Why is it necessary to change the filter in a recovery unit when switching refrigerants?

Changing the filter in a recovery unit when switching refrigerants is essential primarily to prevent cross-contamination of refrigerants. Different refrigerants have varying chemical compositions, properties, and operating characteristics. If a residual amount of one type of refrigerant remains in the filter and a different refrigerant is introduced, it could lead to a chemical reaction or degradation of the refrigerants, affecting their performance and potentially harming the equipment.

Cross-contamination can also pose environmental and safety risks, as some refrigerants are more harmful than others, especially if they are released into the atmosphere. Ensuring that the filter is clean and specific to the refrigerant being used helps maintain the integrity of the refrigerant recovery process and promotes safe practices in compliance with environmental regulations.

While maintaining the warranty of the recovery unit and compliance with local regulations are important considerations, the immediate concern when switching refrigerants is to avoid any mixture that could compromise both the efficiency of the recovery and the safety of the environment.