Chimney Set-up- First fire - Lotsa smoke - Help!

[tahleel]

Hi guys,
This is my first post. I just bought a wood furnace used. I also bought the Class A metal chimney that he was selling. I assembled my chimney in a non-conventional way. I'll try my best to explain what I did, and some questions I have.

The return:
The return/motor has a 6" inlet. I bought a 6" starting collar and attached/screwed it onto the motor housing. It spins freely with no obstructions. I then used a 6" -> 8" reducer. Then I used 8" fiberglass insulated flex-pipe R4.2 into the return of the old furnace.

The outlet:
I have a 24" section of 8" pipe. I ran 8" fiberglass insulated flex pipe R4.2 through it, from top to bottom of the pipe (up to the stove). Then I connected that into a 8" starting collar in the ductwork of my old furnace. I know flex-pipe can be used in furnace set-ups, but what about a wood furnace?

The chimney/flue:
The flue is 6". I used a 8" section of 6" black-pipe. Then a T. I purposely used a T, so I can take off the cap and use my brush to clean it out from inside. There is a small section of 6" black-pipe, then a connector, then Class A chimney going into the brick foundation. This is where the chimney set-up become non-conventional. Instead of running it directly up to the peak of the house, I ran it horizontally 10 ft away from the house with a slight incline. Then I have a T with one inlet, one capped, and one opening with another 6" chimney section going up 3 ft. Then I have the piece ontop of the chimney that stops water from going into the system.

Fire bricks:
Some firebricks where damaged in the process of moving it into the house. I replaced them some ones that are similar. I tried to pack the bricks as tightly as possible. There is still a 1" gap in both of the sides of the chimney towards the middle. Should I cut a brick 1" to put in there? Or should I space out the bricks so there's small gaps between all the bricks? I've read without the bricks, there would be pre-mature wear in the firebox.

I know codes may/may not allow it. But the chimney setup seems that it should work. I tried to start my first fire this morning. I used paper and broken pallets (which I intend to use to fuel it for the rest of the heating season). I turned the blower on, opened the vent (above the glass door). I lit the paper and closed the door, but the pallet pieces would not burn. I lit the paper and kept the door open, and the pieces would still not burn. Smoke would come out of the air-vent (above the door), and the fire would not stay lit. After awhile, I went outside to see the chimney, and I did see a little smoke coming out. Is there a vent that I needed to open that I missed?

I don't understand why the fire wouldn't stay lit. I also don't know why the smoke doesn't go into the chimney and stays in the fire box. Should I have a bed of (char)coals or something? Attached is a diagram of my setup.

Thanks

-Tahleel

 

[struggle]

When your horizontal run is longer than your vertical run it will never draft properly no matter what. The only appliances that will work like that a power vented like furnaces and on demand hot water heaters with blowers on them.

 

[Brian VT]

Smoke don't like to go sideways.

 

[wg_bent]

Your chimney isn't drafting. As the previous post said, it may not draft with that long a horizontal run. But Let's try... You need to get the draft going. In the early part of the season, if I don't get the draft going I get a downdraft situation and smoke in the room. Some folks put a newspaper peice up over the baffle and light it and that seems to get things going. That can work for me, but isn't as reliable as my usual. I light a small coleman camp stove and set it in the OPEN doorway of the stove for a couple minutes. That stove put's out 9000 btu, so it's no slouch on the heat output and get's the chimney drafting very quickly.

Then I light the stove as you say.. news paper kindling and a few small logs on top. works every time.

Good luck!
Warren

 

[tahleel]

Let's say its because of the backdraft, and not because of the horizontal length vs vertical height reason.

I figured, like any other gas, smoke would go sideways, as it would go to an area of lower pressure as it would like to go to equilibrium. With that theory, and the fact that it is slightly sloped upwards (only a few inches), it should work. I do not know how backdraft works, but when I do take the cap off, I do feel the cold from outside the house. I have two theories that may work with my exisiting set-up (so I won't have to dig the chimney back up), please let me know if either would work.

