Hello! I recently purchased a home that came with a Blaze King Princess 29 insert. Upon further investigation, it looks like the original fireplace was a Vermont Castings Winterwarm Zero Clearance insert with energy box. It looks like the previous owner replaced the insert with the Blaze King unit. From my research on the Winterwarm it looks like only the Winterwarm system was designed only for the Winterwarm insert. However, I was able to use an inspection camera to look around and the energy box is surrounded by concrete blocks, not combustible materials like the typical installation. The only combustible materials touching the concrete blocks are 1/2" furring strips on the front facing of the fireplace that the drywall is attached to. The closest furring strip is 16" above the insert which exceeds the clearance to combustible facing listed in the manual for the Princess by 2". There is also a heat shield with air gap between the furring strip and top of the fireplace. We have a masonry chimney with a 8" SS insulated liner with reducer to 6" single wall stove pipe that is attached to the insert.
