Abstract: A system and method are provided for evacuating fuel from a closed-loop fuel rail after engine testing. The method includes coupling a coaxial hose to a closed-loop fuel rail of an engine. The coaxial hose defines an outer tube section defining an outer passage and surrounding an inner tube section defining an inner passage, and a portion of the inner tube section is inserted a predetermined distance into the fuel rail. The method includes transferring fuel from a fuel supply through the outer passage of the coaxial hose and into the fuel rail for use during an engine testing procedure. After the engine testing procedure is complete, the method includes injecting compressed gas through the inner passage and into the fuel rail, creating a positive pressure. Residual fuel is evacuated from the fuel rail out through the outer passage of the coaxial hose.

Abstract: Responsiveness is improved in valve opening and valve closing of an electromagnetically driven intake valve unit in which a valve is provided on a pressurizing chamber side of a valve seat. The valve includes an annular abutting surface that abuts the valve seat to shut off a fuel intake passage and a bottomed cylindrical part provided at an inner peripheral part of the annular abutting surface. The bottomed cylindrical part is inserted into a fuel introduction hole formed in the valve housing inside the valve seat, and the outer surface of an end part of the bottomed cylindrical part is exposed to fuel in a low pressure fuel chamber provided upstream of the fuel introduction hole.

Abstract: A system according to the principles of the present disclosure includes a fuel injector cleaning module and a fuel control module. The fuel injector cleaning module generates an instruction to clean a fuel injector of an engine based on engine operating conditions. The fuel control module, in response to the injector clean instruction, controls the fuel injector to perform N fuel injections for each combustion event in a cylinder of the engine and, during each of the N fuel injections, deactivates the fuel injector before the fuel injector fully opens. N is an integer greater than one.

Abstract: The invention relates to a starting device (10) for an internal combustion engine, the starting device (10) comprising a hub (12; 70) configured to drivingly engage an internal combustion engine when the hub (12; 70) is rotated in a first direction (A); a pulley (14; 47; 60) interconnected with the hub (12; 70) by a spring (23; 41); a shaft (21) on which the pulley (14; 47; 60) and hub (12; 70) are mounted independently rotatable; a flexible member (16) attached to and coiled about the pulley (14; 47; 60); and where the spring (23; 41) coupled at a first end (26; 53) to the hub (12; 70) and at a second end (28; 54) to the pulley (14; 47; 60). The pulley (14; 47; 60) comprises a recess (15) arranged to receive the flexible member (16), which recess has the shape of a conical helix having a first end (15A) with a first diameter and a second end (15B) with a second diameter, larger than the first diameter; and is attached to the pulley (14; 47; 60) at the second end (15B).

Abstract: A starter has a high voltage direct current electric motor, a speed reduction device, a clutch, an output gear and a switch box configured to turn on the electric motor. The output gear is driven by the electric motor via the speed reduction device and the clutch. The starter also has a stationary axle on which the output gear is installed. The electric motor has an output shaft. The speed reduction device has a drive gear fixed to the output shaft and a driven gear meshed with the drive gear, the driven gear being rotatably mounted to the axle via a bushing.

Abstract: A power supply device for a vehicle which is used in a vehicle, includes: a first switch unit that is provided between a power generator which is driven by an internal combustion engine of the vehicle and a secondary battery which is connected to the power generator and supplies electric power to a starting device for starting the internal combustion engine; a second switch unit that is provided between the power generator and a capacitor which accumulates electric power supplied by the power generator; and a control unit that controls the connection state of the first switch unit and the connection state of the second switch unit.

Abstract: A starter control apparatus outputs a conduction command to a starter relay when an engine start request is generated and starts driving of a starter. After the engine is started, when a condition for executing the failure diagnosis processing is satisfied, the starter control apparatus outputs a non-conduction command to a starter cutoff relay and diagnoses the starter cutoff relay for failure. The starter control apparatus determines that the starter cutoff relay is normal when a voltage applied to the starter after notification of the non-conduction command to the starter cutoff relay does not exceed a predetermined voltage. The starter control apparatus determines that the starter cutoff relay is abnormal when the voltage applied to the starter exceeds the predetermined voltage.

