Rear flue exit VS Top flue exit

[begreen]

So not a test, but a semi-permanent install. My apologies to bholler then, it's a bit crazier plan than I thought. This is not a stove, it's an insert and meant to be installed in a fireplace. I can't see this plan passing inspection or insurance approval. The double-90 turn in the smoke path right out of the insert is not going to help matters.

Here is the passage from manual for the current incarnation of this insert.

• THE INSERT AND ITS STAINLESS STEEL CHIMNEY LINER ARE TO BE INSTALLED ONLY WITHIN A LINED MASONRY CHIMNEY AND MASONRY FIREPLACE CONFORMING TO BUILDING CODES FOR USE WITH SOLID FUEL.

 

[frankm1960]

So not a test, but a semi-permanent install. My apologies to bholler then, it's a bit crazier plan than I thought. This is not a stove, it's an insert and meant to be installed in a fireplace. I can't see this plan passing inspection or insurance approval. The double-90 turn in the smoke path right out of the insert is not going to help matters.

Here is the passage from manual for the current incarnation of this insert.

• THE INSERT AND ITS STAINLESS STEEL CHIMNEY LINER ARE TO BE INSTALLED ONLY WITHIN A LINED MASONRY CHIMNEY AND MASONRY FIREPLACE CONFORMING TO BUILDING CODES FOR USE WITH SOLID FUEL.

I hear ya. No worries, it will be a test and it won't be semi permanent It may be a very short lived test if the chimney draft is a problem. You see I've added a 45 and 9" of horizontal pipe to the original configuration which consisted of a single 45. What affect that will have on the draft I won't know until I burn some paper in it. So the test may end there. If it does end there I"ll re-install the insert. I'll leave the new hearth pad in place. The original step hearth was rather small and awkward so I'm happy to be rid of that. The nice big flat hearth pad will be much easier to work around. I'll also be adding a little roxul around the fireplace before I put the insert back in. Maybe that will help the stove radiate a little more heat. Other's have done that and claim it worked well for them.

You know I had to take the insert out to remove the step hearth and insulate around the masonary fireplace in any case so it made sense to me to install the insert outside the fireplace for a "quick test". Removing the step hearth and building a big flat one means I'm a lot closer to being able to install a free standing rear vented wood stove down the road if I'm still not satisfied with my insert. The hearth pad I make will be somewhere around R value of 3 which should be plenty for most stoves.

In any case many thanks for the comments everyone, much appreciated. I did learn a lot in this thread.

PS: I have a design in mind for building a R value 3 hearth pad but I'll start another thread for that Maybe there's already a design on this forum somewhere ?

 

[frankm1960]

An update to cap off this thread. I did do a burn with the stove installed outside the mason fireplace you see in the pics. It did heat up my room quicker with a little less wood than when it's installed in the fireplace. That's as I expected. The stove didn't radiate heat like my dads jotul F3 CB. I turned the blower off for a bit to check that. I started the burn slowly, paper at first then some kindling etc. Shutting the draft down stopped the burn in it's tracks so I wasn't worried about it getting out of control. It didn't draft quite as well in this configuration but it still started fine. I checked the temp around the stove and especially the bottom after it got up to temp. The bottom was cool to the touch which surprised me a little. I had the stove on legs made of brick, the bricks remained cold and were not affected. The stove is essentially air cooled with the large air duck on the bottom (4" x 20") and the air ducts on the top and back (1" x 20").

I'm re-installing the insert back into the mason fireplace after I finish the new hearth pad and insulate the mason fire place with roxul. I'll leave the shroud off for the first few burns to see it that helps dump some more btu's into my room. The hearth pad will have no R value to speak of (ceramic on plywood), it's just for spark protection. I'll have to find a way to integrate it with the fireplace. I think I'll build out the fireplace at the bottom with some "sliced" bricks (about 1" or so) and morter them in and then slide the hearth pad underneath. this should prevent sparks from falling down the joint between the heath pad and fireplace I think. The new hearth pad is going to be 4' x 8' and will just float on top of the existing floor. I wanted a big area to work around

In the end I don't see why an insert cannot be operated outside a mason fireplace. They should test them for that so people have that option.
I'll be looking for a manufacturer that does that with their inserts.

