Ice on the Glass! Cold air pouring in

Hey there,
We are looking to replace our prefab majestic wood-burning fireplace with a gas burning unit. It is in a chase on an outside wall. In the winter ice forms on the doors, the family room (on a concrete slab) is very cold. The fireplace has a brick facing. When I put in an insulating form to block the air from coming in, the air just came out the sides from between the brick facing and the wall. Before we spend the money to put in a gas unit, we want to be sure the work fixes the extreme cold air problem.

We have had conflicting recommendations. A fire place company said to just put in the gas unit, which will seal the the fireplace. Neighbors have said to tear off the siding and insulate the chase(we were told to assume it is not insulated). Another chimney guy we talked to agreed, however, said they do not insulate chases and that is something for a contractor.

Any direction on a real solution would be great!

thanks,
steve

Hey there,

We are in n IL, near the WI line. The ice forms on the glass doors.

Thanks all.
We have blocked off the air intake, but then need to unblock it to use the fireplace. I like just getting rid of it.
mlouwho, does the direct vent unit 'seal' around the opening of the fireplace to stip the draft comming in from around the box, or is this taken care of by the insulation and taking out the air vernt.

I think we like the idea of replacing rather than putting in an insert. we'll expore it. Any recommendations for professionals in northern IL?