Another Mr. Heater Venting Question?

[Terra Nova]

Edit: updated, see new post

Okay, I know I know, another heater venting question... As most have run into on this topic there is a lot of conflicting information out there. I'm planning to install a 50K unit and run a horizontal vent. The vent will come out under the soffit (see below).

The manual for the Mr. Heater says the exhaust vent needs to be 4' from any vented soffit. It's a 12" soffit and I would really like to avoid having 5 feet of pipe sticking out the back (and over the sidewalk, another no-no). I would like to run it out 24-30ish inches max. I called the building inspector and he said they don't have a rule on it, only to follow the manufacturer's instructions.

Question is if I were to move the soffit vent itself to where there is 4' of clearance between the heater and soffit vent would that satisfy the requirement? Or just block off the one vent?

Edit: wow, looks like I need to get around the washing the back of the house...

Thanks!

 

[Showkey]

Reality is………..Nobody has the vent sticking out 4-5’. Maybe 2’ from the wall ?

Really concerned……..block that one soffit vent closest to heater vent ?

 

[gmcgeo]

Mine is 2ft out of wall, cap is just passed soffit where it would not vent into it.

 

[Terra Nova]

Thanks for the input. I think I'll shoot to be a foot or so past the soffit and plan to move or block off the one vent (double check that there would be enough venting with out that one in place).

Probably overthinking this but that's just how I work sometimes...

 

[woodfirenewbie]

They make those venting kits that face down and angle the exhaust outwards too, like these guys

 

[Terra Nova]

Okay, made some progress on the install. Waiting on a friend to come plumb the gas line and we’ll be in business.

Only question I have is the vent termination. Have one of those T-shaped caps. Do they go vertical or horizontal? Google image search brings up installs in both directions. As with most things hvac the instructions seem to leave that part out

Thanks!

 

[woodfirenewbie]

Looks good. Make sure you've got that downward slope! Bubble levels FTW

Our termination is vertical, wanted to get the exhaust up and out of the way.

 

[Terra Nova]

Looks good. Make sure you've got that downward slope! Bubble levels FTW

Our termination is vertical, wanted to get the exhaust up and out of the way.

Thanks!

It's currently sloped up ≈1/4" per foot following the install instructions. Read a lot about the up vs down slope and there was no real consensus, some ran them down while others ran them up. I chose up mainly because that's how it's shown in the instructions, from my reading the short runs like mine the flu gas should remain hot enough to not condense. I'll keep an eye on it this winter and see how it goes.

Thanks again!

 

[PoorUB]

from my reading the short runs like mine the flu gas should remain hot enough to not condense. I'll keep an eye on it this winter and see how it goes.

I will guarantee the flue gas will condense, at least on start up and in cold weather. That is why stainless steel is required.

 

[AldeanFan]

Mine angles down and I’m always surprised how much moisture comes out of the vent. In the winter it freezes on the ground and there will be a mound of ice there after a month.
I definitely recommend angling down.

 

[fitter30]

Run of the tee is vertical. Slope it down but a drain tee right before it exist the garage don't want any condensate dripping outside.

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www.google.com

 

[Terra Nova]

Thanks for all the info. I'll get the tee mounted vertical.

Interestingly enough BOTH the Mr. Heater install manual and the Saf-T vent manual agree on the 1/4 per foot minimum upward slow toward the termination.

The Mr. Heater manual shows a condensate drain only for commercial installation but not residential and doesn't give a reason that I can find. It does say the drain must be within 5 feet of the appliance, so runs less than 5 feet it may not be an concern?

It's currently installed with an upward slope to the termination and I'm planning to run it that way. I'll keep an eye out for condensation and can add a drain easily enough. Menard's has them in stock.

Mr. Heater


Saf-T Vent

 

[Dagny]

reznor slopes down

 

[gmcgeo]

good thing he doesn't have a reznor then

 

[blairjw]

I just installed my Mr. Heater 80k yesterday... I expected a pretty tight fit on the pipe to thimble... It's probably a 1/2" gap... so yes air can flow pretty well through there (makeup air?)... is that how yours is? I was considering shoving that fiberglass rope in there, the kind that is used for a door gasket on a wood stove... thoughts?

 

[Terra Nova]

I just installed my Mr. Heater 80k yesterday... I expected a pretty tight fit on the pipe to thimble... It's probably a 1/2" gap... so yes air can flow pretty well through there (makeup air?)... is that how yours is? I was considering shoving that fiberglass rope in there, the kind that is used for a door gasket on a wood stove... thoughts?

The directions mention sealing the gap with caulk. I used a high temp sealant for stove pipe.

 

[blairjw]

The directions mention sealing the gap with caulk. I used a high temp sealant for stove pipe.

Thanks, I just thought 1/2" gap was excessive for caulk.

 

[AldeanFan]

Mine was probably 1/4” gap all the way around, I remember caulking it with high temp silicone and having to make a second pass after the first bead had cured.