Thimble size for Hot Dawg

[jeclarke]

I'm ready to cut a hole in the side wall of my garage for my 75K Hot Dawg heater but am confused about the thimble size requirements. I have not purchased the vent parts yet.

The Modine installation manual has a diagram of a horizontal vent thru a combustible wall It's not dimensioned very clearly but seems to be saying that regardless of the vent pipe diameter (mine will be 3"), the outer sleeve of the thimble should be 2" min larger per side than the pipe diameter and filled with fiberglass insulation. This means a 7" outer diameter thimble.

The thimble's I'm looking at, like from Z vent, have a 5" outer diameter for a 3" vent pipe. I also don't see where they have fiberglass in them either.

Does my thimble need to be 5" or 7" outer diameter? (We're talking CAT3, single wall, stainless piping).

Thanks,
John

 

[Showkey]

Your NOT a ready to cut the hole........until you have every thing on site. Everything is all the pipes, connectors, thimble and hardware. Each manufacturer is slightly different.

This ........Includes the heat unit mounted and the pipe location determined.

 

[gmcgeo]

I'm ready to cut a hole in the side wall of my garage for my 75K Hot Dawg heater but am confused about the thimble size requirements. I have not purchased the vent parts yet.

The Modine installation manual has a diagram of a horizontal vent thru a combustible wall It's not dimensioned very clearly but seems to be saying that regardless of the vent pipe diameter (mine will be 3"), the outer sleeve of the thimble should be 2" min larger per side than the pipe diameter and filled with fiberglass insulation. This means a 7" outer diameter thimble.

The thimble's I'm looking at, like from Z vent, have a 5" outer diameter for a 3" vent pipe. I also don't see where they have fiberglass in them either.

Does my thimble need to be 5" or 7" outer diameter? (We're talking CAT3, single wall, stainless piping).

Thanks,
John

https://www.acfgreenhouses.com/modi...ositive,locking band among other requirements. you can find all your vent parts here to meet the manual specs, however we use aluminum not stainless . we use dura vent, b-vent system. the vent application comes to us from our supplier. if you choose to stay with the manual specs that website is good info with part numbers

 

[Showkey]

https://www.acfgreenhouses.com/modi...ositive,locking band among other requirements. you can find all your vent parts here to meet the manual specs, however we use aluminum not stainless . we use dura vent, b-vent system. the vent application comes to us from our supplier. if you choose to stay with the manual specs that website is good info with part numbers

OP is going with horizontal vent CATIII stainless is required.