Abstract: A control apparatus, which is for an internal combustion engine with a spark plug having a center electrode and a ground electrode disposed so as to form a spark discharge gap therebetween, includes a voltage applying section for applying a voltage to the spark discharge gap, a constant-voltage path including a constant-voltage element parallel-connected to the spark discharge gap of the spark plug for preventing the spark discharge gap from being applied with a voltage higher than a set voltage, and an operation control circuit for controlling an operating condition of the internal combustion engine. The operation control circuit is configured to measure a current-flowing time during which a current flows through the constant-voltage path when a voltage higher than the set voltage is applied to the constant-voltage path, and change the operating condition of the internal combustion engine in accordance with the measured current-flowing time.

Abstract: A method for operating a combustion engine is disclosed. In an embodiment, the method includes: generating several sparks to ignite a fuel-air mixture in a combustion chamber by an ignition device of the combustion engine, determining a combustion duration of at least one of the sparks, detecting a deviation of an actual operation from a target operation of the combustion engine at least depending on the combustion duration, compensating for the deviation by implementing at least one measure which influences a combustion of the fuel-air mixture in the combustion chamber, determining the combustion duration of the chronological first of the sparks, allocating the first spark to a first spark type or to a second spark type depending on the combustion duration, and implementing the at least one measure if at least one value which characterizes a frequency of one of the spark types exceeds a threshold value.

Abstract: A method for controlling a corona ignition system in which a corona discharge is produced at an ignition electrode by exciting a resonating circuit with an AC voltage produced by a high-frequency generator. The AC voltage is adjusted to a target value depending on an operating state of the engine. Combustion onset is determined by evaluating an electrical variable of the resonating circuit and the target value of the AC voltage is reduced by a predefined value following a predefined number of engine cycles or a predefined operating period. The determined combustion onset is evaluated in one or more engine cycles. The target value for the momentary engine operating state is then increased if, by evaluation of the combustion onset, it is found that a predefined requirement is no longer met. Otherwise, the reduced target value is stored as a new target value for the momentary engine operating state.

Abstract: An underwater pumped storage power plant that includes: an accumulator system with pressure vessels fillable with water and; a water outlet for water flow out of the system into a surrounding ocean against hydrostatic water pressure (PT) corresponding to water depth (T); a pump at the water outlet to pump water out of the system by converting electrical energy into potential energy corresponding to a displaced water column PT; a water inlet to allow water flow into the system from the surrounding ocean; a common generator at the water inlet, to convert the potential energy back into electrical energy when water flows in; electric lines to transport the electrical energy from the ocean surface to the power plant and back, wherein the pressure vessels are pressure-resistant and resistant to deformation from the PT at the ocean floor.

Abstract: A wave energy converter (WEC) 10 has a body portion 18 with a face 20 and at least one flexible membrane 16 bounding at least part of a volume of a fluid to form a variable volume cell 22. The membrane is inclined from vertical providing a flow smoothed passage for wave energy from a wave 14 to travel over the WEC whilst deforming the at least one membrane towards the body to compress the fluid. The cell(s) can be submerged or floating. The inclination of the at least one membrane assists conversion of potential and kinetic energy of the wave to pressure within the fluid. Fluid pressure within the WEC cell(s) and/or system can be optimised to suit wave and/or performance conditions.

Abstract: A wind turbine having a rotor blade geometric design which reduces blade loads in particular, blade root bending moments, tilt moments and yaw moments.

Abstract: A rotor blade of a wind turbine with a first rotor blade segment and a second rotor blade segment is provided. The rotor blade has a hollow space surrounded by a shell. The first rotor blade segment is connected with the second rotor blade segment by a bolt connection. The bolt connection has a first connection of the first rotor blade segment, a second connection of the second rotor blade segment, and a bolt establishing a bolted joint between the first connection and the second connection. At least the bolt is situated in the hollow space of the rotor blade. Furthermore, a method of connecting a first rotor blade segment of a rotor blade of a wind turbine and a second rotor blade segment of the rotor blade is provided.

Abstract: A blade for a wind turbine can include an elongated and curved sheet having a curved root, a curved tip, a leading edge, and a trailing edge. The root and the tip can be rotated relative to each other such that the blade is twisted along its length. The root can include an edge having curved projections, the curved projections being distributed along a curvature of the root. A wind turbine can include a mounting element and a plurality of turbine blades. Each turbine blade can be attached to the mounting element closer to the trailing edge than to the leading edge such that an intersection of the leading edge and the root projects upstream from the wind turbine. A wind turbine generator assembly for converting wind into electrical energy can include a wind turbine and a generator. In addition, a support structure can support the wind turbine and generator.

