Abstract: A cross flow fan structure comprising: a) a housing integrally formed by plastic material in an injection molding process; b) a cross flow fan integrally formed by plastic material in an injection molding process, the right side of the cross flow fan having a mounting hole in axial direction and a damping/positioning body; c) a motor with an end portion attached to a mounting base whereupon the motor is attached to the housing by use of the mounting base in such a way that the driving shaft of the motor is extended into the mounting hole of the damping/positioning body in a tightly clamping state for driving the cross flow fan in rotational operation. In this way, a cross flow fan module made by material is created. Moreover, a convenient assemble and a vibration resisting effect are achieved for a smooth operation with low noise by use of a skillful combination of the material and by a special structure.

Abstract: A transverse fan assembly that includes a fan rotatably disposed in an air plenum for drawing air through an inlet opening and drivingly forcing air from an outlet opening defined by the air plenum, the inlet opening having an elongate, bladed, inlet rotor oriented on a rotational axis parallel to the fan, extending the length of the fan, and positioned proximate to the fan periphery to increase air flow from the outlet of the air plenum along the length of the fan while generating less noise.

Abstract: A transverse fan assembly, including for use with agricultural combine harvesters, which fan assembly includes a supplementary air feed inlet for the infill of air flow voids or deficiencies in the air flow pathway from the air inlet of the transverse fan assembly to the air inlet entryway so as to effect a desired, generally more uniform, output air flow pattern across the entire expanse of the air outlet of the transverse fan assembly, and a method of use thereof.

Abstract: A stable portable air moving device capable of generating an air stream elevated above a support surface allowing the air stream to be directed as desired by the user is provided. The device includes an air blower assembly located within an elongate housing generating an exhaust air stream that exits the elongate housing at an elevation above the air blower assembly.

Abstract: An air blowing apparatus is disclosed having an elongate housing with an elongate scroll defining an airflow passage. An elongate blower is surrounded by the scroll and adapted when energized to move air through the airflow passage. The airflow passage is partially helically-shaped to cause the moved air to be distributed into the surrounding environment in a partially helical pattern.

Abstract: An indoor unit of an air conditioner capable of enhancing heat exchange efficiency and reducing noise/vibration is provided. The indoor unit includes a main chassis, a front panel, a cross-flow fan, a fan motor, a heat exchanger, and a discharge port. The main chassis has a backside fixed on a place to be installed. The front panel is formed on the front of the main chassis and has a spacer formed in an inside thereof. The cross-flow fan is disposed in the inside of the space and provided in plurals on the same shaft. The fan motor provides rotational power to the cross-flow fan. The heat exchanger is formed on the front of the cross-flow fan with respect to the flowing direction of air. The discharge port guides discharge of the air blown from the cross-flow fan.

Abstract: In a supercharger (10) with an electric motor in accordance with the invention, an inner side of the center housing (10) is provided with an air introduction path (38) introducing a part of a compressed air within the compressor housing (8) to the electric motor (20), and a cooling structure portion (40) cooling the air flowing through the air introduction path (38). The center housing (14) has a cooling fluid flow path (34) which is formed so as to surround the electric motor (20) and puts a cooling fluid for cooling the electric motor (20) in circulation inside. The cooling structure portion (40) is structured such as to be capable of heat exchanging between the cooling fluid and the air flowing through the air introduction path (38).

Abstract: A cross-flow fan that variably maintains a distance between a blade and a fluid flow guide by varying a height of an outer edge and an air conditioner having the cross-flow fan are provided. Therefore, a noise and a peak value of a spectrum between the blade and the outer edge can be reduced.

Abstract: A cooling fan is provided that does not place limitations on the installation conditions for the fan, is capable of cooling a backlight unit of a display panel with high efficiency, and produces less noise during operation. Also provided is an image display apparatus equipped with the cooling fan. The cooling fan includes a fan rotator composed of a rotational shaft that is rotationally driven by a driving motor and two vanes that have parallel revolution shafts that rotate together with the rotational shaft, are freely rotatable on the shafts, face one another, and revolve around the rotational shafts and a vane angle control unit that implements control so that each vane has a maximum rotation angle when a revolution angle of the vanes is in a vicinity of a first revolution angle and each vane has a rotation angle of 0° when a revolution angle of the vane is in a vicinity of a second revolution angle that is perpendicular to the first revolution angle.

