Investigations on the Performance of a Non-Inverter Air Conditioner under Varied Supply Voltage

An experimental investigation on the effect of supply voltage variation on the performance of a non-inverter air conditioning (AC) unit has been carried out. In this test, the supply voltage was varied from 170 to 240 V with 10 V increment and was supplied to an air conditioner with a nominal compressor capacity of 1 hp. The test was conducted under ISO 5151, in which the indoor and outdoor compartments conditions were maintained at constant temperatures as defined by the standard. From the experiment, it was revealed that the operating conditions of the air conditioner are not significantly affected. The suction temperature, discharge temperature, and condensing temperature are almost constant during the test. However, the performance of the air conditioner is significantly affected. In comparison to the standard voltage of 220 V, the power consumption decreased when the supply voltage was set at 170 to 190V. It then increased when the supply voltage was increased from 190 to 240 V. The cooling capacity of the AC unit constantly increases with the increase of voltage from 170 to 220 V. A constant cooling capacity was observed for a voltage range of 220 to 240 V. The energy efficiency ratio (EER) tends to increase with the increase in voltage from 170 to 220 V and then decreases with the increase of voltage from 220 to 240 V. The optimum AC performance is obtained at a supply voltage of 220 V that gives power consumption of 717 W, cooling capacity of 2369 W, and EER of 3.30. In addition to performance evaluation, the results also highlight the environmental aspect of energy consumption. Using appropriate supply voltage on a single AC unit with a compressor capacity of 1 pk has the potential to reduce CO2 emissions by up to 1.7 tons per year.