Abstract: An assembly of rotor blades and hub for a turbine, such as a tidal current turbine. Each rotor blade includes a cavity and at least two ribs extending into the cavity at a radially inward (lower) region of the rotor blade. The hub includes a journal for each blade and the journal extends into the cavity and is supported by the at least two ribs.

Abstract: The invention provides a vertical axis wind turbine to produce power relative to wind speed resulting in high torque output. During operation, all the blades of the turbine are in a continuous movement of changing their angles from fully open to fully overlap position during each rotation. At the heart of this concept is a frame circumventing the rotor, formed of a pair of top coaxial rings superimposed over bottom coaxial rings defining a central vertical axis distant from the shaft axis, each pair of top and bottom rings are freely movable by being mounted on bushings to the shaft by radially disposed beams and vertically disposed mounting members fixedly connecting the top and bottom rings. The Blade angle relative to incoming wind is controlled by these pair of rings which are controlled by the pair of weathervanes rotating on the central turbine shaft axis.

Abstract: A blade comprises a first blade surface, a second blade surface forming the reverse surface of the first blade surface, a front edge portion connected to the front end of the first blade surface and the front end of the second blade surface and formed in a curved shape convex toward the travelling direction, and a back edge portion connected to the back end of the first blade surface and the back end of the second blade surface extending toward the opposite of the travelling direction, and formed in an acute angle, and the blade is formed to be curved in an arc viewed from the side of the travelling direction.

Abstract: An upwind wind turbine comprising a tower and a rotor is described. The wind turbine additionally includes a pressure-sensing device supported by the tower at a location within the wake of the rotor. The pressure-sensing device is configured to sense air pressure and provide a signal indicative of the sensed air pressure to a wind turbine controller for use in controlling the rotor of the wind turbine.

Abstract: In a first aspect, the present invention provides a blade pitch system for a wind turbine, comprising at least one multi winding motor comprising a main independent set of control windings and at least one auxiliary independent set of control windings; and at least a main independent power electronic converter for controlling the main independent set of control windings, and an auxiliary independent power electronic converter for controlling the auxiliary independent set of control windings.

Abstract: The present invention relates to methods and apparatus for operating a safety system in a floating wind turbine. The floating wind turbine comprises one or more sensors 202, 203, and receives a fore-aft inclination signal from the sensor 202, wherein the fore-aft inclination signal indicates an inclination of said floating wind turbine in a fore-aft direction. A side-to-side inclination signal is also received from the sensor 203, wherein the side-to-side inclination signal indicates an inclination of said floating wind turbine in a side-to-side direction. An operational parameter of the floating wind turbine is altered based on either or both of said fore-aft inclination signal and said side-to-side inclination signal.

Abstract: The present disclosure is directed to a system and method for controlling a wind farm. The method includes operating the wind farm based on multiple control settings over a plurality of time intervals. A next step includes collecting one or more wind parameters of the wind farm over the plurality of time intervals and one or more operating data points for each of the wind turbines in the wind farm for the plurality time intervals. The method also includes calculating a contribution of the operating data points for each of the wind turbines as a function of the one or more wind parameters. Further steps of the method include estimating an energy production for the wind farm for each of the control settings based at least in part on the contribution of the operating data points and controlling the wind farm based on optimal control settings.

Abstract: A direct driven wind turbine and a main bearing used in such a wind turbine is provided. A rotor of the wind turbine is directly connected with a rotating drive train of the wind turbine, the rotating drive train is directly connected with a rotor of an electrical generator of the wind turbine. The rotating drive train is connected with a stationary part of the wind turbine via at least one bearing, which allows the rotation of the drive train in relation to the stationary part. The at least one bearing is a plain bearing and the bearing is a tapered bearing, which comprises at least one conical shaped sliding surface.

Abstract: The invention is on the one hand a power generating apparatus exploiting wind energy, comprising a body (10), a main rotor unit (12) comprising a front rotating part being fitted with front blades being adjustable at an angle, and a rear rotating part being fitted with rear blades adjustable at an angle, said front rotating part and rear rotating part have rotation axes aligned parallel to each other, preferably being coincident with each other, a blade adjustment unit being adapted for adjusting of the front blades and the rear blades to rotate in opposite directions, a cable (18) enabling kiting of the body (10), a generator unit adapted for generating electric power from rotation of the front rotating part and the rear rotating part, and a wire adapted for conducting electric power generated by the generator unit, and the main rotor unit (12) is arranged in an opening (11) of and coupled to the body (10), and the main rotor unit (12) comprises blades being turnable into a covering position covering at leas

Abstract: Systems and methods for generating electricity using solar panels to power compressor fans that force air into a nacelle that turns a spiral turbine. The turbine is connected to a gearing system that is connected to a generator. The generator is connected to a master control unit and a transformer. The master control unit decides whether to store the electricity in batteries, power the compressor fans or send the surplus electricity to the grid. The horizontal or vertical embodiments of the invention do not require a tower or the long blades connected to a hub.

