R-22 & 410-A Coolant Mixed Systems

Did an inspection last week and the exterior AC compressor was labeled R-410 coolant, but the cooling system in the attic was labeled R-22. We call this out. Although we only are required to test and report on the functionality of the unit was this the right thing to do?

Yes, simply check the system for functionality. If you have HVAC knowledge, training etc. all the better to help you inspect. However, its best to stay within the scope and SOP of home inspecting.

The coil was likely old stock and the system would be charged with R410A.


Scott, thanks for the reply. So was it the right thing to do or was it exceeding the standards in your view as a Master Inspector and we should not do point it out going forward should we see it again. We have no formal HVAC training, but we have done our research on what will happen with two incompatible systems and thought is waise to point it out to or client.

Ok for conversation but would most likely just create confusion.
When you recommend in your report, have a licensed HVAC company conduct a clean and check service, this would hopefully be noted.

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Did this very thing with my own system a few years ago - R410A condenser and slightly older R22 coil. We simply adjust the amount (added) R410A to compensate.

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Label under my hood reads 410a but the system has 12a. I know that because I put block-offs for the rear unit, vacuumed and installed 12a. 410a is not available off the shelves in Canada but 12a is and is compatible with the system.

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Don, I know that Scott knows his HVAC stuff…No offense, Marcel, and it sounds like you know what you are talking about, too. :grin:

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Report your observations.
Recommend referring to the manufacturer’s to see if that piece of equipment, model# evaporator can updated/converted to R401A refrigerant.

Converting HVAC Equipment from R22 to R410A refrigerant can be achieved in most cases. Line pressure is reduced.
Just my 2 cents.

I have been doing inspections since 2007and thus year was the first time I ran into this. My cooling guy stated that in the early days of the refrigerant change, if the test pressure of the coil was>300 PSI, they would change out the metering device , evacuate the system and charge with the newer refrigerant. This sounds like what you ran into? Frankly, until then, I NEVER even thought to check for evaporator and condenser comparability.