I have a direct vent, horizontally vented fireplace that is vented into a screened room. There is an accumulation of moisture, water droplets and ice around the roof of the chase and along the soffits. It appears that hot air is escaping from the fireplace housing/chase and condensing around the top of the chase. Does that make sense? Should I insulate the attic of the chase and seal it off; will that prevent hot air escaping and stop the condensation? Any advice would be appreciated.