Can anyone tell me which indoor gassifier/natural downdraft, etc units can be vented thru a side wall. I would have to vent vertically ~30' and go thru 1.5" of gypcrete then a ceiling then the roof and would still end up on the north side of my house. I have an icf home with brick exterior so was wondering if I could vent it horizontally like I did my nat gas fireplace on the same wall?
Side-wall venting
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SE Iowa said:
To the best of my knowledge, among the wood boilers, only the Garn is designed/rated for sidewall venting.
There are several other induced draft boilers which theoretically have enough fan power to do it, but it would certainly violate codes as well as give insurance companies a fit.
Joe
Have you considered exiting the home horizontally and then going vertical? Many of us with standard boilers operate in this manner (myself included)...
![[Hearth.com] Side-wall venting](https://www.hearth.com/talk/attachments/3168427901_4ee7c5f1f6-webp.208839/ "[Hearth.com] Side-wall venting")
In the words of Homer Simpson, "doah!" That throws a wrench in all my schemes. I don't think I want to cut a hole big enough to fit a GARN thru my 18" solid walls.
I guess I could go horizontal then vertical. Are the induction/forced draft fans strong enough to do this?
I guess I could go horizontal then vertical. Are the induction/forced draft fans strong enough to do this?
SE Iowa said:
30 feet of vertical chimney should provide plenty of draft for most systems.
The limitation is moreso in the amount of horizontal run that you have.
Joe
I've got just over 10 FT of horizontal run from my boiler to flue- longer than I'd have preferred, but that's just a result of limited and awkward options in an old farmhouse cellar, and my boiler manufacturer, Econoburn, said it's OK when I checked. The flue does slope uphill from boiler to chimney flue. It seems to work fine with the possible exception of smoke coming back out the door when loading, which might be less if I had more of a straight shot/ less horizontal run, but there's no real way for me to know for sure, since I have no alternative point of reference.
pybyr said:
That's the sort of situation where induced draft really helps.
And insulated stainless pipe, to prevent/reduce condensation.
Joe
BrownianHeatingTech said:
Thanks Joe- I have 24 GA galvanized, and am going to stick with that and keep an eye on it for now- but if and when I shift to something else, what would you recommend? Metalbestos type seems like it'd be too heavy to suspend over a sideways run of this distance. Thanks
SE Iowa said:
How about a "Garn Barn"- an outbuilding for the unit? I am not a Garn owner, but I admire the design and engineering.
pybyr said:
Honestly, for that sort of application, I would buy the corrugated stainless material that is used for lining chimneys, suspend it, and wrap it with rockwool. That way, there is one continuous run, with no points for leaks to form between sections.
Alternately, there's the double-wall stainless pipe which provides more insulating value than bare pipe, but without the cost/weight of something like Selkirk (Metalbestos) or ICC chimney sections. Both manufacturers have a line of double-wall stainless pipe available. It also has reduced clearance to combustibles, due to the insulation value.
Joe
Well, I've been dreaming of a GARN for 2+ years now. My major hang-up with the GARN is its size and the fact that it would have to be housed in an outdoor building (which I would have to build). This would probably have to be in a large building close to the house for ease of loading, stocking of wood and operating. My fear is that this would be sort of an eye-soar. I could attach it to my chicken coop to help keep them warm as a bonus but then I would have to pipe the water/fluid 150'. The other drawback is freeze protection in the event of loss of electricity/vacation.
So my love affair is slowly erroding and I'm leaning towards other indoor units that have to extra benefit of radiating heat into the house. I could core drill a hole thru the wall and then there would be no underground work/extra expense. In addition most of these units are much cheaper than a Garn.
I sure wish the midwest would catch up to you new englanders with regard to wood boilers. I guess it is b/c we don't have the massive timbre's that are characteristic of the NE. In addition, NG is relatively cheep and readily available here too. We just don't have the experts like you guys and we don't offer many reasons for any of you to take a vacation out here either. I just hate being dependant on commodity traders (remember I farm row-crops).
