Patent ID: 7791882

Claim:
An apparatus for cooling of an electronics rack, the apparatus comprising: at least one heat extraction mechanism for facilitating cooling of the electronics rack, the at least one heat extraction mechanism comprising at least one liquid-cooled cold plate coupled to at least one heat-generating component within the electronics rack; an enclosure comprising at least one wall, a cover coupled to the at least one wall, and a central opening sized to accommodate the electronics rack and the at least one heat extraction mechanism therein, wherein when operatively employed, the enclosure surrounds the electronics rack; a heat removal unit disposed external to the enclosure and in fluid communication with the at least one heat extraction mechanism within the enclosure for removing heat from liquid coolant passing therethrough, the at least one heat extraction mechanism and the heat removal unit being coupled via a liquid coolant loop, wherein the heat removal unit comprises a liquid-to-air heat exchanger, a coolant pump and an air-moving device, the liquid-to-air heat exchanger removing heat from the liquid coolant within the liquid coolant loop before passing through the at least one heat extraction mechanism, the coolant pump pumping the liquid coolant through the liquid coolant loop, and the air-moving device moving air across the liquid-to-air heat exchanger; and a control unit coupled to the heat removal unit to automatically control and minimize energy consumption of the heat removal unit while achieving a specified level of cooling of the electronics rack employing the liquid coolant passing through the at least one heat extraction mechanism within the enclosure, wherein the control unit is coupled to the coolant pump via a first variable frequency drive and is coupled to the air-moving device via a second variable frequency drive, and wherein the control unit dynamically adjusts energy consumption of the heat removal unit by: determining thermal resistance (R) of the at least one liquid-cooled cold plate; initially setting RPMs of the coolant pump via the first variable frequency drive using a first pre-generated relation relating thermal resistance (R) of the at least one liquid-cooled cold plate to coolant pump RPMs; and subsequently setting RPMs of the air-moving device via the second variable frequency drive using a second pre-generated relation relating a target liquid coolant inlet temperature of the at least one liquid-cooled cold plate and the coolant pump RPMs to air-moving device RPMs.