Combustion Air

[GG Woody]

I guess my question now is, does a chimney chase suppose to be sealed? If it is, I will have my problem resolved as soon as I can. Perhaps pull off the siding and filling the gaps with fireproof sealant. I frankly don't know why I didn't connect the two things but I suppose I didn't imagine chase air as being part of the systems. Hope I'm not too excited about an easily sounding, and easily doable, resolution...

Well, if the "chase" is not sealed and the fan plenum is open to the chase I see an easy route for the draft.
If the plenum is sealed and the combustion pipe is open to the "chase" I see an easy route for your combustion air.
My chimney is not sealed, I piped combustion air into it.

 

[Rotro]

I understand. I previously asked for an addendum from the manufacturer that the installation manual is wrong for warranty purposes at least. I doubt I get it. They got their money. Most people wouldn't even ask. What am I going to do about it?

Getting a PE who actually knows about chimneys in my area is like stumbling upon a unicorn in the woods. I've been through that with the footing being wrong.

 

[Rotro]

Well, if the "chase" is not sealed and the fan plenum is open to the chase I see an easy route for the draft.
If the plenum is sealed and the combustion pipe is open to the "chase" I see an easy route for your combustion air.
My chimney is not sealed, I piped combustion air into it.

I guess in my view, if they are using the chase as part of their "systems," it needs to be sealed to only allow their systems. Not gaps to outside air.

 

[GG Woody]

I guess I forget that this should be someone else's problem, not yours, since it was contracted out. I guess they are their systems and your systems...

 

[Rotro]

I agree. I've been complaining about the insert blowing air and they have defended their position apparently backed by the manufacturer. I've not brought up the chimney issue yet - which they also installed - because I didn't relate the two things.

Even if they don't come to fix it, sealing the gaps with fireproof caulking is something I can do over a weekend just to see. If it doesn't, I'll be back. But it's a very reasonable explanation of the exact problem.

Thank you so much sir. You have no idea how happy I am to have come to this website.

 

[GG Woody]

The first on my to do list would be sealing the fan plenum and getting the combustion intake out of it.

 

[Rotro]

If sealing up the chimney resolves the air blowing into the house, that will be next. Then I will know what's going on.

 

[begreen]

The chase sealing doesn't need special fireproof caulk assuming it is all wood construction. A good acrylic latex caulk will suffice. The only caulk touching the chimney pipe should be on top, at the storm collar. A good, non-acidic, sililcone adhesive caulk is used there.

Moving to the PE forum. Keep us posted and take pictures and ask questions once the issues are visible.

 

[Rotro]

I decided against the sealing up the chase. It's two stories and I still have to think about the cap at the top. Plus, it won't be warm enough to mess with siding without cracking it for quite some time. And like GG Woody said, his chase isn't sealed.

So I argued with the installers this morning. I said either the chase is sealed or the ventilation is sealed, otherwise the vents are open to the outside world. Mice, dirt, bugs, wind.

They won't budge. I told them I need a statement from the manufacturer that the vent and combustion air both should be open to the chase since the manual doesn't state that. If they won't provide that, I will look into filing a complaint that the manufacturer is refusing to give the customer the necessary documentation for a safe and proper installation of the product. I don't know if I can file a complaint with their UL listing since NFPA references numerous times the manufacturer's literature which doesn't say what they did, or what. But I'll figure it out I suppose.

Little worked up so I'll probably stop for the day... or at least a couple hours.

 

[Rotro]

Surely this product doesn't suppose to have the ventilation open to chase air. I have no idea how to figure out what suppose to have been done. I've not found in the manual anything addressing this. Someone above mentioned a kit - but what is the kit?

 

[GG Woody]

I didn't look very hard but the best explanation I saw was on page 22 of this:
https://www.pacificenergy.net/wp-content/uploads/2024/02/100004186-FP30_FP30AR-LE-071124-52.pdf
It seems really simple to me, but I am in the ducting industry. Let me know if you have any questions referring to page 22.
4" dryer flex from any hardware store should be the easiest way to achieve this, although I might try to impress myself a bit doing it a bit differently?

 

[Rotro]

Yeah but I don't think that's going to fix it as you helped me work out the real problem. On page 42, it shows the location of the ventilation recirc fans. It also shows the hole the installers just left open for combustion air.

Ignoring the combustion air for this comment, and being confident the air we're getting out the vents is from the chase's air in leakage from the outside, I see no way to isolate the ventilation recirc system from the chase without pulling the entire insert out and modifying the unit - which would void the warranty and I suppose could be dangerous if there's reasons for it that I can't imagine. I am so thankful we didn't go with the remote ducting as this air would be blowing in every location all year long.

Not quite sure what to do about it. I did find a company who works on Pacific Energy a few towns away and I guess I'll see if they know what to do. If there's nothing, I'll turn it over to the wife and she can do her complaining... sometimes wondrous things happen when she's not happy as everyone suffers.

 

[Rotro]

Or I could have the chase sealed and run the combustion air to opening I cut out on the brand new chimney. Wish I could find some standard that says the chase suppose to be sealed. We live on a dirt/lime/gravel county road so this is going to be a huge source of dirt among other problems.

