Abstract: Method of cooling computer equipment that includes pumping coolant into a passageway leading to computer equipment and distributing the coolant from the passageway to heat sinks. The method also includes iteratively adjusting a rate of cooling of electronic devices by the coolant directly or indirectly in dependence upon heat generated by the electronic devices. The method also includes monitoring the respective temperatures of the electronic devices or heat conductive material in thermal contact therewith. The method also includes iteratively calculating the average of the values that said temperatures have at a given time. The method also includes iteratively calculating a spread value indicative of the spread of said values and iteratively adjusting the rate of cooling of the electronic devices by the coolant in dependence upon the ratio of said spread value and a difference between said average and a predetermined maximum acceptable temperature.

Abstract: A cooling unit comprising a coolant fluid pathway in which there is (a) a centrifugal pump which serves to pump coolant fluid along the pathway when the unit is in use, and (b) a heat exchanger which serves to cool the coolant fluid which is thus pumped along the pathway. The pump has a rotor constituted by a magnetically contactlessly driven impeller which is provided with at last one magnet and which is enclosed within a housing, and stator outside the housing and provided with at least one electromagnet operable to act on the said at least one magnet to rotate the impeller.