A WATER HEATER AND A METHOD OF HEATING WATER IN A TANK

摘要

A water heater 10 including a tank 12, a burner 28, a gas directing casing 30 and a gas directing duct 38. The tank 12 has a substantially central flue 14 having an outlet 22 substantially adjacent the top 18 of the tank 12. The tank is adapted for mounting with the flue 14 substantially vertical. The burner 28 is located beneath the tank 12 and is adapted to burn a fuel to discharge heated gases up through the flue 14. The gas directing casing 34 is around at least some of the exterior of the tank 12 and is spaced away from the at least some of the exterior of the tank 12 to define a space 32 between the interior of the casing 30 and said at least some of the exterior of the tank 12. The space 32 has an inlet 34 substantially at or adjacent the bottom 16 of the tank 12 and a relatively higher outlet 42. The gas directing duct 38 is remote from the tank exterior and is adapted to direct the heated gases from the flue outlet 42 to the space inlet 34 without substantial heat transfer from the heated gases in the duct 38 to the tank exterior. The heated gases sequentially flow from the burner 28, up the flue 14, down the duct 30 and through the space 32. A method of heating water in the tank 12 is also disclosed.