Which methods can remove non condensables from a refrigerant system?

• A. Filter dryers, flushing the system
• B. Purging with nitrogen
• C. Running the system with open valves
• D. Recycling refrigerant

Answer: (A)

Non-condensables are gases (like air or nitrogen) that won’t condense at the system’s operating pressures. They raise head pressures, reduce cooling efficiency, and can cause improper refrigerant charge behavior. To remove them, you typically purge and flush the system while a dryer is in place. Flushing pushes the non-condensables out through the service ports using an inert purge gas, and a filter dryer helps remove moisture and any entrained contaminants that can accompany those gases. Using a dryer and flushing together gives a more complete cleaning of the system than either alone. Opening valves with the system running would just leak refrigerant and is unsafe, while recycling refrigerant doesn’t address the non-condensables themselves. Purging with nitrogen is a valid method, but the combination of flushing the system and using a filter dryer is the standard, effective approach.