Gas-water heat exchanger for providing hot water in building consists of pipe wound in double spiral coil round flue rising vertically from combustion chamber of fire

摘要

The water heating system (10) may use the fire (12) in a wood-burning stove. A metal flue (14) rises vertically from the stove. It has a bend at the top discharging into a chimney (17) which rises through the building roof (18) and discharges into the atmosphere. A pipe (20) is wrapped in a spiral around the vertical flue and is surrounded by a high quality non-rusting steel cladding (28). A pump (26) at the top of the heat exchanger circulates water through an inlet pipe (22) down through the first part of the spiral. It returns through the second part of the spiral to an outlet pipe (24) and the pump.