Author Topic: Replacing AC unit only or whole system?  (Read 1420 times)

emiloots

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Replacing AC unit only or whole system?
« on: March 03, 2017, 08:19:51 PM »
We bought our house this past summer, it was built in 2003 - typical builders grade AC (actually undersized for our house so it works overtime), 80% efficient propane furnace.  We have a new EPA wood stove which we use to reduce our propane use in the winter significantly.  So...our AC is on it's last legs, but both systems are 14 years old.  Our options are:

1.  Just replace the AC unit with as efficient of a unit that our furnace can accommodate (no 2-stage or variable stage units will work with our furnace - which happen to be the most energy efficient)  Cost ~6300

2.  Replace both the propane heater and the AC unit, upgrading both to more efficient 2-stage systems and we'll be set for the next 15 or so years Cost ~11-13k depending on the exact units we choose (also includes putting 2 heat vent drops in our unheated basement)

I'll kick myself if we just replace the AC and the furnace goes shortly thereafter, but monetarily it's a bill pill to swallow.
« Last Edit: March 03, 2017, 08:22:08 PM by emiloots »

awilbur27

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Re: Replacing AC unit only or whole system?
« Reply #1 on: March 09, 2017, 04:42:31 PM »
Depending on where you live and the size of your house, it might be worth the money to convert to a heat pump to get both A/C and heat.  They are crazy efficient.  I nearly installed a heat pump in the building I was renovating, but was talked out of it because they may quit on you if the temperature ever falls below -15 or so (not great for Maine!)


bacchi

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Re: Replacing AC unit only or whole system?
« Reply #2 on: March 09, 2017, 04:56:28 PM »
Replace them both. The furnace is probably on extended life support as it is and they're meant to work in pairs.

Yeah, a heat pump is definitely the way to go unless you can get natural gas. From these two sources, propane is the most expensive fuel used to heat a house. Except for maybe burning dollar bills.

http://shrinkthatfootprint.com/wp-content/uploads/2015/09/USprices.gif
https://www.nh.gov/oep/energy/energy-nh/fuel-prices/


emiloots

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Re: Replacing AC unit only or whole system?
« Reply #3 on: March 09, 2017, 08:02:37 PM »
Thanks for the responses, I'm leaning towards replacing both as well.  We might try and limp through this summer and pray the AC doesn't die in the process so we can have the full amount in cash to do the work.

WhiteTrashCash

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Re: Replacing AC unit only or whole system?
« Reply #4 on: March 09, 2017, 08:07:32 PM »
From the age of your system, you are better off just replacing both. It will be less expensive in the long run.

BlueMR2

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Re: Replacing AC unit only or whole system?
« Reply #5 on: March 11, 2017, 08:09:04 AM »
I was in a similar situation about 2 years ago.  I had a high end furnace with A/C and had just dropped a new (expensive) fan motor in the system that Winter only to find the A/C was dead just a few months later.  19 years old on both and the HVAC guys said the furnace could easily go another 5 years and possibly 10 based on his experience.  I ended up replacing both anyways as the labor was virtually free for the furnace (as it all has to come out anyways to get at the A/C).  Even though I was already high efficiency, the new one was slightly higher, so there was a tax credit.  Plus replacing before 20 years got me a credit from the manufacturer.  Initial quote was $10k, but at completion (with manufacturer credit) it ended up being only $6900, plus then another $500 tax credit.