Decisions Decisions Upstairs AC crapped out after 40 years

[Bigbandguy]

My Trane "Executive High Efficiency " AC has crapped out after only 40 years. It is a 2.5 ton unit that has cooled the upstairs of our house since the place was built in 1985 (I am third owner) So far we have quotes on Goodman and Rheem units (model numbers to follow) but there are so many models that I am not sure which would serve better. I cannot see an advantage to variable speed units but I am sure the experts on here will have some good opinions. We are old so a 20 year service life would be plenty. Thoughts? and thank you all.

 

[fitter30]

The higher the seer the sharper the service person as to be. Might need a laptop with the correct program to look at all the sensors and expansion valve. Programs might update 2-3 times a year. Say this all the time. Contractor has to committed to high efficiency equipment.Training and the tools. Have the sharpest service person but the install crew is just as important.

 

[PoorUB]

Buy low/mid SEER, single stage, keep it simple! All this variable speed, inverter driven equipment takes a good tech to get it installed and working properly and most will not take the time. Also, it is not as dependable as the plain Jane single stage equipment. Any savings on utilities will be easily spent on service calls.

I had a friend build a home and bought a Bosch cold weather heat pump set up. The guy that installed it couldn't get it to work properly and he was a dealer and installed many of them. After the first year was up the contractor told my buddy, no more warranty, and he was charging for every service call even though he never got the unit working properly from day 1.

My buddy asked me to take a look. He was a few miles out of town so one Saturday I ran out and spent a couple hours looking the unit over, I went back a week later after cramming in some time studying the manuals and thinking of options. This was equipment I had never seen before. I spent an hour on he second trip and when I left it was working like it should have been from day one. All I did was add an out door sensor to the existing thermostat and reprogram the 'stat and it worked great. Why the original installer couldn't figure it out I will never know.

 

[Codyboy]

What's wrong with it?

 

[Bigbandguy]

What's wrong with it?

40 years old, lost charge.

 

[Bigbandguy]

Buy low/mid SEER, single stage, keep it simple! All this variable speed, inverter driven equipment takes a good tech to get it installed and working properly and most will not take the time. Also, it is not as dependable as the plain Jane single stage equipment. Any savings on utilities will be easily spent on service calls.

That is what we are looking at.

 

[Bigbandguy]

One of our estimators wants to install new duct work. The other did not mention it. The one who wants to said that the cover over the duct insulation is deteriorating. In a few places it is, but my thought was to wait till it is finished and then go up there with insulation and tape. I cannot see 5 grand for new ducts.

 

[PoorUB]

One of our estimators wants to install new duct work. The other did not mention it. The one who wants to said that the cover over the duct insulation is deteriorating. In a few places it is, but my thought was to wait till it is finished and then go up there with insulation and tape. I cannot see 5 grand for new ducts.

Is it metal duct with insulation over it?

 

[Bigbandguy]

Is it metal duct with insulation over it?

Yes, pretty sure it is all like that. Did they even use plastic ducts in 1985?

 

[PoorUB]

Yes, pretty sure it is all like that. Did they even use plastic ducts in 1985?

They had flex or some sort and fiberglass duct board.

If it is it metal duct I see no reason to replace it as long as it is sized properly and in good condition. The insulation on the outside can be replaced. If you have the insulation off, I would check over the joints in the duct and reseal them as needed.

 

[Bigbandguy]

They had flex or some sort and fiberglass duct board.

If it is it metal duct I see no reason to replace it as long as it is sized properly and in good condition. The insulation on the outside can be replaced. If you have the insulation off, I would check over the joints in the duct and reseal them as needed.

Pretty sure it is metal. It is in good shape with only a couple of places where insulation is even showing. I could easily tape those up. Ducts have not been disturbed and air flow was good with the old unit. Thanks very much for all the info.

 

[nadogail]

Solar Panels and a Heat Pump.

 

[BillK]

Someone else already asked this but .... what is wrong with your old unit ?? Might be a simple fix and keep it going. Personally our system is about 25 years old and working fine but if I had to replace it I would be looking at the absolutely simplest system available. Keep it simple and dont worry about the efficiency. One crazy electronic problem on a real high efficiency unit will do away with any savings you get.

I am saying this even though one of my best friends in my HVAC guy He would suggest the same thing.

 

[BurtEggley]

he said it lost the charge.

The cost of energy is only going up. Is this a heat pump or AC only? I would have a air leak test done before replacing it to see how sealed the ducts are. If you have 20% leakage, that 20% may be lost. Deduct 20% from your annual cooling bill and see how much that is, then compare it to new ducts. Lots of that 80's stuff was fiberboard. Much of the steel ducting has rusted or is not sealed with mastic.

 

[danski0224]

I would have a air leak test done before replacing it to see how sealed the ducts are.

I can guarantee that damn near every residential duct system installed prior to the adoption of the 2012 energy codes has a minimum of 20% leakage.

I have personally tested 30% leakage.

Unfortunately, testing methods and reports can be falsified.

"Sealed ductwork" does not mean that the ductwork is properly sized, or that it flows air properly.

 

[Bigbandguy]

OK here is what we did. Goodman 2.5 ton single speed. Kept the duct work. It was undisturbed in the attic and 98 percent of the plastic wrapping was intact on top of the insulation. Unit is mostly only used at night. Company was well recommended and was in and out in a day. I am pleased with the work and the 90 degree weather that is predicted for tomorrow can kiss my A**.

 

[PoorUB]

Glad it worked out.

If you are ambitious and want a project I would be tempted to rip of a bit of insulation ans see if the joints in the duct are sealed, then re-insulate. Attic air can loose a lot of efficiency from leaking duct and poor insulation.

 

[scooterbum46]

Someone else already asked this but .... what is wrong with your old unit ?? Might be a simple fix and keep it going. Personally our system is about 25 years old and working fine but if I had to replace it I would be looking at the absolutely simplest system available. Keep it simple and dont worry about the efficiency. One crazy electronic problem on a real high efficiency unit will do away with any savings you get.

I am saying this even though one of my best friends in my HVAC guy He would suggest the same thing.

When I replaced my '92 Goodman 3 ton in 2024, the primary reason to replace rather than refurb was the low availability/high cost of the Freon in use in '92. My tech company wouldn't even talk about a refurb..

I am very happy with the multi-stage heat pump and furnace combination from Carrier, and agree that a good installation/setup and first startup were dependent mostly on the involved techs..

 

[danski0224]

see if the joints in the duct are sealed,

They won't be, maybe a house in California could be an exception.

 

[PoorUB]

They won't be, maybe a house in California could be an exception.

I agree that they won't be sealed, but stranger things have have happened!