Fireplace insert: Insulate the exterior, or not?

[sean donato]

The rock wool should last, basically indefinitely, given it doesn't get knocked around. (Not likely in your use.) There's a rock wool panel on the inside of the feed door on my furnace. I replaced it shortly after we bought the house, the previous owner had partially ripped it off. So far going on 14 years and zero degradation of it. I did use a ridgedizer on it to stiffen up the face thay sees the flames, but not needed in your application. You should be good to go for a very long time. Happy it worked well for you.

 

[slabMan]

Really? It's the back side of metal box, inside of a conventional brick fireplace. I guess I could, but I didn't think that mattered.

At this point, I don't even have the stove out of the fireplace all the way. Getting the flexpipe detatched has been extra difficult. I had to heat the dinky 1/4' sheet metal screws cherry red before I could get them out. Then I had to let it cool off before proceeding, now I'm completely cold to the thought of going any further tonight.

I'll put up some pics when I get it out all the way. OK?

ABSOLUTELY insulate the top and sides of the insert before you put it back into the hearth opening. I realize this is months old, but for those who might have the same question, the more you "delay" the heat searching for the cold air, the more it can heat the thermal mass of your room/house inside. Your quad relies on preheated air to burn efficiently and I might think twice about pulling outside air in, but that is your baby. I would also surround the stainless flex pipe [inside existing masonry chimney] with rockwool or other certified insulation. The more you keep your pipe and flue heated, the better the draft, less creosote and more efficient burn. As you probably already know.