Rufus T. Firefly wrote:MurphOnMillerAve wrote:Rufus T. Firefly wrote:Was 42 this morning at the house in PA; nice fire in the fireplace last night took the chill off nicely.
Is it true that 90% of the heat of a fireplace goes up the chimney ?
Depends on a lot of variables. Draft and how open the front is, etm. If it's wide open, probably a lot goes up the stack vs. radiant heat. But you have to remember that everything surrounding it gets hot, too. Mine in PA is a pretty good sized stone fireplace with a heavy steel front and steel fire box and then the stone all gets heated up over the day and carries through the night. Mine in VA is not as large and brick with glass doors. Brick also gets heated up and carries for a long time.
I put a cast-iron fireback in the fireplace a few years back and that made a big difference. After 30 minutes or so, it gets extremely hot and increases the amount of heat radiated back into the room. Another advantage of the fireback is that it moves the fire slightly forward, again helping with radiation. Still, I expect easily half the heat goes up the chimney. A stove insert likely would greatly increase the efficiency, but half the appeal, at least for me, is the big roaring fire.
