What does a "vacuum" do in refrigerant recovery?

A vacuum in refrigerant recovery plays a crucial role by removing moisture and air from the system before it is charged with refrigerant. This step is essential for the proper functioning of the refrigeration or air conditioning system. When moisture and air are present in the system, they can lead to several issues, including the formation of ice, acid build-up, and decreased efficiency of the refrigeration cycle.

By creating a vacuum, technicians can effectively draw out any residual moisture and non-condensable gases. This process helps ensure that the system is clean and optimized for performance, allowing for efficient operation once the refrigerant is added. Additionally, removing these contaminants helps to prolong the life of the compressor and other components within the system.

The other choices do not accurately describe the purpose of creating a vacuum in refrigerant recovery. For example, pressurizing the system is not what occurs in this context, nor does increasing the system’s cooling capacity relate to the vacuuming process. Filtering out contaminants from refrigerant typically refers to other procedures, not the vacuuming step itself. Thus, the correct answer emphasizes the vital maintenance of system integrity prior to charging.