Insulating OAK?

[DougA]

I'm just finishing the hearth and have put in a 3" flexible alum. vent for the fresh air supply. I remember someone posting about insulating the fresh air duct, however, how can you do that when the flexible pipe is within the combustible zone to the stove?

Does anyone have problems with frost on their air supply or am I overthinking this.

 

[TimfromMA]

My OAK line would drip with condensation. Some fiberglass pipe insulation fixed that.

 

[DougA]

OK. I looked it up and fiberglass insulation is not considered combustible but if it has a facing on it (paper, tape, etc.) it is. I was hoping for a solution that was a bit nicer looking than fiberglass since it will be exposed, even though it is at the back of the stove. I was thinking of frost on the pipe but you are right, it would be condensation and I'm not keen on water dripping into the wall recess area.

 

[etced]

OK. I looked it up and fiberglass insulation is not considered combustible but if it has a facing on it (paper, tape, etc.) it is. I was hoping for a solution that was a bit nicer looking than fiberglass since it will be exposed, even though it is at the back of the stove. I was thinking of frost on the pipe but you are right, it would be condensation and I'm not keen on water dripping into the wall recess area.

Wrap the fiberglass with heavy duty aluminum foil.

 

[moey]

Id wait and see what it did before doing some hack insulation job. Id rather put a tray under it for that one day rather then looked at some bunchy pipe all year.

 

[Candlewick8]

You have a few options here. If it's a straight run, you can get a legnth of "snaploc" or "kd" (knochdown) pipe from a hardware store like Lowes or Home depot. If you're covering a 3" pipe with 1/2" insulation, you'll need a 4" diameter snaploc pipe. If you have elbows and turns, plumbing supply shops have a component metal insulation covering in any configuration that you'll need . I've used both on jobs where you don't want insullation exposed. It makes for a nice, clean appearence.

 

[DougA]

It's not a straight run. I decided to cut a few pieces of soapstone and make a proper cover for it. I'll post photos soon.

 

[Candlewick8]

Google "metal insulation jacket". It may save some fabrication time