Abstract: Lightning protection system (LPS) with an integrated anti-icing system for wind turbine blades that comprises a smart protection system (10), an integrated IPS characterized by some conductive sheets (13) embedded in the carbon laminate of the wind turbine blade (1), some overvoltage dischargers (11) installed between the conductive sheets (13) of the IPS and the downlead cable (2) for the lightning protection system (LPS) and an external receptor frame (17).

Abstract: A contribution is made to the assembly of a wind turbine intended to comprise, in a final assembly condition, a tower (2) surmounted by a nacelle (4) cooperating with a rotor (5) receiving a plurality of blades (3a-3c). To this end, a temporary association is made between at least some blades from said plurality of blades and the tower, so that said blades extend substantially in the longitudinal direction of the tower.

Abstract: A wind turbine having one or more magnets for reducing friction between the turbine support and a turbine rotor. The reduction of friction between the turbine rotor and the turbine support allows for an increase in energy production and scale of the wind turbines. The magnet configuration employs a ring of cylindrically-shaped magnets at the bottom and opposed by a corresponding number of generally rectangular-shaped magnets. Bearing magnets are also employed for axial stabilization.

Abstract: An energy storage system comprises a cable (13) and a mass 20 suspended from the cable (13) in a shaft (12). The cable (13) is attached to a winch 11 by which the mass may be raised in the shaft (12) to store potential energy, and the mass is lowerable in the shaft (12) to release the potential energy. The mass comprises at least two sections clamped together around the cable (13). More particularly, the system comprising a plurality of cables (13) and a plurality of multi-section masses each suspended in the shaft (12) by a respective cable (13), the masses being raised and lowered in synchronism in the shaft (12). The multi-section masses fit together side-by-side in the shaft (12) to form an overall cylindrical mass body, the multi-section masses each forming a quadrant of the cylindrical mass body.

Abstract: A method for generating a steam cycle at a pressure around 200 bars and a temperature around 600° C., using an industrial steam generator with a solar receiver admitting an incident solar flux around 600 kW/m2, includes: generating a water-steam mixture in the evaporator by transferring heat from the incident solar flux onto the evaporator; separating the water-steam mixture into saturated water and saturated steam in the separator drum, the saturated steam having a pressure from 160 to 200 bars and a temperature from 347 to 366° C.; injecting the feed water into the mixing drum, where it is mixed with the saturated water from the separator drum, the mixed water next returning toward the evaporator via the return pipe provided with the circulation pump, such that the temperature of the mixed water entering the evaporator is below the saturated steam temperature, by a value from 5 to 15° C.

Abstract: An offshore power generation structure comprising a submerged portion having a first deck portion comprising an integral multi-stage evaporator system, a second deck portion comprising an integral multi-stage condensing system, a third deck portion housing power generation equipment, cold water pipe; and a cold water pipe connection.

Abstract: A high-pressure fuel supply pump includes a plunger, a valve member, a valve seat, a pressurizing chamber, and a fuel passage. The fuel passage includes a gap passage portion formed in a gap between the valve seat and the valve member. The fuel passage also includes a bent passage portion extending in a bent direction with respect to the gap passage portion, on the downstream side of the gap passage portion. The inner surface of the valve member, on a side thereof that faces the valve seat, has a convex shape in an area of the valve member that is between the bent passage portion and the gap passage portion.

Abstract: An apparatus for connecting a resilient member 1 to a magnetic actuator 2 of a linear compressor. The apparatus includes at least one support member 6 cooperating with a resilient element 1, the support member 6 includes a substantially cylindrical part equipped with intermediate perimeter salient portion 61; at least one fastening element 7 cooperating with the support member 8 and the magnetic actuator 2, and enabling interconnection between a magnetic actuator 2 and a resilient member 1 of a detachable and electrically insulated linear compressor, the fastening element 7 being made in electrically insulating and non-magnetic material.

