Hvac School - For Techs, By Techs

In this short podcast, Bryan talks about the times when subcooling is meaningless. It is important to understand subcooling fully before using it as a charging or diagnostic method, particularly in refrigeration systems. When we need to charge TXV systems in residential HVAC, many technicians rely on subcooling to set the charge. However, refrigeration systems don't quite work the same way; charging a refrigeration system by subcooling may lead you to overcharge the system. We take subcooling on the liquid line between the condenser and the metering device. The condenser takes superheated vapor and rejects heat. This process turns the superheated vapor refrigerant into a liquid-vapor mixture midway through and subcools the liquid refrigerant at the bottom of the condenser. That liquid "stacks" at the bottom of the condenser. Adding more refrigerant will cause more liquid refrigerant to stack up at the end of the condenser and increase subcooling. These conditions can cause an increase in head pressure. Howeve