vent pellet stove through brick without 7" protection pipe

[cheezebeetle]

I am about to install my new Harman Accenture pellet stove. I purchased all of the things I need, including the wall shield/thimble. See (broken link removed)

I am extremely handy and do most work myself (electrical, plumbing, carpentry, etc.) and don't want to spend $700 to have someone else install it. I am perfectly confident I can do it myself.

My question is this. Since my outside wall is brick, is it still necessary that I cut the 7" diameter hole in the brick for the exhaust pipe? Or could I just do that for the wall, creating the protection barrier for the 3" exhaust pipe and then once I get to the brick (from the inside) just cut a 3" hole for the pipe to fit through. It is hard to explain. Try and picture this. The shield found in the link above is installed on the inside of the house with the appropriate plate. Inside of the wall is the 7" pipe which keeps all insulation and studs away from the 3" exhaust pipe running through it. Now walk ouside and you see only the 3" pipe sticking out from the brick (no plate or protection).

There are several reasons I would like to do this. Aesthetics, cost & damage. The place the exhaust pipe exits the outside wall is the front of the house, very close to the front door. I want to keep it as low profile as possible (not having the 12" square metal plate). Cost - to bore a 7" hole through the brick requires a core bit and tool that costs $250 to rent. That's ridiculous! Finally, the damage to the bricks by drilling a 7" hole will be much more difficult to fix if I ever decide to pull the stove.

My concern obviously is the heat put out by the pipe being dangerous by heating up the brick. My dad did it several years ago similar to this (through cinder block and not brick). However, he tends to do things like this without worrying about consequences. Thought I would get a bit of feedback from others. Has anyone else done this successfully?

Thanks.

 

[bostonbaked]

No thimble is needed through the brick itself, as it can't burn. As for what you describe. I would think that the tube of the thimble would have to go at least into the hole drilled into the brickand and over lap somewhat. The hole would only need to accomadate the pipe diameter. I'm no expert though. But there are some here so wait and see.

 

[Mainiac]

Cheesebeetle, I'm I think in the same boat as you are... and haven't been able to find a solid answer to the question. I've been to the duravent site and seems most installations are in living space not basement installations? Not impressed with the site at all. Lots of "flash but not much substance".

I'm looking at doing the same as you and installing a pellet stove in the basement. (I've got floor vents from a FHA system no longer in service) so should have heat easily rise up. So now installing the stove / venting has been the issue.... I think for the air "intake" I'll go through the sill. Nice clean hole, no clearance needed as it's cold air. But the exhaust is another story... I too am going to go through the brick as it's not flamable. But like you don't want to cut a huge hole if I don't need to for the thimble if it isn't necessary (7" thimble is for going through walls)... I'm all ears if you have a solution / find a solution or someone helps us out? I think using the thimble like you said to make it a "clean appearance" is a good idea but I'm leaning towards just cutting out one brick or 3" hole myself... but like you and not your dad I'm considering the consequences of my actions before doing it...

By the way this is the one I'm looking at going with... it's HUGE but going to be in the basement and liked the oversized hopper.
SUPER 240 PELLET BURNING MODEL - 2,200 sq. ft. / offered by local hardware store for $1,899. Not bad considering it will burn up to 5 days.

 

[DiggerJim]

Cheesebeetle, I'm I think in the same boat as you are... and haven't been able to find a solid answer to the question. I've been to the duravent site and seems most installations are in living space not basement installations? Not impressed with the site at all. Lots of "flash but not much substance".

I'm looking at doing the same as you and installing a pellet stove in the basement. (I've got floor vents from a FHA system no longer in service) so should have heat easily rise up. So now installing the stove / venting has been the issue.... I think for the air "intake" I'll go through the sill. Nice clean hole, no clearance needed as it's cold air. But the exhaust is another story... I too am going to go through the brick as it's not flamable. But like you don't want to cut a huge hole if I don't need to for the thimble if it isn't necessary (7" thimble is for going through walls)... I'm all ears if you have a solution / find a solution or someone helps us out? I think using the thimble like you said to make it a "clean appearance" is a good idea but I'm leaning towards just cutting out one brick or 3" hole myself... but like you and not your dad I'm considering the consequences of my actions before doing it...

By the way this is the one I'm looking at going with... it's HUGE but going to be in the basement and liked the oversized hopper.
SUPER 240 PELLET BURNING MODEL - 2,200 sq. ft. / offered by local hardware store for $1,899. Not bad considering it will burn up to 5 days.

