Why does the removal rate of refrigerant slow down when using a portable compressor recovery unit?

The correct answer relates to the concept of vapor density and its impact on the efficiency of refrigerant recovery. As the refrigerant is removed from the system, its vapor density decreases. This means that the vapor becomes less concentrated, which can slow down the rate at which the portable compressor recovery unit can remove more refrigerant.

When vapor density is high, there are more refrigerant molecules available for the recovery unit to capture efficiently. As some of the refrigerant is evacuated, the concentration of those molecules in the vapor phase diminishes, leading to reduced efficiency in the compressor’s ability to remove the remaining gas. Consequently, this results in a slower removal rate. Understanding the relationship between vapor density and recovery efficiency is crucial in optimizing the refrigerant recovery process.