A heat exchanger includes a thermal reservoir, a plurality of grooves formed in the thermal reservoir, and a plurality of fluid tubes. Each of the fluid tubes is disposed in a respective one of the grooves such that it is in thermal contact with the thermal reservoir. In a particular embodiment, the grooves form helices around the outer surface of the thermal reservoir. Additionally, each of the grooves can be formed parallel to the other groove(s) such that each of the process fluid tubes will be disposed in parallel to the other process fluid tube(s). The heat exchanger can also include a heating apparatus and/or a cooling apparatus.

A spiral heat exchanger features: a cold fluid inlet manifold, a hot fluid inlet manifold and at least one spiral fluid pathway. The cold fluid inlet manifold receives cold fluid and provide cold inlet manifold fluid. The hot fluid inlet manifold receives hot fluid and provide hot inlet manifold fluid. The at least one spiral fluid pathway includes cold spiral pathways configured to receive the cold inlet manifold fluid and provide cold spiral fluid pathway fluid, and hot spiral pathways configured to receive the hot inlet manifold fluid and provide hot spiral fluid pathway fluid. The cold spiral pathways and the hot spiral pathways are configured in relation to one another to exchange heat between the cold spiral pathway fluid and the hot spiral pathway fluid so that the hot spiral fluid pathway fluid warms the cold spiral fluid pathway fluid, and vice versa.

A heat exchanger includes a heat exchanger body having a first end and a second end opposed to the first end along a flow axis. A plurality of flow channels is defined in the heat exchanger body extending axially with respect to the flow axis. A first set of the flow channels forms a first flow circuit and a second set of the flow channels forms a second flow circuit that is in fluid isolation from the first flow circuit. Each flow channel is fluidly isolated from the other flow channels. The flow channels all conform to a curvilinear profile.

A heat exchanger arrangement includes walls defining at least two circuit passages for porting a first fluid, a first of the circuit passages defining a first passage length, and a second of the circuit passages defining a second passage length, the second passage length being different from the first passage length, the walls being in thermal communication with a second fluid while isolating the first fluid from the second fluid, at least one of the first circuit passage and the second circuit passage includes a flow control feature configured to decrease an imbalance in flow between the first circuit passage and the second circuit passage compared to if the flow control feature were not present.

A first conduit having a cylindrical upper entrance region with the axis of the cylindrical region oriented vertically, which accepts incoming downwardly flowing hot drain water, a central region of said first conduit below the said entrance region having a conical shape of increasing diameter, reaching a maximum diameter 2-7 times larger than the upper region, the shape then transitioning to a decreasing diameter area of a conical shape, the shape transitioning to a cylindrical lower region with a diameter similar to the upper region diameter; a second conduit for the flow of the shower cold water supply, with a diameter 10-40 times smaller than the maximum diameter of the drain water conduit, and a length 10-40 times longer than the vertical length of the drain water conduit, the second conduit tightly wrapped around the first conduit and in close thermal contact with the first conduit.

A spiral heat exchanger features: a cold fluid inlet manifold, a hot fluid inlet manifold and at least one spiral fluid pathway. The cold fluid inlet manifold receives cold fluid and provide cold inlet manifold fluid. The hot fluid inlet manifold receives hot fluid and provide hot inlet manifold fluid. The at least one spiral fluid pathway includes cold spiral pathways configured to receive the cold inlet manifold fluid and provide cold spiral fluid pathway fluid, and hot spiral pathways configured to receive the hot inlet manifold fluid and provide hot spiral fluid pathway fluid. The cold spiral pathways and the hot spiral pathways are configured in relation to one another to exchange heat between the cold spiral pathway fluid and the hot spiral pathway fluid so that the hot spiral fluid pathway fluid warms the cold spiral fluid pathway fluid, and vice versa.

A heat exchanger. The heat exchanger comprises a plurality of primary fluid tubes configured to carry a primary fluid, a plurality of secondary fluid tubes configured to carry a secondary fluid, and a plurality of intervening layers, each intervening layer being thermally conductive and impermeable to both the primary and secondary fluids. Each intervening layer has one or more of the primary fluid tubes on a first side, and one or more of the secondary fluid tubes on a second side opposite the first side, such that the region between each pair of neighbouring intervening layers contains either primary fluid tubes or secondary fluid tubes, but not both primary and secondary fluid tubes.

A heat exchanger includes a first header tank, a second header tank, and a plurality of tubes. The plurality of tubes is arranged in braided pairs that extend in and are configured to direct a fluid between the first and second header tanks in a first direction. Each of the plurality of tubes have opposing ends that are respectively secured to the first and second header tanks via elbows such that the plurality of tubes are offset from the first and second header tanks.

A heat exchanger arrangement includes walls defining at least two circuit passages for porting a first fluid, a first of the circuit passages defining a first passage length, and a second of the circuit passages defining a second passage length, the second passage length being different from the first passage length, the walls being in thermal communication with a second fluid while isolating the first fluid from the second fluid, at least one of the first circuit passage and the second circuit passage includes a flow control feature configured to decrease an imbalance in flow between the first circuit passage and the second circuit passage compared to if the flow control feature were not present.

A heat exchanger includes a heat exchanger body having a first end and a second end opposed to the first end along a flow axis. A plurality of flow channels is defined in the heat exchanger body extending axially with respect to the flow axis. A first set of the flow channels forms a first flow circuit and a second set of the flow channels forms a second flow circuit that is in fluid isolation from the first flow circuit. Each flow channel is fluidly isolated from the other flow channels. The flow channels all conform to a curvilinear profile.