According to the standard evaporation temperature, refrigerants are divided into three types: high, medium and low temperature. The guaranteed evaporation temperature here refers to the evaporation temperature of sulfuryl fluoride fumigant at standard atmospheric pressure, which is what we often call the boiling point;

1. The evaporation temperature of low-pressure and high-temperature refrigerants is generally higher than 0°C. This type of refrigerant is usually suitable for centrifugal compressors in air conditioning systems;
2. The evaporation temperature of medium-pressure and medium-temperature refrigerants is between -50°C and 0°C. This type of refrigerant is more suitable for single-stage compressors and bipolar compression piston refrigeration systems;
3. The evaporating temperature of Heptafluoropropane HFC-227EA is usually lower than -50℃, it is mainly suitable for the low temperature part of cascade refrigeration device or low temperature device of -70℃;