VENTILATION FAN

Abstract

A ventilation fan includes a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet opening into the interior space and spaced apart from the inlet. A fan wheel is coupled to the scroll within the interior space and includes a plurality of fan blades configured to rotate about a vertical rotation axis to draw air into the interior space to ventilate a room positioned adjacent to the ventilation fan. An inlet collar is coupled to an exterior surface of a bottom wall of the scroll and extends through the inlet. The inlet collar has a upper, distal end located above a lower end of each of the plurality of fan blades when the ventilation fan is installed above or adjacent to a ceiling of the building.

Description

BACKGROUND

The present disclosure relates to ventilation fans, and particularly to ventilation fans configured to be mounted to a building to ventilate at least one room of the building. More particularly, the present disclosure relates to a ventilation fan including a fan housing and a fan wheel contained within the fan housing.

SUMMARY

According to the present disclosure, a ventilation fan includes a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet opening into the interior space and spaced apart from the inlet. The ventilation fan further includes a fan wheel coupled to the scroll and arranged to lie within the interior space. The fan wheel includes a plurality of fan blades configured to rotate about a vertical rotation axis to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan.

In illustrative embodiments, the ventilation fan further includes an inlet collar coupled to an exterior surface of a bottom wall of the scroll and extending through the inlet. The inlet collar has a upper, distal end located above a lower end of each of the plurality of fan blades when the ventilation fan is installed above or adjacent to a ceiling of the building.

In illustrative embodiments, the ventilation fan further includes a fan grille arranged to overlie the inlet of the scroll. The fan grille includes a perimeter rim adapted to engage at least one of the scroll and a wall of the room when the fan grille is fully installed. The fan grille further includes a grille plate arranged to extend substantially parallel to and in spaced apart relation to the inlet. The fan grille further includes a plurality of spokes interconnecting the perimeter rim and an outer edge of the grille plate and spaced apart from one another to define a plurality of grille intake openings.

In illustrative embodiments, the fan grille further includes a flow director coupled to an interior surface of the grille plate facing toward the scroll and arranged to extend toward the inlet collar and the inlet to the scroll and to cooperate with the inlet collar to guide air being withdrawn through the plurality of grille intake openings into the inlet of the scroll. The flow director includes a proximal end fixed to the grille plate, a distal end arranged to lie at the inlet or within the interior space of the scroll, and a flow-director body extending between the proximal end and the distal end and having a diameter that decreases from the proximal end to the distal end.

In illustrative embodiments, the flow-director body decreases exponentially from the proximal end to the distal end such that an outer surface of the flow-director body has a first slope at a first distance from the proximal end and a second slope at a second distance from the proximal end. The first slope is less than the second slope and the first distance is less than the second distance.

In illustrative embodiments, the outer surface of the flow-director body cooperates with the inlet collar to provide a curved flow path between the flow-director body and the inlet collar.

In illustrative embodiments, a diameter of the proximal end of the flow director is greater than a maximum diameter of the inlet collar.

In illustrative embodiments, the flow-director body is hollow and the flow director further includes a noise-reducing filler within the flow-director body.

In illustrative embodiments, the inlet collar includes a collar mount fixed to a bottom wall of the scroll, a collar elbow coupled to the collar mount, and a collar extension extending into the interior space and having the upper, distal end located above the lower end of each of the plurality of fan blades.

In illustrative embodiments, the collar mount extends radially outward away from the collar elbow and the vertical rotation axis and the collar elbow has a convexly-shaped curvature relative to the fan grill.

In accordance with another aspect of the present disclosure, a ventilation fan includes a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet opening into the interior space and spaced apart from the inlet. The ventilation fan further includes a fan wheel coupled to the scroll and arranged to lie within the interior space. The fan wheel includes a plurality of fan blades configured to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan. A fan grille is arranged to overlie the inlet of the scroll.

