First time I've seen this...

Two furnaces, two A-coils, one condenser unit, one plenum, one thermostat; all installed in tandem. I’m just wondering if there’s anything specific I should be aware of with a system installed like this or would it all be way outside the concerns of a home inspector?

Thank you in advance.

I have inspected numerous set ups like yours mostly on light commercial I have had several churches with that set up, nothing wrong. Can be on a single thermostat or a zone system just be aware of what you have.

Just remember the more you know and the more info you provide the client the more you charge for the inspection.

Just operate the unit from the thermostat and tell the client yes it operates you charge $199.00

Operate the unit from the thermostat explain to the client how it operates and what he can do to make it more efficient you can charge $400.00 to $500.00 your choice:p:D

Lets delve into that. :slight_smile:

  • regular maintenance is a gimme.
  • keep the filter changed and edges sealed to prevent blow by
  • have coils and ducts cleaned regularly
  • seal every joint in the ductwork you can
  • insulate the ducts in unconditioned spaces
  • balance the airflow to rooms by properly sizing ducts and using dampers?
  • Purchase and/or program a programmable thermostat
  • air seal and insulate everything
  • control indoor (basement) humidity?
  • have fan speeds on blower/s set correctly?
  • have gas/air mixtures at burners properly adjusted?

Are those a good start? Which ones matter, which ones don’t? What other more involved steps can be taken? :slight_smile:

That is a good start I am writing a report that has to be out. I would like to go into some about return air systems had a good example on todays inspect

Look forward to it. I’ve been trying to figure how to add return air to the two bedrooms at my second floor, I think it would significantly improve the air temp up there.

I highlighted in red what I would consider the most important concerning efficiency.

All my years working in the industry I would list as my # 1 item concerning efficiency would be the return air system as a whole. Just because a contractor has the correct amount of sq inches of return air openings for a given tonnage does not in itself make a balanced system. To me tthe most important is where the return air is taken from.

The least efficient return air is the one we refer to as a local return, the return air grill is directly above or directly below the furnace no duct work just a plenum. This type system does not allow for even distribution of air and there will always be hot/cold pocket within the home

The home I inspected today was just over 3300 SQ FT two systems one upstairs and one down stairs each system having its own thermostat. The Realtor had it listed as zone central air. This type installation is not a zone system its simply put two systems.

The downstairs foot print had 3 bedrooms ,1 full bath and one 1/2 bath on one end of the home. I will call it the south end, the south end had a hall with the return air grill in the ceiling. No other return grill down stairs the north end had the master bedroom/bathroom these bedrooms were seperated in the center of the home with the living rooms, kitchen and family room.

This is horrible set up the master bedroom stays hot in the summer cold in the winter no circulation except beneath the door. Most reasonable people except Linus sleeps with the bedroom door closed.

I snooped around the home until I found a easy way to install a return air in the master bedroom and informed the client that this would make the system more efficient and help with the hot/cold spots in the home. Did I put this on the sellers repair list absolutely not this was just info for the buyer to do with as he pleases. I will post a couple of pics from the attic above the first level the second level consisted of one large game room and a upstairs bathroom. The upstairs area had attic areas on all four sides of the room and also above the room, made it very easy to add additional return air ducts