Abstract: In an air conditioner, reverse inhalation is prevented while broad band noise and wind sound are reduced. A projection arranged at the leading end of a stabilizer on the downstream side of an air stream flowing along a surface of the stabilizer opposing an impeller and protrudes toward the impeller to define the shortest distance to the impeller. A plurality of grooves or projections are provided on the opposing surface on the upstream side of the projection to disturb the air stream flowing along the opposing surface. The positions of the grooves or the projections are arranged apart in a rotational axis direction. A plurality of convex portions are provided to disturb an air stream flowing along a surface of a casing opposing the impellers. The positions of the convex portions are arranged apart in the rotational axis direction of the impeller.

Abstract: A personal ventilation system uses a cross-flow fan and one or more filters, where the filter preferably has a cylindrical or elongated elliptical shape that at least partially surrounds the rotor of the cross-flow fan. The filters preferably remove particles, undesired gases, and micro-organisms.

Abstract: An improved cross flow fan assembly applicable but not limited to a panel meter of fitness equipments includes: a housing and a cross flow fan made of plastic; a fan body, having symmetric circular flanges integrally formed on both lateral ends by plastic injection molding; two side covers, embedded into two circular flanges; and a shock absorption positioning member, installed at an external side of the right panel, and including: an axle center with a front section embedded into a bushing of the right cover and a rear section sheathed into a bearing, and a rubber pad, embedded into a circular hole of the right panel by its circular groove at the periphery for wrapping the bearing, so as to constitute a plastic cross flow fan module, and achieving a fast and convenient assembling and a vibration resisting effect, and the fan comes with a smooth operation to reduce noises.

Abstract: An indoor unit for an air conditioner capable of performing cooling and heating, as well as ventilation functions as a single unit is provided. The indoor unit includes a main chassis, a ventilation port, a cross-flow fan, a side fan, and a ventilation duct. The main chassis is installed on a mounting portion and composing its exterior. The ventilation port formed to pass through the main chassis for inletting and exhausting air. The cross-flow fan is installed on one side of the main chassis to blow air in a direction perpendicular to its rotating shaft. The side fan is formed next to the cross-flow fan. The ventilation duct is connected to the ventilation port of the main chassis to ventilate the air forcibly blown by the side fan.

Abstract: There is provided a cooling apparatus for a flat display device. The cooling apparatus includes a flat display module, a cover for protecting an exterior of the flat display module, an air inlet formed on one side of the cover, for introducing external air, an air outlet formed in the other side of the cover, for discharging high temperature air contained inside the cover, and a shield for selectively closing the air outlet to prevent inflow of foreign substances.

Abstract: There is provided a cooling apparatus for a flat display device. The cooling apparatus includes a flat display module, a front cover for protecting a front portion of the flat display module, a back cover for protecting a rear portion of the flat display module, an air inlet formed on a portion of the back cover to allow external air to be introduced into the back cover, an air outlet formed on another portion of the back cover and extending along a longitudinal length of the flat panel display module; a fan disposed inside the back cover and aligned with the air outlet formed on the back cover, and an air outlet channel formed in the back cover and aligned with the air outlet formed on the back cover, the air outlet having an effective exhaust area having a longitudinal length extending in a longitudinal direction of the flat display module.

Abstract: A cooling apparatus for a flat display device includes a flat display module, a front cover for protecting a front portion of the flat display module, a back cover for protecting a rear portion of the flat display module; an air inlet formed on a portion of the back cover to allow external air to be introduced into the back cover, an air outlet formed on another portion of the back cover to allow the air introduced into the back cover to be exhausted therethrough, a cross-flow fan disposed inside the back cover and aligned with the air outlet formed on the back cover, and an air outlet channel formed in the back cover and aligned with the air outlet formed on the back cover. A ratio of an inner diameter of the cross-flow fan to an outer diameter of the cross-flow fan is 0.69±0.03.

Abstract: A secondary air system providing a regeneration air pump wherein the vanes of the impeller are tapered from a point along the length of the vane to the root of the vane inside the air pump. The tapered vanes create desirable flow characteristics. The tapered vanes create a non-linear flow versus pressure characteristic. Thus, the tapered vanes in combination with a divider that extends circumferentially around the impeller and through the vanes causes the flow to increase. This non-linear characteristic created by the tapered vanes allows the secondary air system to maintain suitable operation at lower flow and pressure levels. Due to the tapered feature on the impeller, a dead head pressure is obtained at a lower pressure. The impeller arrangement also provides overall pump efficiency improvements.

