Vertical vent running questions need guidance

[mnster]

I'm installing a 65,000 Btu Westinghouse forced air natural gas heater. Made in 1982 this heater does not have a blower assist for the vent. So I am tossing out the idea of horizontal venting. Vertical it is, 5"type B vent to be specific. I know there are a few rules to follow like you measure horizontally10' out from the pitch of the roof and the rain cap must be above it. Also the vent must not be within 10' of a vertical wall like the house for example. But, I am planning to mount it in the back corner of my attached garage. I plan to tuck it up to the wall the minimum measurements listed on the heater which is 6". I only have 9' ceilings so to avoid smacking my head on the heater I want it close to the wall in the corner and out of the way in the spring and summer months.

The problem is when in the corner it also puts the flue exit very close to the edge of the roof. Which I feel would look kinda silly and has to be improper in some way. So do I 90 it back to the mid point of the roof? I'd imagine but I've been told I should't have a horizontal run right after the exit of the heater. That it should stay vertical to maintain good flow. I am looking at maybe 4ft of horizontal run to a 90 to maybe 5 or 6ft of vertical run. Is that a acceptable way to vent?

Pretend my chop saw box is the heater, it is my mock heater if you will as it is a size replica.

 

[Jackfre]

The info you are getting is correct. Vertical piping directly off the unit makes the unit much happier. A 90 right off the back will stall the draft. Get as much vertical as you can and adjust the 90's or better yet, the 45's to parallel the roof line. Those fittings are somewhat adjustable. As well, don't forget to add some head bump protection to the lower corners bTW, you could side wall vent with the addition of a power venter. I'm a fan to the Tjernlund product. The GPAK model should do it for you. Field controls is the other manuf of power venters.

 

[Steevo]

Here is how I did the vertical vent on my heater.
I didn't want a tall pipe/cap sticking up from the lower corner of my roof either, so I piped it vertically at an angle up through the attic space until it was near enough the peak that a short stack and cap ended up above the ridge.

 

[mnster]

THANKS! those were just the photos I was looking for. Looking to run a replica setup. Anyone have any idea if it will work with a natural draft heater? I think it should as long as I keep the angle 45 or less. I have no reference material for my heater regarding flue length.