Hotblast 1500 install, Opinions?

[sambrent18]

Hey everybody,
Just thought I would share my plans for installing my add on wood furnace. It's a us stove hotblast 1500 I got from Northern tool back in september. After numerous calls and no show contractors I've had enough so I'm doing it myself (the stove has been sitting in my basement since the first of october).
I'd like to see what you guys think since most of you have been using these things for a while. Is it gonna work, am i doin the right thing or not. Brutal honesty please, I'm a big boy I can take it.

So heres my plan

I'm having a local sheet metal shop build me a piece to mount to the top of my stove instead of running two 8 inch pipes. Its gonna be 30 inch by 8 inch at the bottom and kinda triangle up to an 8 inch by 10 inch probably be 12 inches tall or so. From there I am installing a backdraft damper then a short way 90 over to a long way 90 then into my 8x10 duct. The first few branches coming off the trunk line i'm going to put metal to the registers and get rid of my flex ( just the three closest to the stove). I plan on installing a backdraft damper above the air handler for the electric heat pump. The wood furnace sets about 12 feet away from the air handler I have about 15 feet or so of ductwork to go through before it gets there. On the other side I have fiber duct board which I plan on leavin alone for now and flex duct coming off it to the other registers which i figure by then the air from the wood furnace should be cooled down enough not to have any worries. I am tapping into my existing cold air return with a 10 inch round pipe over to the cold air return box on my stove in which i will install a filter before the air gets to my fans. Im not to concerned of a power outage I have a 10,000 watt generator I can run a cord to to power the blowers and I dont plan on burning unless im home. I work shift work and the wife is kinda scared to use the stove. I plan on starting on this install in the next week or two if I can find my dampers I'm waiting on a couple quotes now. So tell me what you think good or bad lay it on me.

Thanks

 

[laynes69]

Installing a woodfurnace isn't a big deal. There are a few things that won't allow you to install one currently on the ductwork. One is no flex ducting is allowed for ductwork. The temps can be too high for the rating of the flex, and two ductboard isn't rated for the temps either. At any time temperatures can get very high, especially with a power outage and can create unsafe conditions. Also duct clearances must be followed according to the manufacturer. If those few things can be corrected, everything else sounds okay.

 

[sambrent18]

Thanks Laynes,
I'm replacing the fiber board with metal duct in which I'll wrap with insulation. I will also go ahead and replace all the flex line with solid as well just to be on the safe side.
Thanks for the reply.

Also, can the insulation i'm going to wrap around my metal duct be wrapped all the way down to the top of my stove to prevent heat loss or do I have to stop it so far from the stove. I think the heat rating on it is 250 degrees.

Thanks again

 

[laynes69]

I wouldn't wrap within 10' of the furnace. You will find that the furnace will put of a ton of heat just from the surface of it. The jacket can get hot during a good burn. When you install make sure you can open the backdraft dampers manually in case of a power outage. The 2 8" holes on the top do not allow for gravity heat removal during an outage. We had that furnace for years and normally the part of the outage that woke us up was the smell of burning paint in the middle of the night. They aren't the most efficient furnace, but they will do the job. How big of house are you going to heat with it?

 

[sambrent18]

I can't remember right off the top of my head but I know the stove was rated for 2400-2500 sq ft. I know i'm not over that but i'm real close thats finished space up stairs plus the unfinished basement and garage downstairs. I have two small vents on the basement side and none on the garage side which you can tell abig difference just by walking through the doorway into the garage. The stove sits on the basement side. Do you know of a place where I can get dampers in case the guy i'm waiting on falls through I cant find rectangular ones anywhere. I'm gonna need an 8x10 and a 14x16.

Thanks

 

[laynes69]

Check with some local hvac people to see if they can make one, or post an ad on Craigslist. I made ours, which was custom for the setup.

 

[sambrent18]

Laynes I've checked with hvac suppliers and sheet metal shops and they all say they don't carry or don't make dampers like this. How did you make yours, what did you use, could you send me some pictures. I had thought about doing that but could'nt really get the picture in my head out on to paper.

I called a guy in Knoxville TN with Envirosystems. He is supposed to be getting me a quote fixed up and call me tomorrow with it. If I could make them myself I'd rather do that so I know what Ive got

I'm soooooo ready to get this thing installed. I've had the stove sitting in my basement since September, I've called four hvac guys since I got the stove, one showed up and did'nt have a clue, the other two never showed and the other one showed took measurements and never called back (and he's my brother-in law). So to say the least I'm tired of depending on somebody else.....lol.

Thanks

 

[laynes69]

I don't have any pictures of the dampers I made. I wouldn't recommend making them unless you know what your doing. There are a couple of things you can do to make it easier. You can run 2- 8" ducts off the woodfurnace and use manual hand dampers you can buy in the store, or the butterfly dampers they sell online. Personally I would want manual dampers that way you can open them in case of an outage. The jacket on the woodfurnace will get very hot and having some flow will help. As far as the other damper goes, having it open only when the central furnace operates is fine. You just want to stop any backflow. Here is a couple of different dampers to give you an idea. I made a large butterfly damper that was custom because the two were side by side. Hope this helps.

http://www.grainger.com/Grainger/FANTECH-Back-Draft-Damper-5C525?Pid=search

http://www.grainger.com/Grainger/DAYTON-Backdraft-Exhaust-Damper-2FTU9?Pid=search

 

[sambrent18]

Thanks Laynes,
Thats a big help, I'll probably go with the square one above the air handler and do the manual ones above the wood furnace.

Went today and picked up all my other stuff gonna start installing tomorrow I'll try and post some pics.

Again, thank you