Abstract: A cross flow fan of an indoor unit of, for example, an air conditioner includes a pair of disc-shaped end plates and a plurality of fan blades attached to the end plates in a ring-shaped arrangement. Each of the fan blades has a cross sectional area ratio of Sa/Sb in a range of 1.3 to 1.6, preferably, 1.4 to 1.5, in which Sa is a sectional area of a fan inner peripheral side half portion of the blade and Sb is a sectional area of a fan outer peripheral side half portion of the blade at a time when the fan blade is cut perpendicularly with respect to a longitudinal direction of the fan blade and divided into two sectional areas along a central division line in a blade chord direction.

Abstract: A fuel pump for a vehicle comprises: a driving motor; an impeller having a substantially circular shape, the impeller being rotatable by operation of the driving motor; and a pump casing covered with a casing cover, the pump casing and casing cover together defining a central cavity for receiving the impeller rotatable therein, the pump casing and casing cover including a fuel inlet port and a fuel outlet port, the pump casing and casing cover each further including a circular groove formed along the surface thereof in respective fluid communication with the central cavity of the pump casing and casing cover.

Abstract: A flat display device includes a flat display module, a front cover supporting a front portion of the flat display module, a back cover supporting a rear portion of the flat display module, a peripheral portion formed on the back cover and having an inclined surface inclined toward a center of the flat display module as it goes rearward, and a cross-flow fan disposed in the back cover and aligned with the inclined surface of the peripheral portion of the back cover. The cross-flow fan has an air exhaust channel having an air outlet inclined toward the center of the flat display module as it goes rearward.

Abstract: In a supercharger (10) with an electric motor in accordance with the present invention, the electric motor (20) is arranged at a position adjacent to a compressor impeller (6), a center housing (14) has a cooling fluid flow path (34) formed in such a manner as to surround the electric motor (20) and be adjacent to a diffuser portion (25). A first cooling structure portion (38) is formed at a position in the electric motor (20) side in the cooling fluid flow path (34), a second cooling structure portion (39) is formed at a position in the diffuser portion (25) side in the cooling fluid flow path (34). The electric motor (20) is cooled by the first cooling structure portion (38). The diffuser portion (25) is cooled by the second cooling structure portion (39).

Abstract: A transverse fan assembly including a fan rotatably disposed in an air plenum for drawing air through an inlet opening and drivingly forcing air from an outlet opening defined by the air plenum, the fan having elongated fan blades angled toward a peripheral center plane of the fan such that the blades have a chevron-like configuration between opposite ends of the fan, the plenum having an inverted V-shaped inlet opening edge structure whereby the edge angles mirror the chevron angles of the adjacent fan blades thereby improving air flow uniformity and flow from the outlet of the air plenum while generating less noise.

Abstract: A centrifugal compressor has a housing assembly and an impeller rotatably connected to the housing assembly. Gas introduced into the housing assembly by rotation of the impeller is compressed at least by centrifugal force. One aspect of the present invention is that the impeller includes an inducer portion having a pressure surface and a suction surface and a hole extending between the pressure surface and the suction surface. Another aspect of the present invention is that the centrifugal compressor includes a diffuser located downstream of the impeller, a volute in communication with an outlet of the diffuser, and a reflux passage connecting the diffuser with the volute for returning part of gas in the volute to the diffuser.

Abstract: A pump having a housing with a torus and a stripper region. The stripper region has a housing groove formed on the surface of the stripper region. The housing groove has a surface forming a length, width and depth of the groove. The pump also has a cover connectable to the housing. The cover extends over the housing groove formed on the surface of the stripper region. An impeller has a plurality of vanes that extend radially outward from an impeller frame, wherein the impeller is rotatably positioned between the housing. The cover and the plurality of vanes are positioned in operable relation to said housing groove.

Abstract: A portable, vertical tower fan capable of generating a vertically oriented exhaust air stream that conforms better to a user at an elevation above a support surface. The device includes an vertically elongated housing, an air blower assembly located within the elongated housing and a base provides a space saving design.

Abstract: In a turbine apparatus comprising a runner rotatable to be rotationally driven by a water, a gain of a derivative calculation element generating a derivative component of a control signal for controlling a flow rate of the water which derivative component is to be applied to the derivative calculation element and the integration calculation element by performing differentiation on a difference between an actual rotational speed and a desired rotational speed of the runner with respect to a time proceeding has a value sufficiently increased to converge a value of the control signal toward a desired value in accordance with the time proceeding in S-characteristic portion.