I don't think the OP said he was going to install in the basement - from his description where the pipe will exit near the front door, it sounds more like a 1st floor/living space installation.

One of the reasons you don't see many basement installs here is because most people are trying to heat living space not their basement. Pellet stoves are space heaters and they don't do a super job of heating spaces they aren't in/directly connected to. You will get some warmth rising through the floor vents (open to the basement?) but either it's cooking down there and comfortable upstairs (translates to lots & lots of pellets) or it's comfortable in the basement and chilly upstairs. Lots of experience here with people trying to make them work in the basement and getting the warmth around the house without tons of success.

To the question of the hole you need, if you are going only through masonry (concrete, cement block, solid brick wall) then you don't need a thimble. But, if part of the wall is combustible - like a finished drywall interior wall - then the combustible portion must have a thimble installed. You can potentially cut a much smaller hole lined up with the center of the thimble through the brick wall and use silicone to seal the thimble piping to the interior face of the brick wall...but you really need a conversation with the building inspector if he'll sign off on that.

 

[cheezebeetle]

Digger,

Yeah. You are right. I am installing it in a living space, not in the basement. But it sounds like a couple of people are thinking the same thing, regardless of location. Luckily, I am heading to my parents this weekend (3 hours away) and while there am going to check out my dad's install. See what he did. My plan was to do exactly what you explained (which I greatly appreciate). My followup question would be, is this based on what I would call "common sense" or have you actually seen/done this.

Mainiac, once I check out my dad's set up I will let you know what he did. He has had it installed this way for 10 years, and his IS in the basement. Its not that I don't trust him, I just wanted to see if anyone else has done this. He also sometimes does things I kind of wonder about.

If anyone else wants to give me feedback, specifically if they have done this set up, PLEASE I would love to hear from you.

Thanks everyone

 

[DiggerJim]

Digger,

Yeah. You are right. I am installing it in a living space, not in the basement. But it sounds like a couple of people are thinking the same thing, regardless of location. Luckily, I am heading to my parents this weekend (3 hours away) and while there am going to check out my dad's install. See what he did. My plan was to do exactly what you explained (which I greatly appreciate). My followup question would be, is this based on what I would call "common sense" or have you actually seen/done this.

Mainiac, once I check out my dad's set up I will let you know what he did. He has had it installed this way for 10 years, and his IS in the basement. Its not that I don't trust him, I just wanted to see if anyone else has done this. He also sometimes does things I kind of wonder about.

Omigod I'm turning into your dad Next I'll be telling you to eat your green beans and how I used to walk 5 miles uphill in the snow both ways to school.

I've seen this done but the inspector was a pretty decent guy and okayed it - some won't because it's not explicitly covered in the NFPA regs (which are used as the basis for most local codes). That's why you need to run it past the inspector before you drill.

 

[Mainiac]

Take / post a few pics if you could?????

 

[cheezebeetle]

If anyone is interested, I thought I would follow-up on this forum I posted several months ago. Soon after posting this question, I actually went ahead and did it and it worked fine. I have been keeping an eye on it for the last month, running the fire almost daily, and there have been absolutely no problems. The wall doesn't even get warm. I live in the mid-atlantic area. By the way, I have the Harman Accentra and so far couldn't be happier.

Here is what I did. I rented something called a 3 1/2" core bit and a hammer drill from Home Depot. The bit cost $18 to rent and the drill was like $60. The bit looks like the kind you would use to put a door knob hole in a door, except it is designed to be used on cement. It took a whole 15 minutes or so to cut through the wall. I then decided to connect the outside air vent to the stove, so I drilled a smaller 1 1/2 inch hole (that bit was $8). By the way, Home Depot was by far the cheapest price I found. Also, you want to drill from the outside in, the drill will kick up a good bit of dust. I also cut through the wall on the inside as necessary. The one thing I can recommend is to try and drill a small center hole with a 12" long 1/2 inch cement drill bit (normal home depot purchase) all of the way through all walls and brick. Do this as a starting point from the inside. The reason I recommend this is that it helps keep all holes in line with each other regardless of size and what they are going through. Since you are starting from the inside it helps also make sure you are in line with correct height of the pipe of the stove.

