I am in the early stages of building a 8x8 green house as a extension of my wood boiler shed. The green house will be built out of reclaimed insulated glazing from a commercial office building. The current shed houses my boiler which is a 300,000 btu outdoor wood boiler that supplies heat and hot water to the main house. The idea of the green house was to get a early start on seedling in the spring but i have started to wonder if i could heat it using capture heat from the wood boiler. I have seen several homesteaders wrap the chimney flue with copper pipe to create hot water and store it in reclaimed h/w tanks. What i am wondering is if i wrap the flue and store any hot water created in a 55 gallon drum ( or 2) in the center of my 8x8 greenhouse would it radiate enough heat to keep the green house warm enough to grow year round? Any idea how much heat i could generate this way? Or what water temp i could achive? I am zone 6b by the way....
