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Community and Q&A

Direct vent fireplace instead of furnace

toymaker | Posted in Mechanicals on

I am building a 1400 sq ft super insulated home in Wisconsin. The total heat load will be 22,000 BTUs and the floor plan is mostly open. I am considering a modulating direct vent fireplace as my sole heat source. I wonder with the high insulation R values planned might it work fine. Am I crazy? Are they too noisy? Will it last a decade or so? Other than heat circulation issues are there other downsides.

thanks, john linck the toymaker

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  1. Riversong | | #1

    At 1400 SF and 22,000 btu/hr design heat load, that hardly sounds like a super-insulated house.

    What is the configuration (1 floor or 2, flat or cathedral ceilings), what is the wall and ceiling/roof section, what is your HDD total and your minimum design temperature, and have you incorporated any passive solar?

    What is the output of the fireplace? Is it gas-fired? And does it have a circulator? What kind of whole house ventilation have you incorporated?

  2. aj builder | | #2

    Never heard of a noisy or modulating direct vent fireplace.

    Post the name and model.

  3. Riversong | | #3

    Rinnai and several other manufacturers offer these. Some are quite sophisticated, but they're not very efficient.

  4. toymaker | | #4

    Well, maybe super isn't the right word. Walls R32, Ceiling R60, Andersen low e windows. Air sealed to the max. There will be a HRV. Crappy subdivision lot doesn't allow for much solar gain. Gas burners do come in a modulating variety? Rinnai makes a 7 stage burner in their fireplace with 7 different heat outputs depending on need. Other manufacturers make similar units. But my question isn't really about heat output or heat load. I can do the the math. I just wondered if anyone had experience with a gas fired, modulating burner, direct vent fireplace and how they worked for them. As for noisy, I know they are built with lots of "tin". Does it creak and pop every time the burner kicks on? When at full output (say 25,000 BTUs) does the fan sound like a jet engine?

    Thanks for your time, john

  5. wjrobinson | | #5

    All I know is that the new sealed wood fireplace fans are way quieter than days of old and not an issue. They still bother me for the fact that they blow hot hot air at you. What we all like about a fireplace is the feel of the radiant heat IMO. John, I assume you are going to get into a store and see for yourself what you think of them as to noise and all. And maybe the store can point you to some satisfied customers to talk to. Also my fireplace store people have let me know exactly what they think of their units. Good luck, let us know what your progress is on this quest.

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