Cold air return venting maximum run

[Scott Stewart]

Installing a pellet stove in my basement, and the window/door locations are killing me. I can't achieve 4 feet clearance from doors and windows that open, but the manual says that reduces to 18 inches if using cold air return venting. The manual also says cold air return vents must not exceed 4 feet in length, which seemingly rules out a basement floor application ( 4 feet is below grade). 2 inch pipe.

My question - does going to 7 or 8 feet, from stove to vent end, not "work"? What am I pushing by doing 8 vs 4? Safety? Efficiency?

The stove pipe would be between my front door and a window, neither which will remain open if the stove is operating. I'm not one to open windows if the heat is on. It would be 30 inches from the window and 42 from the door.

Second question - if the vent length is a real constraint, can i just live with the vent being 2.5 and 3.5 feet from openings, vs the stated 4 feet, and dispense with the cold air return? IOW, which is worse - the 8 foot vent pipe or the closeness to openings?

 

[johneh]

Make and model of stove, please
In my 22 years of repairing, installing and owning a pellet stove
I have never seen one with a return air vent

 

[Scott Stewart]

LOPI AGP - manual here https://www.travisindustries.com/docs/100-01566.pdf

Manual says cold air return venting HIGHLY RECOMMENDED, but owner of Store says they infrequently install them. I'm only interested in them for the smaller clearances. Install in basement on slab, stove pipe through the insulated cement block wall.

Thanks for the help - it's appreciated.

 

[johneh]

Ok it is in your terminology
Vent = chimney
Return vent = OAK = Out Side Air used to feed the fire combustion air
air is then not sucked in around windows or doors
So you can reduce your window and door clearances by
using an OAK the reduction amount is 18 inches
Now the clearance can be 30 inches
Hope this helps
And WE DO RECOMMEND OAK's
in most installs

 

[Scott Stewart]

Ok it is in your terminology
Vent = chimney
Return vent = OAK = Out Side Air used to feed the fire combustion air
air is then not sucked in around windows or doors
So you can reduce your window and door clearances by
using an OAK the reduction amount is 18 inches
Now the clearance can be 30 inches
Hope this helps
And WE DO RECOMMEND OAK's
in most installs

Thanks. And sorry about my loose use of the terms.

I understand the reduced clearance, but the manual also says the OAK pipe can't exceed 48 inches long and I need 96. So my question is can I use a 96 inch OAK pipe when the manual says max 48, to get smaller clearances, and if not, can I install the stove pipe closer than 48 inches to the door and window? It would be about 3 feet from both.

For clarity, the clearance is 48 inches and is OAK-reduced TO 18, not BY 18 inches. The manual says: "This clearance may be reduced to18” if using outside air". But that doesn't matter if my 2 inch OAK pipe can't be 96 inches long.

I live alone and don't usually open windows when the heat is on, and will nail that window shut to be safe if I don't have 4 feet or an OAK. I have zero point none locations that don't violate the clearance requirements. I have smoke and CO2 detectors and run a woodstove upstairs for heat. If I can't OAK (96>48), can i get by with 36 inches clearance from a nailed window and a closed door?

Thanks again.

 

[johneh]

Your smoke pipe can be installed closer than 48 inches as long as the termination is a foot above the window or door
Any chance of seeing a drawing of where you would like your stove and how you would run the chimney and Oak

 

[gruesome]

Going by the picture on page 12 of the manual you linked to, why can't you be 1' above your window or door (the example with the 'B' clearance), and 2' below the eaves ('G' clearance), and forget about the outside air kit? What forces you to locate the exhaust between the window and the door? Can we see a picture of that outside wall?

You could also (but this is more complicated) dig a light or window well at the point where you want to exit the 4' length outside air kit, and terminate the outside air kit pipe in that hole. They make prefabricated light/window well linings, but some bricks or corrugated metal will no doubt be a lot cheaper.

 

[johneh]

forget about the outside air kit

We could argue about that for a day or Two
The biggest reason I use and recommend an OAK is
Why pay to heat air only to use some of it to feed combustion
air to the stove and send it out the chimney when with an OAK
the combustion air comes from outside not causing a negative draft in your home

 

[gruesome]

We could argue about that for a day or Two
The biggest reason I use and recommend an OAK is
Why pay to heat air only to use some of it to feed combustion
air to the stove and send it out the chimney when with an OAK
the combustion air comes from outside not causing a negative draft in your home

Sure, sure, but he can't install one (at least not compliant with the stove manufacturer instructions) from his basement without digging a hole in the ground.

