double wall pipe question

[kevinmerchant]

My current project is an Englander 30 install through cathedral ceiling. I will be using single wall to the adaptor. To reduce clearances I plan on using either a half round shield or 8 inch galvanized pipe. If I use the 8" my understanding is there needs to be an opening at the bottom and top for the air to flow. My concern is will that hot air be to hot leaving the top by the ceiling. How does this work on a double wall pipe, never had one in hand to see.

Also, Ive read that galvanized can release toxins. Is that a danger in this application. And can galvanized be sprayed with some hi-temp paint.

 

[begreen]

If the connector is over 8 feet long, it's recommended to use double-wall pipe to reduce flue gas cooling and maintain good draft.

 

[LLigetfa]

If the connector is over 8 feet long, it's recommended to use double-wall pipe to reduce flue gas cooling and maintain good draft.

+1 and it will look better too.

 

[Renovation]

If the connector is over 8 feet long, it's recommended to use double-wall pipe to reduce flue gas cooling and maintain good draft.

+1 and it will look better too.

+2 and last longer, and lower your risk of chimney fires.

 

[kevinmerchant]

My total length of single wall pipe from flue collar on stove to adaptor will be 7ft.

 

[Renovation]

My total length of single wall pipe from flue collar on stove to adaptor will be 7ft.

The advantages of double wall still apply. As long as you'd need a shield on single-wall, why not just go with the better solution?

Just a suggestion, good luck whatever path you choose.

 

[kevinmerchant]

Forgot to mention that I already have all the 8" pipe needed for the job from a previous wood furnace. Also already have the 6" black. I probable would have gone with the double wall if I didn't already have all these materials.
So, if I use the 8" pipe with 1" screws to keep an even 1" air space around the 6" pipe and the 8" shielding pipe ends at the adapter which is approx. 18" below the ceiling, does this sound right.

 

[Renovation]

Forgot to mention that I already have all the 8" pipe needed for the job from a previous wood furnace. Also already have the 6" black. I probable would have gone with the double wall if I didn't already have all these materials.
So, if I use the 8" pipe with 1" screws to keep an even 1" air space around the 6" pipe and the 8" shielding pipe ends at the adapter which is approx. 18" below the ceiling, does this sound right.

It sounds right to me, with two caveats: meet the reduced clearance requirements for shielded and (unshielded, if any is exposed) single wall pipe (there's a page here about it), and do not use galvanized pipe. My understanding is that galvanized pipe outgasses at high temps, and poses a health hazard.

Having your shield pipe unobstructed top and bottom, so air can circulate through, should be a good thing too.

I hope others will be along to check my work...

 

[kevinmerchant]

So you think the galvanized will get to hot with 1" air space from flue pipe?

 

[Renovation]

So you think the galvanized will get to hot with 1" air space from flue pipe?

Yes, when you least expect it and are least prepared.

Like when you have a chimney fire in the middle of the night, and it fills your house with poisonous gas while you sleep. :bug:

That's what code is about--protecting you from the unexpected, unlikely, worst case scenario.

"Nobody expects the Spanish Inquisition!" -- Mel Brooks