Abstract: A water heater includes a heat exchanger. A controllable three-way proportional valve provides a proportionally controllable flow to the hot water inlet of the heat exchanger and a boiler return water outlet. A mixing tank mixes a cold water and a hot water. The mixing tank provides a time delayed mixed water. A temperature sensor is disposed in or on the mixing tank to measure a temperature of the time delayed mixed water to provide a time delayed mixed water temperature. A feedforward control process running on a processor adjusts a proportional operating position of the controllable three-way proportional valve to regulate a temperature of hot water at the hx domestic hot water outlet based on the temperature of the time delayed mixed water temperature. A method for controlling a hot water temperature of a water heater a water heater using a flowmeter based feedforward control are also described.

Abstract: A water heating apparatus includes a water inlet port and a hot water supply connection water outlet port. A burner assembly includes a burner disposed within a combustion chamber housing. At least two heat exchangers are operated in parallel. At least two of the at least two heat exchangers have at least a first heat exchanger water inlet port on a same side of the water heating apparatus. A water jacket is defined by an area between an outer containment vessel and the combustion chamber housing. The heated water flows out of each of each of the at least two heat exchangers through the portion of each of the at least two heat exchangers into the water jacket. The heated water which flows into the water jacket is further heated by the combustion chamber housing and the further heated water exits the water heating apparatus at the hot water supply connection water outlet port.

Abstract: A heat transfer device for transferring heat energy to or from a gas or fluid flowing radially across a plurality of posts or tubes includes a plate having a plate surface. A plurality of posts or tubes are disposed on and protrude substantially perpendicular to the plate surface. At least about 50% of the plurality of posts or tubes are disposed according to a phyllotaxis layout. Each arc of a plurality of phyllotaxis spiral arcs of the phyllotaxis layout terminates at different locations along an arc radius on the plate at a phyllotaxis arc termination radius less than a perimeter radius.

Abstract: A water heating apparatus includes a fluid inlet conduit configured to split into a plurality of supply legs, and a plurality of heat exchangers configured for parallel operation. Each heat exchanger includes an outer housing, an inlet connected to a respective supply leg of the fluid inlet conduit for receiving an inlet flow of liquid into the outer housing, an outlet for allowing an outlet flow of liquid to leave the outer housing, and a heat exchange element positioned within the outer housing and configured to heat a flow of liquid passing through the outer housing from the inlet to the outlet. The water heating apparatus further includes a burner assembly comprising a combustion chamber housing and a burner positioned internally within the combustion chamber housing. The burner assembly is coupled to the plurality of heat exchangers for supplying heat to the flow of liquid.

Abstract: An igniter assembly includes a bushing for installation in a burner. The bushing has a proximal end and an opposing distal end. A gas tube is secured through a central portion of the bushing, and an electrode assembly is secured through the central portion of the bushing. The electrode assembly includes an electrically conductive conductor element and an insulator element in surrounding relationship to the conductor element. The igniter assembly further includes a flame holder element secured to a distal end of the electrode assembly, and a ground rod secured to the electrode assembly. A distal end of the ground rod defines a spark gap with the flame holder element.

Abstract: A water heating system includes a burner assembly for providing a source of thermal energy to a heat exchanger. A water inlet conduit is coupled to the heat exchanger assembly for supplying fresh water to be heated, and a water exit conduit is coupled to the heat exchanger assembly for delivering the heated water to a point of use. A bypass conduit connects the water exit conduit to the water inlet conduit, and a pump disposed in the bypass conduit circulates at least a portion of the heated water from the water exit conduit to the water inlet conduit. A feed-forward sensor positioned in the water inlet conduit between the heat exchanger assembly and the bypass conduit monitors a parameter of the water entering the heat exchanger assembly, and a processor controls the operation of the of the burner assembly in response to the feed-forward sensor.

Abstract: Water heating system and method including a boiler, a combustion chamber, and a burner housed inside the chamber. A conduit fluidly coupled to the combustion chamber to channel gas into the chamber wherein the burner causes combustion of gas. An oxygen sensor is coupled to the chamber and positioned within the chamber to detect an amount of oxygen in the products of combustion. The oxygen sensor outputs data representative of the amount to a control unit. The control unit controls the feedback control of the water heating system and wherein the combustion of the gas in the chamber is controllable by the control unit at least based on the data. A heat exchanger system is coupled to the chamber to heat water in the heat exchanger with the products. At least one flue coupled to the heat exchanger system to channel products out of the heat exchanger system.

Abstract: A water heating apparatus includes a fluid inlet conduit configured to split into a plurality of supply legs, and a plurality of heat exchangers configured for parallel operation. Each heat exchanger includes an outer housing, an inlet connected to a respective supply leg of the fluid inlet conduit for receiving an inlet flow of liquid into the outer housing, an outlet for allowing an outlet flow of liquid to leave the outer housing, and a heat exchange element positioned within the outer housing and configured to heat a flow of liquid passing through the outer housing from the inlet to the outlet. The water heating apparatus further includes a burner assembly comprising a combustion chamber housing and a burner positioned internally within the combustion chamber housing. The burner assembly is coupled to the plurality of heat exchangers for supplying heat to the flow of liquid.

Abstract: An igniter assembly includes a bushing for installation in a burner. The bushing has a proximal end and an opposing distal end. A gas tube is secured through a central portion of the bushing, and an electrode assembly is secured through the central portion of the bushing. The electrode assembly includes an electrically conductive conductor element and an insulator element in surrounding relationship to the conductor element. The igniter assembly further includes a flame holder element secured to a distal end of the electrode assembly, and a ground rod secured to the electrode assembly. A distal end of the ground rod defines a spark gap with the flame holder element.

Abstract: Water heating system and method including a boiler, a combustion chamber, and a burner housed inside the chamber. A conduit fluidly coupled to the combustion chamber to channel gas into the chamber wherein the burner causes combustion of gas. An oxygen sensor is coupled to the chamber and positioned within the chamber to detect an amount of oxygen in the products of combustion. The oxygen sensor outputs data representative of the amount to a control unit. The control unit controls the feedback control of the water heating system and wherein the combustion of the gas in the chamber is controllable by the control unit at least based on the data. A heat exchanger system is coupled to the chamber to heat water in the heat exchanger with the products. At least one flue coupled to the heat exchanger system to channel products out of the heat exchanger system.

Abstract: A water heating system includes a burner assembly for providing a source of thermal energy to a heat exchanger. A water inlet conduit is coupled to the heat exchanger assembly for supplying fresh water to be heated, and a water exit conduit is coupled to the heat exchanger assembly for delivering the heated water to a point of use. A bypass conduit connects the water exit conduit to the water inlet conduit, and a pump disposed in the bypass conduit circulates at least a portion of the heated water from the water exit conduit to the water inlet conduit. A feed-forward sensor positioned in the water inlet conduit between the heat exchanger assembly and the bypass conduit monitors a parameter of the water entering the heat exchanger assembly, and a processor controls the operation of the of the burner assembly in response to the feed-forward sensor.

Abstract: A water heating system having an electric heater and an automatic temperature control system having high dynamic response for supplying water on demand at a substantially constant, controlled temperature is provided. The device includes a heat exchanger, and inlet diverting pipe, an outlet diverting pipe, a mixed flow pipe and a temperature control system. A tuning valve on each of the inlet flow diverting pipe and the outlet flow diverting pipe controls the ratio of heated and unheated flow entering the mixed flow pipe. The temperature control system controls the temperature of the water by establishing an empirical, monotonic relationship between the current applied to the heater and the temperature of the mixed flow.