Abstract: As more and more new buildings are mainly high-rise buildings, in order to protect the life safety of air-conditioning installers and prevent outdoor units from falling off during the use of the air conditioners, more and more outdoor units are installed in blinds style which is hidden way. But blinds will block the air out of the outdoor unit, causing poor air flow and exhaust air backflow to the outdoor unit, and the actual temperature in the blind space where the outdoor unit is located is higher than the external environment temperature, this will adversely affect the performance, energy efficiency and reliability of the air conditioner. The purpose is to summarize the design process of the air duct structure of the air supply system in the development process of an air-conditioner product's outdoor unit, comparing the influences on the air supply wind field of the whole machine with different air duct heights and air duct R angles, to get the optimal value of the height of the air duct by fitting the test data, and making the actual comparison test of air supply wind field in both two situations which before and after the improvement, the machines with two different air-duct heights simulate the overall performance in the blinds installation environment with different operating frequencies. It has been verified that the heat reflow rate of the whole machine is reduced by more than 50% after the improvement, which can significantly improve the performance and reliability of the whole machine in the blinds installation environment.

Key words: Harsh installation, Heat return rate, Air duct height