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General Forestry => Firewood and Wood Heating => Topic started by: Woodcutter_Mo on October 31, 2017, 03:23:24 PM

Title: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on October 31, 2017, 03:23:24 PM
 Hello, I recently bought a forced air outdoor wood furnace that will set just under 4' from the house. With it being this close to the house, the chimney will need to be about 16-18' tall to to get it above the peak of the roof above the furnace.

What do you all use to support a chimney this tall? I've looked on the internet quite a bit but most show the chimney making a 45 degree bend to the wall and run up the side of the house fastened to the wall. I don't know if that setup will work on this setup. Do you just use a guide-wire setup? I'm using Selkirk insulated double wall stainless chimney pipe if that helps. Thanks
Title: Re: Chimney on outdoor wood furnace
Post by: TKehl on October 31, 2017, 04:55:45 PM
My parents is close to the house and they have a couple bands and brackets that anchor to the side of their A frame house house.

Similar to this but just solid brackets instead of adjustable.

https://www.efireplacestore.com/cpf-69870.html (https://www.efireplacestore.com/cpf-69870.html)

Title: Re: Chimney on outdoor wood furnace
Post by: thecfarm on November 01, 2017, 01:57:01 PM
selkirk? I'm on lunch at work,hardware store and I sell support brackets for them. Longest I have is 3 or 4 feet. Web site might show longer ones.
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 01, 2017, 03:36:52 PM
 Ok, I may be able to use something like that at the bottom to brace the chimney to the furnace it's self. Ill measure it when i get home but the wall of the house is probably atleast 7' from the chimney so those brackets might be a bit short, I'll look around and see if they make longer versions of them. :)
Title: Re: Chimney on outdoor wood furnace
Post by: TKehl on November 01, 2017, 03:42:35 PM
Otherwise extending it with metal conduit seems doable.

(My first thought was PVC, but PVC:Chimeny::Water:Electricity)  :D
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 01, 2017, 06:47:56 PM
Quote from: TKehl on November 01, 2017, 03:42:35 PM
Otherwise extending it with metal conduit seems doable.

(My first thought was PVC, but PVC:Chimeny::Water:Electricity)  :D

That's a good idea, I will look into that.  8)
Title: Re: Chimney on outdoor wood furnace
Post by: Iwawoodwork on November 01, 2017, 07:40:02 PM
my thought would be to use a length of 8" well casing. Dig out a footing pad next to the boiler and set the casing in it then bring the chimney out at either a 45* or 90* over to the  hole you made into the casing and the welded a flange around the hole, attach the boiler chimney.   With  the well casing set into the concrete footing it would be free standing, also there could be a clean-out plug at the base. The casing would only need to be shielded up to about 7 or 8 feet, 
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 01, 2017, 08:20:42 PM
Quote from: Iwawoodwork on November 01, 2017, 07:40:02 PM
my thought would be to use a length of 8" well casing. Dig out a footing pad next to the boiler and set the casing in it then bring the chimney out at either a 45* or 90* over to the  hole you made into the casing and the welded a flange around the hole, attach the boiler chimney.   With  the well casing set into the concrete footing it would be free standing, also there could be a clean-out plug at the base. The casing would only need to be shielded up to about 7 or 8 feet,

That would probably be a good option, only problem would be the well casing wouldn't be insulated so it would probably creosote up pretty bad, though like you said it could have a clean out. However, I could probably use a piece of 2"+ pipe set into the ground instead to strap the chimney to.
Title: Re: Chimney on outdoor wood furnace
Post by: gspren on November 02, 2017, 08:28:39 AM
  If your burn chamber has a blower to supply combustion air your chimney height doesn't need to be that tall unless you just want the smoke higher.
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 04, 2017, 12:39:30 PM
 I think I figured it out. I have a few of these 10' antenna sections my dad had taken down for someone several years ago. I may pour a little pad for the antenna to stand on next to the furnace and mount the chimney to it. I will just need a couple insulated elbows to angle the pipe from the furnace to the antenna and a T at the bottom of the chimney for a clean out. This will be more than sturdy enough to attach the chimney to and also make maintenance much easier as I can simply climb up the antenna sections to install and work on the chimney when the need arises.