 

[Scott Stewart]

OK - here's a pic. There is only about a foot above the window and below the roof. The space between the window and door is 6 feet. I suppose I could go up between them and then jog to the right above the door? The wall above the door is a false wall for the dormer, the walls are only one level (vaulted ceiling/loft). I rather have that odd look than a hole below grade for the OAK.

 

[johneh]

If it were me I'd go out close to the window 45 it out at the eve and 45 up
then termination at about 24-30 inches above the roof line
Just an idea

 

[Scott Stewart]

Thanks. Better than going to the right under the porch. Great idea! I feep forgetting the clearances aren't from the pipe, just from the hole at the end.

If it were me I'd go out close to the window 45 it out at the eve and 45 up
then termination at about 24-30 inches above the roof line
Just an idea

 

[usefulidi0t]

I don't think you have to be above or below any windows. You can be within 12-18" of a window (above, below OR beside) if you use an OAK. It doesn't have to be to the side AND above or below.

 

[gruesome]

I don't think you have to be above or below any windows. You can be within 12-18" of a window (above, below OR beside) if you use an OAK. It doesn't have to be to the side AND above or below.

I don't think anybody claimed it was above/below AND to the side. The problem with the OAK reduced clearances is that the OP has a tough time installing an outside air kit. Going around the roof edge, as suggested by Johneh, seems the easiest solution.

 

[usefulidi0t]

Your smoke pipe can be installed closer than 48 inches as long as the termination is a foot above the window or door
Any chance of seeing a drawing of where you would like your stove and how you would run the chimney and Oak

Here - unless I am misinterpreting.

 

[Scott Stewart]

Thanks again everybody. Useful - it seems that the 48 inch limit on my 2 inch OAK pipe won't work in my basement application unless I terminate the OAK below grade, which I am unwilling to do. So I have to go up and I was thinking of going up above the door, but Johneh suggested a better solution - hug the pipe close to the window, not centered as I was thinking, then 45 out a foot or so to clear the roof overhang, and run it the required height above the roof. I prefer an OAK but not in this circumstance, and I'm glad I came back here to get help - you all have been great.

Here - unless I am misinterpreting.

 

[gruesome]

That's a quote from Johneh, not from me, so something went wrong with the quoting software. But either way, in the quote it says the vent has to be 1 foot above the window; that's it. Nothing about being also off to the side. But doesn't matter; going around the roof solves the problem. Let's not get sidetracked.

 

[usefulidi0t]

That's a quote from Johneh, not from me, so something went wrong with the quoting software. But either way, in the quote it says the vent has to be 1 foot above the window; that's it. Nothing about being also off to the side. But doesn't matter; going around the roof solves the problem. Let's not get sidetracked.

i couldn't fix it.. and it doesn't have to be above or below.

 

[Scott Stewart]

FOLLOW-UP - the Shop contacted the manufacturer who said the 48 inch max pipe length for the cold air return can be exceeded and works for my application.

So I am having the hot vent installed through the insulated masonry block, between the window and door, and just high enough to clear snow. It will be below the bottom level of the window and the door, and about 3 feet sideways from each, both of which are closer than the manual says, unless you use a cold air vent, so I'm golden. I'll likely screw the closer window shut for peace of mind.

Thanks for all your help. I asked the installer if he ever visits this forum, and he gave me a dirty look and said something about avoiding the plague. But you helped me laser focus the installer on the constraints and to a quick, awesome outcome. Of course, I do have to pay $150 more plus labor for the too-long cold air vent, which as far as I know isn't solving a problem, but I can feel good about the manufacturer signing off on the installation and if I ever sell I know I ran it to ground.

So thanks everybody.

 

[bogieb]

FOLLOW-UP - the Shop contacted the manufacturer who said the 48 inch max pipe length for the cold air return can be exceeded and works for my application.

So I am having the hot vent installed through the insulated masonry block, between the window and door, and just high enough to clear snow. It will be below the bottom level of the window and the door, and about 3 feet sideways from each, both of which are closer than the manual says, unless you use a cold air vent, so I'm golden. I'll likely screw the closer window shut for peace of mind.

Thanks for all your help. I asked the installer if he ever visits this forum, and he gave me a dirty look and said something about avoiding the plague. But you helped me laser focus the installer on the constraints and to a quick, awesome outcome. Of course, I do have to pay $150 more plus labor for the too-long cold air vent, which as far as I know isn't solving a problem, but I can feel good about the manufacturer signing off on the installation and if I ever sell I know I ran it to ground.

So thanks everybody.

Way back when, this place wasn't as civil or understanding of newbies or those who had different opinions than those of a certain clique. Maybe that person was part of it back in those days and got banned (which was not uncommon back then).

This place is much better than back then!