Of dampers and doors

[tgbrew]

Hi All,

I've been reading for a long time - but a first-time poster.

We bought a 1921 house with a fireplace that was converted to a gas log by running a gas line up the ash pit. We had the chimney checked (it needs two caps) but were told that it would be fine to convert it back to a wood burning fireplace. One warning was that the flue is only 9x9 so we might have some smoke issue that could be mitigated by opening a window or raising the grate a little bit. There was also a chance that it just wouldn't work well because of the small flu (so we were told).

So we converted it and it seems to draw really well. Maybe too well. We are now seeing the need to seal up the house of the cold drafts that are pouring in and not so much heat coming out of the fireplace.

My question is about doors and dampers. We have glass doors but there is no damper because (apparently) you wouldn’t have both for a gas log. I’ve also been told that having a damper is a bad idea because of the small flu and the damper would restrict airflow to some degree even when it is wide open.

Should we be closing the doors when we burn wood in order to retain some more of the heat? It seemed dangerous to me and we have left them open with the screen closed.

Should we think about a damper? I worried about messing with the draft on the small flu. I would love to hear some thoughts!

-Tom

 

[bholler]

You should absolutely have a damper of some sort but it will do nothing to help retain heat when burning an open fireplace the damper should always be all the way open. You can try closing the doors but you still wont get much heat most open fireplaces end up taking more heated air out of the house than they make.

 

[firefighterjake]

Seems to me that without a damper . . . when you're not running your fireplace you'll have a fairly sizable hole in your house to the outside . . . specifically a 9 x 9 inch hole.

 

[tgbrew]

But wouldn't the hole have been there before too with the gas log? So everyone who has a gas log (since they can't have a damper) just has a big hole in the house? The door seem to do a good job of sealing - so I wondered about the need for a damper if the doors are only open when the fire is going. Any thoughts on airflow restriction from the damper?

Is there any hope of turning a fireplace into an energy positive? We would love to get an insert but really enjoy the open fire and, frankly, can't afford the big price tag of a stove right now.

 

[bholler]

But wouldn't the hole have been there before too with the gas log? So everyone who has a gas log (since they can't have a damper) just has a big hole in the house?

I dont know who told you you couldnt have a damper with gas logs but it is not true. The only thing is that if the log set has a standing pilot the mamper needs to be open 1/2" when not in use and then opened when the logs are lit. But ones without pilots can have a damper and have it closed when not in use just the same as if it was wood.

s there any hope of turning a fireplace into an energy positive?

Not really no there are a few things but they only help a little bit.

 

[tgbrew]

Ahh - ok. This one had a pilot for sure. I guess they ripped out the damper. We have a metal flap right at the top of the fireplace (lintel?) on a hinge but the fireplace guy said was likely put in place to help close the size of the fireplace and help with the draft up the small flue. What is the benefit of the damper if we have doors in place? A better seal? It won't interrupt the air flow?
Bummer about heat loss but it really is a just an enjoyment thing. We didn't like the gas log at all and love having a real fire. Our gas bill is cheap enough that we probably can't justify an insert!
(Also - thanks for the help)

 

[bholler]

What is the benefit of the damper if we have doors in place? A better seal? It won't interrupt the air flow?

It is a seal fire place doors are not sealed thay are meant to be closed when the fire is burning if they were sealed that would not be possible. And no a properly installed damper will not restrict flow at all. In your case a top sealing damper would probably be the easiest solution

 

[tgbrew]

Ok - So I'll look into a top damper. I've been told that closing the doors isn't necessary and may not even be smart. I know there is debate around this so I'll probably just leave them open in order to get a little heat back. Anything else we should think about to make the open fireplace more efficient?

 

[Fsappo]

I may have missed it, but have you looked at a wood burning insert, or a good set of glass doors with a grate heater?

(broken image removed)

 

[Fsappo]

Something like a grate heater will give you some heat. Maybe same as a small wood stove. Closing doors will help mitigate heat loss. Damper open on the doors should allow enough combustion air. A top sealing damper, like this should help stop most of your heat from going up the chimney.

(broken image removed)

 

[bholler]

Something like a grate heater will give you some heat. Maybe same as a small wood stove.

Most of them do nothing there are a few that i have seen that do help a bit but still no where near a wood stove.