In illustrative embodiments, the fan grille includes a perimeter rim adapted to engage at least one of the scroll and a wall of the room when the fan grille is fully installed, a grille plate arranged to extend substantially parallel to and in spaced apart relation to the inlet, a plurality of spokes interconnecting the perimeter rim and an outer edge of the grille plate and spaced apart from one another to define a plurality of grille intake openings, and a flow director coupled to an interior surface of the grille plate facing toward the scroll and arranged to extend through the inlet to the scroll to guide air being withdrawn through the plurality of grille intake openings and into the inlet of the scroll.

In accordance with another aspect of the present disclosure, a ventilation fan includes a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet opening into the interior space and spaced apart from the inlet. The ventilation fan further includes a fan wheel coupled to the scroll and arranged to lie within the interior space. The fan wheel includes a plurality of fan blades configured to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan. The ventilation fan further includes an inlet collar coupled to an exterior surface of a bottom wall of the scroll and extending through the inlet, the inlet collar having a upper, distal end located above a lower end of each of the plurality of fan blades.

Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The detailed description particularly refers to the accompanying figures in which:

FIG. 1 is a perspective and partial exploded assembly view of a ventilation fan including a scroll adapted to be secured to a building and placed adjacent to a room of the building, a fan wheel located within an interior space of the scroll and configured to withdrawn air though the inlet to the interior space, and a fan grille arranged to overlie the inlet to the interior space;

FIG. 2 is a cross section of the ventilation fan from FIG. 1 installed on a ceiling of the building showing that the ventilation fan further includes an inlet collar coupled to the scroll and surrounding the inlet and a flow director arranged to extend toward the inlet collar and the inlet to the scroll and to cooperate with the inlet collar to guide air being withdrawn into the inlet of the scroll;

FIG. 3 is a cross section of another embodiment of a ventilation fan without the inlet collar included in the ventilation fan of FIG. 2 showing that turbulent air is allowed to pass over lower ends of each fan blade included in the fan wheel;

FIG. 4 is a cross section of the ventilation fan of FIG. 2 with the fan grille removed to show that the inlet collar includes an upper, distal end which is arranged to lie above a lower end of each fan blade to block air from passing between the lower end of each fan blade and the scroll;

FIG. 5 is a perspective view of the inlet collar;

FIG. 6 is a cross section taken along line 6-6 in FIG. 5;

FIG. 7 is a perspective view of the fan grille and the flow director mounted thereto;

FIG. 8 is a top plan view of the flow director;

FIG. 9 is a cross section taken along line 9-9 in FIG. 8;

FIG. 10 is a side elevation view of the fan grille and the flow director mounted thereto; and

FIG. 11 is a chart showing noise levels produced during operation of the ventilation fan of the present disclosure including the inlet collar and the flow director compared to a comparative fan without the inlet collar and the flow director.

DETAILED DESCRIPTION

A ventilation fan 10 is configured to be mounted to a building and is configured to ventilate at least one room of the building. The ventilation fan 10 includes a scroll 12 and a fan wheel 14 arranged to lie within an interior space 16 defined by a fan housing 44 as shown in FIG. 1. The scroll 12 is also formed to include an inlet 18 opening into the interior space 16 and an outlet 20 spaced apart from the inlet 18 to release air from the scroll 12.

The fan wheel 14 is coupled to the scroll 12 and is configured to displace air into the interior space 16 and through the inlet 18. The air is then expelled through the outlet 20 and is transported away from the ventilation fan 10 by a duct, for example. In one example, the scroll 12 of the ventilation fan 10 is mounted above a ceiling panel 22 of the building and the fan wheel 14 is configured to withdraw air from the at least one room through an opening 24 in the ceiling 22 as shown in FIG. 2. The air being withdrawn in to the ventilation fan 10 follows a flow path F through the interior space 16 defined by the fan housing 44. The withdrawn air may be exhausted to an exterior of the building.

