42 u00b0 to about 50 u00b0 f about 5 u00b0 to about 10 u00b0 c as it leaves the evaporator 16 under normal chiller 10 operation in the event of a disruption in the power supply from the non critical power source 25 e g where a storm forces down a supplying power line the compressor 18 stops pumping and the refrigeration cycle shuts down nevertheless the critical power source 41 can continue to supply power to the controller 46 and pump 36 when the non critical power source 25 fails consequently the cool working fluid continues to circulate through the chilled fluid loop 26 notwithstanding the shutdown of the adjoining refrigeration loop 12 the role of the refrigeration loop 12 as a heat sink for the chilled fluid loop 26 will now be greatly reduced and the temperature of the working fluid will gradually rise with each pass through the air handler 34 nevertheless the working fluid will continue to extract heat from the air of the computer room as long as the temperature of the working fluid is below that of the air eventually the temperature of the working fluid may rise to that or nearly that of the air and may consequently no longer be able to effectively cool the computer room nevertheless the period of time for which cooling is provided by the working fluid from the time of power failure enables the continued or prolonged safe operation of the computer components in the computer room and or the safe and graceful shut down of the computer components.