Freestander in fireplace questions??

[cuttingedge]

We recently had a Jotul F55 installed. We decided to have it somewhat recessed into our existing fireplace opening as we thought it would look better than having it sit outside of the fireplace. After the recent cold snap, I am thinking that I should move it out a little bit more to take advantage of the heat coming from the back of the stove. The way that it is now, the flue collar is oriented at the top and a flexible liner goes up the whole length of the masonry chimney. If I were to move it out, what would I need to accomplish this? A "T" with a clean out at the bottom? What type of pipe should I use to go from the stove collar? How should they be connected? Approximately how much further out would the stove be with the flue collar oriented to the rear with a "T" connection? Also as far as temps go is running this stove at 650-700 too much?
Sorry for all of the questions.

 

[begreen]

Yes, your plan would work. You can get the tee with a snout extension that gets cut to length. There will still need to be adequate hearth (16") in front of the stove door. I would want it to be at least 50% out of the fireplace.

Is there a damper-sealing block-off plate installed? That is a must to stop heat from being trapped up the chimney. The lower it can be installed the better. Is there a blower on the stove?

 

[weatherguy]

Begreen covered it, I have a tee with a 12 inch extender I believe. I have mine almost all the way out, its sets back about 5 inches, I do get a ton of heat but I did make a new one piece block off plate.

 

[cuttingedge]

Yes, your plan would work. You can get the tee with a snout extension that gets cut to length. There will still need to be adequate hearth (16") in front of the stove door. I would want it to be at least 50% out of the fireplace.

Is there a damper-sealing block-off plate installed? That is a must to stop heat from being trapped up the chimney. The lower it can be installed the better. Is there a blower on the stove?

Thank you for the response,
There is no block-off plate but the installers did stuff a bunch of Roxul in the area surrounding the flex pipe. Since the stove is on a stove board, I can just move that out a little further to meet clearances in front of the stove. The stove does have a blower but so far I am not impressed with its performance. It does move some air but it is not anywhere near as powerful as the one from our old insert. I also have an ecco fan on the stovetop and a small box fan in our bedroom facing the stove room to circulate air. I just think that with the stove set back into the fireplace, we are not seeing it's full potential and would like a little more heat output from it.

 

[weatherguy]

Thank you for the response,
There is no block-off plate but the installers did stuff a bunch of Roxul in the area surrounding the flex pipe. Since the stove is on a stove board, I can just move that out a little further to meet clearances in front of the stove. The stove does have a blower but so far I am not impressed with its performance. It does move some air but it is not anywhere near as powerful as the one from our old insert. I also have an ecco fan on the stovetop and a small box fan in our bedroom facing the stove room to circulate air. I just think that with the stove set back into the fireplace, we are not seeing it's full potential and would like a little more heat output from it.

A block off plate would help too, I noticed a big difference when I first installed mine. How much sf are you heating?

 

[cuttingedge]

A block off plate would help too, I noticed a big difference when I first installed mine. How much sf are you heating?

We are heating approximately 1700 Square feet. I am going to build a block off plate while I have the stove out as it seems that it would help a lot. Does anyone know where I can purchase a good quality Tee with a clean out like begreen posted? Since the stove sits about 25% out of the fireplace I would like to go as short as possible. If I orient the flue collar towards the rear and add a Tee, the stove would probably sit all the way out which is fine. I just don't want to have it sitting too far out.

 

[cuttingedge]

Btw here is a photo of the current set-up

 

[weatherguy]

You should be able to get one at any stove shop in your area. You can measure where the flue connects now and measure how far out you want to come and that will give you an idea of what you need to buy.

 

[Grisu]

If I remember correctly, the F55 has only 6" rear clearance which suggests there is not a lot of radiant heat coming out from the back. Not sure if you will see the effect you are hoping for. A block-off plate should certainly help. In addition, is that fireplace at an exterior or interior wall? Maybe adding some insulation in the back of the fireplace may already help. When you run the stove at 700 F how long does a burn last in your hands? How long before you reload and what's the temp e. g. after 6 hours?

