Rittal air/water heat exchangers are capable of cooling the air in an enclosure to a temperature lower than that of the ambient air. Heat to be removed is transferred to a water circuit and may be conveyed to a remote location before being dissipated. The lack of dependence on ambient air results in a maximum operating ambient air temperature of 70 °C. Air is recirculated inside the enclosure maintaining an ingress protection category of IP 55.
Cooling with water may also be considered from an energy saving perspective. Air/water heat exchangers supplied with the eComfort controller incorporate the Eco-Mode control functionality. This employs an intelligent strategy to effectively target the use of energy by disabling the internal fan when the temperature inside the enclosure falls to a predetermined level below the setpoint. The fan is then pulsed periodically to ensure the accuracy of the sensed temperature before being permanently enabled when the temperature rises above the predetermined level.
Although the capital cost of a cooling system incorporating multiple air-to-water heat exchangers and a single water chiller may be greater than that of an equivalent number of refrigerant based cooling units, energy savings are typically in the region of 40 per cent. Efficiency of water cooling systems may be further improved, particularly in the climate of the United Kingdom, by locating water chillers externally and integrating dry air coolers to take advantage of free cooling.