new stack damper- an idea whose time is overdue

[pybyr]

I do not think this would be a good idea with normal non-gasification wood devices,

and am not yet sure it will work with wood gasification appliances,

but for those of us with "oil back up" it can at a minimum help stop heat loss up through a dormant oil appliance and its associated chimney

apparently they will not actually be available until mid-late January, and "recommended" price is about $154 per unit; actual price is up to the wholesalers and dealers

I've thought for a long time that someone should come up with a safe device to prevent heat escaping up a chimney (and also drawing replacement air, in the form of drafts, into the house elsewhere) when an oil appliance is not running-and someone finally did come up with it:

http://www.fieldcontrols.com/pdfs/4325OilVentDamperSS.pdf

 

[smokinj]

Seen them for natural gas as well seems like it would pay for its self

 

[chuck172]

The stack damper would take away the disadvantage of connecting a woodboiler in series with an oil boiler.

 

[Nofossil]

The stack damper would take away the disadvantage of connecting a woodboiler in series with an oil boiler.

Well, it would take away one disadvantage. You'd still have a slower response between the time you build a fire and the time you get usable heat to your living space. This makes a LOT of sense if you have to keep your oil boiler hot for other reasons such as a hot water coil in the oil boiler.

 

[pybyr]

part of the appeal of this device to me is that not only does it elimiinate (or immensely reduce, to the point close enough to be considered practical elimination) the movement of air through the combustion appliance and up the chimney--

but also -- for appliances with a barometric damper, this device, as I am understanding the install diagrams, also cuts off the flow of warm air from the house (assuming your combustion appliance is in a heated space) that is constantly potentially wafting into the barometric damper and up the chimney, and once it is out of the house, depressurizing the house and pulling unheated air in somewhere. It probably varies by location, chimney, and who knows what else, but with my barometric damper on my oil unit set for a proper draft, the thing is at least 1/4 to 1/3 open during most normal winter weather, even when the oil unit is not running-- and all that warm air going up the flue has to be replaced by cold air leaking being drawn in somewhere else by the resulting "pull" of the chimney. Note that I am _not_ arguing for elimination or disabling of barometric dampers-- properly installed, they will make the combustion unit more efficient, unto itself, during a burn, by making sure that excessive draft is not pulling the fire/ heat through the heat exchanger faster than the heat can be captured. This device, however, would seem to let one have a "best of both worlds" where the barometric damper can play its role when the fire is burning, but the combustion appliance and chimney won't have air travelling up (and out) when there is no fire.

I am not a pro, just an enthusiast -- so if I am getting this wrong, I hope one of the pros will set it straight

 

[pybyr]

Can anyone who has more engineering and chemistry qualifications and experience than me in general, and with regard to combustion byproducts in particular, hazard a moderately informed WAG (the first part of that stands for wild, and the last part, guess) of whether this thing, being made of stainless steel, would be reasonably likely to hold up in the flue of a wood gasifier?

I know that fuel oil combustion byproducts are pretty significantly corrosive (or at least they certainly were before the move to low sulfur- not sure if that's still as true) so I am tending to think optimistically that this device could probably be used on a wood gasifier's stack.

my reason for wanting to do so has to do with the fact that Econoburn tells me that for top possible efficiency, I should definitely be using a barometric damper with their wood unit. And the only downside I can see to the barometric damper is the way that, as I mentioned in my post above (at least at my site) will be letting warm air up and out the chimney even when theres no fire. with this unit, and appropriate controls, I could perhaps wire it in so that the flue closes once the fire is totally done--

although, as I am thinking, it'd take some significant safety planning to make very sure that it could only close when the wood fire really, truly was done, and stood no chance of rekindling itself. while I am asking for ideas, any ideas of a simple, afforable, reliable type and installation location of sensor to do that?

thanks

 

[2.beans]

this is my prototype. im working on some stainless stuff. this actually is holding up well for run of the mill steel. installed on a seton w200.same function i think.

 

[brad068]

I'm wondering if you guys could use an old jake brake off of a semi. I thinking they gotta make some close to 6" They should withstand anything a oil burner can create.

