Q&A How many BTU do i need to heat my house

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New Member
Staff member
Nov 27, 2012

We have a 4 years old cottage in Canada. Downstair is 851 square, the first floor is 875 square feet and the second is 954 square feet for a total of 2680.

Some folks told me that I should calculate 100% of the downstair, 50% of the first floor and 25% of the second floor to evaluate the real square feet that i should heat. Does it makes sense ?

We are looking for a Hearthstone woodstove. We've been recommend the Mansfield model that can output 80000 Btu/Hr. I'm affraid that with that stove, I'll be overheating downstair. What do you think ?

Finaly, I would like to know how to understand something like 80000 BTU/Hr. Does that mean 80000 Btu/hr for all the burn time (10 hrs for the Mansfield) or does the burn time represent the maximum burn time that we could have if we ajust the stove to output a minimum of BTU


The HearthStone Mansfield would be a good stove for the job. The 80,000 BTU is the ultimate MAX under extreme conditions. The stove would put out 25,000 to 40,00 during most everyday use. This is a good supplement for the are you talked about. Square feet and other methods are just rules of thoumb, since insulation factors, windows, climate and many other factors are involved. Rest assured the Mansfield will not be too large. Check out the Hearth.com BTU calculator and Hearthstones website at the links below.

Link: HearthStone Web Site

Link: Hearth.com BTU Calculator
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