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171104_113646.jpg?easyrotate_cache=1509813499)
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 04, 2017, 12:44:21 PM
Quote from: gspren on November 02, 2017, 08:28:39 AM
  If your burn chamber has a blower to supply combustion air your chimney height doesn't need to be that tall unless you just want the smoke higher.

If the furnace was further out from the house I would just put a 6' chimney on top of it but as close as I have it now I would like the smoke up over the house and also to keep potential sparks up high. There is an attic vent in the wall above the furnace so I was afraid if the chimney was too close it might let smoke in the vent.
Title: Re: Chimney on outdoor wood furnace
Post by: Jim_Rogers on November 04, 2017, 01:05:19 PM
I don't know if you need to follow any building code or not. But they usually ask for the top of the chimney to be at lease 2' above any roof withing a 10' radius of the chimney.
This would/could/should be a minimum even if you don't have to comply with a code, for safety sake.

Jim Rogers
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 04, 2017, 01:48:42 PM
Quote from: Jim_Rogers on November 04, 2017, 01:05:19 PM
I don't know if you need to follow any building code or not. But they usually ask for the top of the chimney to be at lease 2' above any roof withing a 10' radius of the chimney.
This would/could/should be a minimum even if you don't have to comply with a code, for safety sake.

Jim Rogers

I should be at about 2'-3' above the peak when it's all said and done  :)
Title: Re: Chimney on outdoor wood furnace
Post by: DDW_OR on November 04, 2017, 02:43:49 PM
Quote from: Woodcutter_Mo on October 31, 2017, 03:23:24 PM
...the chimney will need to be about 16-18' tall to to get it above the peak of the roof ....
Quote from: Woodcutter_Mo on November 04, 2017, 12:39:30 PM
.....10' antenna sections .... pour a little pad for the antenna to stand on next to the furnace and mount the chimney to it. ....and a T at the bottom of the chimney for a clean out...... simply climb up the antenna sections to install and work on the chimney when the need arises.

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171104_113646.jpg?easyrotate_cache=1509813499)

it would be best if you can have the antenna as close to the furnace as possible to not use any 45's.
maybe have the antenna to the house side of the chimney.
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 04, 2017, 06:41:29 PM
Quote from: DDW_OR on November 04, 2017, 02:43:49 PM
Quote from: Woodcutter_Mo on October 31, 2017, 03:23:24 PM
...the chimney will need to be about 16-18' tall to to get it above the peak of the roof ....
Quote from: Woodcutter_Mo on November 04, 2017, 12:39:30 PM
.....10' antenna sections .... pour a little pad for the antenna to stand on next to the furnace and mount the chimney to it. ....and a T at the bottom of the chimney for a clean out...... simply climb up the antenna sections to install and work on the chimney when the need arises.

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171104_113646.jpg?easyrotate_cache=1509813499)

it would be best if you can have the antenna as close to the furnace as possible to not use any 45's.
maybe have the antenna to the house side of the chimney.

Ok I was planning to put it right next to the furnace, there will need to be a couple slight bends if I mount the chimney to the antenna like I planned as the chimney goes strait off the top of the furnace. The antenna will be sitting about 20" from the chimney outlet so a 15° or 30° should be enough offset .

Here I stood up a piece of the antenna by the furnace to show approximately where it would stand.

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171104_173302595_HDR.jpg?easyrotate_cache=1509835218)
Title: Re: Chimney on outdoor wood furnace
Post by: TKehl on November 04, 2017, 10:33:36 PM
OK.  This may be a dumb question, but why not just move the stove a bit further from the house and just use 6 or 12' of chimney?  Seems like a lot of extra work for not a lot of gain...   ???

It's bad enough cleaning dad's chimney cap with a couple pallets on hay forks on the front loader.  Can't imagine trying to remove and clean the cap while hanging from an antenna pole... 

