• Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

ua2pants

New Member
Sep 5, 2023
2
Pennsylvania
Hello! New member here! I grew up from basically birth all the way until I was 19 years old, using and familiarizing myself in the use of the family wood stove.

Now that was 15 years ago and I fondly remember the days of stoking and chopping. However, I was not born prior to the stoves installation.

Fast forward, I am now renting a place, I already got the all clear from my landlord to install a wood stove due to the rising cost of oil. I have since purchased a Nashua NFP-2 Wood Stove from the marketplace on facebook and WOW was it HEAVY! The tag on the back says it was inspected in December of 1978. It is still currently in the back yard as I did test it out to ensure everything would function as intended and it performed well (for being outside).

My question is this; I have never installed a flue before. I do currently still have an oil furnace that this unit would be installed approximately 5 feet away from, with the oil tank approximately 15 feet away from where I would install this. I also have kicked the idea around of building a cinder block wall between the tank and the furnace as a just in case. I am unsure of the flue size however. The exhaust is out the back near the middle of the unit, and I measured it at 8 1/2" in diameter. The stove did come with some flue pipe as well, about 16 feet of it, though none of it is insulated and I cannot find any other pipe that would fit this as i've found 8", 10" and 12" flue, but not 8 1/2". I've read a lot on this site dealing with draft, flow, clearances, etc. but I am still unable to figure out this part.

It is going to go out an existing window. I will remove the window (from the basement) for the flue to extend out of, and run it up 2 feet taller than the highest point on my house. I know about ensuring it has as little bends/turns as possible, but would require it to have two 90 degree bends to have it go out and straight up.

I guess what I'm asking here is, Where would I find 8 1/2" flue pipe? Should I use double wall insulated the instant it goes to the window and the entire way up for proper draft? Is cement pavers an adequate hearth to use for such an appliance? I've also tried locating the owner manual for this but due to its age, am highly doubtful I will ever located one.

I can also take any pictures anybody would be interested in seeing!

Thank you all and I look forward to any and all advice!

Edit: I wanted to add that it does contain ceramic fire brick inside, 2 of which are cracked. I plan to replace the damaged pieces before I would use it indoors just to ensure all is well!
 
It is an 8" exhaust inside the collar most likely. So use an 8" chimney. And yes it needs to transition to chimney pipe before it enters the wall and all the way to the top from there. The distance to the furnace and tank are not an issue. What is the floor it's going on made of?
 
  • Like
Reactions: ua2pants
It is an 8" exhaust inside the collar most likely. So use an 8" chimney. And yes it needs to transition to chimney pipe before it enters the wall and all the way to the top from there. The distance to the furnace and tank are not an issue. What is the floor it's going on made of?
I thought that's what it was! I just wasn't 100% sure. The floor is poured concrete, as well as the wall behind/beside it is the foundation (rock and cement/concrete) so zero flammable materials near it. There is the floor above with the joists and flooring but those are about 5' above the top of the stove.

Should I use double wall for the entire outside with a top cap though?
 
Class A, high-temp chimney pipe is what goes through the wall to the tee and then up to the cap. This can be double or triple wall chimney pipe, but double-wall is better and recommended.