Horizontal vs vertical venting; clearance to access door

[exactly]

Does the presence of an access door in the same back corner I hope to install a natural gas unit heater (I don't know where else it could go) make it difficult or even impossible to vent horizontally / out the side wall? It's an 80" door in a space with a 9' ceiling.

If it matters, the roof pitch is 9/12 (I believe), the garage ceiling is drywalled but not insulated (yet), and there is nothing but attic and trusses above (I will be adding insulation soon).

See attached graphics and photos for a depiction of the space and surrounding structure. Note the 3D model is missing the overhang / soffit, but it is depicted in the photos.

 

[purediesel]

Read the installation manual for the unit heater your looking at. They have the clearances listed in the manual from door, eaves, soffits etc. Just go vertical since you have a shingled roof, its very easy and it'll save money

 

[ddawg16]

Like pure said....read the manual. Building codes will also dictate. I believe the exhaust has to be at least 10' from any window.....

Just go up....the last thing you want is for any CO to get into your garage.

I would also install a CO/Smoke detector in the garage. I'm pretty sure building code would require it anyway

 

[mrobins297aaa]

go up thru the roof.

iirc most of those heaters can use type "B" venting when you vent up thru the roof. (cheap)

when you vent horizontally you have to use much more expensive stainless venting material.

 

[D45]

3" b-vent kit was $65 shipped

Nice, complete kit

I never have had a leak

 

[Jackfre]

That space can easily be heated by a Rinnai EX22.side wall venting for DirectVent appliances according to the Nat’l FUel Gas Code, NFPA 54 says a DV less than 10kbtu has a 6” clearance to a door or window. Less tha 50 kbtu is 9” and over 50 is 12”. The Rinnai is a one box buy. Vent kit, built in programmable stat. Cool to touch and QUIET. Vent only takes a 2 3/4” hole saw. You can install this in 2 hrs other than the gas line. I’ve included pics of the vent Terminations on my house unit and the shop unit.