Patent ID: 8656867

Claim:
A heat exchanger comprising: a generally cylindrical housing comprising a cylindrical wall having an upper section and a lower section, an upper opening, a lower opening, a lumen, and a central longitudinal axis, wherein said lumen connects said upper opening to said lower opening; a generally cylindrical burner comprising an open upper end, a closed lower end and a cylindrical wall connecting said open upper end and said closed lower end, wherein said cylindrical wall comprises a plurality of regularly spaced apart apertures; a helix coil comprising a plurality of coil loops defined by a first coil section, a second coil section and two end coil loops wherein each of said two end coil loops is terminated with an inlet port or an outlet port, a plurality of heat transfer fins, an inner perimeter, an outer perimeter, an external helix coil diameter, a central longitudinal axis and a lumen, wherein said plurality of heat transfer fins are placed in thermal contacting engagement with said plurality of coil loops and said two end coil loops; and a buffer tank comprising a generally cylindrical tank having a top end wall, a bottom end wall, an outer diameter, a central longitudinal axis, a cylindrical wall connecting said top end wall and said bottom end wall, an outlet tube having an opening, and an inlet port, wherein said buffer tank is disposed substantially within said second coil section of said helix coil and said outlet tube extends substantially through said bottom end wall and terminates with said opening of said outlet tube substantially disposed at a distance from a peak of said top end wall and said inlet port is disposed away from said opening of said outlet tube on said bottom end wall; wherein said inlet port of said helix coil receives incoming cold water and outputs heated water via said outlet port of said helix coil, said external helix coil diameter is substantially the same as the diameter of said lumen of said housing, said helix coil is disposed within said housing such that said central longitudinal axis of said helix coil is substantially collinear to said central longitudinal axis of said housing, said first coil section substantially surrounds said burner, said second coil section substantially surrounds said buffer tank, said first coil section is disposed atop said second coil section, and the diameter of said lumen of said helix coil is substantially the outer diameter of said buffer tank.