Forced air furnace advice

[Matt78]

Well I got a hole through the wall. Took about a full day. Wasn't real terrible. Air conditioner went out Sunday. Go figure. Its fixed now, thank the lord. I was planning on cleaning hole up a bit. Then mounting tee to outside the house next. Then my nephew is going to cut out my eve. Then I was going to run the chimney up. Then box the chimney in with a chase. Does this sound like a good order of doing things? Also how far in should I run the class a chimney into the basement? I'll have more questions I'm sure. Thanks

 

[brenndatomu]

Looks good. Git 'er done! Poured walls are a lil more work to make a hole that size through than a block wall.
Are you under a porch outside there?
Once the tee is mounted you'll see how much pipe will stick through the wall. The tee kits usually come with a 1' pipe but you could go longer if you need it for CTCs or whatever works best for your planned setup. Sounds like you have the outside stuff handled, like I said before, just mind your CTCs and overall height rules, oh, and make sure to leave access to the tee cleanout cover.

 

[Matt78]

Thanks. Always nice to do a little of the work and save a little cash. Yes it has to pass through the deck between two doors. I know it's not ideal but about the only option I had. There is a access door for under the deck.I think I'll run chimney into basment till I get past that electrical conduit. Then down with double walled stove pipe. I figured 15' to of chimney. From tee to the peek of the roof is about 12'. Is that kosher? Should I put a baro damper on the stove pipe? I did buy a mark II manometer.

Just a stupid question here. If I ever did have a chimney fire with that Chimney. How hot would the outside pipe get?

 

[brenndatomu]

So the chimney is gonna be 3' over the peak of the roof? That should be good as long as there aren't any big trees real close.

Probably won't need a baro on a 15' chimney, especially external chimney.

Well, I had a chimney like yours a few years back, had a chimney fire, pipe was hot but not too hot to touch. Wasn't a real major fire though, so...dunno how it'd be if you really got one rippin. Normally it wasn't warm at all.

 

[Matt78]

 

[Matt78]

Starting to come together! Should I elevate the furnace on blocks? Do I want to put a damper in. I noticed the manual says not to. And in the last picture. Is it OK to have gaps between the pipes where they fit together? Thanks again

 

[Matt78]

I forgot another question. Does the tee just set on the top of the support?

 

[brenndatomu]

Should I elevate the furnace on blocks?

I would, once you start using it you will quickly realize how low that firebox is. Keeps the steel from sitting directly on potentially damp concrete too. Or buys you some time if the basement ever flooded.

Do I want to put a damper in. I noticed the manual says not to

You probably won't need it but I would throw a manual damper in just so that it is there in case of chimney fire with a fresh load of wood in the furnace, at least you can slow things down some. Without it, the firebox just becomes a runaway train.
The only bad part is you have to remove it to clean the pipe...easy enough to do that though

Is it OK to have gaps between the pipes where they fit together?

Looks fine to me.

What's your plan for connecting the furnace to the chimney? Any way you could make use of 45* elbows instead of 90s? It improves draft a lot. They say each 90* turn has the same effect on the chimney as removing 3-4' from it's height...so (3) 90s = 9-12' off your total chimney height...not good

 

[brenndatomu]

I forgot another question. Does the tee just set on the top of the support?

It's been a while but I am thinking mine did kind of attach...can't remember exactly how it was now. What brand do you have there?

 

[Matt78]

I was thinking about 45 deg. But I think I would be to far out in the middle of the room. The pipe is supervent. Should I run the chimney higher?

 

[brenndatomu]

Supervent was what I had. How tall were you planning on...from the top of the furnace to the top of the chimney?
If you put it up on blocks it will also be that much closer to the wall too, if using 45s. Also, what length pipe is that coming though the wall? 2'? You could maybe gain some room there...
Just a tip, when building your black pipe from the furnace to the chimney connector, keep in mind how you are going to access things for cleaning the pipe and the section of chimney going through the wall, put it together so it is easy as possible to clean

 

[velvetfoot]

I've seen a lot of stuff on termite blocks.

