Energy saving for air conditioning by proportional control, variable and constant speed motor compressor

Due to cost problem (e.g. fuels and electricity), energy cases are an urgent need to solve specially in industrialized country, like Malaysia. Variable speed at compressor by using of manual (without control system) and control system have been purposed in air conditioning system, it has big potency in the effort of usage electrics energy saving. In this research, the usage of central type air conditioning with capacities 3 kW, with nominal motor rotation is 1450 rpm. Base on reference, the room temperature is 22 o C while the motor rotation variation are : 20, 25, 30, 35, 40, 45, and 50 Hz. Our results indicated that the value of electric energy saving consumption is 20,77 % at motor frequency 40 Hz, and 22,54 % by using proportional control systems.