Wood fireplaces are the least expensive way to heat a large area and
they are the biggest waste of heat in a home.
I know - doesn't make much sense, but stick with me. There are three
basic categories to the heat output of a wood fireplace.
The big, open wood burning fireplace that doesn't have a heat
exchanger (even though it has fans as an option) will suck heat out of
your house faster than you can feed it wood. These fireplaces are
decorative, and there isn't any magic wand to make them put out heat
in an emergency. They just don't.
Mid-efficiency fireplaces will have some sort of air control to slow the
rate of burn, but won't seal tight and have controlled combustion. These
fireplaces will provide good heat in an emergency and you can open
the doors and use them for looks as well.
High-efficiency fireplaces will put out heat almost always. They can
have optional screen door facings to use open, but not all the time.
When the doors are shut, these fireplaces can heat up to 3500 sq ft
with under 4 cords of wood per year. Overnight burn times are the
norm and they require good dry wood to achieve optimum