Liquid-to-liquid Cooling Systems (LCS)
A liquid-to-liquid cooling system cools below ambient temperature and offers similar temperature stability to a recirculating chiller. Instead of rejecting the waste heat to the room, it transfers it to chilled facility water via a liquid-to-liquid heat exchanger.
The process side circuit is completely isolated from the facility water, protecting your equipment from fluctuations in temperature, flow rate of the facility water and any contaminants that may be present. Since the facility water provides the cooling, the facility water temperature is the lower limit for fluid exit temperature.
Liquid-to-liquid cooling systems are popular for high heat load applications as they are compact - approximately 1/3 the size of a refrigerant-based chiller of similar capacity. Without a compressor, they are also very quiet and energy efficient.
Recirculating chiller or liquid-to-liquid cooling system?
For low heat loads, recirculating chillers are usually the simplest solution as installation is so easy. At high heat loads, liquid-to-liquid cooling systems are more cost effective. However, their use is restricted to situations where chilled facility water is available. The necessity to plumb them into facility water may affect the locations they can be used in and the portability of the equipment.
If you have high heat loads and need to reject the heat to facility water, the choice between an LCS and a recirculating chiller with a water-cooled condenser depends on your set-point temperature. If your set-point temperature is higher than your maximum facility water temperature, an LCS is more cost-effective. However, if you need to cool close to or below the facility water temperature, you will need a refrigerant based chiller with a water-cooled condenser.