A heat exchanger unit according to the present invention comprises: a sensible heat exchanger including a sensible heat exchange pipe disposed in a sensible heat exchange area for heating water used for heating by receiving sensible heat generated by a combustion reaction, wherein the sensible heat exchange pipe receives the water used for heating and flows same through the interior, and a sensible heat fin disposed in the sensible heat exchange area, wherein the sensible heat fin is formed in a plate shape across the sensible heat exchange pipe and penetrated by the sensible heat exchange pipe; and a latent heat exchanger positioned downstream from the sensible heat exchange area on the basis of a reference direction, which is a flow direction of combustion gas generated during the combustion reaction, the latent heat exchanger including a latent heat exchange pipe disposed in a latent heat exchange area.

A tankless water heater includes a scale control module (SCM). The SCM is mounted inside or outside of a cabinet which encloses a heat exchanger and source of heat of the water heater. The SCM may include a connector and a cartridge removably attaching to the connector or may only include a cartridge permanently affixed to the tankless water heater. The tankless water heater includes a continuous water pathway inside the cabinet to supply water to all components of the tankless water heater, including the SCM. The tankless water heater receives supply water at its inlet, treats the supply water in the SCM to generate treated water having reduced scale-forming characteristics compared to the supply water, and heats the treated water in the heat exchanger to generate heated treated water.

A heat exchanger for supplying heat includes a housing, a bundle of helical fin-coil tubes, and a flue channel. The housing includes a burner, a water inlet, a water outlet and a flue gas outlet. The burner is disposed on a top portion of the housing and connected to an air/gas mixture unit. The bundle of helical fin-tube coils is disposed tightly, circularly, and coaxially around the burner. The flue channel is disposed below the burner and is formed by a plurality of serpentine bent fin-tube coils. A flow of flue gas vents from the flue channel to the flue gas outlet. The water inlet is connected to the plurality of serpentine bent fin-tube coils which forms the flue channel below the burner. The plurality of serpentine bent fin-tube coils below the burner are connected to the bundle of helical fin-tube coils. The bundle of helical fin-tube coils are connected to the water outlet.

Provided is a heat exchanger. The heat exchanger may include a plurality first through third heat exchange pipes connected between a first side part and a second side part, each of which comprising a path of moving heat-exchanger fluid inside; first blisters formed on the outer side surfaces of the first side part and the second side part, thereby connecting gaps between each neighboring first heat exchange pipe; second blisters formed on the outer side surface of the first side part, thereby connecting the first heat exchange pipes with the second heat exchange pipes or the second heat exchange pipes with the third second heat exchange pipes; and third blisters formed on the outer side surface of the second side part, thereby connecting neighboring second heat exchange pipes or neighboring third heat exchange pipes. The second heat exchange pipes may be spaced apart from the first heat exchange pipes and formed above the first heat exchange pipes and the third heat exchange pipes may be spaced apart from the second heat exchange pipes and formed above the second heat exchange pipes.

A combined hot water and air heating and conditioning system including a first heat exchanger, a heat pump, a chilling tower loop, a burner and a second heat exchanger to provide hot water, air heating and air cooling. The system provides hot water, air heating and cooling all in one single unit. The system utilizes a heat pump to remove heat from ambient air and transfer the rejected heat into a hot water system, thereby using waste heat to heat the hot water system. The system utilizes a heat exchanger not only for the purpose of transferring heat from a heating source to a fluid in the heat exchanger but also for the purpose of dissipating heat from the fluid in the heat exchanger to the surroundings of the heat exchanger, thereby allowing a heat pump to act both as an air heating and conditioning device.

A tankless water heater includes a scale control module (SCM). The SCM is mounted inside or outside of a cabinet which encloses a heat exchanger and source of heat of the water heater. The SCM may include a connector and a cartridge removably attaching to the connector or may only include a cartridge permanently affixed to the tankless water heater. The tankless water heater includes a continuous water pathway inside the cabinet to supply water to all components of the tankless water heater, including the SCM. The tankless water heater receives supply water at its inlet, treats the supply water in the SCM to generate treated water having reduced scale-forming characteristics compared to the supply water, and heats the treated water in the heat exchanger to generate heated treated water.

A heated flue includes a flue section configured to be fluidly coupled to an exhaust outlet of a boiler. At least one heater is mechanically coupled to the flue section to heat an exhaust gas flowing within. A sensor is mechanically coupled to the flue section or disposed within the flue section. The sensor is configured to measure a parameter of the exhaust gas flowing within. A controller is operatively coupled to the at least one heater and the sensor. The controller is configured to control a temperature of the exhaust gas based on the parameter. A method to vent a condensing boiler into a non-condensing rated stack is also described.

A method and an arrangement for recovering heat from flue gas of a boiler (10). The method comprises passing the flue gas (G) of the boiler though a flue gas cooling unit (1), cooling the flue gas (G) by transferring heat from the flue gas (G) into a circulation (3) of a flue gas cooling liquid (CL), transferring heat energy of said flue gas cooling liquid (CL) into a heat pump (2), and arranging the heat pump (2) for receiving heat energy also from a circulation arrangement (8) of a district cooling system. The heat pump (2) is coupled to a circulation arrangement (6) of a district heating system, wherein the method further comprises transferring in the heat pump (2) heat energy (H) received from said cooling liquid (CL) and from said circulation arrangement (8) of district cooling system into said circulation arrangement (6) of district heating system, for lowering the temperature of said flue gas cooling liquid (CL) and cooling fluid of said district cooling system, and raising the temperature of heating fluid of said district heating system.

A heat exchanger unit according to the present invention includes a sensible heat exchanger including a sensible heat exchange pipe disposed in a sensible heat exchange area for heating water used for heating by receiving sensible heat generated by a combustion reaction, wherein the sensible heat exchange pipe receives the water used for heating and flows same through the interior, and a sensible heat fin disposed in the sensible heat exchange area. The sensible heat fin is formed in a plate shape across the sensible heat exchange pipe and penetrated by the sensible heat exchange pipe; and a latent heat exchanger positioned downstream from the sensible heat exchange area on the basis of a reference direction, which is a flow direction of combustion gas generated during the combustion reaction, the latent heat exchanger including a latent heat exchange pipe disposed in a latent heat exchange area.

A heat exchanger unit according to the present invention comprises: a sensible heat exchanger including a sensible heat exchange pipe disposed in a sensible heat exchange area for heating water used for heating by receiving sensible heat generated by a combustion reaction, wherein the sensible heat exchange pipe receives the water used for heating and flows same through the interior, and a sensible heat fin disposed in the sensible heat exchange area, wherein the sensible heat fin is formed in a plate shape across the sensible heat exchange pipe and penetrated by the sensible heat exchange pipe; and a latent heat exchanger positioned downstream from the sensible heat exchange area on the basis of a reference direction, which is a flow direction of combustion gas generated during the combustion reaction, the latent heat exchanger including a latent heat exchange pipe disposed in a latent heat exchange area.