1.) Use my kerosene torpedo heater (150,000 btu) to blow hot air into chamber. Then when it gets nice and hot (and the air drafts out and up), start my fire. If I do this, can I put the torpedo heater output right into the wood stove?

2.) Set a fire in the stove. Take the chimney cap off, and cover it, and allow the chimney to become pressurized. Once it does, then take the cover off the top, and the smoke SHOULD go the path of least resistance to equilibrium and out.

Please let me know if either would work.

Thanks a lot guys!

-Tahleel

 

[Hogwildz]

That set up will never work. Usually minimum chimney/pipe length needs to be around 15'.
The t's you have are equal to a 90 elbow. An elbow = 5' loss equivalent on the length of pipe.
I can't comment any more. That entire set up is just begging to get you & your family hurt.
Common sense man, common sense.

 

[struggle]

Maybe someone remembers the thread about the person that had a horizontal run just like he has and it was installed (pipe) going under a porch. They had the exact same issue you are dealing with for the exact same reasons.

Try the forced air heater and see how it works. It just seem like a stretch that it will ever work right but maybe once you get it pulling for you it will work but when it decides not to and back drafts you are the one that is going to suffer so I am not completely sure it will ever be safe in terms of go to sleep and think nothing will ever happen to fill the house up with smoke.

You still have to factor in prevailing winds as well and the pressure changes from storm fronts coming in and your set up will always be victimized be these other factors.

Is the pipe actually buried under ground before it comes to the surface?

 

[begreen]

Welcome tahleel. What is the make and model of this furnace? Do you have the manual?

The reason I ask is that there are multiple errors with the installation, some which are outright dangerous. It would be helpful to have the manual as a reference. But lacking that, I agree that the flue is completely wrong. lThe flue system is critical to the proper operation of the furnace. As described this flue is dangerous. The horiz. run should be as short as possible and the vertical run should be at least 12-15' high.

As to the ducting, the supply duct should be metal, not flex duct. There is the potential for very high temps in the supply duct, especially if the power fails. It needs to be changed to 8" metal duct asap.

 

[tahleel]

The forced heater worked great.. but only for a few minutes. It heated up the flue, then we lit the fire and it worked. We let the fire go with the door open. Then once we closed the door, the smoke started coming from the air inlet again.

I then decided to dig it up, and do it the right way. Now, how should I do the set-up?

I planned on doing the following, please let me know if its sufficient. From the furnace, it goes up 8 inches to a T. Then the T is connected to a pipe going horizontally 5 feet. This is then connected to another 3. Then it would be going up 12 feet. Does this seem like a good set-up? Is there enough height for the T's and horizontal section?

-Tahleel

 

[struggle]

12' vertical is not enough. With the longer vertical run you need to have more like 20' vertical.

Even a 12' straight vertical chimney no elbows off a wood stove is considered marginal at best for most people.

Also your horizontal run needs to rise something like a 1/4" per foot to create the upward lift.

I bet if you put your vertical at 20' with the shorter horizontal run you will see night and day difference in draft and performance. I cannot imagine there being anything safe about burying the pipe coming out of the wall. Build a box around it or something so it is accessible.

 

[begreen]

The horizontal connector section is going to need a generous pitch uphill towards the chimney. At a minimum it will need 1/4" per foot.

I just looked at the diagram again. Is the exterior portion of the flue underground for some part?

By all means post some indoor and outdoor pictures. Getting partial advice for a serious heater like a furnace can be dangerous. We may not even catch everything with pictures, but will likely see more issues if they are present. Will you be getting a final, local inspection by a professional?

 

[MrEd]

Is that chimney actually running underground? if so I suggest you get some professional help before you kill someone - seriously. No offense intended.

 

[Hogwildz]

Getting rid of the T's and using 30 degree elbows will let it flow & draft better and give you a good pitch on the piping.