A draft inducer blower assembly for use with a water heater has a housing, a motor, and a fan. The housing has an exhaust volute surrounding the fan and a base adapted to be mounted atop a water heater. The base has an inlet port adapted to receive exhaust gas from the water heater. The fan is connected to the motor for rotation about a rotation axis. The exhaust volute has a cut-off at a cut-off angle relative to the rotation axis. The exhaust volute has an exhaust outlet passageway that extends to an exhaust port. The exhaust port is lower than the top of the exhaust volute.

A water heater includes a burner generating combustion gas, a heat exchanger heating water which flows through the inside, through heat exchange with combustion gas generated in the burner, a fan supplying air to the burner, and a housing storing these components. The water heater has a water entry portion in a top plate of the housing. A water supply pipe for supplying water to the inside of the heat exchanger is connected to the water entry portion. The water entry portion is arranged to be included, in a plane view, in at least one component constituting the heat exchanger and an exhaust path for combustion gas which has passed through the heat exchanger. The component is made of a material having corrosion resistance against drainage water resulting from condensation of combustion gas.

A vacuum pump includes a vacuum pump having a discharge port to which an abatement part for treating an exhaust gas discharged from the vacuum pump to make the exhaust gas harmless is attached. The vacuum pump includes a cylindrical member having an exhaust gas introduction port for introducing the exhaust gas to be treated and a gas outlet port for discharging gases which have been treated, a plurality of fuel nozzles provided at a circumferential wall of the cylindrical member for ejecting a fuel, and a plurality of air nozzles provided at the circumferential wall of the cylindrical member for ejecting air so as to form a swirling flow of air along an inner circumferential surface of the circumferential wall. The air nozzles are disposed at a plurality of stages spaced in an axial direction of the cylindrical member.

A vacuum pump includes a vacuum pump having a discharge port to which an abatement part for treating an exhaust gas discharged from the vacuum pump to make the exhaust gas harmless is attached. The vacuum pump includes a cylindrical member having an exhaust gas introduction port for introducing the exhaust gas to be treated and a gas outlet port for discharging gases which have been treated, a plurality of fuel nozzles provided at a circumferential wall of the cylindrical member for ejecting a fuel, and a plurality of air nozzles provided at the circumferential wall of the cylindrical member for ejecting air so as to form a swirling flow of air along an inner circumferential surface of the circumferential wall. The air nozzles are disposed at a plurality of stages spaced in an axial direction of the cylindrical member.

A water heater is provided that can suppress backflow (entry) of drainage water into a fan from downstream of the fan in a path of a flow of combustion gas. The fan includes a fan case, an impeller housed within the fan case, a drive source attached to the fan case so as to drive the impeller, and a rotation shaft connecting the impeller and the drive source. An exhaust connection portion has a connection portion case and is provided with an exhaust port for emitting combustion gas delivered from the fan to outside of the water heater. The exhaust connection portion also has a drainage water discharge portion for discharging drainage water accumulated downstream of the fan in the path of the flow of combustion gas.

Compact smoke or air diluter for high-temperature flue gas and contaminated air for being mounted at the top of or integrated in a chimney stack or a ventilation system that dilutes and dissipates high-temperature flue gas or contaminated air in the atmosphere, and ensures a normative draw/sub-atmospheric pressure defined on the basis of preceding requirements to or from connected functional applications consisting of cooling unit/ventilator part: Cooling pipe 9 mounted inserted in cooling top 12. Motor 1 mounted in interior cooling cup 4. The motor shaft is caused to continue out through a circular opening at the bottom of interior cooling cup 4 in a dimension that allows cooling air to pass below the motor 1, past the motor shaft, and out through the opening to exterior cooling cup 5. Between the bottom of interior cooling cup 4 and exterior cooling cup 5, there is, on the motor shaft, securely mounted a cooling medium 8. Through a hole at the bottom of exterior cooling cup 5, the motor shaft is caused to continue, where, at the end, there is mounted a ventilator medium holder 11, on which the ventilator medium 3 is mounted.

A fuel-fired heating appliance comprises a fuel source, an air source, a chamber in which fuel and air mix, a burner downstream from the mixing chamber, an igniter proximate the burner, a heat exchanger, a blower and a flue pipe. An ambient air inlet may be defined by at least one of the outlet end of the blower and the flue pipe extending between the interior of the flue pipe and an area ambient to the flue pipe. A flow rate of combustion gas may be controlled to a level below a steady-state flow rate during appliance warm-up.

A high efficiency heating apparatus for heating fluids and cooking mediums, such as oil or shortening within a fryer, includes a natural draft (non powered) combustion chamber with internal baffles that is affixed to an exterior surface of a fry tank.

A fuel-fired heating appliance comprises a fuel source, an air source, a chamber in which fuel and air mix, a burner downstream from the mixing chamber, an igniter proximate the burner, a heat exchanger, a blower and a flue pipe. An ambient air inlet may be defined by at least one of the outlet end of the blower and the flue pipe extending between the interior of the flue pipe and an area ambient to the flue pipe. A flow rate of combustion gas may be controlled to a level below a steady-state flow rate during appliance warm-up.

A method is provided for controlling combustion in a modulating gas furnace. The method includes receiving an indication of a firing rate setpoint for a burner assembly, and applying the firing rate setpoint to first and second continuous functions that map the firing rate setpoint to air-to-fuel ratio and combustion system pressure setpoints. A variable-speed draft inducer blower is set to drive to a combustion system pressure setpoint, and the modulating gas valve is controlled during combustion in the combustion system. In this regard, a combustion system pressure measurement is obtained and applied to an inverse of the first continuous function that outputs an adjusted firing rate for the combustion system pressure measurement. The adjusted firing rate is applied to a third continuous function that maps the firing rate to gas valve position, and outputs a gas valve position to which the modulating gas valve is set.