1. Poor refrigeration system effect  
　　The most common problems of high-precision constant temperature and humidity air  
　　conditioners are temperature alarms, too high air supply temperature, and poor refrigeration system effect. The main reasons are summarized as follows: 1) The outdoor unit heat sink of the high-precision constant temperature and humidity air conditioner has too much dirt and dust accumulated, and has not been cleaned in time.  
　　The condenser of the outdoor unit works by discarding the heat absorbed by the indoor unit during refrigeration in the outdoor environment. Because the outdoor unit will accumulate a lot of dirt during operation, the heat exchange efficiency of the heat exchanger will become lower and lower, causing the condensation pressure of the air conditioner unit to gradually increase, resulting in the problem of deterioration of the refrigeration effect.  
　　2) Too much dust on the filter of the top return air outlet  
　　The indoor part of the high-precision constant temperature and humidity air conditioner is equipped with a filter to filter out dust in the air. If the filter is too dusty, it will increase the indoor wind resistance, thereby affecting the air intake and indoor circulation air volume. Especially when the filter mesh is clogged with too much dust, the circulating air volume will be greatly reduced, and heat exchange cannot be carried out normally, resulting in a significant reduction in refrigeration capacity.  
　　3) In the daily operation of high-precision constant temperature and humidity air conditioners, there may be R22 (commonly known as refrigerant) leakage, resulting in insufficient R22.  
　　The cooling of the air conditioner compressor is achieved by refrigerant. If the refrigerant is insufficient, the cooling effect of the compressor will also deteriorate accordingly.  
　　4) The outdoor filter is dirty and blocked. 
　　This fault is manifested by a significant temperature difference between the front and rear welding points of the outdoor filter, frequent startup of the outdoor unit, low pressure alarm of the indoor compressor, and the compressor stops running. The refrigeration system fails and cannot refrigerate normally.  
　　5) Aging of the indoor fan belt.  
　　After a long period of operation, the fan belt becomes aged and loose, resulting in a decrease in the fan speed, which affects the air supply and cannot meet the needs of cooling the indoor temperature.  
　　6) Excluding the above factors, if the cooling effect is still poor, it can be preliminarily determined to be a circuit fault.  
2 Humidity alarm  
　　Another common problem in the IT system environment is humidity alarm. First, the humidity is too low to alarm. The main reason is that the humidification tank of the unit has been used for a long time, resulting in serious rust inside the tank, or the heating electrode of the humidification tank is seriously corroded, and the humidification tank cannot be charged and heated normally. In addition, too high indoor humidity can also cause this phenomenon.