A heat exchanger tube includes a first pass for at least partially combusting a fuel and the first pass having a modified shape including a minor diameter and major diameter that reduces the external pressure drop of an external fluid flowing across the heat exchanger tube. A HVACR system includes a heat exchanger tube with a first heat exchange pass that at least partially combusts a fuel and has a modified shape. A method of making a heat exchanger including configuring a first heat exchange pass such that the major diameter of modified portion of the first heat exchange pass is oriented towards an incoming direction of the process fluid.

A forced air supply combustion apparatus sucks combustion air from an air supply port. An air filter for collecting foreign matters in the air is mounted on an air-supply-port-formed plate in an insertable and drawable manner. A filter frame is arranged to be brought into close contact with a peripheral part of the air supply port in a state of having mounted the air filter in position. The air-supply-port side edge parts are provided with retaining pieces to clamp a filter side frame part in the Z-axis direction against the side edge parts. A distance in the Z-axis direction between the air-supply-port side edge parts, and the retaining pieces is set larger than a dimension, in the Z-axis direction, of the filter side frame part, and is set smaller than a sum of the dimensions to be obtained by adding to said dimensions the projection height of the projections provided in a projecting manner.

An air heating apparatus includes a burner configured to cause combustion reaction, a heat exchange part configured to receive heat from a combustion gas generated by the combustion reaction so as to heat water, a heating heat exchanger configured to receive the water heated by the heat exchange part so as to be heat-exchanged with air to be discharged for heating, a fan configured to blow the air to the heating heat exchanger, a condensed water receiver configured to collect and discharge condensed water generated in the heat exchange part, a case in which the burner, the heat exchange part, the heating heat exchanger, the fan, and the condensed water receiver are embedded, and a condensed water trap disposed outside the case and configured to receive the condensed water transferred from the condensed water receiver so as to provide a trap configured to block leakage of the combustion gas.

A furnace has a cabinet having at least one wall at least partially defining an interior space of the cabinet, a heat exchanger disposed in the interior space, and a protrusion formed integrally with the at least one wall, the protrusion extending generally inward into the furnace to at least partially obstruct a circulation airflow through the cabinet.

A water heater has a water supply line, a heat exchanger in fluid communication with the water supply line, a heating element positioned proximate to the heat exchanger, such that when activated, the heating element conveys heat to the heat exchanger and thereby heating water supplied by the water supply line, an output line in fluid communication with the heat exchanger and configured to receive heated water therefrom, a flow sensor configured to cause the heating element to activate in response to sensing a predetermined water flow rate through the water heater, and a bypass flow line operably connected between the water supply line and the output line.

A water heater includes a burner, a heat exchanger, a passing water quantity control unit, a temperature detection unit, and an operation control unit. The operation control unit performs the output hot water temperature control by configuring the passing water quantity control unit to have a predetermined passing water quantity that is further restricted compared with a predetermined water quantity, and upon confirmation that a predetermined release condition of the passing water restriction is satisfied, executes the passing water control in which the passing water quantity is returned back to the predetermined water quantity by gradually releasing the passing water restriction, and the operation control unit, when a predetermined undershoot factor of the detected temperature is confirmed while the passing water quantity is returned back to the predetermined water quantity, temporarily stops the release of the restriction of the passing water quantity until the undershoot factor is resolved.

A heat exchanger tube includes a first pass for at least partially combusting a fuel and the first pass having a modified shape including a minor diameter and major diameter that reduces the external pressure drop of an external fluid flowing across the heat exchanger tube. A HVACR system includes a heat exchanger tube with a first heat exchange pass that at least partially combusts a fuel and has a modified shape. A method of making a heat exchanger including configuring a first heat exchange pass such that the major diameter of modified portion of the first heat exchange pass is oriented towards an incoming direction of the process fluid

A forced air supply combustion apparatus sucks combustion air from an air supply port. An air filter for collecting foreign matters in the air is mounted on an air-supply-port-formed plate in an insertable and drawable manner. A filter frame is arranged to be brought into close contact with a peripheral part of the air supply port in a state of having mounted the air filter in position. The air-supply-port side edge parts are provided with retaining pieces to clamp a filter side frame part in the Z-axis direction against the side edge parts. A distance in the Z-axis direction between the air-supply-port side edge parts, and the retaining pieces is set larger than a dimension, in the Z-axis direction, of the filter side frame part, and is set smaller than a sum of the dimensions to be obtained by adding to said dimensions the projection height of the projections provided in a projecting manner.

A housing includes a back plate portion, a pair of side plate portions which extend forward from both side ends of the back plate portion, and a front opening. A chamber is arranged inside the housing and includes a first attachment surface 31ba inclined with respect to the back plate portion in a plan view and an intake port which opens forward in the first attachment surface. A fan includes a second attachment surface provided with an emission port and is attached to the chamber in a state in which the second attachment surface is opposed to the first attachment surface to communicate the emission port with the intake port of the chamber.

It is common in heating systems, such as in a hot water heater for there to be a combustor with the exhaust gases from the combustor provided to a heat exchanger to heat up the water. Disclosed herein is an integrated heat exchanger and burner assembly in which the combustion occurs proximate the surface of the heat exchanger. Such a system may include at least one tube that is coiled into a number of turns, that is a tube coil with the at least one tube having an inlet and an outlet and the distance between adjacent turns is less than a predetermined distance, i.e. a the quench distance.