Hi Frank,
Mine is a Dickinson Newport, which is probably the most affordably priced unit out there, at least here in the states. There's some really nice cast iron heaters, like the "sardine," but they're a little too pricey for me. I installed my heater at the base of the mast, starboard side, on the bulkhead. The heat stays low in the cabin -- no drafty toes. This does not follow Dickinson's installation recommendations, which calls for 8 inches between the heater and all unshielded combustible materials. There's no good place on the Ballad that adheres to those standards, and the spot between the mast and the stbd bunk is, in my opinion, perfect. So, in order to use that spot without for the installation without subsequently using the boat as firewood, I made a "box" around the heater itself from Marinite, a material similar to drywall, and sheathed the box in aluminum sheeting. Marinite is used in the commercial ship industry to contain high temperature cargos. Basically, it can withstand absurd amounts of heat on one side and remain completely cool to the touch on the other. I'm talking temps like 25000F. Just to try it out, I held a propane torch to a piece of the stuff, and held the stuff itself in my bare hand. After a half hour, all I had was sore arms from holding the torch. It's only 3/4" thick. Crazy. It is expensive, though. Anyway, I housed the heater in that and then shielded the bulkhead from the chimney with it as well. The chimney is a charlie-noble. The whole installation took two hours, and it was by far one of the best things I've done to my boat. There are pictures on this site at this link:
http://albinballad.multiply.com/photos/album/90/Littlebits_new_gear. Let me know if there's anything else I can explain.
Joe