After recovering refrigerant from an air-conditioning system, how can the refrigerant be reused?

The correct choice indicates that refrigerant recovered from an air-conditioning system may be charged back into that same system if it meets certain criteria. This involves properly checking the refrigerant for purity and ensuring that it is free from contaminants and has not been mixed with other types of refrigerants. The ability to reuse this refrigerant aligns with environmentally responsible practices, reduces waste, and can save costs associated with purchasing new refrigerant.

In addition, the U.S. Environmental Protection Agency regulates the handling of refrigerants to prevent environmental damage, and the practice of charging recovered refrigerants back into the system is permitted as long as the aforementioned conditions are satisfied. This promotes a sustainable approach in managing refrigerants, reinforcing the importance of proper recovery methods and system maintenance in HVAC operations.

The other options reflect misunderstandings of how refrigerant recovery and reuse works in practice. For instance, proper disposal of refrigerant is necessary when it is no longer usable, and using recovered refrigerant only for leak tests limits its potential to be reused effectively within the same system. Additionally, converting the recovered refrigerant to a different type is not a standard practice and could pose further regulatory challenges and safety concerns.