Whether or not I buy a rear venting stove or not remains to be seen. I may opt to "poke" a hole through my chimney above the fireplace and install a normal top venting stove. Might be a job for next summer. There is more selection when it comes to top venting stoves.

So there ya have it. Lot of work and a little gained knowledge

 

[Grisu]

In the end I don't see why an insert cannot be operated outside a mason fireplace. They should test them for that so people have that option.
I'll be looking for a manufacturer that does that with their inserts.

Good luck finding one. UL-testing is expensive and most manufacturers offer a similar stove model. So why would anyone buy a new insert to install it as a freestanding stove instead of getting (the usual cheaper) stove with legs and tested for that application?

 

[mellow]

Plenty of stoves out there that can be either freestanding or Insert, Buck and Appalachian and High Valley off the top of my head has models that can be either.

 

[TMonter]

I would recommend a rear vent freestanding over an insert any day if you have the clearance to combustibles and the hearth area to support it. It will heat better (due to not being IN the fireplace) and does not require a blower.

An insert to me is a last resort heating device, you have the fireplace but don't have the room for a freestanding then an insert will have to work.

Not all inserts require a blower though. I have had my insert installed for 10+ years and never used a blower. I do however agree, a freestanding is the best way to go if you can make it fit.

 

[frankm1960]

Good luck finding one. UL-testing is expensive and most manufacturers offer a similar stove model. So why would anyone buy a new insert to install it as a freestanding stove instead of getting (the usual cheaper) stove with legs and tested for that application?

I didn't buy a new insert... it came with the house I bought 18yrs ago. I don't know where you got the idea I bought a new insert to install as a standalone stove. If you read through some of my previous posts you will get a better idea of the situation and why I started this thread.

 

[frankm1960]

Not all inserts require a blower though. I have had my insert installed for 10+ years and never used a blower. I do however agree, a freestanding is the best way to go if you can make it fit.

Without the blower I would freeze.

 

[Grisu]

I know that you did not buy a new one but you were asking manufacturers to spend extra money to have their inserts UL-tested for a freestanding application. However, manufacturers only care about selling new stoves. What happens 18 years down the road is not really their concern. Thus, they just won't do it because someone years later may find an insert that he/she wants to use as a stove.

 

[frankm1960]

I know that you did not buy a new one but you were asking manufacturers to spend extra money to have their inserts UL-tested for a freestanding application. However, manufacturers only care about selling new stoves. What happens 18 years down the road is not really their concern. Thus, they just won't do it because someone years later may find an insert that he/she wants to use as a stove.

So the manufacturers only care about selling new ones and they don't care what happens to their stove down the road ? Ok.

 

[Grisu]

So the manufacturers only care about selling new ones and they don't care what happens to their stove down the road ? Ok.

Businesses care about their profits and testing inserts for a freestanding installation would be a profit-losing endeavor so companies won't do it. That's called capitalism. (And not that I agree with it; just stating the reality we live in.)

 

[TMonter]

Without the blower I would freeze.

Which is more a function of the stove design than the fact it's an insert. My 3100i has no problem putting out heat with natural circulation.

 

[Grisu]

Which is more a function of the stove design than the fact it's an insert. My 3100i has no problem putting out heat with natural circulation.

Agree. It's the same with mine. I usually turn the blower off after the peak burn and rely just on the convection then. (And that I turn it on at all is more for getting the heat out quickly and/or to make sure the insert does not overheat especially on the pine I was feeding it a lot last winter.) I suspect the OP is losing a lot of heat from the insert through the back of the fireplace (or up the chimney if there is no block-off plate; don't remember that anymore).

 

[TMonter]

Agree. It's the same with mine. I usually turn the blower off after the peak burn and rely just on the convection then. (And that I turn it on at all is more for getting the heat out quickly and/or to make sure the insert does not overheat especially on the pine I was feeding it a lot last winter.) I suspect the OP is losing a lot of heat from the insert through the back of the fireplace (or up the chimney if there is no block-off plate; don't remember that anymore).

