Lennox Cascade Installation Question

[Abunker11]

Hi - I have purchased a Lennox Cascade pellet stove through a local stove store and they will be doing the installation in my 1st floor living room. But I was surprised when they recommended through wall exhaust vent because I have openings through the 2nd floor ceiling and to the roof.

Secondly they are not recommending any rise in pipe elevation and, now that I have read the manual, I see that's really the the third and least desirable option. I think the reasoning is that I just don't need the snorkel or vertical pipe on the outside of the house, well just because. On the inside I planned to vent through a corner wall that will be custom built. The stove will be in a corner of the room and the corner has a copper heating pipe and a metal-bestos chimney from the basement. So I plan to wall that corner off. I didn't realize this would create complications. So the other reason for no rise on the inside is that it is either not safe, or too expensive to make it safe because the entire vent pipe would need to be shielded. I was steered away from that idea.

Also the installer did not like the installation through to the roof because of how close it is to where the metal-bestos is and because the entire length of vent pipe would be shielded or inside a second chimney. So he felt that it would be expensive and complicated by the roof situation making it even more expensive.

I understand that this model uses a motor to propel the fumes out and so therefore it may run just fine without much rise, but I want to be sure. I'm all for saving money on installation but not if it will run poorly or I will get back drafts if the wind blows a little towards the opening of the flu. Any opinions ?
Thanks
Andrew

 

[alternativeheat]

I don't own a Lennox but I can tell you none the less that the least desirable install in the book is usually the least desirable that works. If that makes any sense. Horizontal vents usually work if the run is short enough. However, you do have a point about back drafts but they make some pretty good vent caps these days. Some rise is very desirable none the less. I ran my vent up the masonry chimney 23 ft, never an issue with draft or back draft or flame out due to power failure. I never think about wind direction regarding the stove because any wind direction produces the same result, even draft. Be careful that your installer isn't just taking the easy way out.

 

[CaptSpiff]

I cringed a little when you described the existing chimney. Any roof penetration has the possibility for minor water leaks down the road. Penetrating the new next to the old, within 1 to 2 feet horizontally gets complicated, especially if an existing roof chase has to be modified. Also I'm a bit confused about running it "inside the second chimney". Is there a chase in the room containing the existing chimney, which you want to expand to also contain the pellet flue pipe?

So I'd probably suggest a "straight out" also. It's safe as long as it is not exhausting near a walkway (look carefully at the install manual for distances). It's nice when you want to clean also because at ground level or a short ladder you could easily do your own cleaning, or even use the leaf blower.

The only drawback is the lack of any natural draft, but that is really only an issue if you have a power outage while the stove is running. You may get some smoke in the room while the pellets in the pot burn out. This could be minimized by installing a minimum 36" rise on the outside. Any rise on the outside complicates the clean out chore, so it's good & bad.

 

[Abunker11]

Yes. Others have cringed at the situation. There had been a wood burning zero clearance in the living room but it was inefficient and smoked whenever the doors were opened to feed it. The chimney was, I think a 14" triple wall situation. A contractor convinced me that it should go because he saw some rust and he didn't like how close the two stove pipes were on the roof. At the time I thought I would go for a direct vent gas fireplace but I was shocked at the price and decided I would try pellets instead. So I do have a big opening in the roof where the 14" pipe went through and yes there had been a leak or two. I have it capped for now while I decide how to proceed. The metalbestos from the basement had been inside the same wall that contained the zero clearance. I took the wall down and will build it closer to the corner. It is a safe distance for horizontal venting. Another drawback to going out vertically within a wall is the problem of cleanout. I thought maybe the T for cleanout could go through the floor for access in the basement but the installer was not happy about that.

I understand what Allternativeheat meant. This installation is "in the book" and is "the least desirable" but since it is in the book it will work. It's not my main source of heat. I will know if a major storm might knock out power so I can avoid that situation. It will be a bummer if a surprise outage fills the house with smoke or the performance of the stove is just so so.

