Furnace

A fireplace after three hours of burning two logs of dry birch and 3 logs of small, fresh birch pieces.. at his point, the greenhouse has been HOT for nearly 3 hours and the floor also holds the warmth for a long time. Also, the new 8mm thick steel heart ensures that the heat holds very well and the air will be hot quite a while after all the fire and embers have died down. Works perfectly as planned!! The basic principle for this furnace here: http://www.fatalii.net/growing/images/furnace2.gif