 

[Matt78]

Its going to be 16' to 17' from the top of the wood furnace to the top of the chimney. I may try to shorten pipe coming into the basement, but I don't know if its possible due to electrical conduit.

 

[brenndatomu]

but I don't know if its possible due to electrical conduit.

Heat shields my friend, heat shields. A layer or two of galvanized duct work type metal between the pipe and the conduit should make things kosher (with at least an inch or two between each)
Worse comes to worse you add height to the chimney if it doesn't draft well...

 

[Matt78]

 

[Matt78]

This is the shorter version with 45. I have 7" between pipe and conduit. Should it go that far out before 45. Or I'm I doing some thing wrong. I have a piece of 1/4" aluminum plateiI could use for a heat shield. Pictures go in series how it went together. I'm using double walled black pipe

 

[brenndatomu]

Me personally I'd still be OK with a couple heat shields in between there, especially with using double wall pipe, not sure what the code would be exactly in that situation though.
Looks like that is about as short as you can go using double wall.
Is it possible to turn the furnace sideways so it doesn't stick out so far. In that scenario you'd turn the 45 elbow 45 degrees to the side and then do the same on the elbow on the back of the furnace, just a thought.
Or if going sideways you could use the 45 on the chimney connector and a 90 on the furnace, just turn the 90 elbow 45 degrees to the side

 

[DoubleB]

Should I elevate the furnace on blocks?

I agree that you should, if nothing else to try to minimize moisture and corrosion. Heck, I even taped thick plastic to the underside of 1/2" cement board and set the blocks and furnace on top of the cement board. I have an old concrete farmhouse floor that seeps a little visible moisture in the summer. Moisture still wicks up around the edges of the cement board, and I'm glad to know that isn't happening under the furnace.

Only downside to the blocks is I have less height difference to help gravity airflow in a power outage, but I can't imagine a few inches is going to make much difference for those rare occasions.

 

[Matt78]

Well I'm going to be stuck with 90 deg elbows. So would it be better to run the chimney up at least 18'?

 

[brenndatomu]

I would say yes but you could always try it and then add another section on if needed.
Just FYI, my sister has a Tundra running on a 18' Supervent chimney and has 90s on the stove pipe...seems to work fine so far but limited experience due to a late winter install earlier this year
Oh, and I don't know what brand double wall pipe you have but Drolet list the CTC on their Vortex line of pipe at 5-6" depending on the setup. So most likely you are good to go on that conduit

 

[Matt78]

 

[Matt78]

Some more progress today. Starting to come together. I'll run the chimney up the rest of the way tomorrow.

I'm using the Selkirk double walled stove pipe. CTC is 6". So good to go on the conduit. I'll still put a 1/4" pc. Of aluminum between it.

 

[brenndatomu]

Some more progress today. Starting to come together. I'll run the chimney up the rest of the way tomorrow.

I'm using the Selkirk double walled stove pipe. CTC is 6". So good to go on the conduit. I'll still put a 1/4" pc. Of aluminum between it.

Looks like you are making good progress Matt.
I would assume the duct to the right of the Tundra is the return air duct for your main furnace? Maybe you already planned this, but you could cut a register or two into that to help keep the Tundras blower from pulling a negative pressure on the basement. Just get closable registers or you can buy magnetic sheets that will cover the vents when you are not running the Tundra.
Also, when you install the supply pipes you will want to put a damper in each to help set the blowers static pressure once you get fired up.
Make sure you get good ones that have a pivot on each side otherwise the pressure will just lay a single pivot one over. Like this...http://r.search.yahoo.com/_ylt=AwrB...02907133/RK=0/RS=F5DW0aSThpV6xyLA2RcF.1z0DJ8-

 

[Matt78]

 

[Matt78]

Got the chimney up today. Tried watching browns. That lasted almost three quarters. Decided to get some work done going to be a long year.

I'm not sure I understand the negative pressure thing. Can you explain it better? Sorry. I am a Newbie