Introducing Brand New Wood Furnace to Market - The Drolet Tundra!

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Lingo:

Barometric Draft Regulator. It mounts on your flue pipe, has a weighted door that regulates the draft that the wood stove/furnace see's to your preset spec.

They work great although a little controversial, I think most people that knock 'em, don't really understand 'em. Some people say that they cool the chimney too much, cause creosote. That hasn't been my experience at all. Anyways, not trying to veer fryebugs thread off in the ditch with BDR pizzin match. My Yukon (and a lot of other wood furnaces) are required to have a BDR. It is almost impossible to overfire a wood burner with a BDR on the stack and, because they actually regulate the velocity of the smoke/gasses/heat, it gives time for heat exchange to take place in your stove or furnace's secondary heat exchanger, instead of just zipping right up the chimney, and everybody likes increased efficiency, right?

Edit, BARO, different term for the same thing.

Thank You. I'm trying to wrap my head around all this info, and sometimes it gets confusing.
So, now I'm wondering if this new furnace needs a bdr?
 
Fyrebug:

Fyrebug-- Would I need a BDR on this stove? I'm thinking of building a small outside structure to house this furnace, then push the heat into my garage. My insurance company said No Heater in garage.
What do you think?
Thanks
And thank you for the photos.
 
I am wondering what effects would an outside air intake have on a bdr? Also, on a wood furnace such as the Tundra, would an oai be beneficial to heat efficiencies?


Outside Air Kit, or OAK, is a good idea, probably a necessity with a BDR. The BDR can send a large volume of air up the chimney, so unless you have a REALLY leaky house, a OAK keeps the chimney from pulling a small negative pressure (or vacuum) on the house (which can mean starving the fire for air, smoke leaking back in the house, etc)


Thank You. I'm trying to wrap my head around all this info, and sometimes it gets confusing.
So, now I'm wondering if this new furnace needs a bdr?


We'll see what fryebug says, but I'm betting they will want a BDR on it. The Tundra has an insulated firebox to promote high temps and clean burning. That means your heat transfer has to happen in a secondary heat exchanger, so as explained in my previous post, the BDR would slow the velocity of the flue gasses enough for that heat transfer to have the time to take place.
 
I am wondering what effects would an outside air intake have on a bdr? Also, on a wood furnace such as the Tundra, would an oai be beneficial to heat efficiencies?

An OAK (outside air kit) is recommended for air tight houses or house where chronic negative pressures is present. Older houses typically do not need an OAK.

BDR's are recommended on tall chimneys or where the chance of fluctuating draft pressures is present... ie house on top of hill or where wind affected draft. A BDR function is to ensure the furnace/chimney system do not go in overdraft.
 
An OAK (outside air kit) is recommended for air tight houses or house where chronic negative pressures is present. Older houses typically do not need an OAK.

BDR's are recommended on tall chimneys or where the chance of fluctuating draft pressures is present... ie house on top of hill or where wind affected draft. A BDR function is to ensure the furnace/chimney system do not go in overdraft.

I think the proper thing to do here is to get a measure on the draft. My chimney is 25' tall with a 7x11 flue tile. This chimney was right on the border line volume wise for this current stove I have calling for no more than 3 times the stove outlet volume which was 28" for the 6" outlet. This made me think that my draft was on the slower side as I was thinking a smaller flue would increase exhaust velocity much like smaller headers on small block engines. Could be a different ball game altogether with stove exhaust of which I'm a bit ignorant on.
 
Arrow, A lot of basement installs run into 2 problems. the first being from a cold start a reverse flow( i get this even with a insulated 6" liner) in the flue mostly when it is a cinder block and clay tie unit and almost always oversized, the second which is what we are speaking of here is the overall length of the flue. Once that nice big flue gets hot it really starts to suck( draft ) leading to short burn cycles and less than adequate heat output , just like a fireplace unit, as it is getting sucked up the flue. By adding the damper we can regulate the amount of draft (in inches of vacuum ) when the unit is at operating temperature ( likely 4-6 ") There are special tools for measuring the draft so that one can properly set the damper. The damper is a t shaped unit about a foot long, it should be placed apx 18" away from the appliance in a vertical setting This can be a real challenge in a lot of basement installs. I have a hotblast in the basement ( el cheapo model) I am not happy with it ( wood hog ect.)and I do have a baro damper on it. The flue is apx 25-30 ft to the top. It has served its purpose in as much as it reduced the NG bills. I haven't used it in the last 2 heating seasons due to having the NC30(big stove) on the main floor( ranch style). avg temp in house mid 70's gas bill about $25/mo ( hot water and dryer)
 
