Vent Minimum Clearance Help

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Res5cue

New Member
Jun 2, 2008
36
Bangor, Maine
Need some help with vent clearance for a Harman P38. I’m looking to install this through my outside wall but was bummed when reading through the manual and found you need minimum 48” from opening window. This is just not going to happen in my common rooms. My only other option, I had thought at the time was to go up from the middle of the house through the roof adding allot of money to the installation. During my visit to the local Harman dealer I was thrown a curveball.

“If you add an outside air kit the minimum clearance is 18 inches.”

Well I couldn’t find it in the P38 manual but I do see a reference to that in other manuals by Harman. I stopped by the local code enforcement guys and they let me know that when they inspect the installation, they go by the manufacturer’s recommendation.

Does anyone know why some models have the reference and some don’t?
 
We never open those windows during winter and dont plan to either. I just want to pass code. Modifying a window that was manufactured to open, then changing it to "non-opening" window wouldnt pass code. The window would have to be manufactured as nonopening.

I offered to superglue the window shut....lol.
 
Can you go up 48" above the window? If you can that will meet code. The code doesn't specify whether horizontal or vertical, if it were me and my house layout would allow, I would just extend the pipe 48" above the window and add an extra wall bracket for support.
 
Guess should have mentioned that too. Im in a craftsman style so low roofline, then I would run into the dormer's for upstairs, same 4 foot clearance problem.

This is how the P38 manual reads:

B. The clearance to a window or door that may
be opened must be a minimum of 48" to the side
and 48" below the window/door, and 18" above the
window/door.1
(above window/door with outside air installed, 9”)


This is from a P68 manual:

B. The clearance to a window or door that may
be opened must be a minimum of 48" to the side
and 48" below the window/door, and 12" above the
window/door. 1
( with outside air installed, 18” )
Also in the P68 manual it has this:

Outside Air
Here are four benefits of outside air:
1. Having air introduced from outside the living area
boosts overall efficiency.
2. It eliminates draft problems that can occur in tight
homes.
3. It reduces smoke spillage in the event of a power
failure.
4. It allows your vent termination to be as close as
18" from windows or doors.


Why the difference?
 
I am facing the same issue. I bought a P38 for a new location in the house and it will be installed close to a window. I can satisfy the 18" requirement (for the P68), but not the P38. It's pretty silly IMO since who is going to have their window open when the stove is in use? A door I can see, but a window? Anyway, I'm going to put a screw in that window so it can't be opened during the winter months. If the inspector breaks your stones, just cover the window on both sides with a sheet of plywood. :D
 
Go to Lowes or HD and get a quote on a replacement window. You will probably be looking at like $150.00 for a replacement window, non opening. Problem solved. Keep your old window if you want to switch back.
 
With fresh air kit, it is considered a sealed combustion appliance.

NFPA 211 sect 10.7.1.2 211-33

apliance with over 50K BTU input can be installed not less than 12" from an opening in a building. ie window.


NFPA 3.3.2 211-6

3.3 Appliance

Utilzation equipment normally built in std sizes and types that is installed and connected as a unit, to perform one or more functions such as clothes washing, air conditioning, food mixing, heating, or refrigeration.

3.3.2 Direct Vent appliance
(Sealed Combustion sytem Appliance)

A system consisting of an appliance, combustion air and flue gas connections between the outside atmosphere and a vent cap supplied by the manufacturere, and constructed such that all the air for cumbustion is from the outside atmosphere and all flue gases are discharged to the outside atmosphere.
 
TurboZ said:
With fresh air kit, it is considered a sealed combustion appliance.

NFPA 211 sect 10.7.1.2 211-33

apliance with over 50K BTU input can be installed not less than 12" from an opening in a building. ie window.


NFPA 3.3.2 211-6

3.3 Appliance

Utilzation equipment normally built in std sizes and types that is installed and connected as a unit, to perform one or more functions such as clothes washing, air conditioning, food mixing, heating, or refrigeration.

3.3.2 Direct Vent appliance
(Sealed Combustion sytem Appliance)

A system consisting of an appliance, combustion air and flue gas connections between the outside atmosphere and a vent cap supplied by the manufacturere, and constructed such that all the air for cumbustion is from the outside atmosphere and all flue gases are discharged to the outside atmosphere.


I believe the P38+ is rated at 43,000 btu input.
 
Thanks for the info guys, I've got a call into the dealer too. He looking into getting something in writing from Harman on the installation for the P38. He blamed the instructions as being older then the newer stoves, hence the differance. If I can get something from Harman and also have the NFPA code 211. I should be fine.

Now I just need to get past my stupid Home owners insurance. The Desk jockey kept calling it a wood stove chimney over the phone. I corrected her then she replied "same thing". LOL....I told her to just send me the darn paperwork.
 
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