Mine only uses a single 6 footer.  I climb up on the stove and reach up to remove the rain cap.  Easy peasy.   ;)  I don't seem to get creosote on anything else even with the **** wood I burn. 
Title: Re: Chimney on outdoor wood furnace
Post by: DDW_OR on November 05, 2017, 11:01:58 AM
this drawing is just a guess since your photo has limited info

I suggest to put the antenna as close to the side of chimney, that way the antenna does not get in the way of the clean-out T


 (https://forestryforum.com/gallery/albums/userpics/27421/EXAMPLE_1.jpg?easyrotate_cache=1509897387)
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 05, 2017, 11:32:07 AM
Quote from: TKehl on November 04, 2017, 10:33:36 PM
OK.  This may be a dumb question, but why not just move the stove a bit further from the house and just use 6 or 12' of chimney?  Seems like a lot of extra work for not a lot of gain...   ???

It's bad enough cleaning dad's chimney cap with a couple pallets on hay forks on the front loader.  Can't imagine trying to remove and clean the cap while hanging from an antenna pole... 

Mine only uses a single 6 footer.  I climb up on the stove and reach up to remove the rain cap.  Easy peasy.   ;)  I don't seem to get creosote on anything else even with the **** wood I burn.

Not a number question at all. On my house Im sort of limited to where I can place the furnace at the moment. The house has a rock foundation with 2 access's to the crawlspace. There's one on the east side and one on the west. On the west side there is also a closet where I could even pipe it strait in but also a large cedar tree on that side that would be in the way. I currently have the furnace placed on the east end which is also next to my driveway and placing it out too far would somewhat restrict my entrance to my garage. Plus I already had a concrete pad where I put the furnace.

The house was built in the 1890's and wasn't at all layed out for an outdoor furnace, and when they remodeled it in the 50's-60's they didn't help matters at all  :D
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 05, 2017, 12:01:27 PM
Hard to get a good pic, but here's quick drawing of the layout

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171105_105851.jpg?easyrotate_cache=1509901260)
Title: Re: Chimney on outdoor wood furnace
Post by: DDW_OR on November 05, 2017, 12:05:52 PM
that helps alot.

looks like you are between a rock and a hard place ;D
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 05, 2017, 12:11:08 PM
Quote from: DDW_OR on November 05, 2017, 12:05:52 PM
that helps alot.

looks like you are between a rock and a hard place ;D

Yup, I'll make it work out one way or another. It's just requiring a little extra effort and $$$, but I think it'll be worth it in the long run.  ;D
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 09, 2017, 12:55:33 PM
 I found some elbows and a Tee w/clean out cap on eBay. They should be here within the next several days so I can mock up where the pipes will go to figure out exactly where to place the antenna.
Title: Re: Chimney on outdoor wood furnace
Post by: Crusarius on November 09, 2017, 01:02:08 PM
Heating the shop at the same time?

oops. nevermind that says driveway :)
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 09, 2017, 03:08:18 PM
Quote from: Crusarius on November 09, 2017, 01:02:08 PM
Heating the shop at the same time?

oops. nevermind that says driveway :)

If it were a boiler I would definitly heat the garage with it :)
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 25, 2017, 09:14:52 PM
Got a start on the chimney, I bought a Selkirk "T", a Selkirk 30° elbow to come off the T. Also using the two 30° elbows from a super vent 30° offset kit to attach to the furnace since that's what the stove is setup for. I used my Selkirk anchor plate as an adapter to connect the Selkirk pipe to the SuperVent elbows. Sounds like alot of work but I saved several hundred dollars combined just on these pieces getting them from eBay.

We put up the antenna tower set in concrete next to the furnace to mount the chimney to.

Here's where I'm at now, I'll have to figure out a good sturdy way to attach the chimney to the tower sections but just using some steel strap for mock up.

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171125_170138033_HDR~0.jpg?easyrotate_cache=1511662353)

(https://forestryforum.com/gallery/albums/userpics/35112/IMG_20171125_170154484.jpg?easyrotate_cache=1511662435)
Title: Re: Chimney on outdoor wood furnace
Post by: DDW_OR on November 25, 2017, 11:39:33 PM
Now put a weather station on the top of the antenna tower

i have the Vantage Vue, the remote sensor is solar powered
Title: Re: Chimney on outdoor wood furnace
Post by: Woodcutter_Mo on November 25, 2017, 11:50:52 PM
 Well the chimney will go all the way up or I would do something like that