So my love affair is slowly erroding and I'm leaning towards other indoor units that have to extra benefit of radiating heat into the house. I could core drill a hole thru the wall and then there would be no underground work/extra expense. In addition most of these units are much cheaper than a Garn.
I sure wish the midwest would catch up to you new englanders with regard to wood boilers. I guess it is b/c we don't have the massive timbre's that are characteristic of the NE. In addition, NG is relatively cheep and readily available here too. We just don't have the experts like you guys and we don't offer many reasons for any of you to take a vacation out here either. I just hate being dependant on commodity traders (remember I farm row-crops).
SE Iowa said:
Be careful on assuming indoor units will be "much cheaper" than a Garn. All told, with 1000 gallons of storage, my EKO 40 system weighs in at about the same cost as a similarly sized Garn. But the flexibility associated with a more modular design is what I required. A Garn was never even an option for me...
Also per the above - I have 7' of Selkirk (Supervent) Class A chimney supported at a 30 degree angle running from my EKO to the hole in my foundation. If you buy a 30 degree offset kit from Super Vent you'll get some brackets that work perfectly for hanging a section from the floor above. Works well in my situation and a 30 degree angle, for me, drafts quite well.
stee6043 said:
I think he was referring to the cost of building an outbuilding and running underground piping for the Garn. Otherwise, the pricing is very similar, in my experience.
Joe
BrownianHeatingTech said:
Joe- not to hijack the other poster's thread, but let me run this by you since you are here on this thread and I am here on this thread. I was originally going to use stainless, and long sweep seamless stainless fittings. Then the need to just get the darn thing running during the January cold snap put pragmatism in the driver's seat over perfectionism, so I grabbed the 24 GA galvanized locally. It draws _really_ well (0.08+++ under any conditions) if the barometric damper is closed off, so I use the B.D. to get to the range between 0.02 and 0.05 that Econoburn recommends). The stack temps are usually between 300 and 600 depending on the "phase" of the burn. No moisture ever appears at the joints of the pipe, which tends to make me think I have no condensation. I wish I had stainless, and would, if time and $$$ were no object, but part of me now thinks "why mess with success?" At the same time, if I am flirting with hidden problems down the road, I _DO_ want to take action before they manifest themselves, so please fill me in if there are things I should factor in that I am not thinking of so far.
I agree pybyr - don't mess with success. If you were starting from scratch, i would recommend going with the double wall smoke pipe Joe mentioned. However, everything you say indicates good draft, minimal or no condensation, good stack temps, so I'd leave it alone. If it does eventually rot out from condensation it will be years down the road and you can do the double wall then. My two cents.
sorry, forgot to mention that I too am not aware of any side-wall vented wood boilers. Anyone ever try this with a Tjerenlund Side Shot? Sounds like your best bet would be to go with the set up stee6043 showed. Nice job, by the way, stee! Factory chimney works great and is easy for the average DIY'er to handle. An insulated chase like I think stee6043 did will make the chimney work even better.
I don't under stand why you couldn't side vent if you could produce enough draft. It seems like you could get enough if the run was short and you had induced or forced draft. If you had forced draft you could add and inducer. What is the safety issues? I could see if it was in an living space but in an out building or shed I don't see a problem but there must be a reason. OWB only have a very short stack and it's not a problem except getting the smoke up over living space. With a gasifier the small amount of smoke shouldn't be a proplem in most cases.
What am I missing here???????????????
leaddog
What am I missing here???????????????
leaddog
Chris Hoskin said:
Thanks, Chris- glad (but not surprised) that you folks from Bioheat support users of other brands. I stopped in your Lyme NH location back in late June and was completely agog, with both the products and the show-around that I received, and would have probably ordered one on the spot, except that they were already back ordered into late September. That said, I am really happy with my Econoburn. Some day, if I get back down that way on other errands, I'd love to see a Froling under burn!
leaddog said:
Here's my non-professional $0.02-
The Garn can vent through a side wall because it has such an immense thermal mass of water immediately surrounding the firebox that even if the power fails, there is little risk of overheat/ steam/ overpressure, or, apparently, of combustion byproducts entering the space around the boiler.
