Isle Royale corner clearance confusion

[MattFoley772]

New member here. Isle Royale 2008, bought used for $900. Through the wall and up outside with prefab chimney.

For corner installation manual says clearance (dimension E, rear heat shield to wall) is:
single wall pipe: 22"
double wall pipe: 6"

I have single wall pipe and put my E at 12" for best alignment with thimble. This puts the pipe about 18" from walls. Fired her up and used my hand to feel walls (drywall and paneling). Walls near pipe were somewhat hot but not overly so. However, walls nearest stove itself were very hot, which means the stove is too close. Now my question: double wall pipe obviously reduces wall temperature near pipe but how can it reduce wall temps down near the stove sides? Again, my E dimension is 12", that's 6" farther away than required yet walls are already way too hot. I have difficulty understanding how switching to double wall pipe will reduce wall temps that far down by the stove.

Also, the manual says nothing about reducing clearance with wall heat shields. Huh? If wall shields are good enough for NFPA211 then why aren't they good enough for Quadrafire?

 

[begreen]

The IR is an intensely radiant stove. The wall temp can be up to around 170F and still be safe. Double-wall will help reduce warming, but it may not give you full peace of mind. You can put in a proper NFPA wall shield for that. There's no harm doing it when you have already met the requirements. If you do install one be sure it is about 6" taller than the stove's flue collar and that it is non-combustible, open at least 1" top and bottom to allow good air convection behind the panel.

(I see that they do discuss a wall shield in a note at the bottom of the clearance chart)

 

[MattFoley772]

The IR is an intensely radiant stove. The wall temp can be up to around 170F and still be safe. Double-wall will help reduce warming, but it may not give you full peace of mind. You can put in a proper NFPA wall shield for that. There's no harm doing it when you have already met the requirements. If you do install one be sure it is about 6" taller than the stove's flue collar and that it is non-combustible, open at least 1" top and bottom to allow good air convection behind the panel.

(I see that they do discuss a wall shield in a note at the bottom of the clearance chart)

Thanks for your quick answer.

I have no way to measure wall temp but I've read that if wall is too hot to touch than stove is too close.

I don't understand how the walls from the stove's sides will be cool enough if I use double wall and move it 6" closer than it is now!

The way I read it the wall shield is for rear vent installations, not for top vent (my case). Other stoves and NFPA211 give clearances when wall shield is used--but not the IR. They also say nothing about installing pipe heat shields instead of double wall pipe.

 

[northwinds]

Perhaps a photo of your installation would help. An inexpensive infrared thermometer will take your wall temp.

My nearest corner is 13" and the wall is warm but not too hot to touch. I have the double wall pipe.

 

[MattFoley772]

I suppose I could trust the manual and buy double wall pipe and be done with it. I suppose I could buy an infrared thermometer and experiment. But 1) I'm trying to save money and 2) I want to understand how it works. Somebody must know.

My confusion remains. Heat is radiated by stove AND pipe. Since we want to move stove AND pipe closer to walls, why don't stove AND pipe need shielding? We are talking about 16" closer! (22" vs. 6"). Why must I use double wall pipe only and not wall/pipe shields to get closer? I can't believe I'm the only one who finds this confusing and unusual. This is the only stove I know of like this.

See clearance chart, attached.

 

[begreen]

You can not take single-wall pipe closer than 18" from a combustible surface without proper wall or pipe shielding.

 

[Jags]

If you can hold your hand on the wall for more than a moment - you are probably less than 170F. 170F is extremely hot to the human touch. 150F water can scald the skin in two seconds.

 

[MattFoley772]

You can not take single-wall pipe closer than 18" from a combustible surface without proper wall or pipe shielding.

I would've agreed with you until this stove came along. See clearance "A", single wall pipe to rear wall is only 15".

 

[Jags]

"NOTE: “A”, “C” and “F” Dimensions are to the inside diameter of the flue collar."

There is your 3" difference. (assuming that this is supposed to mean "the center").

 

[MattFoley772]

If you can hold your hand on the wall for more than a moment - you are probably less than 170F. 170F is extremely hot to the human touch. 150F water can scald the skin in two seconds.

That sounds like good rule of thumb advice. But it does not specify material of wall. Some materials feel hotter than others at same temp due to higher conductivity.

 

[Jags]

But it does not specify material of wall.

I think you are splitting hairs here.

 

[oldspark]

NOTE: “A”, “C” and “F” Dimensions are to the inside diameter of the flue collar.

 

[MattFoley772]

"NOTE: “A”, “C” and “F” Dimensions are to the inside diameter of the flue collar."

There is your 3" difference. (assuming that this is supposed to mean "the center").

Ok, if it's 15" to center then that makes it only 12" to wall of pipe!

 

[Jags]

15" to edge (inside) of flue collar = 18" to center of collar. (I probably was not very clear in my post above).

By the way - the NFPA211 is the rules outside of the instruction manual. The manual precedes NFPA211.

 

[MattFoley772]

I think you are splitting hairs here.

15" to edge (inside) of flue collar = 18" to center of collar. (I probably was not very clear in my post above).

Yes. And the pipe is against the inside edge of the collar which means the pipe is 15" from the wall vs. the usual 18" noted earlier.

 

[Jags]

According to the manual it allows for it to be that way.