I think the proper thing to do here is to get a measure on the draft. My chimney is 25' tall with a 7x11 flue tile. This chimney was right on the border line volume wise for this current stove I have calling for no more than 3 times the stove outlet volume which was 28" for the 6" outlet. This made me think that my draft was on the slower side as I was thinking a smaller flue would increase exhaust velocity much like smaller headers on small block engines. Could be a different ball game altogether with stove exhaust of which I'm a bit ignorant on.

Just an FYI, I have a manometer permantly installed on my flue pipe, the draft downstream of the BDR (chimney side) fluctuates wildly day to day (second by second when it is windy) upstream (furnace side) of the BDR, the draft stays pretty constant. About -.03" WC in my case. With the BDR pulled closed, I've seen steady draft readings as high as -.15" WC, which is 5 times what Yukon calls for! 27' insulated 8" SS liner in a masonry chimney, (external chimney) just for reference.

And your thinking sounds perfectly correct as far as the velocity in your chimney. So if you have any draft issues (other than too much draft) a liner would help.
 
Last edited:
So if you have any draft issues (other than too much draft) a liner would help.


As a matter of fact a liner is mandatory if you do not have a 6" dia. HT2100 rated chimney. If you are venting into a masonry chimney, you will need a liner.

The reason for this is the furnace is so efficient, you will have a hard time drafting if you vent into anything bigger than 6".
 
As a matter of fact a liner is mandatory if you do not have a 6" dia. HT2100 rated chimney. If you are venting into a masonry chimney, you will need a liner.

The reason for this is the furnace is so efficient, you will have a hard time drafting if you vent into anything bigger than 6".

Yahoo!…..another $2000 to spend for a liner install. I don't suppose you'd sell me the Tundra for $29.95?
 
A $2,000 liner??!? You have a 125 ft tall chimney???:msp_scared:

A 25 ft liner kit will set you back $400. 316Ti Chimney Champion Easy Flex Chimney Liner Kit - 6" | WoodlandDirect.com: Chimney Liners, Chimney Pipe

Well thanks for that link Frye. $2000 was the price for liner and installation. I got 3 estimates and they were all around the same. One of the guys was not going to pour insulation in for 3 reasons. First he said that it hardens like a rock and when you attempt to get it out for replacement (15-20 years) its next to impossible. Secondly he said that insulation will not make a bit of difference as the I would have only 3/8" gap on two sides on the 7" flue. Not worth it he said. Thirdly he said the pipe he uses (316Ti) does not need insulation. He said for insulation to be effective I would have to knock out the tile flue, and insert a liner with a blanket around it as he said there would be no room to have a blanketed liner with my current tile size and thus reverting to the pour type which he said was useless. That job was $3500. But he was still charging me $1995 w/o the insulation for the flexible liner install. Its like every step here needs a whole nother education and then trust you are being given the right information. I should just put my head in my current stove and call it a day.
 
A liner install is simple and straight forward, unless your uncomfortable with heights or the install. I went one year without a liner, and the next season it was in. There's a big difference with and without a liner. Without a liner draft was sluggish with our 32' chimney, once hot the draft speeds were too high. Once the furnace hit the coaling stage, there wasn't enough draft to keep things burning well resulting in unburnt coals. The liner cured all this as well as a condensation issue within the chimney. Whether it's a EPA stove or furnace, you won't be happy with the performance without a liner.
 
As Layne said you dont have much choice. Here in Canada you dont need to have an insulated liner. But in the US it's code. There's different ways of doing it. Poured insulation (there are different types). Ceramic blankets, pre-insulated flexible liners and insulated solid liners.

finally as another option most sweeps have special tools to break down your clay tile if the fit is too tight.

