Barometric flue

[msherer]

I am getting used to my new Vogelzang Ponderosa stove. One thing I notice is that I am having trouble controlling the burn. After I load the stove it seems to get very hot and closing both air intakes does not do anything to slow down the temperature rising. Several times after loading with wood the stove temp went up to 900 or 1000 degrees (stove did not glow red). I called the company today and told them what I was running into and they told me I needed to install a "barometric flue." I told them that their manual recommends not to install a flue because the burn is controlled by the air intakes. They then told me that was meant for a manual flue and that a barometric flue is needed. What does this type of flue do and does anyone have any thoughts?

Matt

 

[HotCoals]

I'm surprised that they recommend a barometric damper.
What it does is it slows the draft but it also lets room temp air into the flue which will cool the flue down .

Google a image of one too see what they look like.

 

[brenndatomu]

Do you have the stove installed in a fireplace or freestanding? You will need to be able to access a section of flue pipe to install a baro.
A baro (or BD) is a weighted flap installed on the flue that opens up under high draft situations, it keeps the draft at a specific, steady #, that you set using a manometer (available used on fleabay $20 or less sometimes) Wood and coal (well, oil too) furnaces often require BDs to be used.
You will need to know what Vogelzang wants the draft to be, to set the BD. On most modern stoves, they call for somewheres in the -.05" to -.08" water column range (my Yukon furnace is -.03")
One side note, I have a Vogelzang Defender stove. I was not happy with how fast it seems to burn, even on "low" Now I'm not sure how similar your stove is to mine, but on mine, it has the primary air control holes behind a removable metal cover right above the door. I covered the large center hole by about 50% with a piece of that high temp aluminum "duct" tape. Made a HUGE difference for me, although it DID NOT make the temp go down, actually went up. Just a lil FYI, may or may not apply to your situation.
A full description of my problem/results here https://www.hearth.com/talk/posts/1624431/

 

[shoot-straight]

My dealer swears by them. I understand how they work. That's why won't install one... cold air in the flue is bad IMHO.

 

[brenndatomu]

Why? If the flue cools off too much, draft drops, BD closes...maintains draft, problem?

 

[begreen]

I would sooner put in a manual key damper in the flue pipe. That is positive predictable control without any air cooling dilution of the flue gases. Msherer, how tall is the flue on this stove? Are you getting the high temps mostly on reloads or even with cold stove starts?

 

[bholler]

in my opinion and csia's opinion also a barometric damper should never be used ona wood burning appliance. it cools the flue down to much and in the case of a chimney fire it will supply an almost unlimited air supply to the fire with no way of shutting it down. if you are having trouble controlling it install a stack damper

 

[brenndatomu]

BD install required to maintain UL certs (therefore required by HO ins) by several wood furnace manufacturers, recommended as needed by many more...OP was told by the Mfgr to install a BD, and, they said (also, per the OM) to NOT install a manual damper.
Not to seem stupid, but who is csia? Never heard of 'em

 

[begreen]

www.csia.org

 

[msherer]

I would sooner put in a manual key damper in the flue pipe. That is positive predictable control without any air cooling dilution of the flue gases. Msherer, how tall is the flue on this stove? Are you getting the high temps mostly on reloads or even with cold stove starts?

Both. My flue is about 18' tall. I have a manual damper installed already, just leave it open. I left it in place when I installed the new stove.

It doesn't eat wood anywhere near the rate my old stove did. I'm using a little less than half of what I did in a 24 hr period. I'm getting a steady burn time of about 6.5 hours a load and I've only been filling the unit 1/2 of it's maximum capacity. If I can figure out how to comtrol the burn better I'm hoping to increase the burn time.

I've noticed a couple of things recently. To empty out the ashes from the burn chamber, you need to pull out this small square iron plug (3"x3"). You just push the ashes through that opening and replace the plug. The plug has a stove gasket on the bottom to make a seal when replacing the plug. I have to take good care to make sure the opening is clear of any debris or it becomes an air intake. Since we've paid better attention to this it seems to be cooperating better.