The ventilation fan 10 in the illustrative embodiment further includes a fan grille 26 arranged to overlie the opening 24 in the ceiling 22 to block substantial view of the opening 24 in the ceiling 22 as shown in FIG. 2. The fan grille 26 is depicted as having an exemplary substantially square shape when viewed from below the opening 24 in the ceiling 22; however, in other embodiments, the fan grille 26 may have any suitable shape (i.e. circular, rectangular, etc.).

The ventilation fan 10 in the illustrative embodiment further includes an inlet collar 28 coupled to the scroll 12 as shown in FIGS. 1 and 2. Specifically, the inlet collar 28 is coupled to an exterior surface of a bottom wall 48B of the scroll 12 and extends circumferentially around the entire inlet 18.

The fan grille 26 includes a perimeter rim 30, a grille plate 32, and a plurality of louvers 34 extending between and interconnecting outer portions of the perimeter rim 30 and the grille plate 32, as shown in FIGS. 1 and 2. The perimeter rim 30 is adapted to engage the ceiling 22 of the room when the fan grille 26 is fully installed. The grille plate 32 is arranged to extend substantially parallel to and in spaced apart relation to the inlet 18 and the perimeter rim 30. The plurality of louvers 34 extend between and interconnect the perimeter rim 30 and the grille plate 32 to provide the spacing between the grille plate 32 and the ceiling 22 and allow airflow therebetween.

Each louver of the plurality of louvers 34 is spaced apart from one another to define a plurality of grille intake openings 38 between adjacent louvers as shown in FIGS. 1 and 2. The plurality of grille intake openings 38 allow for air to be drawn between the grille plate 32 and the ceiling 22 along the flow path F.

The fan grille 26 in the illustrative embodiment further includes a flow director 36 as shown in FIGS. 1 and 2. The flow director 36 is coupled to an interior surface 40 of the grille plate 32 facing toward the scroll 12. The flow director 36 is arranged to extend toward the inlet collar 28 and the inlet 18 to the scroll 12. In some embodiments, the flow director 36 extends into the inlet 18. In some embodiments, the flow director 36 is configured to cooperate with the inlet collar 28 to guide air being drawn through the plurality of grille intake openings 38 into the inlet 18 fan housing 44 in a more uniform flow.

Together, the inlet collar 28 and the flow director 36 provides various advantages over other ventilation fans such as flow advantages, including increased flow rate, decreased turbulence, decreased pressure drop, power saving advantages, and/or noise reduction advantages. In some embodiments, the inlet collar 28 may be omitted from the ventilation fan 10 such that the flow director 36 alone provides the flow advantages, the power saving advantages, and/or the noise reduction advantages. In some embodiments, the flow director 36 may be omitted from the ventilation fan 10 such that the inlet collar 28 alone provides the flow advantages, the power saving advantages, and/or the noise reduction advantages.

The fan housing 44 includes a plurality of walls 46 defining the interior space 16. The scroll 12 is located within the interior space 16. The scroll 12 includes a plurality of walls 48 defining a second interior space 50. The fan wheel 14 is located within the second interior space 50.

The plurality of walls 46 of the fan housing 44 may form a substantially rectangular prism shape having sidewalls 46S and a top wall 46T as shown in FIG. 2. The fan housing 44 may be formed without a bottom wall to provide for an opening that lies adjacent to the opening 24 in the ceiling 22 when the ventilation fan 10 is fully installed to the building. The scroll 12 is mounted to the top wall 46T of the plurality of walls 46 of the fan housing 44. The plurality of walls 46 of the fan housing 44 may form a different shape in other embodiments.

The plurality of walls 48 of the scroll 12 may also form a generally cylindrical shape having a perimeter wall 48P, a top wall 48T, and a bottom wall 48B as shown in FIGS. 1 and 2. The perimeter wall 48P extends between and interconnects outer edges of the top wall 48T and the bottom wall 48P. The top wall 48T is coupled to an upper end of the perimeter wall 48P and is mounted to the top wall 46T of the main housing 46. The bottom wall 48B is coupled to a lower end of the perimeter wall 48P and is formed to include the inlet 18.

