are keys to performing an accurate （是执行一个准确的关键）.pdfVIP

SUPERHEAT SUBCOOLING Subcooling and superheat can be used to effectively check the proper operation of any air conditioning system. A complete understanding of superheat and subcooling are keys to performing an accurate troubleshooting session. Cooling’s Dynamic Duo by Al Maier Subcooling Ed. Note: Superheat and subcooling are the most popular When heat is removed from a saturated refrigerant, the tem- technical topics published in Contracting B. perature of the liquid is reduced. The difference between the Here, from one of the industry’s leading experts on the sub- saturated liquid temperature and the actual liquid tempera- ject, is a review of key superheat and subcooling concepts, ture is the subcooled temperature. for technicians to keep in mind as they venture into the Let’s use an R-410A operating system in this example, where i eld for a new cooling season. the condensing pressure is 295 psig. Again, checking the PT M chart we’ll see that the condensing temperature is 95F. Now, O Superheat when we measure the temperature of the refrigerant leaving C . When a refrigerant is at its saturation point, the temperature the condenser, we find it to be 85F. The difference between S T of the liquid and vapor are the same. However, if additional the condensing temperature and the actual t