Abstract: In a turbine apparatus comprising a runner rotatable to be rotationally driven by a water, a gain of a derivative calculation element generating a derivative component of a control signal for controlling a flow rate of the water which derivative component is to be applied to the derivative calculation element and the integration calculation element by performing differentiation on a difference between an actual rotational speed and a desired rotational speed of the runner with respect to a time proceeding has a value sufficiently increased to converge a value of the control signal toward a desired value in accordance with the time proceeding in S-characteristic portion.

Abstract: An integrated crossflow cooler for electronic components comprises a heatsink with at least two openings, a crossflow blower and an electric drive with a stator and a magnetized rotor. The heatsink comprises a base and heat exchanging means; the base provides thermal contact with the electronic component and the heat exchanging means. The crossflow blower hydraulically connected to one of the openings and comprises a casing rigidly built-in to the heatsink and a drum type impeller comprises magnetic means and serves as a magnetized rotor of the electric drive. The stator made as printed circuit board and rigidly built-in to the casing. The integrated crossflow cooler comprises two types of electric drives—when the magnetic means magnetized in the direction parallel to the axis of rotation and when the magnetic means magnetized in the direction perpendicular to the axis of rotation.

Abstract: Cross flow fan having a plurality of unit fans assembled in succession with the unit fans twisted from each other at sides, and an air conditioner fitted with the same. The unit fan includes an annular rim, and a plurality of impellers arranged on a side of the rim vertical to, and along a circumference of the rim. The present invention provides a cross flow fan extension lines from the impellers of the unit fan have a phase difference with the extension lines from the impellers of an adjacent unit fan.

Abstract: A cross-flow fan is operated in a suction mode, mainly in air-ducts with a large width, to provide a smooth flow of regulatable air. In accordance with the invention, a smooth flow suction separation device is suitable for the regulated suction to a large width of an amount of air containing a solid fraction, and is also suitable for the separation of the solid fraction on the inlet side. In certain forms of its construction, the flow of air is made to circulate. The smooth flowing suction separation device is equipped with a curved centrifugal separation device and a fraction outlet. A characteristic feature of the invention is that it has a cross-flow rotor, a housing constructed as a pneumatic duct, and a closed suction element attached to the internal edge of a centrifugal separation device.

Abstract: A cross flow fan mainly includes an enclosure, a cross fan and a motor. When the cross fan rotates by the motor, air is drawn into the cross flow fan through the intake hole and then is exhausted through the ventilating hole. The device is characterized in that the ventilating hole and the intake hole is located on the position of 0 degree and 180 degrees respectively and the end point of the arched wind fending board is located on the range from 70 to 150 degrees. The wind fending board installed between the intake hole and the ventilating hole is arched in an radian a bit larger than that of the fringe of the cross fan so as to have better ventilating efficiency.

Abstract: To obtain an air conditioning apparatus which provides a favorable atmosphere to the ear and saves energy even if the suction resistance of the impeller becomes high due to such as dust in the air conditioning apparatus. The air conditioning apparatus is provided with an impeller which is formed by a plurality of vanes and a ring for supporting the plurality of vanes, and includes a nozzle portion formed by a stabilizer and an air outlet, a cross flow fan formed by a guide wall, and a heat exchanger. The ratio H/&phgr;D2 of the outside diameter &phgr; D2 of the impeller to the height H of the air conditioning apparatus is 2.2 or above and 3.0 or below.

Abstract: A once-through pump is provided which is able to improve air-blowing efficiency, reduce operation noise, and achieve a sufficient amount of blast or flow rate even within a limited design space. The once-through pump for accelerating fluid (F) in a flow passage (P) while passing the fluid (F) through the flow passage (P) includes a cylindrical impeller (10) rotatably supported in the flow passage, a plurality of vanes (11) provided on the outer periphery of the impeller (10), and a motor for driving the impeller to rotate. The impeller (10) has a substantially D-shaped cross sectional configuration with a suction side, at which the fluid (F) is sucked into the impeller (10), being formed into a straight portion (10a). Each of the vanes (11) has a positive vane angle with respect to a fluid advancing or flowing direction (A) in the straight portion (10a).

