Finally got around to insulating my fireplace

Been able to run for a few days straight with the cold temps, I really do not see that much difference in everyday operating, where I see the difference is in how much longer the fan stays on because the insert stays warm longer and I now have large coals in the morning after an overnight burn to get the stove going again, before I would just have a few small coals and it would take more effort to get the fire started.

So far it was well worth the $40 for the Roxul and the time to install it.

The insert runs as normal with peaks to 550-575 top plate temp. then back down, the added insulation does not make the insert over fire.

Thank you for the update! Sounds like it was well worth it. I just insulated the attic above the den where the stove is at, put 8x R30 (9") rolles for a total of 200 feet. I only had 6" insulation before, I hope this will help with retaining the heat in the house longer.

Did you paint the insulation?

Nope, if there are fibers that drop the surround will block them from coming into the living area. The secondary air intakes feed the fire box so no fibers would get into the house.