Physics of Fireplaces
Somebody ‘plain to me please! We have a wbf in our 2nd fl sitting room which we never use. I’m thinking if we install a fireplace insert it would be much less messy/smoky and we’d be inspired to have fires more often. All the ads say inserts are more efficient at heating. But how can…
Somebody ‘plain to me please! We have a wbf in our 2nd fl sitting room which we never use. I’m thinking if we install a fireplace insert it would be much less messy/smoky and we’d be inspired to have fires more often. All the ads say inserts are more efficient at heating. But how can that be? If the fire is burning behind a glass front, doesn’t all the heat go up the chimney?
My wife and spent less than $7k into our two fireplaces and chimney flue for our boiler. We shopped around and most company’s wanted between $7-$9k just to do the two fireplaces excluding the boiler flue as well. We used Dynasty Chimney 718-338-4741
We used Andre from A&A Chimneys. He advertises on this site. Good guy, very honest. But it’s not cheap — about $7k if I remember correctly for 2 fireplaces. That included new terracotta flues. If you only need stainless steel flue liners, it’s less. He also built a fire box and smoke chamber in each fireplace.
Grand Army – may I ask who you used and what we should expect to pay to have that done? I feel like its such a shame to have 5 fireplaces, none of which work.
Thanks.
ALL: Thanks so much. I’m getting it. Convection heat + radiant (although since the surround area can’t be large in a small brownstone fireplace, I think that’ll be the smaller contribution).
Bedstuytownhouse: We’re looking at the Vermont Castings Winterwarm insert — recommended by several people on this site. But our fireplace has already been relined with terracotta so all we have to do is get the insert installed and we’re ready to go.
How exactly do they work? We have several fireplaces that are closed but would obviously like to make use out of a couple of them. Is this the sort of thing where you have to hire someone to come in and open up the chimney or is this ventless?
Thanks guys.
All post are right. We put in an insert in 2003 and vented it up the rear of the house. It does a great job. Also noticed that we’re burning fewer logs each night and that the burn is complete (i.e. we’re left with fine ash the next AM and no charcoal). You don’t hear or smell the fire though, so ambiance is sacrificed.
Many inserts have a separate fresh air flue so they don’t draw air from the house.
Radiant heat from the flames passes right through the glass.
Some even have small fans that blow hot air out to the room through vents-so you get convection as well.
You don’t get the crackle or that great smell though…
Pretty much what Putnamdenizen said. They regulate the air flow of the fire and they also radiate the heat back out into the room.
non expert answer – most fire places are a net loss of heat, as they draw air from the house up and out of the chimney. Inserts and wood stoves heat the house air by radiating heat out without sucking air out.