Flue dampers

[MagraAdam]

Hi guys, quick question (though I'm sure it'll lead to a lot of opinions). I have a freestanding slow burning wood heater (an older model of something like this https://saxonwoodheaters.com.au/saxon-blackwood-freestanding-wood-heater/ )

I was wondering if there was any point in installing a flue damper? Not to stop things entering from the top - I have a flue cap for that. Not to stop a draught in summer - I can close the air inlet. I was thinking of one to help keep more heat in the fire box. Or is it the sort of thing where I'll either smother the fire or die of CO positioning?

Thanks heaps,

Adam

 

[sean donato]

Some people do, some don't. I don't as I have a wood furnace and there's no point to it, when in doubt follow the manufactures reccomedations.

 

[Marine5068]

Hi guys, quick question (though I'm sure it'll lead to a lot of opinions). I have a freestanding slow burning wood heater (an older model of something like this https://saxonwoodheaters.com.au/saxon-blackwood-freestanding-wood-heater/ )

I was wondering if there was any point in installing a flue damper? Not to stop things entering from the top - I have a flue cap for that. Not to stop a draught in summer - I can close the air inlet. I was thinking of one to help keep more heat in the fire box. Or is it the sort of thing where I'll either smother the fire or die of CO positioning?

Thanks heaps,

Adam

First off I would suggest going to a newer EPA model stove. You wont regret it all. Just the opposite.
I had a older wood stove when I bought my house too. It was ok but I didn't know what I was missing with nothing to relate it to.
The old stove would burn ok but only for about 2-3 hours at a time. It was harder to start and ate up firewood too.
The new EPA (Drolet HT2000) stove has the reburner tubes to inject air into the top of the burn chamber and burns up all the smoke gases. Its about 40% more efficient and burns about 50% less wood for same heat output and burns about 8-10 hours now.
I also got $400 for my old stove and the guy loaded it himself (heavy).
Now all that being said, I do have a good 8" (I/D) Stainless chimney with a flue damper in the adapter pipe that connects the stove to chimney. It works great and lets me adjust the flow on windy days or open it a bit at startup.
Then I damper it down some to get longer burn times and keep more heat in the burn chamber. So the best of both worlds I guess.
Anyways, that's my two cents on woodstove systems.
Newer is Better.
(old stove left) (new Drolet HT200 stove right)

 

[GoBigRed]

Also, most states require a damper to meet their code requirements. It does make the stove more efficient and it holds the heat down in the box. At least that is the theory. I use mine mainly for burn control.
Whatever stove you go with I think it’s a great thing to have for a few reasons, and I’m glad I put on in. Took a little while to figure out how to tune the burn with it on our stove but now it works like a champ. At the very least, I know for a fact it helped control wood consumption.

 

[sean donato]

Also, most states require a damper to meet their code requirements. It does make the stove more efficient and it holds the heat down in the box. At least that is the theory. I use mine mainly for burn control.
Whatever stove you go with I think it’s a great thing to have for a few reasons, and I’m glad I put on in. Took a little while to figure out how to tune the burn with it on our stove but now it works like a champ. At the very least, I know for a fact it helped control wood consumption.

My furnace manufacturer specifically says not to use a flue damper. I have also found no regulations on flue dampers in PA state regulations. If your referring to a draft damper then yes you do need one to limit draft.

 

[moresnow]

Never heard of a US state requiring a flue damper myself. Suppose there could be? Only reason to have one in my opinion is if your stove is apt to running away, running hotter/faster than you desire, or uncontrollably when the stove's built in primary air control can't keep it in check.
No pipe damper here now. I did run one years ago on a much different stove that had poorly designed (cheap!) primary air control. Worked like a charm on that stove.

 

[GoBigRed]

My furnace manufacturer specifically says not to use a flue damper. I have also found no regulations on flue dampers in PA state regulations. If your referring to a draft damper then yes you do need one to limit draft.

Maybe my lingo is wrong. Draft dampener is for air control and located on the stove. Flu dampener is on your first section of pipe that comes out the top of the stove. Draft dampeners are inherent to the stove but flu dampeners are installed in your pipe.

