The effect of pre-cooler on performance of evaporator was investigated on a mid-temperature vertical open-type display cabinet. And an experimental investigation was undertaken in the test room (temperature of 25℃ and relative humidity of 60%) to characterize the effect of pre-cooler on performance of evaporator in display cabinet. The results showed that: the condition of the air inlet evaporator were changed

and temperature of the air inlet evaporator was reduced by 2.4℃; the accumulation rate of frost on the evaporator was dropped and the defrost time was reduced by 28%; and the use of pre-cooler could lead to significant decrease in the cooling load by 19.2%.