I guess I'm either really dense, or what I'm thinking about just isn't done, because I've looked & can't seem to find an answer to my question, so here goes.
I am anticipating renting a room in an attic that along one wall has what appears to be a cinder block type chimney that has 3 sides exposed to the room. They tell me it produces a lot of heat in the room in the winter. Well, I was wondering if you can put some type of insulation around it like you see around a water heater, lets say, to keep the heat out of the room. I am wanting to put up a wall in the middle of the room, but it would be way too hot with the heat from the chimney with no windows to open in that area. so much!
The International Residential code, IRC 2006 requires a two inch clearance to this wall from combustible material. I would frame the wall with this required clearance and insulate the wall rather than the chimney. Maintain the two inches and you are good to go. I would recommend an NFPA-211 level II inspection of the chimney system as well. Best of luck to you.