2 AC units and 1 air handler

Today I had an hvac system that appears to be 2 ac compressor/condenser units connected to 1 air handler unit. Could I have missed a air handler or this sometimes used. There was a thermostat for the upstairs and one for the downstairs.

Not one in the attic?

No, we looked and could not find one in the attic.

Did the handler have zoned duct dampers depending on what was called for?

You should have seen two sets of Freon lines then I would think.

One furnace as well or heat pumps?

Two thermostats and two condensers would mean a zoned or dual split system, would see/trace line sets as Bob said… Did you see zone controls at equipment? Many thermostats for Zones are identified as such.

I’d recommend to isolate handler operation by using individual thermostat to call for condensers individually, then identify the handler being called for… allow the system to cycle down then repeat for second control. Just an idea.

Pic?? Seeing multiple coils on the distribution portion of the system would be indicative as well.

I would say if you don’t individually operate the condensers one at a time or have pics… it would be hard to provide information… Is it a situation where you can explain and go back or let them know you don’t have an accurate description of the components?

Picture from a newer zone control and damper for reference.

How big was the home?
Did it have a split or (double evaporator )

I’ll go back today and do more investigation based on what some of you have said. Thanks so much.

Was one a package unit outside???

Back when I had the heating and cooling company, we ran across air handler with two A-coils and two outside condensing units. The second A-coil kept freezing up. I wonder why?](*,):shock:

I think you have it Sean.

Someone needs to take some NACHI classes I guess…

There is no residential application that uses two condensers. Two evaps, maybe.

Did they look like this?

This is one package and one split.

Unless they are window units…:slight_smile:

I thought you meant 2 compressors . I think Sean may be right

Sorry guys, I am embarassed to say. We asked for the lock box code and went back in. There was a brand new Trane air handler in the attic. Jr. got a little lazy and took the easy way out. Lesson learned is to keep up with your inspectors and make sure the inspection passes the smell test. Thanks again for all your comments and I learned some things from your input I would not have had I not asked the question. The Nachi message boards are the best!!!

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I actually have two Compressors and one air handler. The thermostat has two control arms that are linked together (move one control and the other moves). It appears that the second compressor only comes on during high demand times. I am not a HVAC person at all and have no idea how it works. I was just wanting upgrade the old manual thermostat with one that can be programmed.