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Recommended gas furnace for 3550 square foot house

Vissu | Posted in Energy Efficiency and Durability on

Please let me know recommended gas furnace for 3550 square foot colonial house in Detroit area

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  1. walta100 | | #1

    Find a good local installer and follow his advice. In most cases a 92% + furnace makes sense.


  2. GBA Editor
    Martin Holladay | | #2

    Step one to designing a heating system -- or specifying a furnace -- is to perform a heating load calculation. Here are links to articles you should read:

    Who Can Perform My Load Calculations?

    Saving Energy With Manual J and Manual D

    How to Perform a Heat-Loss Calculation — Part 1

    How to Perform a Heat-Loss Calculation — Part 2

  3. Reid Baldwin | | #3

    There are at least three aspects of selecting a furnace: brand, features, and size.

    Regarding features, my prioritized list would be condensing (first digit of efficiency is 9), ECM-type blower motor, and two stages.

    Regarding brand, my advise would be to select a contractor you trust and use whatever that contractor prefers. The hard part is finding a contractor you trust. After you read the articles Martin mentioned, you will know what question a good contractor should be asking you. If you call a contractor, and the only question they ask is square footage, or the label on the existing furnace, keep calling others. If this is a replacement and they ask about recent natural gas bills, that would be a good sign.

    Regarding size, even if the contractor asks the right questions to calculate it properly, you cannot necessarily trust the recommendation. Contractors typically have a "make sure you don't undersize" mindset rather than a "size it right" mindset. If this is a replacement, use the method described by Dana Dorsett at to cross check the recommendation.

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