Evaporative cooling of air-cooled condenser

The vast majority of air conditioning units used in comfort and industrial plants today use air cooled condensers to reject heat collected in the building. In this situation, ambient air is used to cool the hot coil or the condenser. Thus the performance of air-cooled air-conditioning is highly dependent on the dry bulb temperature of the ambient air.

As outside temperatures rise, the capacity of an air cooled air conditioner decreases. The result is a significant loss in effectiveness of heat transfer from the refrigerant to the outside air. This will cause higher electrical energy consumption and reduce cooling capacity. As a result, the air conditioner consumes more electricity and runs longer time to achieve the same interior cooling requirements.

The above problem could be solved by using supplemental evaporative cooling in front of the air-cooled condenser. This technology is known as evaporative pre-cooler of air-cooled condenser. Evaporative pre-cooler reduces air conditioner load by cooling the air that surrounds air conditioner condenser. After this process, moister and cooler air pass across the condenser coil with high heat transfer efficiency, allowing the system to run efficiently during hot outdoor conditions. Also, since peak cooling capacity is increased it may be possible to downsize equipment.

REF: EMSD 2014, Energy Land http://www.energyland.emsd.gov.hk/en/appAndEquip/equipment/air_conditioning/evaporative_cooling.html

From our working reference, the result is approximately 12% power consumption saving.