The fan wheel 14 is mounted to the top wall 48T of the scroll 12 for rotation relative to the scroll 12 as shown in FIG. 2. The fan wheel 14 includes a wheel motor 52 fixed to the top wall 48T of the scroll 12, a wheel hub 54 coupled to the wheel motor 52, and a plurality of fan blades 56 coupled to the wheel hub 54. The wheel motor 52 includes a drive shaft 53 that is configured to rotate about a central rotation axis 58 of the fan wheel 14 when the wheel motor 52 is powered on. The wheel hub 54 is fixed to the drive shaft 53 for rotation about the central rotation axis 58 therewith. The plurality of fan blades 56 are arranged circumferentially around the rotation axis 58 and around the inlet 18. Most of the components of the fan wheel 14 may be located in the second interior space 50 of the scroll 12. In some embodiments, some components of the fan wheel 14 may be located exterior to the second interior space 50 such as within other areas of the interior space 16 or even exterior to the interior space 16.

The plurality of fan blades 56 are shaped and oriented relative to the rotation axis 58 to displace air through the inlet 18 when the plurality of fan blades 56 are driven in rotation about the rotation axis 58 by the wheel motor 52. The plurality of fan blades 56 have a proximal end 60 fixed to the wheel hub 54 and arranged to lie near the top wall 48T and the wheel motor 52 and a distal end 62 arranged to lie near the bottom wall 48B and the inlet 18. The distal end 62 of each of the fan blades 56 are arranged slightly radially outward of the inlet 18 and are spaced apart from the bottom wall 48B by a clearance distance 64.

The ventilation fan 10 is shown in FIG. 3 without the inlet collar 28 to suggest various air flow paths occurring within the second interior space 50. A first flow path F is shown entering the inlet and passing through spaces formed between each of the plurality of fan blade 56. A second, turbulent flow path FT is shown passing though the inlet 18 and then passing over the distal end 62 of each fan blade 56 through clearance gap 64. The turbulent flow path FT adversely affects one or more of flow, pressure, power consumption, and/or noise of the ventilation fan 10.

The ventilation fan 10 is shown in FIG. 4 with the inlet collar 28 installed on the scroll 12. The inlet collar 28 is fixed to the bottom wall 48B of the scroll 12 and extends through the inlet 18. The inlet collar 28 has an upper, distal end 28U configured to extend through the scroll inlet 18 and be located at or above the distal end 62 of each of the plurality of fan blades 56 so as to be arranged closer to the top wall 48T than the distal end 62 of each of the fan blades 56. Stated differently, the upper distal end 28U of the inlet collar 28 is located between the blade proximal ends 60 and the blade distal ends 62 and, radially, between the axis 58 and the blades 56. In the illustrative embodiment, the inlet collar 28 spans the entire clearance gap 64 to form a barrier that blocks air from flowing along the turbulent flow path FT shown in FIG. 3. The inlet collar 28 is configured to guide air along flow path F toward a space surrounded by the plurality of fan blades 56 to bypass the clearance gap 64. As a result, the plurality of fan blades 56 are able to move more air through the spaces between each of the plurality of fan blades 56 along flow path F while reducing or eliminating air flow through turbulent flow path FT and, thereby, increasing flow, reducing back pressure, reducing power consumption, and/or reducing noise levels.

In some embodiments, the upper end 28U of the inlet collar 28 is spaced apart from the distal end 62 of each of the plurality of fan blades 56 as shown in FIGS. 4 and 6. In some embodiments, the upper end 28U of the inlet collar 28 is aligned with the distal end 62 of the plurality of fan blades 56 relative to the rotation axis 58. The spacing between the upper end 28U of the inlet collar 28 and the distal end 62 of the plurality of fan blades 56 may vary in some embodiments to optimize fan performance (i.e. flow rate, pressure, etc.).

