horizontal or vertical vent for unit heater?

[biggziff]

I'm about to install my unit heater and am torn on how to vent it. I know vertical is cheaper, but I don't want to put a hole in my beautiful new roof that I worked so hard on. Horizontal is more expensive, but are there any other negatives for one vs the other? Venting will be on the back side of the building where no one will see it (if horizontally vented)

thanks

 

[D45]

My vertical kit was cheap and hasn't leaked, at all

I too, was hesitant on cutting a hole in my roof, but it came out nice

Like $65 shipped for a very complete kit

 

[biggziff]

My vertical kit was cheap and hasn't leaked, at all

I too, was hesitant on cutting a hole in my roof, but it came out nice

Like $65 shipped for a very complete kit

I've watched some videos that make it look easy and my father has assured me it won't leak. Looks simple enough, but the doubt lingers! The fact I'm cheap keeps me looking at vertical also.

 

[dave67fd]

Horizontal venting should "only" be done if vertical venting cannot. If vertical is cheaper for you than it's a no brainer.

 

[biggziff]

Horizontal venting should "only" be done if vertical venting cannot. If vertical is cheaper for you than it's a no brainer.

It's weird...several friends who are pro HVAC folks suggested horizontal over vertical. I didn't ask why.

 

[finn]

If you have a self shedding steel roof, and live in the snow belt, horizontal is preferred.

I noticed last week while driving, that several vertical vent pipes on steel roof buildings were askew.

 

[Showkey]

I am in the horizontal preferred boat.

Not to mention it’s stainless so it’s one and done for just about a life time.

 

[biggziff]

If you have a self shedding steel roof, and live in the snow belt, horizontal is preferred.

I noticed last week while driving, that several vertical vent pipes on steel roof buildings were askew.

Architectural shingles here.

 

[biggziff]

I am in the horizontal preferred boat.

Not to mention it’s stainless so it’s one and done for just about a life time.

Just went to my dad's earlier to see how he installed his Reznor. He used B vent in a horizontal configuration. Been there since 2006 and it all looks great.

 

[Showkey]

Just went to my dad's earlier to see how he installed his Reznor. He used B vent in a horizontal configuration. Been there since 2006 and it all looks great.

Mine had B vent too ........professional install, unknown history, likely 15-18 years old, not my install. Disassembled found inner pipe severely deteriorated. Clean out tee was thin as paper when I moved in. Replaced and 5years later the tee did not look good.

The heater control board failed ( separate issue) and cost was high for an old heater. Replaced the heater and updated the B vent to CAT III.

By code now cat III is required for horizontal vent now. Yes, many are still installing B vent in horizontal vents.

They changed the vent requirements for a reason:
My guess the manufactures know these heaters create a lot of moisure especially at low inside garage temperatures. Plus they use garage air for combustion so the solvents and chemicals in the flame add to the corrosion concern. Failed pipe that goes unnoticed makes for a CO problem.

Menards in my area as CAT III adapter, pipe, wall thimble, termination T for less than $225.

 

[Jackfre]

Vertical is superior in operation and less expensive. Punch the hole in the roof and flash it correctly. There are about a bazillion of them that don’t leak

 

[m123]

Are there restrictions on going vertical up in the attic of the garage, and then out the side of the gable? This way the hole in the wall is outside the insulated and heated space. And you are not punching a hold in the roof. Its the best of both worlds. I was wondering if I could do this? See diagram

 

[biggziff]

Are there restrictions on going vertical up in the attic of the garage, and then out the side of the gable? This way the hole in the wall is outside the insulated and heated space. And you are not punching a hold in the roof. Its the best of both worlds. I was wondering if I could do this? See diagram

A Gable end will be better than venting anywhere near a soffit, which is more likely to happen on an Eave end. Use B-vent and the appropriate thimbles and you'll be fine. Be sure to understand how prevailing winds can affect this and plan accordingly.

 

[Bretny]

Why is everyone so afraid of putting a hole in the roof? They make flashing for every vent pipe. Use a small propane torch to heat and lift up the upper corse of shingles, slip the flashing in.

Patching a roof is no big deal and you dont have to start from the bottom.

 

[Showkey]

Ask any good roofer.........any perforation in the roof is a potential leak point.
Especially in snow county. Warm B vent is also a perfect point for ice dams to form. More concern when the vent is low on the roof.

If professional install horizontal is far less labor making it wash because parts are more $.