Produce odor occurs because air conditioning parts air conditioning smell is usually the evaporator refrigeration system. The evaporator is vaporized refrigerant place, it is a lot of heat of vaporization of refrigerant was produced air-conditioning cooling effect. But at the same time reduce the air temperature, the evaporator will condense a lot of water drops. Coupled with the evaporator itself has the effect of the air filter, so water will condense air containing the dirt. When the air conditioning is working properly, the dirt will be discharged with the water outside the car, but there are a few remain on the evaporator. And when you stop working at the end, Air conditioning, cleaning the host, will be left on the evaporator condensate water has not been discharged, the water again and dust in the air, viruses and soot combined, over time it will mildew, odors. Central air-conditioning maintenance of refrigeration equipment running after a certain time, moving parts will wear and fatigue Tangshan central air conditioning condenser cleaning, clogging and corrosion of piping systems, valves will regulate malfunction or failure of the seal will wear or material fatigue caused by leakage , so as to make the refrigeration unit is not normal and safe operation of central air conditioning how long the cleaning, cooling capacity decrease, increase energy consumption and operating costs. Therefore, in addition to some failure occurs in the refrigeration apparatus, the need for repair Depending on the cause, but also to deal with the refrigeration unit has planned to conduct regular maintenance and repair, which can greatly reduce the failure.