What size BTU furnace for my 2 story house?

Old 09-09-11, 08:51 AM
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Location: Missouri
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What size BTU furnace for my 2 story house?

Should I double the square footage of my house to include the second floor when sizing my new furnace?
Old 09-09-11, 09:11 AM
Join Date: Mar 2006
Location: Wet side of Washington state.
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No. You need to do a heat loss calculation and if you plan to also have central cooling then a heat gain calculation. There are several computer programs available to help you and they run from free (and worth every penny) to around $500. The free ones can get you into the ball park of knowing the correct size but for best results you want a program that allows you to input as much data as possible.

Do a Google search using the term heat loss calculation. There is a program that allows you to access it for a month (or maybe three) for $50 and many people on this forum have used it with glowing responses.
Old 09-09-11, 09:42 PM
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I agree with furd. Also two floors u need two units

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