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Thread: opinions - 80 2 stage or 90 standard gas furnace

  1. #1
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    Which type of gas furnace is most cost efficient when you consider the differences in initial cost, utility bills, life span and repair record?

    80% 2 stage gas furnace or 90% standard

    90% 2 stage or 90% standard.

    I am trying to determine how many years it will take for a
    2 stage furnace to pay for itself or if I just want to stick with a standard.


    Thanks


  2. #2
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    Depends on what you're replacing it with, it could payback in a couple yrs, usually payback is five. With the cost of fuel today...you may break out even.
    Lifespan on equipment nowadays is warrantied for 20 yrs on 80%, limited lifetime on 90's.

  3. #3
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    If you are in a cold climate, 90+ for payback.

    Now FORGET COSTS, the 2-stage equipment is for COMFORT!

    What is your COMFORT worth?

    And to answer the question that normally follows... make sure they install a 2-stage stat to maximize your comfort level.

  4. #4
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    I agree with jultza...how ever most 2 stage furnaces have an ECM fan motor (DC Motor), this can save you big time on your electrical consumption.

  5. #5
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    80% furnaces are dinosaurs in PA. Go with the higher efficiency condensing furnaces.
    Training is important!
    Practical Training is a must!

  6. #6
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    Thread Starter
    Thanks for the help. I didnt even think about getting a 2 stage stat. Thanks again!

  7. #7
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    I have been told by one contractor that you don't necessarily need a 2 stage t-stat to run a 2 stage furnace; that you can set the 2nd stage to kick in after a certain time limit (i.e. 10 minutes if heat call isn't satisfied). Does this make sense?

  8. #8
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    Yes this is true, but why defeature a unit you paid for and the cost of upgrading to a two stage stat is minimal at best.

  9. #9
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    The question came up since I had upgraded to a digital programable single stage t-stat last year, and was wondering if it needed to be replaced with a new XV90 furnace. The contractor said he personally has a 2 stage t-stat at home, but has experimented with both settings with no noticable difference.

    I guess the real question should be: What benefits does a 2 stage tstat give with the new furnace that a 1 stage stat won't? As it stands now, the furnace will be 2 stage but the A/C will still be a 1 stage unit.

  10. #10
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    Originally posted by slab
    I have been told by one contractor that you don't necessarily need a 2 stage t-stat to run a 2 stage furnace; that you can set the 2nd stage to kick in after a certain time limit (i.e. 10 minutes if heat call isn't satisfied). Does this make sense?
    And to answer the question that normally follows... make sure they install a 2-stage stat to maximize your comfort level.

    Why, do you think I posted this?

  11. #11
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    Sorry about that, jultzya! I'm probably WAY overthinking things. Alot of the information I have found relates to a whole system (2 stage VS furnace with 2 stage A/C); just making sure what is right.

    On that note, in your opinion should I step up to something like a VisionPro 8000, or is that over the top/

  12. #12
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    I guess the real question should be: What benefits does a 2 stage tstat give with the new furnace that a 1 stage stat won't?
    Too answer this question first...

    The single stat will bring on the unit in the low fire position. Then after a timer (on the circuit board) times out it will automatically bring on the second stage, whether it is needed or not. Then the unit will continue to run till the stat is satisfied (shutting down while its still on high fire).

    The two-stage stat will bring on the unit in the low fire position. Then if the temp of the home continues to fall, the stat will bring on the high fire stage. After time the home warms to near the stat set point. At this time the unit will drop back to the low stage and continue to operate till the stat is satisfied.

    The benefits to this two-stage stat is that it will provide more even temps, equipment operates quieter on low fire, offers better air filtration, provides better humidification (optional), and lowers operational cost.

    All of which, add to your personal comfort.

    Originally posted by slab
    On that note, in your opinion should I step up to something like a VisionPro 8000, or is that over the top/
    No, the VisionPro is not over the top. Actually I would highly recommend it!

    Hope this helps you as well as the OP.

  13. #13
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    Is it true that most 2 stage motors are DC ?

    I've been told that a DC motor will save electricity as opposed to an AC motor. Is that true?

    What is the difference between variable speed and 2 stage?


    Thanks.

  14. #14
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    Thread Starter
    I was set on getting the 92% furnace but then another contractor gave me a good deal on a 80% 2 stage. Decisions, decisions. Dont know what to do.

  15. #15
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    Thanks, jutzya. That answered everything that I was wondering about. As always, I appreciate your taking the time to help.

    and to pagirl--I hope you didn't mind my adding the question to your post--it just seemed to parallel your theme. thanks

  16. #16
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    mmjh

    Don't be confused, the technology of DC will save you money. Without getting really technical, The new ECM motors use a pultzating DC current, your power curves are not wasted. The average household in the northern part of the U.S. and Canada can reallize a savings of about $227.00 a year..Some contractors are saying $800.00, (they are lying)

  17. #17
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    Originally posted by pagirl
    I was set on getting the 92% furnace but then another contractor gave me a good deal on a 80% 2 stage. Decisions, decisions. Dont know what to do.
    Forget the 80% furnaces. For what is required to do a "proper" install of an 80% furnace and the added savings of a 93+% furnace in your area, the difference for the 93% will pay for itself in a year.

    What kind of chimney do you have? It's location? Water heater?
    Training is important!
    Practical Training is a must!

  18. #18
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    In Peco country we ran the numbers and have actually gone back to heat pumps on furnaces, due gas /electric prices.But 2 stage is the way to go and the only thing is the venting in an existing home.Maybe we can help,if we serve your part of the Commonwealth.
    It's NOT the BRAND,it's the company that installs it!!!!!

  19. #19
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    Here's my 2 cents. The only reason to install a 80% 2 stage would be changing out and old furnace and it would be nearly impossible to vent the 90% (ie, completely finished basement and no way to run the venting up or out). With the 80% you could just tie it into the existing chimney.

    For what it's worth, the only time we really install a 80% furnace is the tract homes where the builder wants cheap cheap cheap.

  20. #20
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    Originally posted by pagirl
    I was set on getting the 92% furnace but then another contractor gave me a good deal on a 80% 2 stage. Decisions, decisions. Dont know what to do.
    Remember this one very important saying....

    You get what you pay for, and will likely never benefit from something CHEAP!

    Get the 90+... or a heat pump...
    These are the two that will save you money!

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