I don't have a block off plate but I did stuff the space between the liner insulation and the chimney at the entrance to the chimney with 3000F ceramic wool so functionally it's the same thing. I don't even have a fan on my insert but I have a split level home so it's a bit easier to heat than a single level home would be.

 

[Charles1981]

There are plenty of free standing stoves with rear exit that work just fine... I'm not sure it really even matters in the case of my stove because it is a down draft and everything has to pass down through the coal bed, back into a refractory and then up into a catalyst in the back before exiting the stove.. maybe some other could enlighten me as to whether or not it matters my vc encore 2n1 is top exit or rear exit.

Not that anyone here would encourage you to purchase a rear exit downdraft stove though...

As I posted last year...I also have 4 feet of horizontal run before it goes vertical. Most would say this is terrible for draft but I also have a 27 foot vertical liner and thus the stove pulls like a draft horse.

Somehow I think i have an ideal setup for a downdraft stove as I have not experienced some of the nightmares other newer VC owners report here, but all in all If I were in your shoes I would be looking at extending that hearth, and just finding a rear exit stove that suited my needs.

 

[begreen]

Some inserts are better than others at convecting heat without the blower. PE specifically designs theirs with this in mind. In general the more the insert projects out on the hearth the better chance of it convecting well.

 

[frankm1960]

There are plenty of free standing stoves with rear exit that work just fine... I'm not sure it really even matters in the case of my stove because it is a down draft and everything has to pass down through the coal bed, back into a refractory and then up into a catalyst in the back before exiting the stove.. maybe some other could enlighten me as to whether or not it matters my vc encore 2n1 is top exit or rear exit.

Not that anyone here would encourage you to purchase a rear exit downdraft stove though...

As I posted last year...I also have 4 feet of horizontal run before it goes vertical. Most would say this is terrible for draft but I also have a 27 foot vertical liner and thus the stove pulls like a draft horse.

Somehow I think i have an ideal setup for a downdraft stove as I have not experienced some of the nightmares other newer VC owners report here, but all in all If I were in your shoes I would be looking at extending that hearth, and just finding a rear exit stove that suited my needs.

That's a really nice set up you have there and I agree my best option is to get a rear venting stove as my situation is almost identical to yours. I think the only difference is you have your stove in the basement setting on concrete where as mine is upstairs on a wood floor so the hearth R value comes into play.

 

[frankm1960]

A quick update. Here's a pic. I redid my block off plate to improve the seal around the liner and I insulated both sides of the plate with roxul board. Any heat entering the fireplace pit from the stove will likely just billow out into the room. Not much chance it going up the chimney like before.

The new hearth has almost no R value, it's only for spark protection.

I did leave the stove outside the fireplace as you can see. To put it back in would require a custom made SS elbow which I don't have. Right now the stove is supported by a rack made of 2 steel bars and 4 bricks.

I've fired it 3 times so far with the stove pipe reaching 500 degrees. The bottom of the stove got warm to the touch and the hearth tiles underneath remained cold. The sides generate a quite a bit of heat so I installed metal heat shields on each side (made from the original shroud).

So far I have not seen any issues with it in this configuration and I'm happy with the heat the stove generates.

 

[bholler]

Did you run this by your insurance company or the local code guys?

 

[begreen]

I'll pick R=3 (very high) which is roughly a 2" ventilated air gap. I'll build a 4' x 8' ceramic tile on plywood hearth which I'll set in front of the fireplace right on the floor you se. On top of the plywood and ceramic hearth I'll put 4 bricks on the flat as "legs" and set the stove on that. This raised the stove up 2" and should give me my R value 3. If you notice the stove has almost a 4" air gap on the bottom as well ( the duct for the blower) so I almost think I could set the stove directly on the ceramic tile hearth but I'll maintain that 2" air gap to make sure.

This thread started out asking for help with a proper F3CB install and has degraded into an unlisted experiment. Closing thread.