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Any better priced options?

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LimitedReality

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York, PA
Modine Class III Venting - Any better priced options?

I'm about to hang a 45K modine hot dawg heater in my garage that I plan to vent horizontally. I've read over lots of threads here and see that many folks suggest going Menards for parts. We don't have them where I live. I've called the local plumbing supply and they're working up a quote for stainless now since they only carry galvanized. Home Depot and Lowes don't seem to list Cat III stainless piping on their websites. So my question(s) are:

1. Any other places to suggest for stainless category 3 parts?
2. I found this online and seems https://www.acfgreenhouses.com/modine-hd-category-3-horizontal-vent-systems.aspx to be most everything I need. Does that seem like a fair price?
3. Since I'm in PA, and we have colder winters should I be looking to go double wall? Both the local supply and the site above said nobody they sell to does double wall so they don't inventory it.

Open to suggestions and looking for feedback before I spend a couple hundred bucks the wrong way :(

Thanks in advance.
 
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James-W

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Single wall vent pipe should be less expensive than double wall vent pipe, but you will need more clearance with single wall vent pipe. If you are leaning toward installing single wall vent pipe I think it would be a prudent idea to check with the local building code people to make sure that double wall is not a requirement.
 
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L

LimitedReality

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York, PA
OP
L

LimitedReality

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Location
York, PA
Alright, I think I got it. Someone smarter than me want to confirm I'm not missing something obvious:

From heater to:
3" Z-Vent Modine Hot Dawg Adapter

To a 1' piece of double wall (required before any bends as per modine manual)
3" x 1 Ft. Z-Vent Double Wall Pipe

To a 45 degree piece to angle to the right wall:
3" x 45° Z-Vent Double Wall Elbow

To a 3' piece that will go 2' into the thimble:
3" x 3 Ft. Z-Vent Double Wall Pipe

To this double wall thimble:
3" Double Wall Stainless Steel Wall Thimble

Which I'll leave 1' outside the building to get it out from under my overhang, to this termination tee:
3" Z-Vent Horizontal Termination Tee

Thoughts?

Correction, that termination tee is single wall. So I'd need a double to single wall adapter, THEN the tee. And I'm officially up to $490 in parts. Seems a bit crazy to me. How's this compare to what you guys have done?
 
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Jackfre

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You should go double wall. Z flex make excellent products. You should check all of your local hvac/p&h wholesalers in your area. If you have a friend in the industry you would do best asking if they can source it for you. Your current situation is why you should avoid Cat III venting products. You end up with as much in the vent as the product.
 
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danski0224

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Double wall pipe (Type B vent) is NOT approved for horizontal use. This is why the stainless Cat III pipe comes into the picture.

The only time that Type B vent can be used horizontally is when there is a power exhauster on the outside wall pulling the flue gases through the pipe.

The OP needs to vent vertically to use Type B vent, or install a power exhauster.

Otherwise, Cat III venting is required for a horizontal vent termination.
 
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Dragfluid

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danski0224 said:
Double wall pipe (Type B vent) is NOT approved for horizontal use. This is why the stainless Cat III pipe comes into the picture.

The only time that Type B vent can be used horizontally is when there is a power exhauster on the outside wall pulling the flue gases through the pipe.

The OP needs to vent vertically to use Type B vent, or install a power exhauster.

Otherwise, Cat III venting is required for a horizontal vent termination.
Click to expand...

^This
Plus the proper thimble for going through the wall. Nothing complicated.
 
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LimitedReality

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Thanks everyone for the replies so far. It continues to be confusing and/or less than ideal. I've called more local suppliers, one categorically denies that b vent can't be used in horizontal runs. Says that everyone in the area uses single wall inside, converts to b vent through the wall.

Right now I'm leaning towards the single wall link in my original post. The thimble it comes with seems to account for the clearances required for single wall inherently, it's much more cost effective than the Z Flex, and is better than what any of the local supply houses are suggesting.

As far as vertical venting goes, my garage is two stories and I only plan to heat the bottom. First floor is automotive with a small bath, and second is my wood shop. I plan to heat the bottom since that has water, more tools, and paint/chemicals stored in it, and let the heat rise through the floor/up the stairway to the second. Don't mind it being a few degrees cooler up there vs. the challenge of putting in a more complex setup. I also don't love the idea of putting holes in the roof.
 
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danski0224

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Dragfluid said:
When it's physically possible, it's better to vent out the side. Why make a hole in the roof and invite a leak down the road?
Click to expand...

Ha.

A correctly installed metal flashing will outlet at least one asphalt shingle roof.

There are thousands of holes made in the process of attaching the shingles :)
 
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pbon

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The correct, code compliant kit I bought was about $300. It was for a Big Max 50k but I would think it would fit a Hot Dawg. It included 3-4” and 4-4” couplings out of the heater.
 
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pbon

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Code today is double walled stainless for horizontal. But there are still plenty of old horizontal b vents in use and seemingly doing fine. If you won’t get inspected and don’t care about code and there is no chance you will kill a tenant or burn your neighbors house down, you can use whatever you want.
 
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cadunkle

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NJ
If you can afford the space upstairs to run B vent through, do that. I would do that and probably build a chase around it. Keep it to the side out of the way of anything if possible.

I vented my unit heater vertically with B vent, as there was already a furnace installed using it. A couple new lengths inside to fit the new install, a trip to the roof to adjust height and reseal the B vent to flashing, and done. Works great and cheap. If there was no existing B vent I would have done the same, though probably put the roof penetration in a slightly different location.

Also, if you're looking to save a few bucks. The Sterling 45k heater is about $100 cheaper than Modine, and is what I'm using. It is also set up from the factory for separated combustion. The housing is sealed and gasketed, intake air through a hole in the rear you can install a flange on to plumb intake air from outside for separated combustion. Not sure I'll ever bother, but the option is there if I ever want to.
 
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