The inlet collar 28 extends annularly around the rotation axis 58 such that there are no gaps or openings leading to clearance gap 64. The inlet collar 28 may be manufactured as a part of the scroll 12 or the scroll 12 may be retrofitted with the inlet collar 28 at a later time. In each case, the inlet collar 28 establishes a new inlet 18′ for the scroll 12 when the inlet collar 28 is installed on the scroll 12 since the inlet 18 is completely surrounded by the inlet collar 28 as shown in FIG. 4.

The inlet collar 28 includes a collar mount 66, a collar elbow 68, and a collar extension 70 as shown in FIGS. 5 and 6. The collar mount 66 is configured to be fixed to the bottom wall 48T of the scroll 12. In other embodiments the collar mount 66 may be fixed to the fan housing 44. The collar elbow 68 is coupled to the collar mount 66 and extends radially inward toward rotation axis 58 and upwardly toward the fan wheel 14. The collar extension 70 is coupled to the collar elbow 68 and extends upwardly from the collar elbow 68 into the second interior space 50. If the inlet collar 28 is coupled to a portion of the fan housing 44, or if the scroll 12 is omitted, then the collar extension 70 extends into interior space 16.

In some embodiments, the inlet mount 66 may be attached to the bottom wall 48B of the scroll 12 by welding, brazing, soldering, and/or by one or more fasteners. In other embodiments, the inlet mount 66 may be sized relative to the inlet 18 to form a friction or interference fit therebetween which holds the inlet collar 28 in position to the scroll 12. The inlet mount 66 includes a radially-extending portion 72 and an axially-extending portion 74 relative to the rotation axis 58. The radially-extending portion 72 is mounted to the bottom wall 48B of the scroll 12. The axially-extending portion 74 extends downwardly away from the bottom wall 48B of the scroll 12 and toward the fan grille 26. The radially-extending portion 72 is substantially perpendicular to rotation axis 58 while the axially-extending portion 74 is substantially parallel to rotation axis 58.

The collar elbow 68 has a convexly-shaped curvature relative to the fan grill 26 and the flow director 36 as shown in FIGS. 2, 4 and 6. The collar elbow 68 has a first end 76 fixed to the collar mount 66 and a second end 78 fixed to the collar extension 70. The collar elbow 68 curves constantly from the first end 76 to the second end 78 to provide the convexly-shaped curvature of the collar elbow 68. The collar elbow 68 makes a 90 degree turn between the first end 76 and the second end 78 to gradually transition from the collar mount 66 to the collar extension 70.

The collar extension 70 is fixed to the second end 78 of the collar elbow 68 and extends substantially vertically away from the collar elbow 68 and toward the fan wheel 14 as shown in FIGS. 2, 4, and 6. The collar extension 70 includes a lower end 80 and the upper, distal end 28U located above the distal end 62 of each of the plurality of fan blades 56.

The collar mount 66 has a first diameter 82 as shown in FIG. 6. The collar extension 70 has a second diameter 84 less than the first diameter 82. The inlet 18 has a third diameter 86 less than the second diameter 84 and greater than the first diameter 82. In some embodiments, the third diameter 86 may be equal to the first diameter 82.

Referring back to FIG. 2, the flow director 36 cooperates with the inlet collar to provide a gradual transition flow path FG therebetween that guides the air from fan grille 26 into the inlet 18. The flow director 36 is arranged to lie along the rotation axis 58 of the plurality of fan blades 56 and includes a proximal end 88, a distal end 90, and a flow-director body 92. The proximal end 88 of the flow director 36 is fixed to the grille plate 32. The distal end 90 is arranged to lie at the inlet 18 and/or within the interior space 16 of the main housing 46. The proximal end 90 may also be arranged to lie within the second interior space 50 of the scroll 12. The flow-director body 92 extends between the proximal end 88 and the distal end 90.

