The use of HFO-1234ze(E) refrigerant, with an ultra-low GWP ( minus 1 ) is proposed based on the criteria of the Global Cooling Prize. Compared to HFC-32 (b pt -52°C), which is widely used for room air-conditioners as a lower GWP refrigerant, the use of the higher boiling point HFO-1234ze(E) (bpt -19°C) leads to are environmental challenges such as the increased use of raw materials as a result of the larger equipment size.
The cooling system adopts the two innovative methods to achieve higher efficiency and lower climate impact cooling solution. First, a multi split method is used to connect three indoor units with one outdoor unit. This method helps optimize refrigerant flow rate for each of three indoor units depending on ever-changing cooling load and use refrigerant control technology to closely modulate the capacity. Second, evaporative cooling method is used to improve the system efficiency by using heat of vaporization to lower the temperature of the air that outdoor unit takes in. The system will use control technology which measures the outdoor temperature with sensors and applies the control system to automatically spray water under the conditions with high ambient temperature where cooling load sees particularly high.
The Global Cooling Prize is an international innovation competition to develop super-efficient and climate-friendly residential cooling solutions for homes. The competitors showcased technologies that reduce or eliminate refrigerants linked to climate change, advances that will be vital as the number of room air conditioners (RACs) nearly quadruples by 2050.
Source 1: Daikin
Source 2: Daikin