When charging a system using the superheat method, what happens when refrigerant is removed?

When charging a system using the superheat method, removing refrigerant generally leads to an increase in superheat. This is because the superheat value is a measure of how much heat is added to the refrigerant after it has completely vaporized in the evaporator. When refrigerant is removed from the system, there will be less refrigerant available to absorb heat in the evaporator, resulting in a higher temperature increase (superheat) of the remaining vapor before it returns to the compressor.

In essence, the less refrigerant that flows through the evaporator, the more pronounced the effect of heat added to the existing vaporized refrigerant, thus raising the superheat reading. This underscores the importance of monitoring superheat during the charging process to ensure that the system is operating efficiently and safely within the manufacturer's specified range.