Proposal of an eco-friendly high-performance air-conditioning system. Part 1. Possibility of improving existing air-conditioning system by an evapo-transpiration condenser

• Experiments to clarify effect of condenser to air-conditioner performance are done.
• Water-cooled condenser can reduce condenser and compressor temperatures.
• COP of water-cooled system increases up to 30% by simulation results.
• An evapo-transpiration heat-exchanger is proposed for higher performance condenser.
• Proposed condenser makes waste of heat from air-conditioner to be minimized.

Air-conditioning (AC) system consumes high energy and releases waste-heat. In the present study, we propose a method to improve its performance and minimize waste-heat by replacing existing air-cooled condenser by an evaporation and transpiration, evapo-transpiration, condenser. The improvement is confirmed by performing experiment for a conventional air-cooled AC system and a water-cooled AC system. Condenser temperature in the air-cooled system is higher than outdoor-temperature by 5–10 °C, while it is −5 to 5 °C in case of the testing system. From simulation results, saving energy consumption is expected to reach up to 30% in summer with the testing system. Based on these results, an evapo-transpiration heat-exchanger was developed as a new condenser. Heat-transfer coefficient of the testing heat-exchanger is at least 4 times higher than that of air-cooled condenser. Even hot fluid is used inside copper-tubing, its outlet-air temperature is as nearly as outdoor temperature.