Is that the same thing we are talking about?

the flu dampener as I’m describing is required by Washington and Oregon state code. As well as an outside air intake to ensure fresh air for the draft dampener.
Let me know so I understand same thing your talking about. I know Went round and round with a saw shop owner because we were calling things different things about saw chains. Him being from Virginia and me being from Oregon

Never heard of a US state requiring a flue damper myself. Suppose there could be? Only reason to have one in my opinion is if your stove is apt to running away, running hotter/faster than you desire, or uncontrollably when the stove's built in primary air control can't keep it in check.
No pipe damper here now. I did run one years ago on a much different stove that had poorly designed (cheap!) primary air control. Worked like a charm on that stove.

so I’ll be honest with you, when I put our stove in I thought about pulling a permit and decided to check code. Turns out several states out west have required it since at least the 2012 code cycle. Can I explain why? Nope. And I wasn’t going to run one until I read that and then read all the theories on holding down heat and controlling the burn. Now that I’ve gotten use to it I wouldn’t go without it. But to each their own. Honestly, I’m more concerned about the free heat and if they want me to add a flu damper, then I’ll do it.
I’m an electrician by trade I find it odd how one jurisdiction has a specific code and another doesn’t. Could be adjacent counties or cities, but each one always wants to add to what the state has adopted. Probably the same for stoves

 

[sean donato]

Yeah I took the op question to be the round flue damper in the first section of pipe to choke the exhaust off, not the daft damper.
As far as I ever looked into it, our local code basically looks at the particular manufacturers specs and goes off of that. They have some silly generic stuff, but ask for the installation instructions when they come to inspect. Or at least that's how my township handled it. I live in PA so I can't say to other states or other counties around me either for that matter. My stove of an air tight model and has permanent baffles that keeps the heat down in the furnace. It's an actual furnace as well and not a stove style, so there may be some differences. There was no requirement for a fresh air inlet either, not that I would need one, the doors and windows don't seal the best in the basement anyway. Lol

 

[GoBigRed]

Yeah I took the op question to be the round flue damper in the first section of pipe to choke the exhaust off, not the daft damper.
As far as I ever looked into it, our local code basically looks at the particular manufacturers specs and goes off of that. They have some silly generic stuff, but ask for the installation instructions when they come to inspect. Or at least that's how my township handled it. I live in PA so I can't say to other states or other counties around me either for that matter. My stove of an air tight model and has permanent baffles that keeps the heat down in the furnace. It's an actual furnace as well and not a stove style, so there may be some differences. There was no requirement for a fresh air inlet either, not that I would need one, the doors and windows don't seal the best in the basement anyway. Lol

I read quite a bit about the fresh air inlet. From what i remember Canada doesn’t require it. Some sat they arent needed. Others say they are needed because newer construction practices have homes much more air tight. My house has four inch holes in the corners of the walls that have a foam insert. I call that good enough and just go with it. I followed manufacturers guidelines and it works great

God bless wood heat

 

[Marine5068]

Also, most states require a damper to meet their code requirements. It does make the stove more efficient and it holds the heat down in the box. At least that is the theory. I use mine mainly for burn control.
Whatever stove you go with I think it’s a great thing to have for a few reasons, and I’m glad I put on in. Took a little while to figure out how to tune the burn with it on our stove but now it works like a champ. At the very least, I know for a fact it helped control wood consumption.

I believe he's in Tasmania, not USA

 

[Marine5068]

I read quite a bit about the fresh air inlet. From what i remember Canada doesn’t require it. Some sat they arent needed. Others say they are needed because newer construction practices have homes much more air tight. My house has four inch holes in the corners of the walls that have a foam insert. I call that good enough and just go with it. I followed manufacturers guidelines and it works great

God bless wood heat

I believe he's in Tasmania, not Canada

 

[Marine5068]

Maybe my lingo is wrong. Draft dampener is for air control and located on the stove. Flu dampener is on your first section of pipe that comes out the top of the stove. Draft dampeners are inherent to the stove but flu dampeners are installed in your pipe.