The flow director 36 may be symmetrical about the rotation axis 58 and has a diameter that decreases from the proximal end 88 to the distal end 90 as shown in FIGS. 2 and 7-9. The flow-director body 92 may decrease in diameter exponentially from the proximal end 88 to the distal end 90. For example, an outer surface 94 of the flow-director body 92 may have a first slope at a first distance from the proximal end 88 and a second slope at a second distance from the proximal end 88. The first slope may be less than the second slope. In some embodiments, the diameter of the flow-director body 92 may decrease constantly from the proximal end 88 to the distal end 90 such that a slope of the flow-director body 92 remains unchanged from the proximal end 88 to the distal end 90. The distal end 90 is circular and flat in the illustrative embodiment, however, in other embodiments, the distal end may include a pointed tip.

The proximal end 88 of the flow director 36 has a first diameter 94 as shown in FIG. 8. The distal end 90 of the flow director 36 has a second diameter 96. The first diameter 94 is greater than the second diameter 96. The first diameter 94 of the proximal end 88 of the flow director 36 is also greater than the first diameter 82 and the second diameter 84 of the inlet collar 28 and the third diameter 86 of the inlet 18. In some embodiments, it may be desirable to position an outer edge of the proximal end 88 of the flow director 36 as close to the plurality of louvers 34 as possible to begin guiding the air as soon as the air passes through the plurality of intake openings 38. The second diameter 96 of the distal end 90 of the flow director 36 is less than the first diameter 82 and the second diameter 84 of the inlet collar 28 and the third diameter 86 of the inlet 18.

The flow director 36 may be formed to include one or more cutouts 98 as shown in FIGS. 7 and 8. The cutouts 98 may be formed in to one or more of the proximal end 88, the distal end 90, and the flow-director body 92. The cutouts 98 provide spaces which can accommodate other features formed on the fan grille 26 such as attachment features 100 which are used to attach the fan grille 26 removably to the fan housing 44 or to the ceiling 22.

In the illustrative embodiment, the flow-director body 92 is hollow such that the flow-director body 92 is formed to include an interior cavity 102 as shown in FIG. 9. The interior cavity 102 may be filled with a noise-reducing filler 104 to attenuate noise produced by the ventilation fan 10 during operation. The noise-reducing filler 104 may be, for example, air, gases with different densities (i.e. different elements or pressures), a foam material, or any other suitable noise-attenuating substance.

The flow-director body 92 may be formed to include a plurality of sub-cavities 106, 108, 110. The sub-cavities 106, 108, 110 are divided by internal walls 112, 114, 116. For example, the internal walls 112, 114, 116 may include one or more horizontally-extending walls 112, 114 and one or more vertically-extending walls 116 that connect to the horizontally-extending walls 112, 114. The sub-cavities 106, 108, 110 may be filled with the same noise-attenuating substance, or the sub-cavities 106, 108, 110 may have different noise-attenuating substances received therein.

An outer surface 93 of the flow-director body 92 cooperates with the inlet collar 28 to provide the gradual transition flow path FG between the flow-director body 92 and the inlet collar 28 as shown in FIG. 2. The outer surface 93 of the flow-director body 92 is concavely-shaped relative to the inlet collar 28. The collar elbow 68 of the inlet collar 28 is convexly-shaped relative to the flow director 36. In some embodiments, the collar elbow 68 of the inlet collar 28 and the outer surface 93 of the flow-director body 92 have the same or substantially the same curvature. In this way, the gradual transition flow path FG may be defined by a distance between the inlet collar 28 and the flow director 36 that gradually changes along at least a portion of the outer surface 93 of the flow-director body 92. For example, the curvature of the collar elbow 68 and the curvature of the flow-director body 92 may share a common center, in some embodiments. Since the inlet collar 28 and the flow director 36 are symmetrical about axis 58, it should be understood that the center of each respective curvature forms a ring round axis 56.