 

[pybyr]

this is my prototype. im working on some stainless stuff. this actually is holding up well for run of the mill steel. installed on a seton w200.same function i think.

interesting- thanks for sharing. I have never seen a Seton in the flesh, although I recently saw a Greenwood, and I understand that they're pretty similar.

Looks as if you have the stack damper hooked by linkage to the air inlet shutter on the furnace? what operates either/both so that the stack damper can only close when the fire is totally out?

 

[pybyr]

I'm wondering if you guys could use an old jake brake off of a semi. I thinking they gotta make some close to 6" They should withstand anything a oil burner can create.

interesting idea, thanks, and it might be ideal for someone who can set it up correctly with the right controls and interlocks for this application. in my case, I revel in making stuff from cast offs and odds and ends, but I don't have ready access to any cheap or free jake brakes, and so by the time I chased one down, and got some things to actuate it, I think I'd be in deeper, in terms of time and money, than the $150+/- retail price that this commercial device should have. Again, great creative suggestion and thanks for offering it- maybe someone else can run with it

As I keep thinking about this, the challenge of using anything like this with a wood unit is this-- unlike an oil burner, which will cease combusting within seconds at most as soon as the power to the burner is cut off, a wood fire keeps going. Field Controls does not yet have a set of detailed instructions available for this unit, so I cannot tell if its actuators and sensors could be set up to "fail open" if the power goes out, which would be critical with a wood unit.

Regardless of what conclusion any of us draw on that once more product details are available, I still think that one of these things is going to find a home on my oil unit. It just plain makes sense to not have an 8-10 inch opening (OK, maybe less but still significant if you figure the pressure loss through the combustion unit and the fact that even a barometric damper is not wide open under nomal conditions-- but it's still a big hole) ducted from a conditioned space to the roof 24/7 all heating season, without regard to whether anything needs to go out the chimney.

 

[Redox]

I put one of these on my father's oil fired boiler years ago. I don't remember who made it, but it was a lot more ruggedly constructed than the Field looks. It had a cast iron frame and a clock motor that drove the damper shut. It had a separate control box that interlocked with the burner 120V controls and was designed for oil burners. I do remember that it had a 3 minute timer to hold the damper open after the burner shut down to purge the firebox and cool the nozzle down to prevent coking.

I have always heard that the newer oil burners with an inlet damper have made these things unnecessary. They are a lot simpler and will hold most of the heat in the boiler on shutdown. Draft through the barometric control isn't closed off, but this is a small amount of heat compared with sucking the heat right out of the boiler.

Chris

 

[pybyr]

I put one of these on my father's oil fired boiler years ago. I don't remember who made it, but it was a lot more ruggedly constructed than the Field looks. It had a cast iron frame and a clock motor that drove the damper shut. It had a separate control box that interlocked with the burner 120V controls and was designed for oil burners. I do remember that it had a 3 minute timer to hold the damper open after the burner shut down to purge the firebox and cool the nozzle down to prevent coking.

I have always heard that the newer oil burners with an inlet damper have made these things unnecessary. They are a lot simpler and will hold most of the heat in the boiler on shutdown. Draft through the barometric control isn't closed off, but this is a small amount of heat compared with sucking the heat right out of the boiler.

Chris

thanks Chris- if you or anyone else can clue me in on any identifying details of the retro cast iron variation, I'd love to try to chase a couple of them down, even if I have to do some fiddling to get them back in running shape

regarding the barometric damper, at least with my chimney in my location/ climate, if my barometric damper on my oil furnace is set to proper specs for the "overfire draft," then the damper is very significantly open, 24/7, even long after the oil unit has shut down and the oil heating unit and chimney are close to stone cold (I've seen the barometric damper wafting steadily open even in conditions during shoulder seasons when I have the oil burner completely shut off and am using only the wood cookstove to keep the chill out)(and again, the barometric damper has been carefully set and re-checked with instrumentation). so if conditioned air (at least if you call the air in an old farmhouse basement "conditioned") is going up the chimney, then even colder air from the outdoors has to find its way in from the outside, into the structure, in order to maintain a pressure equilibrium- which means heat going up the chimney all the time. it's that phenomenon, even more than purported losses of air doing through the heating appliance and then up the chimney, that I'd like to arrest. not sure if my conditions are typical or not- when I tore out my old chimney and planned and helped build this one, I tried to go for a design (8" round tile flues, 28 FT straight up) that seemed like they'd have draft and to spare-- maybe I achieved more draft than normal and now I have to figure out what to do with it?