Is that the same thing we are talking about?

the flu dampener as I’m describing is required by Washington and Oregon state code. As well as an outside air intake to ensure fresh air for the draft dampener.
Let me know so I understand same thing your talking about. I know Went round and round with a saw shop owner because we were calling things different things about saw chains. Him being from Virginia and me being from Oregon

so I’ll be honest with you, when I put our stove in I thought about pulling a permit and decided to check code. Turns out several states out west have required it since at least the 2012 code cycle. Can I explain why? Nope. And I wasn’t going to run one until I read that and then read all the theories on holding down heat and controlling the burn. Now that I’ve gotten use to it I wouldn’t go without it. But to each their own. Honestly, I’m more concerned about the free heat and if they want me to add a flu damper, then I’ll do it.
I’m an electrician by trade I find it odd how one jurisdiction has a specific code and another doesn’t. Could be adjacent counties or cities, but each one always wants to add to what the state has adopted. Probably the same for stoves

He's specifically asking about a flue damper and he lives in Tasmania.

 

[MagraAdam]

Thanks all for the replies. I'll try to respond in this post.

Yes. Tasmania Australia.

No requirements for external air (Australian housing standards are not air tight). And no requirements for secondary burners or flue dampers.

The heater has an air inlet control which is how I currently make it burn for longer. I can get 8-10 hours overnight by shuting it right down with it mostly full of wood and starting out hot.

Yes, I was talking about a flue damper, one of the round ones. I've looked at a few online and it looks like there are cast iron ones that don't seal 100% and stainless thinner ones that seal much better. I'm not after a seal, I'm just thinking about slowing down the burn but retaining more heat.

The heater has a baffle inside the fire box up the top, and that I believe does help do a more complete burn and burn slower.

 

[Marine5068]

Thanks all for the replies. I'll try to respond in this post.

Yes. Tasmania Australia.

No requirements for external air (Australian housing standards are not air tight). And no requirements for secondary burners or flue dampers.

The heater has an air inlet control which is how I currently make it burn for longer. I can get 8-10 hours overnight by shuting it right down with it mostly full of wood and starting out hot.

Yes, I was talking about a flue damper, one of the round ones. I've looked at a few online and it looks like there are cast iron ones that don't seal 100% and stainless thinner ones that seal much better. I'm not after a seal, I'm just thinking about slowing down the burn but retaining more heat.

The heater has a baffle inside the fire box up the top, and that I believe does help do a more complete burn and burn slower.

The cast iron ones will be better and last forever. They allow a little air to pass through and are designed that way on purpose.
It will help keep the heat in the firebox and therefore give off more heat into the room.
Baffles help to do the same task of keeping heat in the box.
Nice thing with a flue damper is that you'll have more control of the fire.
Get one.

 

[MagraAdam]

The cast iron ones will be better and last forever. They allow a little air to pass through and are designed that way on purpose.
It will help keep the heat in the firebox and therefore give off more heat into the room.
Baffles help to do the same task of keeping heat in the box.
Nice thing with a flue damper is that you'll have more control of the fire.
Get one.

Thanks mate. It sounds like I should

 

[sean donato]

Your going to want to be careful you don't choke up your pipes with creosote. Slow cold overnight burns are not healthy for your chimney. From what it sounds you don't have an issue doing an over night burn by controlling the incoming air, but the flue damper is going to restrict the exhaust side of it. Your gonna have to play with it to see if it helps or hurts. Most furnaces it isn't actually nessisary.

 

[jetsam]

If you need a damper to control your fire, it's either because your draft is too high or your stove isn't controllable.

Wood stoves can benefit from dampers when there is excessive draft, usually due to a tall flue. If you're not sure, check it with a manometer.

If your stove isn't controllable because it's leaky, fix the gaskets. If it isn't controllable because it's not designed to be airtight, replace it.

 

[Marine5068]

Also at startup the weather can play on the fire.
Under high pressure, windy days, stove can react different and you may need to adjust flue damper to get fire going.
Once it's up and running good, adjust it more again.
I've run many stoves for many years in different places and lots of factors affect fire.
When you have control of those factors and learn to hone them is when you can start to become a fire master.

 

[sb47]

An air tight stove with an intake dampener that is air tight, they are not necessary in my opinion. Now if you have a leaky stove with a leaky intake dampener and can't shut the stove down by cutting off the air supply then yes you may need one. However with a leaky stove with a fluke dampener it may smoke up the room if you choke off the exhaust too much. The smoke will find the path of least resistance.
I don't run them because my stove's intake will snuff out a fire just by closing it all the way.
The main goal is to have enough control so you can easily snuff out a fire and keep it from becoming a run away fire.