 

[cuttingedge]

If I remember correctly, the F55 has only 6" rear clearance which suggests there is not a lot of radiant heat coming out from the back. Not sure if you will see the effect you are hoping for. A block-off plate should certainly help. In addition, is that fireplace at an exterior or interior wall? Maybe adding some insulation in the back of the fireplace may already help. When you run the stove at 700 F how long does a burn last in your hands? How long before you reload and what's the temp e. g. after 6 hours?

The fireplace is not on an exterior wall. We have a room behind it that will soon become our "T.V." room. If I load the stove right and with good wood it will run at 600- 700 for about an hour or two. After that it's between 500-600 for another hour or so. After that it slowly goes down. If I am pushing the stove, I reload every three to four hours. Otherwise I let it go and approximately eight to ten hours later, I will reload.
I see your point with the six inch rear clearance but think that even if I pull it out another foot or so it should really help. Especially if I put in a block off plate. It will also make cleaning the chimney a lot easier.

 

[Grisu]

The only heat loss you may have is the warm air going up the chimney due to the missing block-off plate. What the stove gives off from the the rear will warm the back of the fireplace which will radiate it into the room behind. You can probably feel on the back of the fireplace wall next door that it is warmer when the stove is running. The easier cleaning is certainly a good point.

What kind of wood are you loading? With good hardwood it should be close to impossible to load the stove again after 3 to 4 hours since the firebox would still be at least half full. I have a smaller stove and see temps of about 400 F six hours after a full load. That is usually the earliest I would consider reloading.

 

[cuttingedge]

The only heat loss you may have is the warm air going up the chimney due to the missing block-off plate. What the stove gives off from the the rear will warm the back of the fireplace which will radiate it into the room behind. You can probably feel on the back of the fireplace wall next door that it is warmer when the stove is running. The easier cleaning is certainly a good point.

What kind of wood are you loading? With good hardwood it should be close to impossible to load the stove again after 3 to 4 hours since the firebox would still be at least half full. I have a smaller stove and see temps of about 400 F six hours after a full load. That is usually the earliest I would consider reloading.

The back of the fireplace is in the next room. It is exposed brick as I am sure the next room was an addition. The bricks in the room behind the stove used to get really hot with our insert but not so much anymore. There is a metal shield behind the stove which I am sure radiates a ton of heat into the stove room. I think that the combo of a block off plate and pulling the stove out another foot could do nothing but help.
Btw we are burning primarily ash, maple, birch, beech and cherry. It will be the same mix until my oak is seasoned properly. We just moved into the house last January so our wood supply was pretty slim. I have worked hard at getting us a few years ahead and will continue to do so over the winter. As of right now we probably have about 9 cords of mixed hardwoods (ash, maple, birch, beech and cherry) along with about 5 cords of red oak that will not be ready for another year or so. I plan on having another 20 or so cords done by winters end.

 

[branchburner]

I also have an ecco fan on the stovetop and a small box fan in our bedroom facing the stove room to circulate air. I just think that with the stove set back into the fireplace, we are not seeing it's full potential and would like a little more heat output from it.

One thing you might want to try (in addition to moving the stove out and/or adding a block-off plate) is putting a small fan on the floor, blowing cool floor air into the fireplace towards the back of the stove. I had a similar fan setup to yours, but I added that, and gave up on the ecco fan, which didn't seem to move much air.

My stove sits about 75% out of the fireplace, and the fan about a foot out from the stove and a foot to the right. When I turn it on, I can feel a blast of warm air coming out from the back of the fireplace, rolling out over the top of the stove.

In my case, it really helps, because 1) I have no blower and 2) my "downdraft" stove has a rear burn chamber that throws a ton of heat from the back of the stove. The right-rear side of stove runs about 100f lower than the left (say, 500f vs 600f) when the fan is on. I'm sure it also pulls heat off all the masonry as well. Without that fan helping the natural convective flow, I would have a tough time heating the house.