The wheel hub 54 may be shaped similarly to the flow director 36 as shown in FIG. 2. The wheel hub 54 includes a hub base 120, a shaft mount 122, and a hub body 124. The hub base 120 is coupled to the proximal end 60 of the plurality of fan blades 56. The shaft mount 122 is spaced apart from the hub base 120 and is coupled to the drive shaft 53 of the wheel motor 52. The hub body 124 extends between and interconnects the hub base 120 and the shaft mount 122.

The hub base 120 has a first diameter 126 as shown in FIG. 2. The shaft mount 122 has a second diameter 128. The first diameter 126 is greater than the second diameter 128. The first diameter 126 of the hub base 120 may substantially coincide with the first diameter 82 of the collar mount 66 and/or the first diameter 94 of the proximal end 88 of the flow director 36. The second diameter 126 of the shaft mount 122 may substantially coincide with the second diameter 96 of the distal end 90 of the flow director 36.

The hub body 124 may be concavely-shaped relative to the plurality of fan blades 56 as shown in FIG. 2. The curved shape of the hub body 124 may substantially match the curved shape of the flow-director body 92. The hub body 124 may be formed as a solid, imperforate component to help guide air toward the plurality of fan blades 56 in some embodiments. In other embodiments, the hub body 124 may include a plurality of spokes 130 that extend between the hub base 120 and the shaft mount 122 and that are spaced circumferentially about rotation axis 58 to define gaps between each of the plurality of spokes 130 as shown in FIG. 4.

Referring now to FIG. 11, a chart is shown comparing noise levels produced during operation of the ventilation fan 10 including the inlet collar 28 and the flow director 36 compared to a comparative fan without the inlet collar 28 and the flow director 36. The chart compares sound level (sones) in the y-axis to frequency (hertz) in the x-axis. The inlet collar 28 and flow director 36 combination was shown to provide reduced or maintained sound levels at each frequency while maintaining or improving one or more of flow rate, power consumption, pressure drop, etc.

In some embodiments, the present disclosure includes a flow director 36 that attaches to a back side 32 of an exhaust fan grille 26 and that extends inside of the fan housing 44. One functionality of the disclosure is to direct air in a more uniform flow. The present disclosure may replace comparative grille designs that do not have any design features on the inside of the grille.

In some comparative grille cover designs, once air passes into the grille there is no feature further guiding the airflow into the blower. The air that passes through the grille openings, behind the grille, is therefore turbulent. By adding the flow director 36 to the inside of the grille, air is guided into the opening of the blower more smoothly and airflow turbulence is reduced. The reduction in air turbulence leads to a reduction in noise. In some embodiments, the flow director 36 can also be filled with different sound dampening materials (i.e. foam, silicone, epoxy, etc.) dampening and absorbing any noise given off from the fan blower.

The present disclosure of the flow director 36 may be used in combination with the inlet collar 28. In some embodiments, the ventilation fan 10 includes inlet collar 28 that attaches to the inlet 18 of the scroll 12. One feature of this ring 28 is the extended inner side wall that extends into the blower overlapping the wheel blades 56. One functionality of this extended wall feature is to block the air gap between the scroll and top of the wheel.

In prior ventilation fans, the gap 64 between the scroll inlet 18 and the top of the wheel 14 allows air to pass through the blower above the wheel blades 56. This may cause a differential in air pressures to occur in the system. The differing air pressures may cause blower turbulent airflow and increased fan noise. The extension 70 of the inlet collar 28 blocks the inlet flow from flossing into the gap 64 and air is thus forced further into the wheel, increasing the effective surface area of the blade lengths of the wheel. This reduces the pressure differential and generates a more uniform airflow through the system.

It should be noted that the various components and features described above can be combined in a variety of ways, so as to provide other non-illustrated embodiments within the scope of the disclosure. As such, it is to be understood that the disclosure is not limited in its application to the details of construction and parts illustrated in the accompanying drawings and described hereinabove. The disclosure is capable of other embodiments and of being practiced in various ways. It is also to be understood that the phraseology or terminology used herein is for the purpose of description and not limitation.