The smaller downdraft boilers have neither the mass of water, nor as much assurance that the fire will die out or that the combustion products will exit out the vent if one loses the "assisted vent" that goes with a power vent.
Sidewall power vents work with oil and gas because the fuel shuts off when the power shuts off. Wood doesn't cooperate with that.
I'll be glad to be proven wrong if someone figures out a safe way to do this- but it seems more complex than meets the eye.
No, Trevor, I think you nailed it. The crux of the matter ad I understand it is that you need to be able to shut the fuel delivery off in case of a venter motor failure or blockage. Not sure how Garn deals with it.
thanks guys, That makes sense now. I always wondered why it wasn't ok to do. It might fill a room up with some bad stuff in a hurry besides over heating.
leaddog
leaddog
pybyr said:
Oh, you're certainly getting condensation at certain phases of the burn. It's a "mist," not a puddle of water that leaks out the joints.
As Chris notes, it may take years to cause a problem. Or it may not. Best bet is to keep an eye on the pipe, and be aware for soft spots.
Chris Hoskin said:
The reason you can't use a typical powerventer is that the manufacturers say that they are not approved for use with solid-fuel appliances. Doing so voids the warranty, violates code (all codes that I'm aware of, at minimum include a "must be installed to manufacturer's specifications" clause), and creates a substantial liability issue with your insurance company, as a result.
The reason that the manufacturers don't allow for such use is a combination of things. For starters, there are the issues you just noted. Additionally, if they allowed installation for wood-fired systems, you know that someone would install it on a large, old woodstove which runs the smoke pipe cherry red, and then complain when the side of the house is jet black with soot and the venter melted into slag. They need to cover themselves, particularly give how few gasifiers are out there right now. There's the added risk, with a gasifier, of being so efficient that corrosive condensate might form in the venter and cause premature failure.
I should amend my earlier comment to note that any of these boilers can be vented through the wall, if you have an engineered venting system. Exhausto makes some wood-rated venters. Nearly all codes will include a clause exempting engineered systems, since it is presumed that the mechanical engineer who designs the system will understand the various issues, and design to prevent anything bad from happening, or inform the client that their application is not something which can be dealt with in the way that they have asked it to be. I left this out of the original reply because I daresay few individuals are going to pony up thousands for an engineered sidewall venting plan for their boiler (plus the cost of the equipment that the engineer will specify), when even a difficult chimney installation is going to cost less and work better.
The reason that Garn can sidewall vent is because the system was engineered for that by the design engineers. Because the draft inducer and the venter motor are one and the same, any failure of the motor will automatically shut down combustion. I've noted how powerful the fan on the Fröling is, and I don't doubt that it could eject the gasses from the house without a chimney, but I don't have any real certainty that it would eject them with enough velocity to get them clear of the house as they drift upward. Which is also something that the Garn's design is engineered to do (part of why they don't allow modifications to the venting - it's only approved when installed the way that they have specified).
It's certainly a physical possibility to install a powerventer on any gasifier, and interlock the blower motor with a draft switch (which would kill the boiler's blower if the venter was not maintaining negative draft inside the vent connector), but I'm not aware of any jurisdiction in which that would be allowed, without an engineer's say-so. It's not a case of "physical impossibility" - just a case of being extremely impractical in the context of jumping through all the legal hoops...
Joe
Joe, "you know that someone would install it on a large, old woodstove which runs the smoke pipe cherry red, and then complain when the side of the house is jet black with soot and the venter melted into slag"
LMAO~!
LMAO~!
Chris Hoskin said:
This is the sort of contingency for which, with solid fuel apparatus, there is the need for the "you are at your own, and only your own, risk if you do something truly, Galactically, Moronic" clause in the BIG BOLD language on the front of the product literature
....
pybyr said:Chris Hoskin said:
This is the sort of contingency for which, with solid fuel apparatus, there is the need for the "you are at your own, and only your own, risk if you do something truly, Galactically, Moronic" clause in the BIG BOLD language on the front of the product literature
Wouldn't be enough, these days...
Sad, but true.
Joe
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