Abstract: A heat-dissipating assembly includes a plurality of heat-dissipating devices, each of which includes a frame having at least one locating window for allowing the heat-dissipating device to inhale air and discharge airflow, and a stream-guiding wall formed beside the locating window; and at least one blade structure mounted in the locating window of the frame. In addition, each heat-dissipating device further includes at least one engaging medium to be engaged with a corresponding engaging medium of another heat-dissipating device, thereby allowing the plurality of heat-dissipating devices to be combined in parallel, side by side, or in tiers.

Abstract: A fan structure having horizontal convention includes a casing and a cross-flow type fan wheel. The casing includes an air inlet, an air outlet, and a horizontal channel directly connected therebetween. The cross-flow type fan wheel is mounted in the horizontal channel and selectively aligned or misaligned with a center of the casing.

Abstract: The present invention relates to a parallel fan. The parallel fan includes an integrally formed fan frame having plural pairs of locating windows and a plurality of fans being respectively mounted in the plural pairs of locating windows. The parallel fan has an external single pair of power lines. Each pair of locating windows includes an inlet and an outlet for respectively enabling the fan to inhale from the inlet and discharge from the outlet.

Abstract: A wind wheel assembly of a separable air conditioner which comprises the following components. A plurality of multi-sectional wind wheels is fixed to a seat of the separable air conditioners. At least one motor is positioned on at least one respective positioning plate, each motor being connected between two wind wheels. A plurality of bearings are positioned on at least one respective positioning plate; each bearing being positioned between two wind wheels or positioned at the outer side of two outermost wind wheels. The at least one motor and the plurality of bearing are alternatively arranged; thereby, the wind wheel assembly is operated smoothly and steadily.

Abstract: Cross flow fan having a plurality of unit fans assembled in succession with the unit fans twisted from each other at sides, and an air conditioner fitted with the same. The unit fan includes an annular rim, and a plurality of impellers arranged on a side of the rim vertical to, and along a circumference of the rim. The present invention provides a cross flow fan extension lines from the impellers of the unit fan have a phase difference with the extension lines from the impellers of an adjacent unit fan.

Abstract: Water is first caused to flow through a first passage and rotate a first impeller. Rotation of the first impeller is linked to rotation of a second impeller, which is in fluid communication with a second, discrete passage. Vanes on the second impeller are constrained to move faster than vanes on the first impeller. Water is subsequently caused to flow through the second passage and to be more aggressively advanced by the second impeller.

Abstract: A blower assembly for a split air conditioner comprises a casing having a bearing trough in one end, a pair of rubber sleeve troughs in the other opposite end, a plurality of central hollow posts each having a threaded hole; and a blower having a plurality of blower units each having a shaft in one end and a hole in the other opposite end, at least one bearing seat, a plurality of bearings, at least one motor, a plurality of rubber sleeves mounted on the motor and together rested on the rubber sleeve troughs, and a plurality of plates for threadedly securing the rubber sleeves. By utilizing these components, a variety of advantages are obtained such as an increase of draft, more stable operation, no abnormal expansion and contraction, and noise reduction.

Abstract: To obtain an air conditioning apparatus which provides a favorable atmosphere to the ear and saves energy even if the suction resistance of the impeller becomes high due to such as dust in the air conditioning apparatus. The air conditioning apparatus is provided with an impeller which is formed by a plurality of vanes and a ring for supporting the plurality of vanes, and includes a nozzle portion formed by a stabilizer and an air outlet, a cross flow fan formed by a guide wall, and a heat exchanger. The ratio H/&phgr;D2 of the outside diameter &phgr;D2 of the impeller to the height H of the air conditioning apparatus is 2.2 or above and 3.0 or below.

Abstract: A siroco fan of a window type air conditioner, in which the rotational speed can be increased without changing the quantity of the blowing air and without increasing the operational noise, thereby improving the marketability of the air conditioner. The siroco fan has a shroud and a plurality of blades disposed at the shroud and spaced apart at regular intervals, each of the blades having a trailing edge angle of 125° to 137°, a leading edge angle of 58° to 63°, a chord-to-pitch ratio of 0.75 to 0.85, an inner diameter-to-outer diameter ratio of 0.82 to 0.86, and a maximum camber position of 0.3 to 0.4 of a chord length of the blade.

Abstract: A once-through pump is provided which is able to improve air-blowing efficiency, reduce operation noise, and achieve a sufficient amount of blast or flow rate even within a limited design space. The once-through pump for accelerating fluid (F) in a flow passage (P) while passing the fluid (F) through the flow passage (P) includes a cylindrical impeller (10) rotatably supported in the flow passage, a plurality of vanes (11) provided on the outer periphery of the impeller (10), and a motor for driving the impeller to rotate. The impeller (10) has a substantially D-shaped cross sectional configuration with a suction side, at which the fluid (F) is sucked into the impeller (10), being formed into a straight portion (10a). Each of the vanes (11) has a positive vane angle with respect to a fluid advancing or flowing direction (A) in the straight portion (10a).

