AHU/Heat pump refrigerant mix

Hello everyone, my name is Chris Phillips. I just got my CPI certificate, I’m new to the profession, and currently working on getting my home inspection business up.

I have found this forum to be really resourceful and typically find whatever questions I have by searching for it within this forum, but recently came across a situation at my wife’s parents which was for a mock inspection.

They have a split system HVAC with a Rheem air handler unit in the basement and a Carrier heat pump outside. My issue is that the heat pump data tag says to charge with R-22 and the AHU says to charge with R-410a. I’m sure that the HVAC techs wouldn’t have installed a system that is completely incompatible with one another, so how would write this up or explain this to the client?

If the system operates - blows hot / cold air at the appropriate temperature settings - that’s as far as you go. Check for air delivery in all the habitable spaces (report rooms without registers). Report on the filter size and access and your done. Don’t diagnose!

It looks like the air handler is newer (2016).
Normally, you wouldn’t pair equipment that require different refrigerants.
However, R22 is still available and most likely what is in this system.

See if your in-laws have the service ticket/invoice.

On Bob’s response …spot on.
Run this one down if you want to satisfy your curiosity and education.
However, if an inspected system is operating properly per SOP standards, note it and on to the next item.

1 Like

The system is still R-22. A new coil was installed.
R-22 operates at much lower pressures than R-410a so it’s ok, but not if it were the other way around.


Awesome, thanks guys. I’ll stick with the SOP, test the functionality, and move on. I’ll ask if they still have an invoice.

Before I moved on, I would also let the client know that the outside unit is 19 years old so even if it was working fine today, be aware that it might not last much longer, based on average service life of units of this type.

1 Like

You never know. Got the same condenser I had 30 years ago. Back then it ran R-12!

1 Like

I inspected an apartment complex a couple months ago. Out of 56 apartments, over 20 still had the original 1982 carrier heat pumps. 38 years old!

1 Like

(6) General Exclusions.
(a) Home inspectors are not required to report on:

  1. Life expectancy of any component or system
1 Like

That’s right, David. Commenting on the life expectancy of any component or system is not REQUIRED by our SOP. I go beyond the minimum in many aspects of work and life.

I hope your health is improving. You are in my prayers, buddy.

1 Like

I report the age/average life expectancy as well. If nothing is wrong with the unit at the time of the inspection, I recommend “Monitor and budget for replacement as needed by a licensed (plumber, HVAC technician, etc)”. Just done an inspection with a 38 yr old water heater, still working fine, no visual damage/defects.

1 Like

This is all good info, I was wondering how some of you handled the appliances that are beyond it’s life expectancy. Do you recommend further evaluation and servicing of these older appliances if no service dates of the units are available, or just recommend monitoring?

What I Reported on For the heat pump, was that it was Beyond its life expectancy and further servicing and evaluation was recommended.

If in good condition, working fine, no damage/defects, I do the same. Age/average lifespan, monitor, etc. I add this as well “An heat pump should be serviced annually and the filter changed/cleaned about every month as needed. Keeping the heat pump properly serviced and maintained will allow for it to run efficiently and help reduce utility costs.”

As would I…
But when it comes to HVAC life expectancy, it’s like predicting when a light bulb will burn out.
Also replacement vs. repair comes into play.

I had a rental property that I had a good friend in the HVAC business who I had working on it for years. On three occasions there was a problem where he recommended I replace the whole unit because it used R-22 refrigerant (was being phased out at the time and getting expensive). Three times I repaired it for less than $45. It finally blew the compressor (broken shaft in a scroll compressor), unheard of!! Then someone stole it off the house! So the insurance payed me for 2 1/2 units, which I installed myself!

My point; often we recommend replacement which is not always the correct course of mitigation…