This ceiling air cooler is freon refrigerating nuits,can be used for the food fresh,cokd storage and quick freezing etc. 1.Coil made of 12.7mm efficient copper tube with internal thread 37.5*2.5,positioned in equilatral triangle. 2.Extermal rotor fan for low temperature,with low noise,hith effciency,and reliablitity. 3.Shell made of alloy of aluminum or stainless plate,easy to be assembled and disassembled. 4.4 different fin space of  4.0,6.0,8.5,10.0 for customer's choice to meet different temperature requirement of the room. 5.Stainless steel electric heater produced by ltalian Zoumoshi company,which evenly placed in the coil with good defrosting effect. 6.Double drainage receivers,avoiding water freezing. 7.Fan motor and electric heater has been connected to the terminal box,convinent for wire connection. 8.Optimized coil design,resulting evenly refrigerant over the evaporator.   The D series of air coolers,features cabinet of steel plate with plastic spray and external rotor motors,with 4.5,6,9.0mm fin space coils,for 0oC~-35oC temperature requirement. The heat transfer capacity of singer unit ranges from 2.0KW~122KW,both R22 and R404a refrigerants are usable.