duct work???

  • 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.
  • Hope everyone has a wonderful and warm Thanksgiving!
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here
Status
Not open for further replies.

nate p.

Member
Sep 15, 2013
26
[Hearth.com] duct work??? [Hearth.com] duct work??? OK I bought a older wood furnace And for the duct work it had a Plenum on the top with a spot to hook up to my existing duct work in my home.... my insurance company says that the plenum is wrong and canceled my policy because I apparently altered the stove. So since I received my cancellation notice I have changed it up a little to see if they would decide not to cancel my insurance does this seem right to you guys? I will add pics the one with the plenum is a before shot and the one without it is a picture of my alternative.
 
Where does the duct go to? Make sure you have at least 2" of clearance between the duct and any combustible (wood framing), I'd double that number if it were me.

TS
 
The duct goes straight through that back wall into a room where my gas furnace is and hooks into my furnaces duct work to blow throughout my home
 
Yeah, that single duct looks WAY too small! Or need several more of them.
Yeah some (most) HO ins co's are just looking for a way of getting out of covering wood stoves furnaces!
 
  • Like
Reactions: JustWood
I thought so myself I was debating on adding one more on... it is a six inch duct coming out of the top now
 
I think the smallest I have seen is (2) 8" ducts. Depending on the BTU rating of the furnace, it may need a good bit more than that. (1) 6" is definitely not enough
 
My wood furnace has a 16" round off of the top feeding back into my propane furnace. That setup is way too small.
My Yukon has 24x24 plenum, (2) 8x24 ducts coming of that. That will flow a lot of air! Your 16" round is almost 200 sq in., his single 6" is only 27! fire hazard city!
 
Well it had the single 12" round duct hook up so would two 6" be good? Because furnaces at menards of a similar size out of the two they had there one had a single 12" hole out the top and one had two 6"
 
Get an add on furnace and put it in the furnace rm. No good can come from the current setup.
 
He's using it as an add-on, no?
My old Hot Blast had 2 8" ducts so you'd not be getting much out of that furnace, imo.
Since the top is just open for attachment to your existing system as needed, I would suspect brenndatomu is right about the insurance co. trying to get out of the policy. My insurance agent told me I could run the add-on as long as I maintaned the propane furnace in place. Their policy didn't permit stand alone wood heat. Not sure what they found dangerous about that. I was only to use it "part time", as well. lol...right! If my house were to burn down, exactly how do they suppose we would determine which burn cycle I was on for my part time permission?
 
Yes it is an add on furnace... I have a lp furnace and it was quite costly to run in the winter and ran across this for a steal of $100
 
On the bottom of the back side of the furnace there are two fans mounted there so that would be the return
 
I'm already over my head since I have no direct experience with hot air systems, so this'll likely be my last post - but you also need to be very careful about negative drafting & your return pulling bad stuff out of your firebox & into your ductwork.
 
+1 on that
 
Yeah some (most) HO ins co's are just looking for a way of getting out of covering wood stoves furnaces!
I agree. That doesn't really change anything. Insurance company definitely looking to get outta policy
 
Well it had the single 12" round duct hook up so would two 6" be good? Because furnaces at menards of a similar size out of the two they had there one had a single 12" hole out the top and one had two 6"
Do the math, (1) 12" is around 108 sq in. (2) 6" is only 54 sq inches! Also, you have to compare actual BTU rating, firebox size, and CFM of the duct blower, the Menards furnace with (2) 6" holes likely was a lot smaller furnace
 
I can not compare the BTU rating due to the fact I don't know mine... I can't find any info on my furnace what so ever other than the mfg. And model number and date
 
Even so, I'm sure that (2) 8" round ducts are gonna be MINIMUM.
Probably gonna be tough to get anyone to insure that furnace, they get REAL gun shy of old stuff. Most will want MFGs recommended install info (and UL or Warlock Hershey certs) to certify that you installed it right, especially as a new customer. Sounds like that info is non existent. Likely part of the reason it was so cheap. What brand/model/age is it anyway?
 
Last edited:
What is the make & model?

And this is more seat of the pants than anything - but looking at that pic, with the way the duct immediately goes down, that looks like a heat trap that could cause some very serious grief if there were a power outage or blower malfunction while there was a wood fire burning.
 
What is the make & model?

And this is more seat of the pants than anything - but looking at that pic, with the way the duct immediately goes down, that looks like a heat trap that could cause some very serious grief if there were a power outage or blower malfunction while there was a wood fire burning.

Oh yeah, I see it now! I thought that the duct just went to the right through the wall, I didn't see the second ninety and the downhill run through the back wall. They would consider that a downdraft install. Yup, no insurance co. will take that, heck, the don't even let you do downdraft fossil fuel furnaces unless it is made/certified that way. Darn shame too, cause your new "plenum" ductwork shur is purty!
 
Status
Not open for further replies.