I've been told that closing the doors isn't necessary and may not even be smart. I know there is debate around this so I'll probably just leave them open in order to get a little heat back.

As long as your doors have air inlets which i have never seen a set that didn't. There is no problem with burning with them closed they are designed to do that and if they are closed it can reduce the amount of heat loss

 

[Fsappo]

"most" of them do "nothing" Is very misleading, unless you have used "most" of them and found them lacking. I've installed dozens of them. Made by a company called Stoll, along with their glass doors.

So by "something" I will tell you from actual experience that they DO add heat to the home, something akin to 20K btus or so which is "something" They WILL add convection heat to a room at the same rate as a small wood stove.

So, for the OP: My suggestion of a grate heater and a proper set of doors would be an excellent compromise between an open draft hole and an air tight wood burning insert. Take it from someone who has had actual boots on the ground when it comes to these things.

Also, check the door manufacture themselves before burning with the glass doors shut. Many of the specify not burning with the glass doors closed. If you want to do it right, research first. I'd go to a fireplace shop and ask a lot of questions.

 

[bholler]

"most" of them do "nothing" Is very misleading, unless you have used "most" of them and found them lacking.

i have worked on many fireplaces with many different ones and most people have not had much good to say about most of them. Yes some work ok but no where near what a wood stove does sorry.

Take it from someone who has had actual boots on the ground when it comes to these things.

i have worked on many so i have plenty of experience as well sorry. And yes stoll was the best i have come across as well but still no replacement for a stove

 

[Fsappo]

Ok, we will agree to disagree on the heat output!

 

[bholler]

Ok, we will agree to disagree on the heat output!

Fair enough

 

[tgbrew]

Regardless of the debate - which I find interesting - we would love to get an insert eventually. The cost is an issue and we can't even justify getting some sort of return on it because our gas-powered steam boiler seems to be pretty darn efficient.

I'm not that interested in the blower just because it would be throwing money in a direction that is different than our ultimate goal. If I could spend a little (fireback or something? ) that would help boost efficiency, that would be great. Otherwise, I think we need to get a damper and look toward an insert if we get some sort of windfall in the future. BUT an insert would clearly be for enjoyment only and not really a practical heat-related decision.

 

[bholler]

BUT an insert would clearly be for enjoyment only and not really a practical heat-related decision.

Why not they can contribute allot of heat

 

[kennyp2339]

A true wood insert is a wood stove designed to fit in a fire place with a blower but act like a stand alone woodstove , its 100% air tight and designed to make useful heat either by radiation or convection, if a standard fire place is 1% efficient for producing heat then an insert is 110% efficient. Most fire place users feel heat due to radiant heat from the flames but the reality is that more ambient household heat is wasted up the chimney than if you had no fire at all. An insert mitigates that by producing heat in an air tight box and radiating it, major heat occurs when you have a blower and you produce convection. when you had the gas fire place it wasn't producing enough heat to draw up your chimney, so it seemed as though it wasn't a big deal because your regular heating system was able to take care of the house with no real drafts felt, when the fire place was reworked and a larger hole up the chimney was opened up, it created an open window effect and even though the thermostat on the wall may have read 70 deg with the draft going up the flue it have made it feel like 65 deg. open fire places are notorious energy wasters, the heat from the wood goes up the flu, the draft created also takes house hold heat and sends it up the flu. At the end of the day you have to ask yourself, deal with the energy loss with a fire in the fireplace, get an insert and tame the beast (plus cut the gas bill for the furnace) or just make limited fires ie xmas, holidays and special occasions and turn up the house heat.

 

[tgbrew]

I see the points – but it costs us approximately $1K-$1.5K to heat our house with gas over the winter. If we shut down our boiler forever and ran only on wood heat, I imagine we would probably spend somewhere in the realm of $1K on wood in our area. So that means we very well may shell out $5K that we may never get back (and likely won’t adequately heat the semi-bizarre layout of our house).

My point was simply that I would love an insert but can’t see it as a practical financial decision, even if we did have that kind of cash.

Spending a few hundred bucks a year on heat because we simply love burning fires every night? That makes sense to me from a quality of life perspective. If there are ways to make that more efficient that won’t break the bank… I would LOVE to hear them!!