I have a wood stove in my garage which is very large, It heats the garage great but I want to get some of the heat into the house. I was thinking of adding a heat exchanger made out of pipe on top of the woodstove and surround it with insulation. it would be hooked into the hydronic system far from the oil boiler. I would add an aqustat and use the existing circulator. I want to know how much black iron or copper pipe to arrange around the top of the woodstove to be efficient, My house is 2,000 sq feet.