Although the present disclosure has been described in the foregoing description by way of illustrative embodiments thereof, these embodiments can be modified at will, without departing from the spirit, scope, and nature of the subject disclosed.

Claims

1. A ventilation fan comprising a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,a fan wheel coupled to the scroll and arranged to lie within the interior space, the fan wheel including a plurality of fan blades configured to rotate about a vertical rotation axis to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan,an inlet collar coupled to an exterior surface of a bottom wall of the scroll and extending through the inlet, the inlet collar having a upper, distal end located above a lower end of each of the plurality of fan blades, anda fan grille arranged to overlie the inlet of the scroll, the fan grille including a perimeter rim adapted to engage a wall of the room when the fan grille is fully installed, a grille plate arranged to extend substantially parallel to and in spaced apart relation to the inlet, a plurality of louvers interconnecting the perimeter rim and an outer edge of the grille plate and spaced apart from one another to define a plurality of grille intake openings, and a flow director coupled to an interior surface of the grille plate facing toward the scroll and arranged to extend toward the inlet collar and the inlet to the scroll and to cooperate with the inlet collar to guide air being withdrawn through the plurality of grille intake openings into the inlet of the scroll.

2. The ventilation fan of claim 1, wherein the flow director includes a proximal end fixed to the grille plate, a distal end arranged to lie at the inlet or within the interior space of the scroll, and a flow-director body extending between the proximal end and the distal end and having a diameter that decreases from the proximal end to the distal end.

3. The ventilation fan of claim 2, wherein the flow-director body decreases exponentially from the proximal end to the distal end such that an outer surface of the flow-director body has a first slope at a first distance from the proximal end and a second slope at a second distance from the proximal end, the first slope being less than the second slope and the first distance being less than the second distance.

4. The ventilation fan of claim 3, wherein the outer surface of the flow-director body cooperates with the inlet collar to provide a curved flow path between the flow-director body and the inlet collar.

5. The ventilation fan of claim 2, wherein a diameter of the proximal end of the flow director is greater than a maximum diameter of the inlet collar.

6. The ventilation fan of claim 2, wherein the flow-director body is hollow and the flow director further includes a noise-reducing filler within the flow-director body.

7. The ventilation fan of claim 1, wherein the inlet collar includes a collar mount fixed to a bottom wall of the scroll, a collar elbow coupled to the collar mount, and a collar extension extending into the interior space and having the upper, distal end located above the lower end of each of the plurality of fan blades.

8. The ventilation fan of claim 7, wherein the collar mount extends radially outward away from the collar elbow and the vertical rotation axis and the collar elbow has a convexly-shaped curvature relative to the fan grill.

9. A ventilation fan comprising a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,a fan wheel coupled to the scroll and arranged to lie within the interior space, the fan wheel including a plurality of fan blades configured to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan, anda fan grille arranged to overlie the inlet of the scroll, the fan grille including a perimeter rim adapted to engage a wall of the room when the fan grille is fully installed, a grille plate arranged to extend substantially parallel to and in spaced apart relation to the inlet, a plurality of louvers interconnecting the perimeter rim and an outer edge of the grille plate and spaced apart from one another to define a plurality of grille intake openings, and a flow director coupled to an interior surface of the grille plate facing toward the scroll and arranged to extend through the inlet to the scroll to guide air being withdrawn through the plurality of grille intake openings and into the inlet of the scroll.

10. A ventilation fan comprising a scroll formed to define an interior space, an inlet opening into the interior space, and an outlet spaced apart from the inlet,a fan wheel coupled to the scroll and arranged to lie within the interior space, the fan wheel including a plurality of fan blades configured to withdraw air into the interior space to ventilate a room positioned adjacent to the ventilation fan, andan inlet collar coupled to an exterior surface of a bottom wall of the scroll and extending through the inlet, the inlet collar having a upper, distal end located above a lower end of each of the plurality of fan blades.