 

[MattFoley772]

15" to edge (inside) of flue collar = 18" to center of collar. (I probably was not very clear in my post above).

By the way - the NFPA211 is the rules outside of the instruction manual. The manual precedes NFPA211.

Re NFPA211 vs. manual, are you saying since manual specifies double wall pipe, that's my only way to get approved reduced clearances? Please provide your source for this claim. If you're right then there's no way around using double wall pipe to reduce clearance. Which means we're back to square one: why does Quadrafire not allow other clearance reduction methods besides double wall pipe? I find it incredible that Quadrafire's labs determined that single wall pipe with shield and wall shield don't offer any clearance reduction. Are they trying to force people to buy double wall pipe?

 

[MattFoley772]

According to the manual it allows for it to be that way.

I am trying to get beyond WHAT the manual says to WHY it says it. I can't make sense of those clearance numbers.

 

[Jags]

Re NFPA211 vs. manual, are you saying since manual specifies double wall pipe, that's my only way to get approved reduced clearances? Please provide your source for this claim.

I am claiming nothing of the sorts. NFPA211 is to cover areas that may not be covered or included in the manual.
HOWEVER - if the manual claims that it can be installed in XXX fashion and it differs from NFPA211 - the manual rules.

If the manual doesn't state anything about heat shields, then you can revert back to NFPA211 for your answers.

 

[MattFoley772]

I am claiming nothing of the sorts. NFPA211 is to cover areas that may not be covered or included in the manual.
HOWEVER - if the manual claims that it can be installed in XXX fashion and it differs from NFPA211 - the manual rules.

Ok...so the manual does not give reduced clearances using single wall pipe with pipe shield and wall protection. Therefore, I can refer to NFPA211? If it's not mentioned in the manual I need the specific source that allows me to do it. I can imagine some inspector telling me "you can't do that, it's not in the manual." So I can answer "oh yes I can, look here."

I may sound picky but I am not leaving anything to interpretation or he said, she said--not when it comes to dealing with insurance or lawyers.

 

[MattFoley772]

Damn, I inserted my reply within yours. Try again:

Ok...so the manual does not give reduced clearances using single wall pipe with pipe shield and wall protection. Therefore, I can refer to NFPA211? If it's not mentioned in the manual I need the specific source that allows me to do it. I can imagine some inspector telling me "you can't do that, it's not in the manual." So I can answer "oh yes I can, look here."

I may sound picky but I am not leaving anything to interpretation or he said, she said--not when it comes to dealing with insurance or lawyers.

 

[begreen]

To me, the A dimension is just plain wrong. You can't have single wall 15" from a combustible surface. The 18" measurement is from the outside of the pipe, not the middle. It's obvious the Quad dropped the ball in the documentation dept. here. This is not the first or last time we've seen this. If you don't want issues with authorities then exceed recommended clearances either with additional distance or added NFPA211 shielding. And for sure make it so that you rest easy when there is a large hot fire in the stove. Our stove exceeds requirements by almost 25%.

 

[MattFoley772]

To me, the A dimension is just plain wrong. You can't have single wall 15" from a combustible surface. The 18" measurement is from the outside of the pipe, not the middle. It's obvious the Quad dropped the ball in the documentation dept. here. This is not the first or last time we've seen this. If you don't want issues with authorities then exceed recommended clearances either with additional distance or added NFPA211 shielding. And for sure make it so that you rest easy when there is a large hot fire in the stove. Our stove exceeds requirements by almost 25%.

Ok, begreen, you and Jags disagree on whether that A dimension is valid. And I still don't know why the manual doesn't give clearance reductions for other than double wall pipe. So yeah, I'll agree Quad dropped the ball on the documentation.

I'm so frustrated at the lack of definitive answers that I am just about ready to say forget the double wall pipe and just use a pipe shield and sheet metal wall shields. For aesthetics I've settled on a final E dimension of 16". That's 6" less than the 22" required with single wall pipe. That's a reduction of 6/22 or 27%. This satisfies the 66% max. and 12" min. in this chart:

https://www.hearth.com/talk/wiki/nfpa-wall-clearance-reductions/

Who knows whether the lawyers at Quad or NFPA or my insurance company agree.

 

[Jags]

Be safe - go with the 18". Yes - it is VERY possible that a mistake has been made by Quad. It wouldn't be the first time a manual has had conflicting info.

ETA - I have emailed quad for clarification. If I get a response I will be sure to post it.

 

[begreen]

Ok, begreen, you and Jags disagree on whether that A dimension is valid. And I still don't know why the manual doesn't give clearance reductions for other than double wall pipe. So yeah, I'll agree Quad dropped the ball on the documentation.

I'm so frustrated at the lack of definitive answers that I am just about ready to say forget the double wall pipe and just use a pipe shield and sheet metal wall shields. For aesthetics I've settled on a final E dimension of 16". That's 6" less than the 22" required with single wall pipe. That's a reduction of 6/22 or 27%. This satisfies the 66% max. and 12" min. in this chart:

https://www.hearth.com/talk/wiki/nfpa-wall-clearance-reductions/

Who knows whether the lawyers at Quad or NFPA or my insurance company agree.

Sketch it out in a drawing and go over the plan with the inspecting authority. That should cover you. If you pass inspection then the insurance company should be satisfied.