Abstract: A swash plate type variable displacement compressor includes a housing having therein a suction chamber, a discharge chamber, a swash plate chamber and a cylinder bore. The compressor further includes a drive shaft and a swash plate that is mounted on the drive shaft for rotation therewith. The compressor further includes a link mechanism, a piston, a conversion mechanism, an actuator and a control mechanism. The actuator includes a partitioning body, a moving body and a pressure control chamber formed between the partitioning body and the moving body into which a refrigerant is introduced from the discharge chamber for moving the moving body. A connecting member and a connecting unit are disposed on radially opposite side of the drive shaft. The compressor further has an urging member that urges the moving body that reduces the inclination angle of the swash plate.

Abstract: A roller assembly comprises a central section with a hub; a plurality of arms coupled to the central section, each arm having a radial section, an arcuate section, and a bent section; and a plurality of rollers, one roller coupled to the bent section of each arm. The arms may be flexible such that the rollers are capable of moving with respect to the central section when the arms flex. The rolling surface of the rollers is arranged to engage a polymer sheet or flexible tubing throughout travel of the arms.

Abstract: A roller assembly comprises a central section with a hub; a plurality of spring assemblies coupled to the central section; a plurality of arms coupled to the central section such that each arm is capable of pivoting independently with respect to the central section; and a plurality of rollers, one roller coupled to each of the plurality of arms. Each roller may be coupled to each arm with a pin.

Abstract: A two-cavity pump having a single valve in one cavity and a bidirectional valve in another cavity is disclosed. The pump has a side wall closed by two end walls for containing a fluid. An actuator is disposed between the two end walls and functions as a portion of a common end wall of the two cavities. The actuator causes an oscillatory motion of the common end walls to generate radial pressure oscillations of the fluid within both cavities. An isolator flexibly supports the actuator. The first cavity includes the single valve disposed in one of a first and second aperture in the end wall to enable fluid flow in one direction. The second cavity includes the bidirectional valve disposed in one of a third and fourth aperture in the end wall to enable fluid flow in both directions.

Abstract: A fluid-working machine has a working chamber of cyclically varying volume, high and low pressure manifolds, and high and low pressure valves for regulating the flow of fluid between the working chamber and the high and low pressure manifolds respectively. A controller actively controls at least one said valve to determine the net displacement of working fluid of the working chamber on a cycle by cycle basis. At least one said valve is a variable timing valve and the controller causes the valve to open or close at a time determined taking into account one or more properties of the performance of the fluid working machine measured during an earlier cycle of working chamber volume.

Abstract: An improved air compressor includes a cylinder fitted with a piston body and an air storage container. The cylinder and the air storage container are detachably assembled to define an air chamber. A metal seat with a through hole is provided on top of the cylinder. A valve plug is spring-biased against the metal seat. The air storage container is provided with a pressure indicator, which includes a tube defining therein a first bore and a second bore, between which a tapered annular surface is formed. When the air pressure within the air storage container exceeds a predetermined pressure set for the air compressor, the pressure indicator allows excess air to flow into the first bore of the tube and sequentially pass through the tapered annular surface and an elongated opening to be released to the ambient environment, so that objects can be prevented from damages due to excessive inflations.

Abstract: Apparatus and methods for detecting pump defects in a pumping system comprising multiple pumps. Each pump includes a pump fluid outlet fluidly connected with the pump fluid outlet of the other pumps. Pump defects are detected by generating information related to fluid pressure fluctuations at each pump fluid outlet and determining harmonic frequencies from the information related to fluid pressure fluctuations for each of the plurality of pumps. The amplitude of the harmonic frequencies is indicative of a defective one of the plurality of pumps.

Abstract: A removable cartridge for use with a liquid diffusion device is provided. The removable cartridge includes a cartridge housing defining an internal housing cavity, partially filled with a liquid to be diffused, and a diffusion head positioned within the internal housing cavity with a venturi device for generating diffused liquid from the liquid contained in the internal housing cavity. The diffusion head defines at least a portion of a gas supply conduit that extends from a bottom end of the removable cartridge to the venturi device through the liquid to be diffused to enable the venturi device to be supplied with pressurized gas from an external source via the bottom end of the removable cartridge.

Abstract: A pump sleeve includes a tubular body extending from a first end to a second end along a center axis. A first hole is formed in the tubular body and is positioned axially on the tubular body between the first end and the second end. A second hole is formed in the tubular body, the second hole being axially aligned on the tubular body with the first hole. A third hole is formed in the tubular body and is positioned axially on the tubular body between the first end and the first hole. A fourth hole is formed in the tubular body, the fourth hole being axially aligned on the tubular body with the third hole.

