Abstract: Energy saving, carbon emission reduction, thermal comfort and health are the inevitable way of the development of room air conditioner. Based on the goal of reducing the climate impact of air conditioner by 80% set by the Global Cooling Prize committee, a 5200 W ultra-efficient air conditioner with smart evaporative cooling ventilation and PV was developed. It is composed of high efficiency gas-injected vapor compression cycle with relay cooling, evaporative cooling fresh air system, photovoltaic system and automatic control system, which take R152a as the refrigerant. The simulated simulation annual power consumption is 585 kW•h in New Delhi, India, which is 80.2% less than the basic prototype with R22 as refrigerant and EER = 3.5. According to the test progress of IS 1391, the tested rating EER is 6.28 and ISEER reach 8.43. Moreover, in the 10-day lab test to simulate year-round performance, the total energy saving reached 82.8%. The results of 31 days field test show that the air conditioner can stably control the indoor temperature and humidity (room temperature ≤ 27 °C, relative humidity ≤ 60%). The calculated comprehensive electricity saving rate is 84.1%, equivalent to 85.7% reduction in climate impact.

Key words: Room air conditioner, Natural energy, Evaporative cooling, Energy saving, Relay cooling