The entire installation took about a day. This included going to HD and renting and returning equipment, messing with the wall, caulking, cleaning, running pipe, hooking up, etc. Since I originally got a quote of $900 to do this (including pipe) I saved a bundle. I bought the pipe from zoobler.com for cheaper then the local store. It cost $150. Bought some high-heat sealant for $10. The rental was like $80. That's it. Simple. OF COURSE... tested for several days during the day while at home to make sure nothing went wrong.

I have attached the design I followed and some pics of the the final product. If anyone has any questions, I will be happy to answer them. I will be "subscribing" to this particular post.

 

[cheezebeetle]

Other pics

 

[rap69ri]

It looks pretty damn good Cheezebeetlw. As long as the insulation isn't touching the round part of the thimble you should be good to go IMHO.

 

[Xena]

Looks great! Only question I have is,
where is your floor protection?
Not trying to bust your chops or anything.

 

[cheezebeetle]

The Harman Accentra actually has an optional cast iron hearth. It is a lot cleaner looking and eliminates the need for one of those huge tile corner things.

Here is the link:

(broken link removed to http://www.harmanstoves.com/features.asp?id=12)

and

(broken link removed to http://www.portersmvs.com/stoves/harman_accentra.html)

But, I do appreciate the call out. It's a good call to be concerned. There are a lot of dumbasses out there who take short-cuts and could burn their houses down if they weren't careful.

 

[Xena]

Ah I see now. I kind of like the tile hearths that folks build tho.
Enjoy the warmth!

 

[terryjd98]

That is a clean looking install, you did a good job and always nice to save money. Wish I could get mine installed that easy. I am going through a 14 inch flat stone wall. Have the hole made, its about 20 inches inside the house and goes down to about 8 inces on the outside. Them big old and little old stones were hard to get out.
Myself I like the looks of them hearth pads the guys on here build themselfs. Seeing my Enviro Evolution came with a steel hearth pad I am planning on using that. What I thought I might do though is see about getting some of the vinal self stick tiles that have a brick look and put on the floor. Room is carpet except in the corner where I am planning on putting the stove the carpet is going to be cut out. Directions say not to use the hearth pad on carpet and with what I have spent I don't want to spend anymore then I have to.

 

[cac4]

How did you attach the 2" flex pipe that comes w/ that thimble kit to the air inlet on the stove...(which is more like 2.5" id)?

 

[heb80]

Other pics

Your cold air intake should be below the outlet. Shouldn't it?

 

[cheezebeetle]

Ha ha ha... great question cac4. Isn't that a groan? They give you a pipe that is smaller than the air intake of the stove. Well, I went to the hardware store and talked to someone who sells these things. He assured me (and he was right) that the air intake hole does not get hot. Hell, it doesn't get any warmer than the room temperature while the stove is actually running. It is seperated from the heated area of the stove. So by this logic, he told me any PVC pipe expander would do. The problem was that they don't make anything which would work. It would either only fit in or around the 2 1/2" hole on the stove but not the 1 1/2 flex tube or the other way around. No simple fix.

So here is what I tried and it worked BEAUTIFULLY and again, have been checking it continually for the past month with no problems. I have run the stove almost every day.

I wrapped the flex tubing with duct tape. Yep, duct tape. I got a high quality (3M) roll of duct tape and wrapped it around the end of the tube. I did this over and over again until I had it as thick on the end as I needed it. I then pushed it into the hole and it was a nice tight (but not too tight) fit. Once the stove was turned on, the vacuum of the air intake completed the seal. The entire wrapping of duct tape is inside of the stove back sheild, so you don't see it at all. I was also careful to keep it clean looking.

I will also add that I spray painted the flex tubing with high heat black paitn. I didn't like the chrome (cheap) look.

 

[cheezebeetle]

Heb 80. Huh, that's a good question. I didn't see that anywhere, as far as instructions or on the internet. I can see why it would make sense, since heat (aka exhaust) rises. But its a bit late for that now.

I haven't had any problems at all and I have a carbon monoxide alarm in the house which hasn't gone off. Haven't had any headaches either. So I think it is working fine. By the way, both the outlet and the intake are covered by a 2 foot saufet.

 

[cac4]

ha! clever solution on that intake pipe. is it really only 1.5"? the description of the thimble/oak combo says "2"....

I'm still debating whether or not I should just spend the money on the harman thimble/oak kit, (which would come with the right size flex pipe), or just get a seperate oak, which will be alot cheaper, but have to be modified to fit. I already have a plain thimble. It came with the vent "kit" I bought. anyway...

