Change out the furnace too?
Existing: Rheen 60 000 BTU furnace and Goodman 2 Ton AC … work well in a 13 year old home with good building envelope
Proposal: change the AC to a heat pump of comparable size (~2.5 ton)
Question: the HVAC contractor wants to change out the furnace too. Is it feasible to change out the heat exchanger in the plenum (for the heat pump) with the existing A-coil?
How many more years does that furnace have?Why increase the A/C 25%?
Can the ducts handle the extra air flow?
What the static pressure on the existing duct system?
Whats the manual J load/loss numbers?
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Originally Posted by pecmsg
All good questions …. the first question if the most important and difficult to ascertain.
The ductwork was measured and is apparently appropriate for the upgrade. The company rep made measurements to calculate ‘roughly’ heat loss/gain. Thanks for the input.
I would ask for the numbers.
90% of what we see is oversized equipment on undersized ducts.
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2 questions…. how does the current ac keep up in hot weather?
Next question is what’s wrong with the current system?
Going bigger is almost always a mistake.
As far as going to a heat pump system on the current furnace, that’s not an issue.
However in order to get rebates, you’d have to have a matched system
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Existing: Rheem 60 000 BTU furnace and Goodman 2 Ton AC … work well in a 13 year old home with good building envelope
Proposal: change the AC to a heat pump of comparable size (~2.5 ton)
Question: the HVAC contractor wants to change out the furnace too. Is it feasible to change out the heat exchanger in the plenum (for the heat pump) with the existing A-coil?Is the furnace only 13 years old? Depending on your location/usage, it could be ok. In Houston, a 13 year old furnace would probably still look new.
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Both heating and cooling systems work fine and are adequate to our needs, but, like all appliances, end of life cycle approaches too. I suspect you’re correct about the requirement of a ‘matched’ system. Thanks.
You need to be aware that the heat from the heat pump is not as hot as the heat from the furnace. Most folks who change from a natural gas furnace to a heat pump complain about the “cooler” air., and regret it.Why change to a heat pump? Is the cost of electricity cheaper than the cost of natural gas in your area?
Philippians 4:13
I can do all things in him that strengthen me.
Apostle Paul inspired by GOD.
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Yes, I’m aware of the temperature differential that moving from NG to HP would be noticeable but have been in many homes heated with hydronic and/or HP systems that were fully comfortable. As long as SCOP stays above 3, the saving can warrant the system change, over time. (I’ll admit …. I’m ‘anal’ about my environmental impact …. and disgusted how my generation has abused energy consumption when using fossil fuels …. but that’s another story.)
Besides the cooler supply air temperature with the HP, they also go into defrost mode occasionally for a few minutes and your basically in A/C mode. Rebates and the federal tax credits typically start at 16 SEER and a furnace efficiency of 95% or higher. Did not see where your located so if your down south you may have a 80% ? To get money in your pocket rebates the system needs to be AHRI rated with a number to submit.If you keep furnace recommend a lower SEER rated AHRI matched system, as typically a higher SEER ( up to ) outdoor unit will not actually get those higher ratings with a older furnace. You don’t go by the rating of the OD unit alone for SEER and EER, ( hopefully the bidding Contractors don’t let you believe you go by outdoor unit ratings only is what your getting ) it’s a combination of indoor selection to outdoor unit that gives you your ratings ( not really real world numbers thou )
https://www.energystar.gov/about/fed…ty_tax_credits
Ask for the AHRI number if your doing rebates from your state/local utility company. Check at this site to make sure it meets your states minimum requirements.
https://www.ahridirectory.org/
Starting in 1/23 they are raising the minimum SEER ( SEER2 ) ratings from the current 13 SEER to 14 SEER for northern states and from the current 14 SEER to 15 SEER in southern states. They are also changing how SEER rating is calculated going from SEER to SEER2 rating which reflects more of a real world efficiency.
Try to have them do a accurate startup/commissioning report on your new system such as this guide.
https://www.energystar.gov/sites/def…0_Rev%2011.pdf
Make sure to register each section including indoor coil as manufacturers warranty decreases if system never gets registered.
Last edited by Bazooka Joe; Yesterday at 04:56 PM.
Rheem makes GREAT furnaces. Rarely lose a heat exchanger. I wouldn’t take it out unless it is having trouble. Same with A/C. Sis has field test furnace. It was when they were testing the 90% 34″ tall models. 1993. Still purring AlC was 1995. Big dog piss hole in the coil but also purring loudly along. Not a scroll compressor..3 of us at the office have dual fuel. The last couple years we didn’t heat with the heat pups because we found it was cheaper to heat with out 95% furnaces. That can change but right now that what we have.