 

[SteveJ]

2.beans,

The new Setons do the same thing as your invention.

http://www.rohor.com/page7.html

The chimney damper is tied to the air damper and both close at the same time to prevent heat loss up the stack and to prevent fire creep when idling.

Steve

 

[2.beans]

2.beans,

The new Setons do the same thing as your invention.

http://www.rohor.com/page7.html

The chimney damper is tied to the air damper and both close at the same time to prevent heat loss up the stack and to prevent fire creep when idling.

Steve

i had told fred that i was doing this before the new setons came out. my problem was smoke out the door so fred told me to try a barometric damper. i ran one for a while then sealed up my boiler and went back to the flap. i want to have both eventually.

 

[2.beans]

this is my prototype. im working on some stainless stuff. this actually is holding up well for run of the mill steel. installed on a seton w200.same function i think.

interesting- thanks for sharing. I have never seen a Seton in the flesh, although I recently saw a Greenwood, and I understand that they're pretty similar.

Looks as if you have the stack damper hooked by linkage to the air inlet shutter on the furnace? what operates either/both so that the stack damper can only close when the fire is totally out?

its called a belimo motor and it operates them at the same time.

 

[Redox]

I'm wondering if you guys could use an old jake brake off of a semi. I thinking they gotta make some close to 6" They should withstand anything a oil burner can create.

Ayuh,... This just Can't work....

A Jake Brake, aka. Jacob's engine brake, electrically stops the Exhaust Valves from opening....
It's got Nothing to do with the truck's exhaust, except for the motor's exhaust Valves....

I thought it opened the exhaust valve early to waste the energy of compression. Hard to do if you don't have an exhaust valve... ;-)

Chris

 

[BrownianHeatingTech]

Some compression brakes do use a butterfly in the pipe.

Joe

 

[pybyr]

I'm wondering if you guys could use an old jake brake off of a semi. I thinking they gotta make some close to 6" They should withstand anything a oil burner can create.

Ayuh,... This just Can't work....

A Jake Brake, aka. Jacob's engine brake, electrically stops the Exhaust Valves from opening....
It's got Nothing to do with the truck's exhaust, except for the motor's exhaust Valves....

I'm not a diesel mechanic, but have played with some diesel engines. my understanding is that some makes achieved the engine braking effect by interrupting the action of the exhaust valves, exactly as you mention-- but that the more common classic Jaobs-type system basically puts a throttle-like valve in the exhaust, and shuts it to create resistance to the engine turning -- since diesels do not have a similar butterfly in the intake that would create engine braking as occurs naturally with gasoline engines.

so, in concept, the right size diesel exhaust brake with the right controls could work- just not sure I can scare up the right part and have it be worth the cost and effort of doing this in that manner

 

[brad068]

I'm wondering if you guys could use an old jake brake off of a semi. I thinking they gotta make some close to 6" They should withstand anything a oil burner can create.

Ayuh,... This just Can't work....

A Jake Brake, aka. Jacob's engine brake, electrically stops the Exhaust Valves from opening....
It's got Nothing to do with the truck's exhaust, except for the motor's exhaust Valves....

I'm not a diesel mechanic, but have played with some diesel engines. my understanding is that some makes achieved the engine braking effect by interrupting the action of the exhaust valves, exactly as you mention-- but that the more common classic Jaobs-type system basically puts a throttle-like valve in the exhaust, and shuts it to create resistance to the engine turning -- since diesels do not have a similar butterfly in the intake that would create engine braking as occurs naturally with gasoline engines.

so, in concept, the right size diesel exhaust brake with the right controls could work- just not sure I can scare up the right part and have it be worth the cost and effort of doing this in that manner

Exactly. I should of worded it a exhaust brake not an engine brake. I just always called them all jake brakes. The exhaust brake is the one that I have seen the most of. I have installed a few Banks systems and a couple others, and when I was reserching them I seen a couple e brakes that were 4" and one that must of been 5" on a Dodge.

I think that a simple louver dampener could control them. Granted, a new one is out of the question but an old used one from a junkyard or ebay may be do-able.