Patent ID: 6880547

Claim:
A water heater comprising: a generally cylindrical, horizontally disposed external enclosure, a corrugated internal enclosure located concentrically within said external enclosure, said internal enclosure forming a combustion chamber, said corrugations increasing said internal enclosure surface area by a factor 1.3 to 5 by comparison to a smooth cylindrical wall of the external enclosure type, a region between said external and said internal enclosures defining a circulation chamber, wherein water may circulate and absorb heat from said combustion chamber, said circulation chamber comprising a water inlet for supplying water into said circulation chamber and a water outlet for channelling water out of said circulation chamber, said outlet being disposed oppositely to said inlet in order to optimize water displacement within said circulation chamber, said internal enclosure surface area increase thus maximizing heat transfer from said combustion chamber to said circulation chamber, a rear face and a front face, disposed oppositely one to the other at each end of said external enclosure, a door in said front face for inserting a fuel like wood into said combustion chamber, means for exhausting combustion fumes from said combustion chamber, means for channelling water from and towards a region of use.