Self install Harman in basement

[Dmack7]

Considering installing Harman p series in my basement. Watched this video
Wanted some of your opinions if this install seems legit? Also, in installs and pics I've seen, the thimble always seems visible. In my basement I'd have the vertical vent pipe go through a drywall ceiling and 90 from there through the plywood just above the sill plate. Is it acceptable that the thimble is behind drywall? Is this method going to create black marks on my siding outside, or does tgat come from those who dont use a thimble?And lastly (for now) is there any consideration for the insulation? Does it need to be pushed aside a certain distance around the venting and thimble? Or is there a certain kind of insulation required? Thanks for any and all help!

 

[bogieb]

Wanted some of your opinions if this install seems legit? Also, in installs and pics I've seen, the thimble always seems visible. In my basement I'd have the vertical vent pipe go through a drywall ceiling and 90 from there through the plywood just above the sill plate. Is it acceptable that the thimble is behind drywall?

No, it is not acceptable or safe. The purpose of the thimble is to keep combustible wall materials (including drywall) away from the hot exhaust pipe.

 

[Polar Bear]

You would require two thimbles... But are you implying some of your pipe might be inaccessible?