Selecting The Cooling Method

Once the coolant is selected, the next step is to select the cooling method. This refers to whether refrigeration is employed or not, and how the heat (which the primary recirculating coolant removed from the heat load) is finally dissipated. Our most popular RU-300, with water as the primary coolant, utilizes refrigeration to remove heat from the water and reduce its temperature below ambient. This heat is then exhausted via the refrigeration condenser to ambient air. This is a refrigerated, air cooled unit. But this heat (a combination of the heat removed from the heat load and motor inefficiencies in the cooling unit) could raise the ambient room temperature beyond acceptable limits, causing the cooling unit to lose efficiency and possibly overload the room's air conditioning system. In such a case alternative types of cooling are available; for example, the cooling unit could be relocated outdoors (be sure to specify an outdoor unit), or the unit could be fitted with a water cooled condenser (if tap or facility water is available) to remove the heat. Another method is to employ a split refrigeration system. This allows the pumping unit to be located indoors and the condensing unit outdoors. Therefore the heat is rejected to the outdoor ambient. It should be noted that all cooling units should be located away from walls and other obstacles to provide for proper air flow.

Remember: The recirculated closed loop coolant is referred to as the primary coolant. The ultimate coolant to which the heat is finally exhausted is referred to as the secondary coolant. All performance measurements of cooling units are measured at the discharge port.

The general types of cooling methods are shown in the chart below. Other cooling methods such as ram air, liquid nitrogen cooling or other special cooling methods are also available.