High-tech manufacturing consumes huge of energy.For example,a 12 in DRAM(Dynamic Random Access Memory)semiconductor wafer fabrication plant(hereafter referred "fab")consumes about 400,000 MWh annually [1] in electricity(as much as 25,000 homes use,each consumes about 4,000 kWh/year [2]).The potential for energy savings in fabs is commensurate with the magnitude of their energy consumption.For air-conditioning,fabs are different from those commercial buildings.