Kaowool Rap Fireplace

There has been threads on doing this..i think with roxul, but you get the idea. Last i read, was thought of as maybe overkill. Some warning for wrapping the insert itself as it wasnt meant to wear a coat. Just lining the fireplace has been done.

Due to cost, roxul maybe a better choice.

It depends on how tight you are going to wrap the insert. Some manufacturers advise against a tight blanket close to or directly on the insert, it makes overheating the unit easier. Other manufacturers say go for it, the stove can take the heat and it will increase efficiencies. I would see how much clearance there would be with the insulation then check with the insert manufacturer.

KaptJaq

Wrapping the insert would mean that less heat would get out of it. Putting insulation over the brick sounds like overkill. Is this an exterior fireplace that you are trying to prevent losing heat through conduction? That may do something I suppose.

If it's an interior fireplace, I would think it's counter productive as the bricks could act as a good slow heat sink.

Hello, fyi I have had my insert wrapped with 1" thick creamic wool for about 4 years now with greatly improver performance. Runs a little hotter, and what I really wanted was alot less coaling. Before running the fan on high would cool off the bottom of the fire box which would leave alot of coals.

This is the first season with the fireplace insulated and I have had no overfire issues, the stove acts like it has normally with the fan on. My fan stays on longer now that is for sure, feels like I get more heat output but with this weather it has been hard to really compare.

I would attach to brick, that is what I did to mine, check out the link in my sig.

Very interesting post. I thought about this before, back when I had a freestanding stove partially inserted into an exterior mason fireplace. I saw the word "drywalling" on your previous post, that I would not do. Drywall is not fireproof. I would put the mineral wool on the fireplace walls. Use the "blob" method with high temp silicone directly applied to the fireplace, a blob every 6-8 inches should do. You could then wrap the insulation or face it with sheet metal. As a union carpenter I work with that type of insulation quite often, it is nasty stuff! I would highly recommend facing it with something to prevent fibers from going into your home's atmosphere. Make flanges at the top so you could screw it to the block off plate then flanges at the bottom of the tin walls that you could anchor to the floor of the fireplace with high temp silicone so you don't damage the firebrick. I don't know if the manufacturer of your insert approves of all this, but it sounds like a good idea to me. On the downside, I could see an increased ability to overheat the appliance. I am no expert though.

The brick in the back of my exterior fireplace has never been warmer than 120F.

Normal silicon is good to 400F, so that should be plenty good to attach Roxul (or similar) to the brick. I'm planning on getting some to insulate over a block off plate, but I don't have it yet. Because the package has 12 batts, I figure I might as well insulate the back of the fireplace too.

I have a sheet of galvanized steel that I'm going to cut to fit to cover the Roxul and spray it (the metal) with stove paint.

How would that affect it when running without the fan? I lost power in an October snow storm this year - my power came back on in 2 days. Insert without the fan kept us warm. Would a wrapped insert overheat with no fan?

Mellow, did you use high temp silicone to afix the Roxul to the walls? I didn't see it in your other thread. Thanks.

velvetfoot said:

Mellow, did you use high temp silicone to afix the Roxul to the walls? I didn't see it in your other thread. Thanks.

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I did not want to chance the out gassing of the silicone so I drilled and tapped into the metal firebox stainless steel screws, I then used the metal wiring for hanging picture frames to loop around the screws and hold the roxul in place.

zhukpavlo said:

How would that affect it when running without the fan? I lost power in an October snow storm this year - my power came back on in 2 days. Insert without the fan kept us warm. Would a wrapped insert overheat with no fan?

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To avoid this I have a 2200VA backup battery attached to my fan, that will hold it overnight if the electricity turns off, for longer power outages than that I would just remove the surround to prevent overfiring.

zhukpavlo said:

How would that affect it when running without the fan? I lost power in an October snow storm this year - my power came back on in 2 days. Insert without the fan kept us warm. Would a wrapped insert overheat with no fan?

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Each insert is a little different. Either your manual or the manufacturer should be able to tell you if your insert should be burned without a fan or if you can either insulate the old fireplace or wrap the insert.

I loose power regularly and checked with Vermont Castings. They told me to wrap my Montpelier for increased efficiency without the fan running. See this thread:

https://www.hearth.com/econtent/index.php/forums/viewthread/86075/

Any modifications to an installation that is not specifically mentioned in your user manual should be run past your manufacturer.

KaptJaq

has anyone spoken to Jotul about wrapping the firebox? right now I have roxul in the damper and behind the stove. I also have a layer on the side walls of the fireplace. this side layer is only 3.5" thick and so there's still about 4" or air space between the firebox and that layer of insulation. I've thought about filling that dead space with insulation. In addition I'd think adding a layer over the top of the insert firebox would help it keep more heat internal, but not sure what Jotul might think of that.

I have to say, like others, that the stove seems to stay hotter longer after doing this.

Brian