I'm doing a corner install, too. just wondering, how far are the back corners of your stove from the walls? (trying to figure out what lengths of pipe I'll need, and its hard to guess without the stove being "in place"...which is isn't. yet.). and then, how long is the pipe run to the thimble? I'm planning to go out, then up on the outside, which will make the pipe that passes through the thimble a fixed length. The vertical rise will be held 3" off the outside wall; I have 1 foot sections of pipe, so however far inside a 1' pipe comes, thats where it is; I won't be able to move that pipe at all to accommodate the stove.

 

[heb80]

You shouldn't have to worry about breathing carbon monoxide as the air that is pulled in is only for combustion and does not get blown into your home. But you do want oxygen-rich air for clean combustion, so if the air it is pulling in is dirty you may not be getting as hot of a flame as you would otherwise.

My instructions said to install the intake below the outlet by a certain distance (1 to 2 ft??? I can't recall what this distance is). But typically you have atleast a 4ft climb on the outlet getting that distance isn't a problem.

Heb 80. Huh, that's a good question. I didn't see that anywhere, as far as instructions or on the internet. I can see why it would make sense, since heat (aka exhaust) rises. But its a bit late for that now.

I haven't had any problems at all and I have a carbon monoxide alarm in the house which hasn't gone off. Haven't had any headaches either. So I think it is working fine. By the way, both the outlet and the intake are covered by a 2 foot saufet.

 

[cac4]

I don't know if that really matters much. the outlet is sticking "out" from the wall quite a bit, and being blown out pretty hard.

consider, on my RV, there is a propane furnace, which works just like a hot-air furnace in your house. It uses outside combustion air. The exhaust port and intake port aren't more than 2" apart, and both the intake and exhaust ports are flush w/ the outside wall. (its made this way by the manufactuere; its not an installer's option...) yes, the exhaust is the top one, but they're so close together. They've been making them like this for years and years...

 

[cheezebeetle]

Well, regarding intake vs. output pipe, the distance is the exact same as the thimble was originally set. So I assume it should be fine. And is noted, the pipe actually sticks out from the wall a good foot or more. So in all reality, the exhaust is about 1 1/2 feet from the intake.

To the measurements I was asked about. My walls are only 2x4s, plus drywall. When you add this to the brick on the outside, the entire width of the wall was about 10 inches thick. This width helped to create my original problem, since the expansion of the thimble was only 7" which left 3" unprotected. Besides, the way I installed looks better anyways ;-)

So, the pipe is actually only 2 feet long, plus the 45 degree angle pipe and the chrome "exhaust pipe" you see in the above picks. Here is what I bought from zoobler.com :

24" black pipe : (broken link removed to http://www.zoobler.com/product.php?sku=3PVP-24B&m=PelletVentPro&b=Simpson&c=Chimney+Systems)
45 degree angle pipe: (broken link removed to http://www.zoobler.com/product.php?sku=3PVP-E45B&m=PelletVentPro&b=Simpson&c=Chimney+Systems)
Exhaust cape: (broken link removed to http://www.zoobler.com/product.php?sku=3PVP-HRC&m=PelletVentPro&b=Simpson&c=Chimney+Systems)
Wall thimble (modified it by pulling off the outside plate and connecting the two 7" protection pipes together with self-drilling screws): (broken link removed to http://www.zoobler.com/product.php?sku=3PVP-WTI&m=PelletVentPro&b=Simpson&c=Chimney+Systems)

That's it. Plus I sealed where the pipes the connected with high tempurature chaulk.

It sits in a corner at 45 degrees. Each corner OF STOVE is ABOUT 9 1/2 inches from wall. The corner of the HEARTH is ABOUT 7 1/2 inches. The center of the pipe is ABOUT 14 inches from corner and ABOUT 8 1/2 inches from the floor. (I had to cut out some of the molding with a dremle to allow for the thimble plate to sit at right height for my stove).

 

[cheezebeetle]

By the way. I just measured the intake flex pipe. It actually has a 2 1/8 inch diameter. So I was wrong when I was saying 1 1/2 inches.

 

[cheezebeetle]

Have one. However, I was trying to cut a 3" hole, not a 7" hole. 3" would be too small to get a clean cut with a 3 1/2" angle grinder. I wanted a "perfect" circle so the pipe would slide through without a broken edge.

Believe me I did consider this orginially. But once I looked into renting the hammer drill with the core bit and it was a perfect size and a good price... it was a no brainer.