Duct Insulation

[Ejectr]

I was going to cover my exit duct coming out of the top of my PF100 pellet furnace with foil faced duct insulation until I read on the Corning site that foil is flamable as well as the paper facing and must be kept away from even a hot electrical light by 3".

I have a few areas where my duct comes within an inch or closer to the exhaust pipe on the furnace, which gives me cause for concern using this stuff. I can keep my hand on the exhaust pipe for quite awhile before I have to remove it and if the ESP is doing it's job, it shouldn't be over 165 degrees.

So what say you gurus? Use it or not use it. It does have a fire rating on the MDS sheet.
Thanks.
(broken link removed to http://www.homedepot.com/h_d1/N-5yc1v/R-100152008/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=duct+insulation&storeId=10051)

 

[SmokeyTheBear]

Remove the foil where the vent is or use a different insulation blanket where the vent is.

 

[Ejectr]

Remove the foil where the vent is or use a different insulation blanket where the vent is.

Yes, I was thinking of doing that. I could use the Corning Eco Touch insulation so it wouldn't be detrimental to human contact.around the exhaust pipe area and use the foil type on the rest of it. Thanks.

 

[Ejectr]

Can just the fiberglass insulation itself come in contact with the vent pipe at all? No foil or paper on it. Just the fiberglass wool itself. It is unfaced.

There is no way I can insulate one area of the exit duct without it doing so. If not, I pretty good sized area will still be uninsulated along the bottom and one side that goes over the exhaust vent.

 

[SmokeyTheBear]

Fiberglass is considered noncombustible I don't see why it wouldn't be fine.

 

[Ejectr]

Fiberglass is considered noncombustible I don't see why it wouldn't be fine.

Thanks. My cellar ceiling is uncommonly low and the existing duct work even lower, so the tin knocker had to go straight up and then a 90 degree turn over the exhaust pipe then a 90 degree turn to the trunk. I don't know why he didn't just have me move the furnace over more to the left and then go straight back, but he said that wouldn't have given him enough height to come straight out and a radius 90 degree bend turn to the trunk. So now the bottom of the left turn duct work is over the exhaust pipe. Had to use a clean out T and then a 45 degree to clear it with the vent pipe.

It is what it is, so that's what I'll do. Thanks Smokey.

 

[Ejectr]

Holey mackerel! What a difference the duct insulation made! Air coming out of heat registers is WAY warmer than before.

 

[SmokeyTheBear]

Make certain it can't burn the piggies...

 

[SmokeyTheBear]

Oh and you should discover a drop in the basement temps so pay attention to any plumbing down there.

 

[Ejectr]

Oh and you should discover a drop in the basement temps so pay attention to any plumbing down there.

Still have plenty of radiation from the furnace itself heating the basement.. No worries about plumbing.

 

[SmokeyTheBear]

Still have plenty of radiation from the furnace itself heating the basement.. No worries about plumbing.

Ok, didn't want you to discover busted pipes or things.