 

[Rotro]

I see what's going on now after reading every word of the installation manual and examining this image.

The lower right is the vent fans for recirc air

The Craftman Surround instructions require an opening into the house for chase air with a specific minimum area. Not outside air. The directions even state the Craftsman's instructions "supperceeds" other instructions (page 35).

They are using the lower grill to satisfy both the requirements for the chase air, and also using it for the recirc air intake.

Even if I can isolate the ventilation system, outside air would still blow out whatever opening I made for chase/combustion air into the house if I followed the instructions.

The only way I see to fix this, and still satisfy the manufacturer's instructions, is to seal off the chimney chase from outside air.

I guess good info for any future people purchasing the PE FP30 AR LE with the Craftsman Surround.

 

[bcar]

I installed the FP30 arch unit with the standard faceplate last year. This is all unprofessional of course, but some thoughts:

• The chase absolutely needs sealed off from outside air. See page 19 regarding firestops at ceiling levels. For an outside framed chase this would still apply with adding a false ceiling that is insulated. Now I believe the vent pipe firestop is slightly larger than the pipe itself to still allow the pipe to cool (like maybe 1/8" all around). There's also a lot of supporting information on this site and elsewhere on the web that vapor barrier needs to be continuous throughout the chimney chase.
• Now at the chimney chase cap is another story... there is tons of conflicting information on the web of how to handle the chase cap. Duratech Class A manual says the cap needs vented.. FP30 manual says a cold climate the chase should be insulated.. I ended up only installing a sheet metal chase cap that is shimmed up allowing it to vent per the Duratech manual. My plan was to check under the cap for any condensation issue's and at that time could add a layer of insulation at the top of the chase and remove the vents. This is still assuming there is an insulated false ceiling or attic level below the chase cap.
• If the above is correct, and the combustion air intake is left un-ducted like yours, then you would just be pulling excessive 'room' air through the stove when burning.
• (My combustion air duct is currently dangling down into my basement waiting to be ran outside) If we're gone for a weekend during a really cold spell I will start to get a back draft that is noticed when I open the stove door. If combustion air is ducted to outside this back draft might not happen at all (won't know till I get mine shoved outside). But with yours not having a duct at all I can definitely see where you could be back drafting out of that combustion intake hole, which is then literally visible from standing in front of the stove and looking into the bottom louver.
  • Not sure how bad your gaps at top of chase are, but I would think you would get a lot more air from a 6" pipe than from a small gap around the top of the chase.
• Page 39 chase inlet is to supplement the recirc fan and clearly states that air is separate from combustion air, furthering your case against the installing contractor.

 

[Rotro]

Thank you for that detailed amount of information. After pursuing the issue, I will be getting the chimney chase sealed off from outside air and the date is scheduled. A firestop "ceiling" in the chase is supposed to be installed and they are to seal up along the chimney structure/house connection. This is being done by the installers with no cost to me.

However Pacific Energy is backing the install with an un-ducted combustion air port left open in the recirc system. I have two text clips, one sent to me from the installers and one from a Pacific Energy sales rep I think in Washington state, where Pacific Energy technicians state this. Since the manufacturer's backing this part of the install, I can't make the installers fix it even though it's not in the manual.

I decided to file a complaint with Pacific Energy's listing agency for the FP30.

I have found that this fireplace isn't UL listed. According to UL, if there's no label/logo for UL, it's not UL rated. The UL127, without their stamp, only means it suppose to be equivalent to the UL rating. For the FP30, it is actually rated with Intertek who I contacted with a detailed complaint and gave them supporting information/documents, some of what you mentioned.

They have opened an investigation however I am realistic in not expecting anything in my favor. So, I have a different company who installs Pacific Energy that will come and fix the combustion air... but it will cost me of course. They want to run the combustion air to the outside with a connection at, or slightly above, the top of the firebox on the outside, and all this work would be done after taking out necessary brickwork on the brand new chimney.

It's obviously a safety issue to me and will lead to all sorts of nusience drafts and dust that I can't stop. I have to have it fixed.

 

[GG Woody]

Combustion air should be at or below the bottom of the firebox to reduce chances of it drafting like a chimney.

 

[bcar]

I think the manual states combustion intake just has to be 5' below the top of chimney, but yeah the lower the better.

 

[Rotro]

I will bring this up with them and look more into it. They stated they needed a sort of p-trap in that ducting thus them going up. Or I misunderstood them - which is quite possible. I don't have this scheduled yet anyway until I find out about my complaint. But thank you for the head's up. It would suck to have to fix this twice.

 

[Rotro]

Intertek says, and gives me their website to look it up, that Pacific Energy's FP30 LE rating with them was withdrawn in 2022. This fireplace is not rated with UL or Intertek.

 

[GG Woody]

I think the manual states combustion intake just has to be 5' below the top of chimney, but yeah the lower the better.

I guess it would depend if the combustion was piped into the "chase", or connected to the appliance.