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  1. #1

    Reuse 1 yr old furnace in attic and match coils to condenser?

    Hi all,

    We just purchased a home and are in the process of moving the current furnace to the attic so that we can get some more space in the house. I'm having trouble deciding what of the current furnace and AC system to reuse and what to replace.

    Our general contractor told us that it is risky to reuse the current furnace because parts in the furnace get brittle after use and might break during the move. I also got a quote from an HVAC specialist and the specialist said reusing the furnace is fine. Both individuals are reputable, so I'm not sure what to make of the differing opinion. Which person is right, and what would you do?

    The furnace was manufactured in 2011 and is a Bryant Legacy 80 Model 310JAV04209 with 84-88k BTU/hr depending on orientation. We'd have to change the orientation of the furnace from up-flow to horizontal flow if we were to reuse it.

    Our general contractor is suggesting to replace the furnace with an 80K or 100K 80% Frigidaire furnace that is roughtly $$$. I'm not sure which model, and I don't know if it's going to be better or worse than the current furnace in terms of performance.

    I also have a dilemma about the AC because we also need to replace the AC coils because of the airflow direction change. Our AC condenser is a Frigidaire FS3BA-036KA 3 ton, using R-22. The unit was manufactured in 2005. Our general contractor and the HVAC specialist have recommended replacing both the condenser and the coils, but the cost is significant.

    A replacement AC system is $$$$ for a 3 ton system (Payne PA13NA0336000 13 Seer), $$$$ for a 3.5 ton system (Heil N4A342AKB) or $$$$ for a 4 ton system (Fraser Johnston TCGD48S41S3), installed. Alternatively, we can just try to find new coils to match our old Frigidaire condenser for $$$$.

    I'm not sure if trying to match the coils will be a waste of money and time, or if it's worth a try. We live in northern California, and so AC is not a major concern.

    If the recommendation is to go with a new AC condenser, I'd appreciate any guidance on picking the best condenser.

    Last edited by beenthere; 01-17-2013 at 07:35 AM. Reason: Pricing

  2. #2
    Join Date
    May 2000
    Indianapolis, IN, USA
    The maroon (that's Bugs talk) that said furnaces get brittle after use sounds like a crook. There's absolutely no reason to trash a 1 year old furnace. You could get a new horizontal coil and keep the 7 year old A/C or replace it. Typical life of an A/C is 12-17 years so obviously have life left in it. Why go 33% bigger on the A/C? If you do you need to add 33% to your supply & return duct system and number of registers & grilles. Also the blower on the furnace isn't big enough for 4 ton. Then you'd have to replace the furnace - or maybe that's what that dealer is trying to do.

  3. #3
    Join Date
    Jan 2004
    Yep, reuse furnace, and condenser.
    Contractor locator map


    How many times must one fix something before it is fixed?

  4. #4
    Join Date
    Sep 2003
    Without question reuse the furnace and get a new coil to
    match and reuse the a/c.

    When changing the orientation of the furnace from upflow to horizontal
    make sure that a secondary drain pan and secondary drain line or wet switch is also installed
    when switching to this configuration

  5. #5
    Join Date
    Mar 2005
    burlington county n.j.
    reuse furnace and condenser.

  6. #6
    Join Date
    Jul 2000
    Northern Wisconsin
    Not sure where your GC is coming from, but I have my suspicions. No matter, taking his advice over a qualified HVAC contractor is like asking your car mechanic if he thinks you should have surgery or not..... IMO.

    First off it sounds as if the remodeling is going to place the furnace in an area that is smaller and maybe a bit harder to get to for service and the eventual change out down the road. Does it make sense to you to move the existing furnace after talking with the HVAC expert? If this HVAC contractor moves the furnace, can they and are they going to be the ones that will service it and perform any possible warranty work on it as a whole system?

    Secondly I'd suggest you balance the savings you might see short term on any options against the long term. This includes heating and cooling costs, maintenance, repairs, yearly service etc.. The cost of the HVAC portion of your remodeling project is going to be added to the monthly mortgage cost I am assuming. If you're getting good financing rates on the money you're borrowing I can pretty much guarantee you that you'll never be able to borrow that same amount of money at better rates at a later date to replace either part of your HVAC system. Factor into those thoughts that once that equipment is moved into a smaller space and the line set from the coil to the outdoor condenser is buried that any changes that need to be made are going to cost X amount more than they will now.

    Third thing is the AC. Yes it will probably be just fine to reuse the outdoor unit and just get a horizontal coil for it. This option reduces the cost during the remodeling process. But, is the savings of X amount at X percentage rate of financing the most cost effective option? Maybe now is the time to get numbers on upgrading the AC to a heat pump system that will give you the option of heating with an 80% gas furnace or a HP. The savings that you could possibly save from the difference in cost of operation of one verses the other might (I stress might) pay for the added cost of your mortgage payment for the upgrade. And! you get an added bonus that you'd have two heat sources just in case there is an issue with one or the other

    Last thing to consider is a lot of HVAC equipment these days come with extended warranties. You might find options for both the furnace and the AC or a HP that come with as long as 10 year parts and labor warranties. How much to factor in for potential savings for the potential cost of repair work on the equipment over a 10 year period no matter whether you change both or neither of them is anyone's guess........... but it is something to think about and add to the thought process.

    I know, you were looking for a simple answer to what was a simple question. I apologize. I just hate to see someone not consider all the options simply because they weren't aware they existed.
    Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.

  7. #7
    Join Date
    Aug 2012
    North Dakota
    keep the equip. get a new general cont.

  8. #8
    Join Date
    Jul 2006
    Reuse furnace and due to r22 refrigerant going away probably would get a new coil and condenser

  9. #9
    Join Date
    Jan 2009
    Keokuk, IA
    Northern Cal?.... must be a big home to need an AC even that large. You want the smallest ac possible that will maintain temp in desing conditions. Which where you are is probably not even 90F and very little humidity overall. Most furnaces on hte west coast and the south end up oversized so the blower is large enough for the AC needs.

    IN California, I think the high electric rates are not favorable to dual fuel.

  10. #10
    Hi everyone, thank you for the responses.

    I think the consensus is to go with the HVAC specialist and reuse the current furnace. I am currently asking the HVAC specialist about the viability of reusing the condenser and the approximate cost and availability of the replacement coils. The current condenser has a warranty that lasts until May 2013, so we have a short window to figure out any problems. If the costs of reusing the condenser is similar to replacing the condenser, then we will go ahead and replace it.

    I assume that I the HVAC specialist will be able to service the system after the relocation, as that seems to be his primary business.

    If we have to replace the condenser, I think we can go with a 3 or 3.5 ton condenser. The HVAC specialist suggested 3.5 ton, and so we might just go with that. The house is 1660 square feet, and so going to 4 ton does not seem necessary, and it would be oversized for our current furnace.

    All of our expenses are being paid out of pocket, and we plan to move within about 5 years.

    Thanks everyone!

  11. #11
    Join Date
    Jun 2001
    Moore, Oklahoma, United States
    FWIW our 1600sqft 13 year old house has a 2 ton AC, it can keep it 75 inside on a 100 degree day. Unless your house has a lot of glass area or is leaky, 3 tons is plenty if not overkill.

  12. #12
    Join Date
    Aug 2012
    North Dakota
    have a manual J done on the house to get the right equipment , your comfort / happiness / money are @ stake

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