Free Cooling is a fast and effective, economic method of using low external air temperatures. It can be used to assist in cooling water for industrial temperature control applications or in HVAC systems.
A chiller’s traditional design uses integral compressor technology to generate the cooling required for process and HVAC applications.
The use of Free Cooling in an industrial temperature control application differs from an environmental cooling solution as fresh ambient air cannot be drawn straight into the cooling circuit. Therefore, to harness the benefits of the low ambient temperatures, a Free Cooling coil needs to be introduced into the circuit.
A Free Cooling coil is installed in series with the chiller system’s evaporator so in lower ambient conditions, partial or 100%, Free Cooling can be achieved. This method of operation, makes the most of natural low ambient temperatures and in doing so benefits from a reduction in energy costs of up to 70%.
As the ambient air temperature drops at least a degree below the process return water temperature, the benefits of Free Cooling start and the external ambient temperature can begin to cool a process in place of a chiller.
As the ambient temperature drops 3°C to 5°C below the required process supply water temperature, total Free Cooling can be achieved, taking over fully from the chiller’s compressors and consequently providing an environmentally-friendly and cost-effective approach to process and HVAC cooling.
When the process return water temperature required is equal to or higher than the ambient air temperature Free Cooling is not suitable. The system’s three-way valve will continue to direct the fluid flow through the chiller’s compressors to be cooled to the required set point temperature.
For mid-season operation the water is partially cooled by the compressor and partially by the ambient temperatures. The percentage of Free Cooling achieved mid-season depends on seasonal temperatures although partial Free Cooling starts when the ambient air temperature is 1o°c below the process return water temperature. The water is partially cooled through the Free Cooler then flows through the chiller’s compressors to achieve the required set point temperature.
When the outdoor temperatures are low enough, the water is chilled solely by the Free Cooling coil. This allows the chiller’s compressors to stop operating, saving significant amounts of energy. The only electrical power used in winter operation is for fan operation. This can be achieved once the ambient air temperature is 3°c – 5°c below the process supply water temperature.
As a leading supplier of temperature control solutions, ICS Cool Energy is able to offer Free Cooling systems for both sale and hire to ensure customers achieve the greatest energy savings to suit their business and application requirements. Please contact us on 0800 774 7426 for more information or a no-obligation consultation.