How important is the insulation AROUND the fireplace insert? (Especially FPX 33, Lopi Declaration)

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bonedoc

New Member
Mar 18, 2007
28
Western CT
Again; I have gotten answers all over the map on this issue.

I am told by the resident woodstove insert guy that these particular inserts are designed to "reflect heat back into the room" and that air circulating around the insert is warmed and blown back into the room. He states that he generally does no see a point in insulating around the insert then, even in an exterior chimney.

Others on this forum swear by the dogma..."insulate your liner AND around your stove".

I have insisted on the insulated rigid liner....(they bitched and moaned about that...)

What's the deal with the insulation around the insert? Not so important with an insulated liner?

Info from Lopi declaration/FPX 33 or Lopi Freedom would be especially helpful.

Thanks.
 
<>I am told by the resident woodstove insert guy that these particular inserts are designed to "reflect heat back into the room" and that air circulating around the insert is warmed and blown back into the room. He states that he generally does no see a point in insulating around the insert then, even in an exterior chimney.<>

That sounds correct...

<>Others on this forum swear by the dogma..."insulate your liner AND around your stove".<>

Insulate your liner & block off your damper area with a plate or insulation...
I've never seen anyone insulate around the firebox...

<>I have insisted on the insulated rigid liner....(they bitched and moaned about that...)<>

Most installers WOULD...the flexible liner can be a bear to get down a terra cotta flue...
Rigid can be damned near impossible...

<>What's the deal with the insulation around the insert?<>

Again, never saw anybody do that...

<>Not so important with an insulated liner?<>

Not REQUIRED, IMHO...
 
So...Insulated liner and a block-off plate at the top of the chimney(without insulation there) and I'm good?
 
bonedoc said:
So...Insulated liner and a block-off plate at the top of the chimney(without insulation there) and I'm good?
Click to expand...

It can't hurt to insulate at the top of the flue - AROUND the liner...
It'll keep that much more heat in & cold out...
Insulate around the bottom - in the damper area -
OR build a block-off plate to take the chimney right out of the equation...
 
Why not use Un faced fiber glass insulation ? If you were going to be using this around the back of the insert and over the top of the insert I would not think temp would ever get beyond that of fiberglass
Would be much cheaper and you can get any where
 
What hasn't been explicitly stated is a block off plate in the damper area with a layer of insulation on top of it. Then you'll have the full set up--sealed plate up top, insulated liner, insulation on top of block off plate in the damper.

The installer is correct about the fans circulating the heat around the insert.
 
With an all exterior chimney and a large firebox to work with I wanted to extract every BTU that I possibly could from my install. I did the install myself as you will be hard pressed to find a pro that will go to such lengths and if you do it will cost you a small fortune to have it done. DIY seems to be the only alternative as you can take your time and go that extra mile to make things as best as can possibly be. Yes, the law of diminishing return comes into to play here but why not go to the extreme? Its your time which is essentially free.

I went with an insulated liner with sealed top an bottom damper plat and also lined the sides, back and bottom of my firebox with 1/2inch ceramic wool all clad in place with 22 guage sheet metal painted with black high temp paint. yes, it was a great deal of effort but I enjoyed the experience overall and learned a great deal in the process. The end result is a fireplace insert that really cranks out the heat bringing the room the insert is located up to 82 degrees within an hour or so and warming the rest of the house into the lower 70's with relative ease..

A few pics to give you an idea of what was done.. Hope it helps you decide on how far you want to go with your install..
 

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forgot to attach, one more shot of the finished install with the surround in place..
 

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44 elite said:
so why not use un faced fiberglass batts?
Click to expand...

rockwool has a much higher melting point
 
I think fiberglass is 1600 ( correct me if wrong) your going to be draping this over the back of an insert rockwoll would be over kill. I didn't think the back and sides of the insert will get any where near that hot. PLease let me know as I used unfaced fiber glass to fill the entire cavity around my insert. I kept it at least 2 in away from the chimney
 
For 40 bucks, I picked up 25 ft of 1/4" kaowool. I used about half to drape over top and sides of insert. I am sure it was worth it. The stove comes up to temp much easier now. Also holds temps longer. However, i have some reservations of going any heavier on the kaowool as i Am more leary of an overfire versus getting more btus out. Below zero outside with full load of oak i can hit 750 easy and cruise along. Last year w/o kaowool, i dont think i got above 650 for a short time. It really shows in mild weather run time!
 
My Declaration is done with an insulated flex, with a sealed top plate and a lower block-off plate.
Brent582 has a real nice looking setup, which would seem to be a bit more efficient and maybe yield a longer burn by reflecting the heat back to the stove. Some would probably debate that you will lose the radiant heat from the hearth, but experience tells me keeping the heat to the core of the stove (insulate w/reflector panels) will yield the best results if you have the time, means, and clearances to do so. When I pull my stove for cleaning after the burn season. I think I will be building some reflector panels to maybe get a longer burn.
 
My understanding is that not allowing enough warmth in the chimney can cause more creosote buildup and a poorer draw.

After I began using my blower (which removes heat that would have gone up the chimney) I found that smoke more easily comes out through the door. My guess is that the lower temperature in the chimney is decreasing the draw.

I have a Lopi Revere insert.
 
I do not have that issue. I have a 6" flex liner, insulated in an wxterior chimney. Total length of @26 ft.
 