I wonder if a 3 foot riser could be removed easily for cleaning?

 

[alternativeheat]

Yes. Others have cringed at the situation. There had been a wood burning zero clearance in the living room but it was inefficient and smoked whenever the doors were opened to feed it. The chimney was, I think a 14" triple wall situation. A contractor convinced me that it should go because he saw some rust and he didn't like how close the two stove pipes were on the roof. At the time I thought I would go for a direct vent gas fireplace but I was shocked at the price and decided I would try pellets instead. So I do have a big opening in the roof where the 14" pipe went through and yes there had been a leak or two. I have it capped for now while I decide how to proceed. The metalbestos from the basement had been inside the same wall that contained the zero clearance. I took the wall down and will build it closer to the corner. It is a safe distance for horizontal venting. Another drawback to going out vertically within a wall is the problem of cleanout. I thought maybe the T for cleanout could go through the floor for access in the basement but the installer was not happy about that.

I understand what Allternativeheat meant. This installation is "in the book" and is "the least desirable" but since it is in the book it will work. It's not my main source of heat. I will know if a major storm might knock out power so I can avoid that situation. It will be a bummer if a surprise outage fills the house with smoke or the performance of the stove is just so so.

I wonder if a 3 foot riser could be removed easily for cleaning?

As to cleanout on a 3 ft rise just put a T at the bottom. When you need to clean uncap the T bottom and run a brush up through to the top.

 

[Abunker11]

As to cleanout on a 3 ft rise just put a T at the bottom. When you need to clean uncap the T bottom and run a brush up through to the top.

The T for the 3 foot rise would allow cleaning on the vertical axis but wouldn't I also need a way to clean the horizontal run toward the stove? Are there parts that are made for that?

 

[Don2222]

Hello

I minimum 3 foot rise is needed in case of a power failure to get the smoke out of the house, like they said. I have also found that this vetical rise should be on the inside of the house to prevent the cold from cooling off the pipe too soon so it does not clog with ash. I have a customer with a corner install with the rise outside. The house is on a hill and the corner is the windy side near the ocean. This pipe must be cleaned every month in the winter or the stove stops working! That is just my experience.

 

[Abunker11]

Hello

I minimum 3 foot rise is needed in case of a power failure to get the smoke out of the house, like they said. I have also found that this vetical rise should be on the inside of the house to prevent the cold from cooling off the pipe too soon so it does not clog with ash. I have a customer with a corner install with the rise outside. The house is on a hill and the corner is the windy side near the ocean. This pipe must be cleaned every month in the winter or the stove stops working! That is just my experience.

Thanks for all the questions and suggestions. Don's point about the cooling of a 3 foot riser on the outside makes sense. But to put it inside my wall would mean building in some access to cleaning, right? The installer already balked at that idea. Plus it would need to be shielded. Do they make insulated vent pipe for pellet stoves so the 3 foot rise on the outside would hold the warmth and not clog up with ash?

 

[Don2222]

Thanks for all the questions and suggestions. Don's point about the cooling of a 3 foot riser on the outside makes sense. But to put it inside my wall would mean building in some access to cleaning, right? The installer already balked at that idea. Plus it would need to be shielded. Do they make insulated vent pipe for pellet stoves so the 3 foot rise on the outside would hold the warmth and not clog up with ash?

The pellet pipe on the inside does not have to be shilded! That is the best install.
Creating an insulated chase on the outside is very expensive and still would not work as well on the inside.
Sure many people like hiding the pipe so it cannot be seen behind the stove, but there is no need to do that. It works the best with the shortest horizontal run by coming out of the stove to a cleanout T and up 3 feet!. You can paint it High temp black to make it look better, but being safe and working well to me is the most important! Just my experience.

