45K Modine HotDawg venting products

[Schu338]

I'm installing a 45K btu Modine Hot Dawg heater in my 9' ceiling insulated, sheet-rocked garage. It will run on propane and vented horizontally with nothing around the exhaust termination (windows, eaves, etc).

Does anyone recommend sources where to purchase type III / UL 1738 venting products? The exhaust is 3" but could increase to 4". Any advantages to doing that? Total run probably les than 10'. Anything else I need to consider?

Thank you

 

[Adk Mike]

I have that same unit. Double wall vent. 4inch is fine it will be 5 inch with the outer pipe.
Wall thimble. Cut it out so the pipe is I inch from combustibles. The pipe wants to run down hill about a 1/4 inch per foot.
The most important thing is read the owners manual. Do excactly what it says. I’ve had mine for 14 years. Very little service over the years. Nice unit.
Get the pipe at a plumbing supply house.

 

[Showkey]

I have that same unit. Double wall vent. 4inch
The most important thing is read the owners manual. Do excactly what it says. I’ve had mine for 14 years. Very little service over the years. Nice unit.
Get the pipe at a plumbing supply house.

They change the venting requirements to Cat III stainless for horizontal vent.

 

[earlybirds]

I purchased my catIII horizontal pipe and fittings at Menards.

 

[k-os]

I purchased my catIII horizontal pipe and fittings at Menards.

Same here. Haven't gotten it installed yet though.

 

[D45]

Menards has a good selection

 

[Schu338]

4" seems more readily available. Any problem with an increasing adapter?