What should be done with used refrigerant?

Used refrigerant must be handled with great care due to environmental regulations and safety concerns. Filtering and returning it to the system is essential because this process allows for the removal of contaminants and moisture that may have accumulated in the refrigerant during its usage. By returning clean, filtered refrigerant back to the system, it ensures that the HVAC system operates efficiently and reduces the likelihood of damage to components.

Furthermore, filtering used refrigerant aids in maintaining compliance with environmental regulations, which prohibit the release of refrigerants into the atmosphere, as they can contribute to ozone depletion and global warming. This practice ultimately helps in preserving the integrity of the refrigeration cycle and extending the lifespan of the system.

The other methods listed are not appropriate for handling used refrigerant. Flared off or expelled to the atmosphere would contribute to environmental harm, and dyeing the refrigerant does not address the need for proper disposal or recovery practices.