Abstract: An operational control device is disclosed for a positive-displacement pump having a motor, means for actuating the motor, state sensor means for detecting an actual operating parameter (e.g., pressure) of the pump, and operating mode means for controlling an operating mode of the pump. A first actuating mode of the operating mode means is set by the actuating means below a first operating-parameter threshold value (P1). This mode brings about a constantly rising pump pressure in the direction of an operating-parameter setpoint value (Pset) in a variable manner, which is dependent on a detected change in the operating parameter over a predefined time interval. A second actuating mode is set as normal operation to the operating-parameter setpoint value by the actuating means above the first operating-parameter threshold value. P1 is fixed or is calculated as a fraction of the operating-parameter setpoint value and/or a pump parameter correlated therewith.

Abstract: In the vane pump comprising the housing, the vane, and the cap, the sliding surface of the cap is configured as arc shape in the view from the rotational axis direction and the width toward the sliding direction of the cap is configured to be smaller than the width at the sliding angle field which is virtual area for contacting the inner surface of the pump room among the circumference including the arc shape of the sliding surface of the cap and to be bigger than the width at the high loading area where the load added to the sliding surface which is bigger than the predetermined value among the sliding angle field.

Abstract: A scroll compressor is provided that may include a casing including a rotational shaft, a cover fixed inside of the casing to partition the inside of the casing into a suction space and a discharge space, a first scroll revolved by rotation of the rotational shaft, a second scroll disposed on or at one side of the first scroll to define a compression chamber together with the first scroll, the second scroll including a discharge, through which a refrigerant pressed in the compression chamber may be discharged, a switching device movably disposed on or at one side of the discharge to selectively open and close the discharge, a back pressure portion including a moving guide that accommodates at least a portion of the switching device, and a top surface that covers one side of the switching device; and an adhesion preventer that reduces a contact area between the switching device and at least a portion of the back pressure portion.

Abstract: A scroll compressor includes a stationary scroll; an orbiting scroll having a pair of first Oldham keyways on one surface thereof, the orbiting scroll defining a compression chamber in combination with the stationary scroll; a frame having a pair of second Oldham keyways and supporting the orbiting scroll; and an Oldham ring for inhibiting rotation of the orbiting scroll, the Oldham ring having a pair of first Oldham keys on one surface thereof and a pair of second Oldham keys on the other surface thereof, the first Oldham keys slidably engaging with the respective first Oldham keyways, the second Oldham keys slidably engaging with the respective second Oldham keyways.

Abstract: Cooling devices for use with electric submersible pump motors include a refrigerator attached to the end of the electric submersible pump motor with the evaporator heat exchanger accepting all or a portion of the heat load from the motor. The cooling device can be a self-contained bolt-on unit, so that minimal design changes to existing motors are required.

Abstract: A fan is provided, including a driving member, a fan bracket, a main fan and a main cover. The fan bracket is assembled with the driving member. The main fan is disposed on a first connecting portion of the fan bracket. The main cover is disposed on a second connecting portion of the fan bracket. An airflow space is formed between the main fan and the main cover. The main cover is formed with a first wind-guiding cover. Thereby, when the driving member drives the main fan to rotate, air can be inhaled through the first wind-guiding cover into the airflow space, and air will be exhaled toward a periphery of the airflow space by using a guidance of the first wind-guiding cover.

Abstract: A ventilation assembly having a main housing that can be pre-installed in a wall or ceiling aperture. A fan assembly can be inserted through the aperture and releasably mounted within the main housing. The fan assembly can be removed from the main housing and replaced without removing the main housing from the wall or ceiling. An accessory component can be releasably mounted to the fan assembly either through the aperture when the fan assembly is mounted or prior to installation of the fan assembly.

Abstract: A method for controlling heater ventilation fan operation increases fan speed from low to high after a short delay after turn-on, and continues fan operation for a period of time based on duration of operation, after turn-off. The higher fan speed improves heat transfer and efficiency while the heating system is operating. Continuing fan operation after turn-off maximizes recovery of additional heat from the heat exchanger. Known methods do not provide sufficient air flow to efficiently transfer heat from the heat exchanger to the air, and leave high temperature air (i.e., 110 to 200° F.) in the heat exchanger after turn-off.