Patent ID: 8583289

Claim:
In a data center having equipment racks in which electronic equipment is disposed and a climate control system that includes a computer room air conditioner (CRAC) and an air economizer, the climate control system including a control module, a method of controlling the climate control system, comprising: measuring a dry bulb temperature of outside air and a parameter indicative of humidity of the outside air and storing the measurements in the control module; controlling a return air damper and an outside air damper of the air economizer with the control module; determining with the control module whether the outside air is suitable for use in cooling the data center based on the dry bulb temperature and the humidity of the outside air; controlling the climate control system with the control module to use only the CRAC to cool the data center when the control module determines that the outside air is not suitable for cooling the data center; when the control module determines that the outside air is suitable for use in cooling the data center, determining with the control module to use outside air and not the CRAC to cool the data center when the dry bulb temperature of the outside air is below a minimum outside air dry bulb temperature set point, and the control module controlling the climate control system as needed to mix a sufficient quantity of the return air with the outside air to heat the outside air before the mixed return air and outside air is introduced as supply air into the data center, so that the supply air is above a minimum temperature; when the control module determines that outside air is suitable for use in cooling the data center and the dry bulb temperature of the outside air is above the minimum outside air dry bulb temperature set point, determining with the control module a cooling percentage of cooling of the data center to be provided by the CRAC and a cooling percentage to be provided by the outside air, where the percentage can range from zero percent to one-hundred percent, and controlling the climate control system with the control module so that the CRAC and the outside air provide cooling of the data center according to their respective determined cooling percentages; further controlling the climate control system with the control module based on user adjustments limiting or expanding use of the air economizer, and thus use of the outside air in cooling the data center, allowing the user to set compromises between energy savings and projected life of electronic equipment in the data center; and using the control module to operate a heat rejection device at a load corresponding to the cooling percentage of the data center being provided by the CRAC.