insulation

[willingmyre]

Avalon Perfect fit professionally installed in brick fireplace. There is much free space between the outside of the insert and the bricks forming the interior of the fireplace. What are considerations in adding insulation to reduce the heat xfer from the insert to the bricks and then to outside? I have searched the forum and saw a post that was ok to use fiber glass or "rock wool" for this purpose. Is one or the other to be preferred or is special high temperature insulation needed? Another post cautioned there had to be some inches of air space between the vent pipe and chimney for some fire safety code. What is this code?

 

[Hogwildz]

You should call Avalon and ask them if this is ok first off. And then if it is, what to use. I would not use fiberglass. Kawool or rock wool should do.
Not so sure its a great thing to contain it like that. You do have a block off plate at damper right? Besides, that heat transfered to the brick will also radiate back to the room for a while, not the same but somewhat similar to a masonry heater. The masonry absorbs & retains heat, then releases back to room.

 

[Gooserider]

Avalon Perfect fit professionally installed in brick fireplace. There is much free space between the outside of the insert and the bricks forming the interior of the fireplace. What are considerations in adding insulation to reduce the heat xfer from the insert to the bricks and then to outside? I have searched the forum and saw a post that was ok to use fiber glass or "rock wool" for this purpose. Is one or the other to be preferred or is special high temperature insulation needed? Another post cautioned there had to be some inches of air space between the vent pipe and chimney for some fire safety code. What is this code?

Is it an interior or exterior fireplace? If it's completely within the house, you really won't gain much by insulating the firebox as the heat lost to the masonry will simply radiate back into the house anyways. If the fireplace is partly or completely exterior (just the back wall or three sides exposed to the outside) then you will definitely benefit from insulating the firebox as any heat that goes into the masonry will be radiated outdoors where it will just warm the squirrels... Insulating the backside in that case will increase the amount of heat radiated out the front of the unit.

Use Kaowool / rockwool, or other high temp insulation boards or blankets, NOT fiberglass (which isn't rated for the temps involved) Be careful not to block any needed air intakes.

It is also VITAL to getting good heat output to have a sheet metal blockoff plate installed in the damper area to prevent hot air from exiting up into the chimney around the outside of the liner.

Gooserider