Free Cooling works with either a chiller with a built-in free cooling coil or a free cooler working in series with a chiller. The latter is more efficient, due to the larger surface area provided by the free cooler. Free Cooling system design will largely depend on your cooling demands and the footprint of your site. Free cooling equipment will need to be cited externally to take advantage of the cooler ambient temperatures.
When the ambient air temperature drops below the process fluid return temperature, a 3-way valve diverts the returning process fluid through the free cooling coil in which the cooler ambient air removes process heat and cools the returning fluid.
Partial Free Cooling
At just 1°C below the process return fluid temperature, the fluid is partially cooled by the free cooler, it then flows through the chiller’s evaporator where the required set point temperatures are achieved – easing the demand on your chiller’s components and extending their operational life.
Full Free Cooling
As the ambient air temperature continues to fall, the amount of process heat taken out of the process fluid by the air increases, progressively reducing the load on the chiller. When the ambient air temperature is 5°C below the process supply fluid temperature, all the process heat is removed by the ambient air in the free cooler – providing full free cooling.
The process fluid is therefore being cooled by the fans, rather than a compressor which is traditionally the most energy-intensive element of a chiller, thus reducing your energy and maintenance costs and improving the lifespan of your components even further.
For more information on Free Cooling System Design and Equipment, please call our technical experts on 0800 774 7426.