Heat exchanger water trap

A method of transferring heat between a discard liquid, selected from the group consisting of wastewater and heated bathing water, and a liquid to be heated without mixing the discard liquid and the liquid to be heated comprising the steps of:

• splitting the discard liquid into a plurality of discard streams,
• introducing a liquid to be heated into a heat exchanger chamber surrounding a plurality of drainpipes being substantially vertically arranged through which the plurality of discard streams passes,
• forcing the liquid to be heated to pass the plurality of drainpipes multiple times,
• releasing the liquid to be heated in a heated state at a gravitationally higher point than when it was introduced,
• collecting and combining the discard streams into a cooled discard liquid, and
• discarding the cooled discard liquid via a weir,
• wherein the heat exchanger chamber comprises a substantially cylindrical shell surrounding the plurality of drainpipes and an inner wall having a longitudinal Z direction positioned within the substantially cylindrical shell.

A method of using a heat exchanger water trap for heating water, comprising the steps of,

• introducing the water to be heated into a heat exchanger chamber surrounding a plurality of drainpipes that are substantially vertically arranged and pass through the heat exchanger chamber, whereby the liquid to be heated is in contact with at least part of the outside surface of said plurality of drainpipes and the heat exchange chamber is defined by a shell, an upper plate, a lower plate at least partially covering an interior of the shell and an inner wall, and wherein the plurality of drainpipes and the inner wall extend in the longitudinal direction Z, and the inner wall is positioned inside the substantially cylindrical shell,
• forcing the water to be heated to pass the plurality of drainpipes multiple times,
• releasing the water to be heated in a heated state at a gravitationally higher point than when it was introduced,
• collecting and combining the discard streams into a cooled discard liquid, and
• discarding the cooled discard liquid via a weir.