I'm not sure I would trust that guy... make sure if you hire someone they are NFI certified.

What is the size of your flue?

As Layne said it's not that difficult to do it yourself. I've done mine as well. Just be safe and handy and have someone else help you and keep an eye on each other when you are on the roof.

If you call Woodland Direct they can help you. All those guys are NFI certified and worked the trade.
 
As Layne said you dont have much choice. Here in Canada you dont need to have an insulated liner. But in the US it's code. There's different ways of doing it. Poured insulation (there are different types). Ceramic blankets, pre-insulated flexible liners and insulated solid liners.

finally as another option most sweeps have special tools to break down your clay tile if the fit is too tight.

I'm not sure I would trust that guy... make sure if you hire someone they are NFI certified.

What is the size of your flue?

As Layne said it's not that difficult to do it yourself. I've done mine as well. Just be safe and handy and have someone else help you and keep an eye on each other when you are on the roof.

If you call Woodland Direct they can help you. All those guys are NFI certified and worked the trade.

Its 7x11. Only way to possibly get an insulation blanket on this size flue would be to attempt to drop down to a 5 1/2" liner. I understand there is a pour formed product called "Golden Flue" This is a cast type liner that must go for some real high bucks.
 
Its 7x11. Only way to possibly get an insulation blanket on this size flue would be to attempt to drop down to a 5 1/2" liner. I understand there is a pour formed product called "Golden Flue" This is a cast type liner that must go for some real high bucks.

Keep in mind your Flue is the most important part of the installation... As wood burning appliances become more and more efficient the need for large flues will not be needed. That's why reducing to 6" will last you a long time.

This is what you should consider...

1) Do not cheap out. Consider it a permanent installation and you are literally playing with fire. Building a really good chimney system should last you 50 - 100 years. It satisfies insurance and more importantly your piece of mind and the lives of those who live in your house.

2) Cheap liners are everywhere. A good quality liner (Hybrid liner by Olympia Chimney for example) is a no-memory, smooth wall liner. The advantage is you can sweep with wire brush where a standard 'light' duty liner you have to be careful not to tear during installation and you have to sweep with nylon brushes. The smooth walls also ensures it is more difficult for creosote to deposit. Finally with a smooth wall liner their ID is greater and you can go down to 5.5".

Hope this helps.
 
Keep in mind your Flue is the most important part of the installation... As wood burning appliances become more and more efficient the need for large flues will not be needed. That's why reducing to 6" will last you a long time.

This is what you should consider...

1) Do not cheap out. Consider it a permanent installation and you are literally playing with fire. Building a really good chimney system should last you 50 - 100 years. It satisfies insurance and more importantly your piece of mind and the lives of those who live in your house.

2) Cheap liners are everywhere. A good quality liner (Hybrid liner by Olympia Chimney for example) is a no-memory, smooth wall liner. The advantage is you can sweep with wire brush where a standard 'light' duty liner you have to be careful not to tear during installation and you have to sweep with nylon brushes. The smooth walls also ensures it is more difficult for creosote to deposit. Finally with a smooth wall liner their ID is greater and you can go down to 5.5".

Hope this helps.

Thanks Frye.
That was part of the problem. I felt I was getting junk for my money with these flexible liners. I wanted at least a rigid liner then perhaps I would be able to insulate it with some type of insulation. Being able to go down to 5.5" will help. Now I just gotta get some ideas on ducting as this would be a central add on retro fit with oil fired back up from the boiler next to a Tundra.
 
Last edited:
maybe a wood fired boiler instead of hot air would be a better match as it sounds like your system now is hydronic.

I did think of that and looked into it from 3 different manufacturers. Cost came in between 10-12K. The boilers are expensive and the hook up is additional. Then there is the aspect of water storage with some of these 500 gallon tanks costing an additional 5K. To me these are all complications and I'm not too keen on the heat exchange thing either. I may need one more run of ducting as I have a register cut into the floor above the stove that is ducted from a hood on the stove. That ducting made all the difference in the world for the wood stove.
 
Back
Top