Latent heat of vaporization is the energy required to convert one pound of liquid refrigerant to vapor at constant temperature and pressure, typically expressed in BTU/pound. This property is fundamental to refrigeration cycles, as it determines how much cooling capacity a refrigerant provides. Different refrigerants have different latent heat values, affecting system efficiency and component sizing.
Refrigerant Properties
R-22 has a latent heat of vaporization of approximately 119 BTU/pound, while R-410A provides about 104 BTU/pound. R-134a delivers roughly 92 BTU/pound. Higher latent heat values mean the refrigerant absorbs more energy per pound circulated, allowing smaller compressors and lower mass flow rates to achieve the same cooling output. This property directly impacts equipment efficiency ratings and operating costs.
System Performance
Technicians use latent heat data when selecting refrigerants, sizing compressors, and predicting system capacity. A change in refrigerant affects the entire system’s performance, requiring adjustments to expansion devices and operating pressures. Understanding latent heat of vaporization helps explain why R-22 systems often performed differently than modern R-410A replacements.