A furnace blower assembly includes a blower housing a blower and a motor. The blower is positioned within the housing and is adapted to rotate relative to the housing. The motor is coupled to the blower. The housing defines an outlet having an external periphery and an internal periphery. The external periphery or the internal periphery of the outlet is adapted to be fitted to a portion of the external periphery or the internal periphery of the duct. The outlet defines a longitudinal axis. The outlet has a peripheral edge and a protrusion extending outwardly from the external periphery or the internal periphery of the outlet. The protrusion is spaced from the peripheral edge of the outlet and is adapted to abut the peripheral edge of the duct.

Systems for controlling an exhaust gas fan system. The control system may control one or more components of the exhaust system to optimize system performance and improve energy efficiency. The control system may be designed to maintain a substantially constant pressure in the exhaust header and provide a substantially constant flow through the exhaust fans. The control system is configured to control one or more of: modulation of one or more by-pass dampers; adjustment of the nozzle outlet area; varying the speed of the fans; the number and staging of fans.

A nozzle assembly for a fan unit includes an inner nozzle having a tapered outer diameter and a flow path radially inward from the tapered outer diameter with respect to a longitudinal axis of the nozzle assembly. The flow path is configured to guide a fluid flow and to expel the fluid flow through an inner outlet of the inner nozzle to a surrounding environment. The nozzle assembly also includes an outer nozzle disposed radially outward from the inner nozzle with respect to the longitudinal axis. The outer nozzle and the tapered outer diameter of the inner nozzle define an annular flow path therebetween. The annular flow path is configured to guide the fluid flow and to expel the fluid flow to the surrounding environment through an outer outlet of the outer nozzle. A cross-sectional area of the outer outlet is adjustable via movement of the inner nozzle, the outer nozzle, or both along the longitudinal axis of the nozzle assembly.

A wood pellet stove operable to mount to a wall includes a combustion chamber, a combustion chamber door, and a hopper. The combustion chamber has a front, back, and side. The combustion chamber door is in the front of the combustion chamber. The hopper is mounted at the side of the combustion chamber. The bottom of the hopper is below a top of the combustion chamber, and a top of the hopper is substantially coplanar with the top of the combustion chamber. The stove may also include a sight glass or fuel level monitoring system for determining a fuel level of the hopper without opening the hopper.

A furnace assembly comprising a non-condensing furnace with a draft inducer. The draft inducer includes a permanent magnet electrically commutated motor and a draft inducer blower fan. The motor includes a stator, a rotor, a motor cooling fan, and a controller. The rotor being rotatable relative to the stator, the fan being operatively coupled to the rotor such that rotation of the rotor causes rotation of the fan, the controller being configured to selectively operate the motor in first and second different torque ranges of the rotor, with the first and second torque range operating within a fixed percentage and within a fixed percentage of each other. The controller being configured such during normal operation, the motor is not operable at any torques between the first torque range and the second torque range except during transitionary periods.

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 ventilator (10) comprises a ventilator stator (12) for mounting to a structure and a ventilator rotor (14) for mounting and rotation with respect to the stator. One or more wind drivable elements (44) are mounted to the ventilator rotor. A motor (20) is provided for operation between the ventilator rotor and ventilator stator for selective motor-driven rotation of the ventilator rotor.

Systems and methods are provided for gas furnace systems, including a pressure transducer and optionally one or more pressure switches for efficiently achieving multiple operating modes and/or multiple fuel-to-air mixtures. The pressure transducer may determine a pressure setting at the heat exchanger and based on the pressure value may determine an amount to open a gas valve. As pressure transducer is capable of detecting a range of pressures, multiple different operational modes may be achieved by adjusting the opening of the gas valve depending on the detected pressure. The pressure switches may be used to calibrate and/or confirm the accuracy of the pressure transducer. For example, the output of a pressure switch may be compared to an output of a pressure transducer at a given inductor fan setting to determine whether the pressure transducer is accurate and/or calibrated.

A heat capturing module for obtaining useful energy from waste heat includes an extendable hood directing hot gas through a heat exchange assembly having a plurality of heat pipes. A closed flow loop directs a heat transfer medium through the heat exchange assembly to heat the heat transfer medium, and directs the heated medium for use by an application. In one embodiment, the closed flow loop directs the heat transfer medium through an organic Rankine cycle unit where heat is converted to electrical power. An exhaust system having a variable-speed induction fan induces flow of the hot gas through the heat exchange assembly. The speed of the induction fan may be controlled to maintain a setpoint temperature of the heat transfer medium. The hood may be extended and retracted based on a measured temperature of gas at an intake region of the hood. The module is transportable by truck trailer.