Pioneer II - air sealing outside air kit

[gerberdude]

I have a newly installed Pioneer II and am wondering about air sealing around the outside air intake kit. The installation instructions do not provide any guidance either way that I can tell. However there is a good deal of air infiltration around the pictured 90° offset adapter, as it is just metal on metal. The chimney air kit is sealed with rtv 600° silicone per the instructions, so I find it strange that the outside air wouldn't be sealed in a similar fashion. Thanks for any help!

 

[semipro]

I think I'd use a good quality HVAC foil tape to seal that up.

 

[gerberdude]

I think I'd use a good quality HVAC foil tape to seal that up.
View attachment 277906

Even where it connects right to the fireplace itself? I'd think it would need to be more tolerant to heat, but I'm a total newbie so I really don't know.

 

[gerberdude]

I am going to try and get an answer from the manufacturer via my distributor. Most of the manual emphasizes air sealing, so this must just be an oversight.

 

[Highbeam]

Sometimes, the outside air connection just dumps into the open cabinet behind the stove anyway and there are other unconnected holes. Only some are actually 100% fed from the outside air pipe.

Couldn't you just unscrew the 90 degree fitting with those sheet metal screws and then lay a bead of high temp RTV under the flange before reinstalling it?

That semi metallic dryer duct stuff is scary too. Isn't it plastic? They make a real metal flex version or you can hard pipe it.

 

[semipro]

Even where it connects right to the fireplace itself? I'd think it would need to be more tolerant to heat, but I'm a total newbie so I really don't know.

I doubt that area gets that hot.
You may fry the adhesive on the tape but you won't melt the aluminum.

I 2nd @Highbeam's concern over the plastic(?) dryer duct. Make sure you use flex or rigid metal.

 

[gerberdude]

Couldn't you just unscrew the 90 degree fitting with those sheet metal screws and then lay a bead of high temp RTV under the flange before reinstalling it?

Yes that's what I had in mind, I just want to make sure that the side of the unit won't get too hot for that solution. I know on the front of the unit for example, the fire resistant board is "air sealed" to the front of the unit with 1k degree sealant, the RTV silicone I have is rated to 600. And I have no idea why this is not addressed in the install manual. I am contemplating asking the installer/distributor to ask the manufacturer but I wanted to see if anyone here had any idea first.

That semi metallic dryer duct stuff is scary too. Isn't it plastic? They make a real metal flex version or you can hard pipe it.

That is what the installers used, so I could change it, but now with the unit installed the clearances are super tight. The texture of it is kind of like a mylar with a metal spring running throughout.

ETA: The install manual lists flex duct as appropriate, so I am assuming this is an ok solution.

 

[semipro]

Yes that's what I had in mind, I just want to make sure that the side of the unit won't get too hot for that solution. I know on the front of the unit for example, the fire resistant board is "air sealed" to the front of the unit with 1k degree sealant, the RTV silicone I have is rated to 600. And I have no idea why this is not addressed in the install manual. I am contemplating asking the installer/distributor to ask the manufacturer but I wanted to see if anyone here had any idea first.



That is what the installers used, so I could change it, but now with the unit installed the clearances are super tight. The texture of it is kind of like a mylar with a metal spring running throughout.

ETA: The install manual lists flex duct as appropriate, so I am assuming this is an ok solution.

There are different types of flex duct.

https://www.lowes.com/pd/IMPERIAL-4-in-x-96-in-Aluminum-Semi-rigid-Flexible-Duct/3134107

 

[gerberdude]

There are different types of flex duct.

https://www.lowes.com/pd/IMPERIAL-4-in-x-96-in-Aluminum-Semi-rigid-Flexible-Duct/3134107

It would appear from the manual that they allow either class 0 or class 1 flex duct, UL181. I don't have any documentation that it is the exact same, but just a visual comparison to the flex duct pictured, they look very similar. I can call them and make sure if it is a red flag.

 

[gerberdude]

Looks like the duct is indeed UL listed class 1 as the manual calls for, I was able to identify the label on the hose and found the spec sheet online. Hart and Cooley F090:

 

[Highbeam]

Looks like the duct is indeed UL listed class 1 as the manual calls for, I was able to identify the label on the hose and found the spec sheet online. Hart and Cooley F090: View attachment 277963

Cool. Polyester (plastic) duct hooked to a woodstove. You can always exceed the minimums. I don’t even use that junk on my clothes dryer.

 

[gerberdude]

Cool. Polyester (plastic) duct hooked to a woodstove. You can always exceed the minimums. I don’t even use that junk on my clothes dryer.

As I said I'm new to this so its difficult to know what is appropriate and what is not. I was only trying to confirm that this was the same product that the manufacturer recommended in the installation manual.

I'm not trying to just get by with the minimum, I paid a well-established (or so I thought) local distributor/dealer for the install so I am just now finding out that they may have cut corners.

I will change it out with 6" class 0 real metal flex duct per your recommendation.

While I am at it, the manual calls for a 24 inch "cold air P trap". Do it or don't worry about it?

 

[begreen]

The intent of the p-trap is to limit cold air siphoning into the room when the fireplace is not burning. That said, if there is negative pressure in the room, cold air will get pulled through regardless.

 

[semipro]

The P trap is a good idea and I don't see a downside to installing it.
If your Pioneer II is relatively airtight it's not going to do much though. If you have the clearance, go for it.

That's a nice looking unit BTW.

 

[FPX Dude]

I'd use an approved mastic.