooling system reduces energy use by using a fluid cooler or cooling tower to cool the process fluid in place of a chiller. The free cooling source is commonly a fluid cooler but a cooling tower may be used.
The free cooling source may be dedicated to free cooling or could be the primary cooling source with a dual or dynamic set point that changes based on the outdoor air temperature. It can use either a dynamic or static set point and can be isolated from the process fluid circuit with a heat exchanger, or can be in a common fluid circuit with the process fluid.