Replace 16 y/o old Heat Pump...

[Chuck in NC]

Bought my retirement home in 2019.  2200 sq ft heated/cooled.  4 BR upstairs.

My 3.5 ton heat pump/air handler was installed in 2006.  Air handler installed in attic.  This is a 3-zone system.
Zone 1 downstairs (kitchen, LR, DR, Study).
Zone 2 Upstairs (Master suite + 2 small bedrooms/1 bath).
Zone 3 Upstairs 1 large finished bonus room/bath.

I have only had the occasional repair issues.
  Full service performed when I bough the house, added a little R22.
  Cap failed 1 year ago, replaced and all good.

I thought about replacing the system and got quotes from 3 HVAC contractors in the area.

1st quote $9300 to install new 3.5 ton system.  No details.

2nd quote $8800.
   Install 4-ton, 14 SEER Carrier Heat Pump/Air handler. Leave 3 zone system intact.  Replace all zone dampers, new zone control board, new Zone Bypass damper, digital thermostats for each zone.  New drain pan and float switch for air handler.
      Contractor recommended 4-ton system but did not provide me with a load calculation.  He told me the 3.5 ton was borderline for the installed system.  He offered to provide a 3.5-ton Carrier at a cost of $8500.

3rd quote $10,200.
  Install 3.5 ton Goodman heat pump/air handler.  Modify dampers/ducts to convert to 2-zone system (separate for upstairs/downstairs).  Similar to 2nd quote except to provide motorized bypass damper with static pressure control.  

The costs seem high but I am pretty frugal.  The costs might be in line with current inflation/limited-supply driven events.

I am trying to figure out why the installed system would attempt to use 3 zones with independent thermostats to adjust temperature for each zone.  The fan is fixed speed.

Let's say all zones are at their cooling setpoint.  Then Zone 1 goes above temperature setpoint.  When the fan comes on, the system will only have Zone 1 damper opened.  So there would be full air pressure being supplied to 1/3 of the load.  I guess the bypass damper will recirculate 2/3 of the COLD air (is that a good idea?).

Wouldn't the 2 or 3-zone system system work better with a variable speed fan control?

The high cost makes me wonder if I should just wait until the system fails to replace.  (probably in the dead of summer or winter).

Should I run window AC units in each of the upstairs bedrooms and downsize the current system to downstairs only?

My biggest concern is the cost.  Is there any chance the cost of these systems will flatten or go down in the future?

[R Clark]

I'm in the "leave it till it fails" camp.  

The original heat pump (installed 2004) on this house made it 14 years until the compressor quit.  It was a heat pump over electric heat strip auxiliary.  I replaced it with a 4 ton 14 SEER Trane Heat pump over propane burner auxiliary.  Cost was about $10,500 installed.  The new unit allowed me to size a new backup generator that can run the AC/Heat Pump.  The old system would not run on a generator because of the high amp electric aux unit.

If I had it to do over again, I think I would install geothermal.  Yes, much more cost up front, but much less demand on backup power and no (rising) fuel costs.  Of course, this is our forever home and we will be here long enough that I could get the payback out of it.  I also have the perfect property for the installation. 

As to the window AC units:  I really don't think that's a viable solution.  IMHO, they look horrendous, are loud, and limited in capability.  You might consider a mini-split instead, but if the old unit cools the upstairs sufficiently, the new one should as well.  I don't think adding more systems seems like the best way to go.

[Chuck in NC]

I'm in the "leave it till it fails" camp.  

The original heat pump (installed 2004) on this house made it 14 years until the compressor quit.  It was a heat pump over electric heat strip auxiliary.  I replaced it with a 4 ton 14 SEER Trane Heat pump over propane burner auxiliary.  Cost was about $10,500 installed.  The new unit allowed me to size a new backup generator that can run the AC/Heat Pump.  The old system would not run on a generator because of the high amp electric aux unit.

