Reversible draft controllers and exhaust systems incorporating reversible draft controllers are disclosed. One system for controlling draft in a chimney includes a sensor for determining condition data, an axial fan blade, an electronically commutated motor (ECM), and a controller. The ECM is configured to rotate the fan blade in a first direction to increase draft in the chimney and in a second, opposite direction to decrease draft. The controller has a processor and a program of instructions executable by the processor to perform steps for controlling draft in the chimney with the fan blade. The steps include: comparing condition data from the sensor to set point data to determine if an intervention is required; addressing insufficient draft by actuating the ECM to rotate the axial fan blade in the first direction; and addressing excessive draft by actuating the ECM to rotate the fan blade in the second direction.

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 movable steam vent system is provided. The system includes a base and at least one pipe member. The base includes a tapered outer surface defined by an outer wall, a frustoconical inner surface defined by an inner wall, a plurality of ribs extending from the inner surface, the inner wall and the outer wall defining a space therebetween, the base further having an opening in an upper surface, the opening having a slot therein, the opening being in fluid communication with a hollow interior defined by the inner wall, the inner wall having an end that is sized to cover the subsurface space opening. The at least one pipe member is removably coupled to the base, the at least one pipe member having a having an outer wall, an inner wall, the inner wall defining a hollow interior that is in fluid communication with the base hollow interior.

A movable steam vent system is provided. The system includes a base and at least one pipe member. The base includes a tapered outer surface defined by an outer wall, a frustoconical inner surface defined by an inner wall, a plurality of ribs extending from the inner surface, the inner wall and the outer wall defining a space therebetween, the base further having an opening in an upper surface, the opening having a slot therein, the opening being in fluid communication with a hollow interior defined by the inner wall, the inner wall having an end that is sized to cover the subsurface space opening. The at least one pipe member is removably coupled to the base, the at least one pipe member having a having an outer wall, an inner wall, the inner wall defining a hollow interior that is in fluid communication with the base hollow interior.

In a stack leading from a fired heater, a plurality of damper blades are positioned at a longitudinal location, each blade being at least partly rotatable around its longitudinal axis to regulate flow through the stack. A plurality of controllers is operatively associated with the plurality of parallel blades to effect rotation of the blades. At least one of the controllers is decoupled from the rest of the plurality of controllers and used to independently control at least one but not all of the plurality of damper blades. The damper blades can be parallel or opposed.

In a stack leading from a fired heater, a plurality of damper blades are positioned at a longitudinal location, each blade being at least partly rotatable around its longitudinal axis to regulate flow through the stack. A plurality of controllers is operatively associated with the plurality of parallel blades to effect rotation of the blades. At least one of the controllers is decoupled from the rest of the plurality of controllers and used to independently control at least one but not all of the plurality of damper blades. The damper blades can be parallel or opposed.

A blower systems includes a blower housing, a gasket, and a clamp. The blower housing includes a dilution air inlet port having a tubular portion with an end margin having a plurality of flanges separated by slits enabling flexing of the plurality of flanges to resiliently move radially inwardly from an unflexed position. The gasket extends within the end margin of the dilution air inlet port. The air supply system includes an inlet portion, a combustion air portion, and a one-piece fitting having an inlet, dilution air outlet, and a combustion air outlet. The clamp is positioned radially about the plurality of flanges such that it can secure a source of dilution air within the dilution air inlet port.

A water heater system includes a tank for storing water; a flue assembly positioned within the tank, the flue assembly adapted to transfer heat from flue gases within the flue assembly to water in the tank; a burner in fluid communication with an inlet end of the flue assembly and operable in at least a high input mode and a low input mode to deliver the flue gases to the flue assembly, the exhaust assembly having a threshold temperature above which the exhaust assembly is not suitable; and an exhaust assembly including a fan, wherein at least in the low input mode, the flue gases condense in the flue assembly, and wherein operation of the fan reduces a temperature of the flue gases in the exhaust assembly to below the threshold temperature at least in the high input mode.

A furnace inducer choke and a gas furnace employing the furnace inducer choke. In one embodiment, the furnace inducer choke includes: (1) a choke body configured to engage a furnace inducer blower, the choke body having an opening extending entirely therethrough to limit an amount of combustion air entering a furnace that the furnace inducer blower is attached, and (2) a tab protruding from the choke body a distance sufficient to identify the opening when the choke body and furnace inducer blower are installed in the furnace.

A controlled kiln and manufacturing system for biochar production includes control systems and subsystems. An example biochar kiln exhaust apparatus, includes a chimney configured for heating by pyrolysis and for exhausting smoke from the combustion chamber. The example biochar kiln exhaust apparatus also includes a plurality of exhaust inlet pipes configured to pass smoke from the combustion chamber to the chimney.