On the back of the pedastal is an opening for an external air intake (mobile home install). It didn't come with any type of cover if you are not using the kit. I wonder if I shouldn't plug that hole and see how it acts. The hole opens into the ash pan bay.

Matt

 

[laynes69]

If your getting 6.5 hour burns on half a load, I don't think your draft is an issue. With a 18' chimney, you shouldn't need a damper, whether barometric or manual. It sounds to me like your not used to a EPA certified stove quite yet. When your loading, I would cut down the air sooner, if it's hitting those temps, your waiting too long. EPA stoves are designed so the fire can't be closed down to the point of smothering. Maybe on a very windy or cold night you may need the manual damper, but I wouldn't worry about a barometric damper.

 

[begreen]

Both. My flue is about 18' tall. I have a manual damper installed already, just leave it open. I left it in place when I installed the new stove.

It doesn't eat wood anywhere near the rate my old stove did. I'm using a little less than half of what I did in a 24 hr period. I'm getting a steady burn time of about 6.5 hours a load and I've only been filling the unit 1/2 of it's maximum capacity. If I can figure out how to comtrol the burn better I'm hoping to increase the burn time.

I've noticed a couple of things recently. To empty out the ashes from the burn chamber, you need to pull out this small square iron plug (3"x3"). You just push the ashes through that opening and replace the plug. The plug has a stove gasket on the bottom to make a seal when replacing the plug. I have to take good care to make sure the opening is clear of any debris or it becomes an air intake. Since we've paid better attention to this it seems to be cooperating better.

On the back of the pedastal is an opening for an external air intake (mobile home install). It didn't come with any type of cover if you are not using the kit. I wonder if I shouldn't plug that hole and see how it acts. The hole opens into the ash pan bay.

Matt

I would leave that air intake port open. There is no indication the stove needs air restriction and you can throttle it down if necessary with the key damper. If you restrict a non-cat EPA stove too much it will lose secondary burn and with that a lot of efficiency.

 

[msherer]

I agree about not being used to an EPA stove. I've followed the instructions in the manual but that's no substitute for experience. Thanks for sharing yours!

How do you go about setting your air intakes? The manual says to open the main intake full after loading wood for about 10 to 15 minutes and then close as desired. Do you normally close your intakes all the way after a load, maybe medium? I'm still trying to figure out this secondary burn as well. One of the first things we noticed is how cool it looks with the flames dancing slowly around the burn chamber. Kind of erie looking.

Matt

 

[begreen]

This varies with the stove, the flue system, the house and atmospherics. Generally this is so, but one has to be ready for extra dry or resinous wood that takes off faster and semi-seasoned wood that takes off slower. Also, a reload on a coal bed is generally going to ignite quicker and the stove secondary manifold will already be warm allowing for faster ignition of wood gases. If you are getting ghostly and wratihlike flame with a bluish tinge you are getting a nice mellow secondary burn.

 

[msherer]

This varies with the stove, the flue system, the house and atmospherics. Generally this is so, but one has to be ready for extra dry or resinous wood that takes off faster and semi-seasoned wood that takes off slower. Also, a reload on a coal bed is generally going to ignite quicker and the stove secondary manifold will already be warm allowing for faster ignition of wood gases. If you are getting ghostly and wratihlike flame with a bluish tinge you are getting a nice mellow secondary burn.

 

[stoveguy2esw]

don't know the model of stove but im thinking he's peaking secondaries hard , seems to be jumping right after the reload and closing drafts isn't helping, remember unless the stove has a separate primary and secondary draft control, as the primary is cut off this intensifies the secondaries creating a crapload of heat in a hurry.

remember X= A+B x being the air pulled by the flue , a is your primary (feeding the log fire)b is your secondary (feeding the reburn) now, most draft controls on reburn stoves (non-cats) only directly control the primary, by reducing them rapidly you go straight to a smolder making a bunch of fuel for the secondaries which are also getting a big boost of air from the change in air balance B becomes much stronger as A is reduced in this way so you have a big burst of fuel and a big burst of air , so the stove takes off.

to the OP , start closing down your draft controls earlier and do it in steps, this will help prevent the big jump I described above

 

[msherer]

This info is all a big help. Many thanks to everyone

Matt