Abstract: A blower assembly for a split air conditioner comprises a casing including a bearing trough in one end, a pair of rubber sleeve troughs in the other opposite end, a plurality of central hollow posts each having a threaded hole; and a blower including a plurality of blower units each having a shaft in one end and a hole in the other opposite end, at least one bearing seat, a plurality of bearings, at least one motor, and a plurality of rubber sleeves mounted on the motor and together rested on the rubber sleeve troughs, a plurality of plates for threadedly securing the rubber sleeves. By utilizing this, a variety of advantages are obtained such as an increase of draft, more stable operation, no abnormal expansion and contraction, and noise reduction.

Abstract: A cross flow fan of an air conditioner for reducing noise and vibration produced due to a rotation of the cross flow fan, by an improvement in a blade arrangement which has a regularity as a whole and an irregularity as respective units. Such a cross flow fan is installed in an indoor unit of the air conditioner, and has a plurality of blades functioning to circulate an inside air. The blades of the cross flow fan are divided into a plurality of blade groups consisting of a uniform number of blades, and the blades in the same blade group are arranged at uniformly increasing angles, while the pattern of the blade arrangement throughout the complete blade groups is uniformly formed.

Abstract: A siroco fan of a window type air conditioner, in which the rotational speed can be increased without changing the quantity of the blowing air and without increasing the operational noise, thereby improving the marketability of the air conditioner. The siroco fan has a shroud and a plurality of blades disposed at the shroud and spaced apart at regular intervals, each of the blades having a trailing edge angle of 125° to 137°, a leading edge angle of 58° to 63°, a chord-to-pitch ratio of 0.75 to 0.85, an inner diameter-to-outer diameter ratio of 0.82 to 0.86, and a maximum camber position of 0.3 to 0.4.

Abstract: The present invention discloses a parallel fan. The parallel fan includes an integrally formed fan frame having plural pairs of locating windows and a plurality of fans being respectively mounted in the plural pairs of locating windows. The parallel fan has an external single pair of power lines. Each pair of locating windows includes an inlet and an outlet for respectively enabling the fan to inhale from the inlet and discharge from the outlet.

Abstract: A fan assembly includes a first fan device having an engaging medium, and a second fan device having a corresponding engaging medium for engaging with the engaging medium of the first fan device, thereby allowing the second fan device to be combined with the first fan device. The fan device includes a fan frame having the engaging medium adapted to engage with the corresponding engaging medium of another fan frame of another fan device, and a fan secured in the fan frame.

Abstract: A fan having a rotor with a plurality of fan blades, the fan having an intake and a pressure side. A blocking device between the intake and pressure sides of the fan. The blocking device comprising a strip-like brush element with a plurality of brush sections that extend radially upwardly toward the edge of the rotor. The brush sections are spaced apart from one another along the direction from the intake to the pressure side of the fan. A cross-flow fan has spaced apart brush sections which are spaced apart in the running direction of the fan. An axial flow fan has brush sections which are spaced apart from one another transversely with respect to the running direction. The brush sections in each of the fans may also be as in the other type of fan. The brush sections may define a v-shape extending from a common block or may be in spaced apart rows or may be individual tufts and the tufts may be staggered along the length of the brush.

Abstract: A modified cross flow fan 10, intake duct 25 and exhaust duct 26 combination has the intake duct 25 spanning 160°-180° of the anterior circumference of the fan 10. The location of the upper surface 27 adjacent fan 10 is determined by a substantially increasing power requirement and a substantial diminishing of exhaust gas outputs. The upper surface 26 near the fan 10 preferably has a curvature similar to the curvature of blades 12. The lowermost location of the lower surface 28 of the intake duct 25 is at the point of an increase in the relative vacuum of the external intake gas pressure. The fan 10 has blades 12 creating an internal working space ratio of at least about 5:1. Blade 12 count will vary with intended usage and size, e.g., from 16-60 or more. Blades 12 are preferably angled at 50°-60° from the radius line of the fan 10 and have an inner surface curvature of 60°-80°. The exhaust duct 26 spans 100°-120° of the fan's circumference at the lower rear of fan 10.