 

[Abunker11]

That makes a lot of sense. The installer and I did discuss this idea come to think of it and it would require cutting a stud to frame the through wall piece. It would also exit directly above my deck railing, which would be ok in relation to the windows. Then it occurred to me I had promised to replace the mantle piece and a 3 foot riser under a mantle would look awkward. Especially since it exits the stove on the far right so it's not centered on anything. But maybe not as bad I am thinking. Safety and performance will make up for a lot of other flaws! lol.

 

[alternativeheat]

The T for the 3 foot rise would allow cleaning on the vertical axis but wouldn't I also need a way to clean the horizontal run toward the stove? Are there parts that are made for that?

There is a T available with double cap cleanout access, one horizontal, one vertical. One of our members posted a link here a few weeks ago.

On another note my clean out T is inside the house about 1 ft inside my fireplace. I don't know what your installer is balking at, it works great for me and gives me a short horizontal run. I was aiming for under 2 ft horizontal and ended up with just under 18" with the pipe and adapter. Perfect and works well too. I get a tiny bit of creosote at the cap if I have had a lot of low burn going on and non if burning hot, like in mid winter.

Pellet vent pipe of the double wall type you can just about stand touching single gets real hot, you not grabbing on to that. I have single wall vertical flex coming off the T, you not touching that with the stove under way. Its stainless steel and after a really good hot burn or two it has a sort of anodized look to it. Off tone at least, so it gets pretty hot. On a Harmon it could have up to 500 deg gases going back through it.

 

[Abunker11]

There is a T available with double cap cleanout access, one horizontal, one vertical. One of our members posted a link here a few weeks ago.

On another note my clean out T is inside the house about 1 ft inside my fireplace. I don't know what your installer is balking at, it works great for me and gives me a short horizontal run. I was aiming for under 2 ft horizontal and ended up with just under 18" with the pipe and adapter. Perfect and works well too. I get a tiny bit of creosote at the cap if I have had a lot of low burn going on and non if burning hot, like in mid winter.

Pellet vent pipe of the double wall type you can just about stand touching single gets real hot, you not grabbing on to that. I have single wall vertical flex coming off the T, you not touching that with the stove under way. Its stainless steel and after a really good hot burn or two it has a sort of anodized look to it. Off tone at least, so it gets pretty hot. On a Harmon it could have up to 500 deg gases going back through it.

I think the balking at the T was around the idea that I could have the vertical inside the yet-to-be-built wall and access the T from through the basement ceiling.

I am thinking that a 3 foot riser from the back of the stove and within the room might look okay even though it's not centered on the stove and there will be a mantle piece. ( I promised to replace the mantle and I wrote off the inside riser because of that) It can then do a 90 go through the interior and exterior wall (about a 18" run) and vent above my decks railing. Hopefully this is enough height above the railing on the outside. I could go higher than 3 feet as long as it has the 90 below a reasonable mantle height.

 

[Lake Girl]

Pics of the proposed area inside and out might be helpful in possible suggestions of solutions... Hope you are remembering smoke and CO detectors and a surge protector.

Welcome to the forum!

 

[Abunker11]

Pics of the proposed area inside and out might be helpful in possible suggestions of solutions... Hope you are remembering smoke and CO detectors and a surge protector.

Welcome to the forum!

Thanks Lake Girl. I posted some pics here...imgur was not letting me post as a group for some reason. I'll try with more later.

inside view http://imgur.com/ARTSoQ1

outside view http://imgur.com/mk4iJAb

The copper pipe is going to be moved inside the wall. The 2x4 on the floor shows where the wall will be.
The vent for this stove is at the lower right rear. One idea has the vent going horizontally at a 45 degree angle to get to the left of the metalbestos chimney, then taking another 45 and exiting to the exterior. That is so the vent will be practically invisible, but not ideal for performance.

A vertical foot rise from the stove then a 90 sends it out above the deck railing but I read that it needs to extend 12 inches from the house so that's not so cool extending out above the railing.