I finished a Lopi Declaration install a couple of weeks ago. I did the sealed top plate, 21' feet of insulated flex liner, and a damper block off plate with a layer of leftover liner insulation on top. Something else you might want to ask your installer would be about sealing the connection between the liner and the stove. I have an annoying whistle on my Declaration and contacted the maker, Travis Industries. They suggested that whistling usually comes from this connection and that is indeed where it sounds like it's coming from. I plan to seal this weekend with some furnace cement, hopefully that will do the trick. Good luck with your install.
 
A couple of years back I wrapped my Lopi Answer insert with mineral wool insulation. It burned much hotter and cleaner (the glass stayed cleaner). Also my intervals between cleanouts was increased. I didn't get any noticeable benefit it terms of length of burn; not too surprising there.

I thought it was OK to do this on the outside of a convection baffle; but still kept an eye on the temps. Overfiring can happen more easily, so be careful.
 
AbeAinPa said:
I finished a Lopi Declaration install a couple of weeks ago. I did the sealed top plate, 21' feet of insulated flex liner, and a damper block off plate with a layer of leftover liner insulation on top. Something else you might want to ask your installer would be about sealing the connection between the liner and the stove. I have an annoying whistle on my Declaration and contacted the maker, Travis Industries. They suggested that whistling usually comes from this connection and that is indeed where it sounds like it's coming from. I plan to seal this weekend with some furnace cement, hopefully that will do the trick. Good luck with your install.
Click to expand...

Finally installed by FPX 33(not quite flush however...).

Regardless, I'm not quite sure I understand the logic behind a block off plate at the top and the bottom of the chimney?

I've only used it for a few days with break-in fires mostly. I'm a little dissappointed in the way it puts out heat. Could be my open floor plan but sitting across the room it doesn't really even feel warm.

Suggestions?
 
I got the mineral wool insulation from McMaster-Carr (just go to mcmastercarr.com). The source of everything you could ever want.
 
rickw said:
I got the mineral wool insulation from McMaster-Carr (just go to mcmastercarr.com). The source of everything you could ever want.
Click to expand...

yup i agree same place i got mine
 
I would not put insulation directly on the insert. I have not seen this mentioned in any install manual. I imagine it could lead to premature metal or weld failure. I really love what bren did, the air space around the unit is preserved but the masonry is insulated to prevent heat loss. One thing that would work a little better though is to leave the metal shiny, black metal will absorb heat where silver will reflect it back. Most people don't have this option though because that must be one huge firebox. Most inserts we do just barely fit.
 
bonedoc said:
AbeAinPa said:
I finished a Lopi Declaration install a couple of weeks ago. I did the sealed top plate, 21' feet of insulated flex liner, and a damper block off plate with a layer of leftover liner insulation on top. Something else you might want to ask your installer would be about sealing the connection between the liner and the stove. I have an annoying whistle on my Declaration and contacted the maker, Travis Industries. They suggested that whistling usually comes from this connection and that is indeed where it sounds like it's coming from. I plan to seal this weekend with some furnace cement, hopefully that will do the trick. Good luck with your install.
Click to expand...

Finally installed by FPX 33(not quite flush however...).

Regardless, I'm not quite sure I understand the logic behind a block off plate at the top and the bottom of the chimney?

I've only used it for a few days with break-in fires mostly. I'm a little dissappointed in the way it puts out heat. Could be my open floor plan but sitting across the room it doesn't really even feel warm.

Suggestions?
Click to expand...

Their are 2 reasons for the block off at the top and bottom. The first is to create a dead air space inside your chimney to act as a form of insulation. The second reason more associated with the bottom plate, is to not send all that heat up inside your chimney where it can't heat your house.

As far as heat output goes. You need to burn that stove hot! You need to get that stove above 500f surface temp before you're gonna start seeing good heating from it. I usually get mine to around 600-700f (surface temp). That is when she will cook you out of the room!

Let us see some pictures of that new stove all fired up!
Good luck with it and happy burning!
 
Bubbavh said:
bonedoc said:
AbeAinPa said:
I finished a Lopi Declaration install a couple of weeks ago. I did the sealed top plate, 21' feet of insulated flex liner, and a damper block off plate with a layer of leftover liner insulation on top. Something else you might want to ask your installer would be about sealing the connection between the liner and the stove. I have an annoying whistle on my Declaration and contacted the maker, Travis Industries. They suggested that whistling usually comes from this connection and that is indeed where it sounds like it's coming from. I plan to seal this weekend with some furnace cement, hopefully that will do the trick. Good luck with your install.
Click to expand...

Finally installed by FPX 33(not quite flush however...).

Regardless, I'm not quite sure I understand the logic behind a block off plate at the top and the bottom of the chimney?

I've only used it for a few days with break-in fires mostly. I'm a little dissappointed in the way it puts out heat. Could be my open floor plan but sitting across the room it doesn't really even feel warm.

Suggestions?
Click to expand...

Their are 2 reasons for the block off at the top and bottom. The first is to create a dead air space inside your chimney to act as a form of insulation. The second reason more associated with the bottom plate, is to not send all that heat up inside your chimney where it can't heat your house.

As far as heat output goes. You need to burn that stove hot! You need to get that stove above 500f surface temp before you're gonna start seeing good heating from it. I usually get mine to around 600-700f (surface temp). That is when she will cook you out of the room!

Let us see some pictures of that new stove all fired up!
Good luck with it and happy burning!
Click to expand...


Thanks for the info. Are you just using a magnetic stove thermometer or one of the infrared ones? I've heard other posters saying that with this stove the IR kind directed to the firebox top through the grate works best.

What has been your experience?
 
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