Hearth Net: Obtaining Hot Water From Wood Stoves Hearth Net article explains (with diagram) how to design a system for getting free hot water from a wood stove using internal or external heat exchangers.
Product Supply
GBA: Tankless Water Heaters Have Long Payback Period Green Building Advisor says energy savings you’ll get from a tankless water heater are too low to justify the high purchase price, but you may want to buy one for its performance specifications and compact size.