Patent ID: 8170724

Claim:
A computer system, comprising: a computer cabinet having an air inlet spaced apart from an air outlet, and at least a first computer module compartment spaced apart from a second computer module compartment, wherein the air inlet, the air outlet, and the computer module compartments define an air flow path through the computer cabinet; an air inlet temperature sensor positioned proximate to the air inlet for measuring an inlet air temperature; an air outlet temperature sensor positioned proximate to the air outlet for measuring an outlet air temperature; at least a first heat exchanger positioned upstream of the first computer module compartment in the air flow path, a second heat exchanger positioned between the first and second computer module compartments in the air flow path, and a third heat exchanger positioned downstream of the second computer module compartment in the air flow path; a heat removal system in fluid communication with the heat exchangers for circulating working fluid between the heat removal system and the heat exchangers; a first valve in a first working fluid conduit corresponding to the first heat exchanger, a second valve in a second working fluid conduit corresponding to the second heat exchanger, and a third valve in a third working fluid conduit corresponding to the third heat exchanger; and a control system operatively coupled to the air outlet temperature sensor and the air inlet temperature sensor, and wherein the control system includes a computer-readable medium containing instructions for calculating a temperature differential according to the following formula: Δ T=T IN −T OUT where ΔT is the temperature differential, T IN is the air inlet temperature, and T OUT is the air outlet temperature, and wherein the computer-readable medium further includes instructions for calculating the temperature differential at a first time and at least partially closing the third valve if the calculated temperature differential is greater than a threshold at the first time, and for calculating the temperature differential at a second time, after the first time, and at least partially closing the second valve if the calculated temperature differential is greater than the threshold at the second time.