If I had it to do over again, I think I would install geothermal.  Yes, much more cost up front, but much less demand on backup power and no (rising) fuel costs.  Of course, this is our forever home and we will be here long enough that I could get the payback out of it.  I also have the perfect property for the installation. 

As to the window AC units:  I really don't think that's a viable solution.  IMHO, they look horrendous, are loud, and limited in capability.  You might consider a mini-split instead, but if the old unit cools the upstairs sufficiently, the new one should as well.  I don't think adding more systems seems like the best way to go.

I have a window unit that I keep in the garage for extended blackout periods following tropical disturbances.  It runs on my portable generator. 

I don’t think the window units would be a realistic long range solution for us. 

This is our forever home so I will install a more permanent solution.

[rudedan60]

My system that was installed in WI is a 3 Ton Concord Lynx 18 SEER Heat Pump w/ Cased Evaporator Coil. and a Furnace Concord 70K 2stage
95% Variable Speed Gas Furnace. The Heat pump was $4575 as was the furnace.  The whole install was $10,600.  Of course the state rebate gave me $1000 back. It has worked very well for us it has kept my gas bills down, I also have a solar system that works when it is not covered in snow. Dan

[Snipe Hunter]

Have no idea how a Goodman system could possibly be more expensive than a Carrier system. I would have guessed the Goodman would be a good bit cheaper.

#1, no Details. I suspect it's a cheaper unit like a Goodman or York. Both are loud systems.

#2. Carrier... no brainer, I'd do this one.

#3 Goodman. No, not at this price

Usually zoned systems are installed because of the layout of the home. Multiple levels? It's a less expensive alternative to 2 heat-pumps.

[fredhargis]

Read Neil's post again and follow his advice...that's certainly what I would do.

[JosephP]

Did anyone do heat loss calculation? Why did #3 go to 4 ton? If 3.5 is the right size, stick with that...but if it is too small, yes, get the higher capacity unit.

Ask for more details on #1...

Is anything wrong with current damper system? What is the typical life expectancy of those?

What does "Contractor thinks 14" mean?

[Chuck in NC]

Read Neil's post again and follow his advice...that's certainly what I would do.

Did anyone do heat loss calculation?  Why did #3 go to 4 ton?  If 3.5 is the right size, stick with that...but if it is too small, yes, get the higher capacity unit.

Ask for more details on #1...

Is anything wrong with current damper system?  What is the typical life expectancy of those?

What does "Contractor thinks 14" mean?

The current dampers and damper controller are original.  I had a problem with the control board in the past and had to move the controls for one zone to a different controller board terminal.  I am okay with replacing them while they are installing the new system.

"Contractor 14" was a typo.  Corrected and added details about capacity.

When the home was built there were 3 bedrooms and an unused "Bonus room".  The bonus room was finished and added to the system 5-10 years ago.  I am not sure whether the existing (original) heat pump system was sized to accommodate the addition of the 400 square foot bonus room, or if the previous owner just added it on.

[Oldwood2409]

i just installed a 4 ton heat pump in my new shop. My good friend, who is a HVAC contractor did the job at his cost ( and I helped). 4 ton heat pump, 10Kw heat strips, new programable thermostat, air handler , vents and etc. Cost was 4600 for material only.The units are American Standard and have a 10yr material warranty. The unit is a 14 SEER and is cooling a 1600 sq ft shop. Lengthy discussions with my friend, going to a higher SEER rating will cost more and adds significant complexity to the system. We were able to install the system, including duct work in 1.5 days with just the two of us.

[Oldwood2409]

i just installed a 4 ton heat pump in my new shop. My good friend, who is a HVAC contractor did the job at his cost ( and I helped). 4 ton heat pump, 10Kw heat strips, new programable thermostat, air handler , vents and etc. Cost was 4600 for material only.The units are American Standard and have a 10yr material warranty. The unit is a 14 SEER and is cooling a 1600 sq ft shop. Lengthy discussions with my friend, going to a higher SEER rating will cost more and adds significant complexity to the system. We were able to install the system, including duct work in 1.5 days with just the two of us.