FRESH AIR INLET

Abstract

An air inlet for an air handling unit includes a duct defining a passageway leading to the air handling unit. The fresh air inlet further includes an intake screen that is formed to include a plurality of openings sized to allow airflow to pass through the openings to the air handling unit. Particles are blocked from adhering and accumulating to surfaces of the intake screen.

Description

BACKGROUND

The present disclosure relates to an air inlet, and particularly to an air inlet that covers a hole in a wall of a building. More particularly, the present disclosure relates to an air inlet that covers a hole in an exterior wall of a building.

SUMMARY

In accordance with the present disclosure, an air inlet for a building structure is in fluid communication with an air handling unit. The air inlet includes a duct mount configured to couple to a duct. The duct mount defines an aperture that opens into the duct to direct air into the building structure toward the air handling unit. The air inlet may further include an intake screen including a plurality of airfoils extending across the aperture. The plurality of airfoil are configured to increase a velocity of air passing between each of the airfoils to minimize formation of debris deposits on or around the plurality of airfoils.

In illustrative embodiments, each of the airfoils has a length extending from a leading end of each airfoil to a trailing end of each airfoil. Each airfoil has a first thickness at the leading end, a second thickness at the trailing end, and a third thickness at between the leading end and the trailing end. The third thickness may be greater than the first thickness and the second thickness to provide a velocity-increasing passageway between each of the airfoils. In illustrative embodiments, a maximum thickness of each airfoil may be located a first distance from the leading end and a second distance from the trailing end, with the second distance being greater than the first distance.

In illustrative embodiments, the plurality of airfoils includes a first plurality of airfoils that extend across the aperture in a first direction and a second plurality of airfoils that extend across the aperture in a second direction perpendicular to the first direction. The first plurality of airfoils and the second plurality of airfoils may be arranged so that an angle of incidence of each airfoil is about 0 degrees relative to an axis extending through a center of the aperture. In some embodiments, the first plurality of airfoils are each arranged so that a first angle of incidence of the first plurality of airfoils is about 0 degrees relative to an axis extending through a center of the aperture, and the second plurality of airfoils are each arranged so that a second angle of incidence of the second plurality of airfoils is within a range of about 5 degrees to about 45 degrees relative to the axis. In some embodiments, the length of the first plurality of airfoils is greater than the length of the second plurality of airfoils.

In illustrative embodiments, the air inlet further includes a screen cover having a sloped top wall and a pair of opposing side walls, lower ends of the top wall and the side walls define an intake opening that allows air to flow under the top wall to the intake screen. The second plurality of airfoil may be angled to extend downwardly toward the intake opening.

In illustrative embodiments, each of the plurality of airfoils is included in a square-shaped pane. The air inlet may further include a plurality of supports interconnecting each of the square-shaped panes and the duct mount to one another.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a perspective view of a fresh air inlet that is configured to be positioned in or adjacent to a hole in an exterior wall of a building and that includes an intake screen spanning the hole to block passage of relatively large objects;

FIG. 2 is a cross sectional view of the fresh air inlet from FIG. 1 showing that the air inlet includes an intake screen having a plurality of strips with an airfoil-shaped cross section to define velocity-increasing passageways between each strip;

FIG. 3 is an enlarged portion of the cross sectional view of FIG. 2 showing details of the airfoil-shaped cross section of some of the strips;

FIG. 4 is a perspective view of a fresh air inlet similar to the fresh air inlet of FIG. 1;

FIG. 5 is rear view of the fresh air inlet of FIG. 4;

FIG. 6 is a velocity profile of the air inlet of FIG. 1;

FIG. 7 is an enlarged portion of FIG. 6 showing air velocity around each of the airfoils;

FIG. 8 is a cross sectional view of another fresh air inlet similar to FIG. 2 including an intake screen having a plurality of strips with a different airfoil-shaped cross section;

FIG. 9 is an enlarged portion of the cross sectional view of FIG. 8 showing details of the airfoil-shaped cross section of some of the strips;

FIG. 10 is a perspective and cross sectional view through a vertical plane of the air inlet of FIG. 8;

FIG. 11 is a perspective and cross sectional view through a horizontal plane of the air inlet of FIG. 8;

FIG. 12 is a velocity profile of the air inlet of FIG. 8;

FIG. 13 is an enlarged portion of FIG. 12 showing air velocity around each of the airfoils;

FIG. 14 is a front view of an intake screen including a plurality of strips having an airfoil-shaped cross section;

FIG. 15 is a perspective and cross sectional view of the intake screen of FIG. 14 showing the airfoil-shaped cross section of some of the strips included in the intake screen;

FIG. 16 is a perspective view of another embodiment of an air inlet including an intake screen having a plurality of strips with an airfoil-shaped cross section; and

FIG. 17 is a velocity profile of another air inlet including an intake screen without any strips with an airfoil-shaped cross section.

DETAILED DESCRIPTION

An air inlet 10 is configured to be coupled to an air handling unit 100 and is configured to receive and direct an airflow to the air handling unit 100 as shown in FIG. 1 or other location. The air inlet 10 is illustratively embodied as an outdoor air inlet 10 for a fresh air system although the air inlet 10 may be used in other applications involving airflows through ducts. The air inlet 10 is configured to be positioned in or adjacent to an opening or hole in an exterior wall of a building. The air handling unit 100 includes one or more fans that are configured to draw fresh air through the air inlet 10. The air inlet 10 covers the opening in the building to block relatively large objects, such as birds or large debris, from passing through the air inlet 10 and reaching the air handling unit 100 and/or entering the building.

The air inlet 10 includes a duct mount 12 that is formed to define an aperture 14 and an intake screen 16 that is sized to span the aperture 14 as shown in FIG. 1. The duct mount 12 may have any shape, but, in the illustrative embodiment, has a square shape and is configured to mount to a duct 18 that leads to the air handling unit 100. The duct mount 12 may couple to the duct 18 or another structure around the duct 18 (i.e. the building) and positions the intake screen 16 relative to the duct 18. The aperture 14 formed in the duct mount 12 is circular in shape to match a shape of the duct 18, but, in other embodiments, may have a different shape (i.e. square or rectangular). The intake screen 16 also has a circular shape that corresponds with the aperture 14.

The intake screen 16 has a diameter that is greater than or equal to a diameter of the aperture 14 to extend all the way across the aperture 14. The intake screen 16 is illustratively embodied as a grid 25 formed by a plurality of strips that define a plurality of openings 20 therebetween. The plurality of openings 20 are smaller than the aperture 14 to block large objects from entering the duct 18. In some embodiments, the duct mount 12 may be omitted and the intake screen 16 is attached directly to the duct 18 or the building.

The intake screen 16 includes a plurality of airfoils 22 (or strips having an airfoil-shaped cross section) that extend across the aperture 14 and interconnect with one another to form the grid 25 defining the plurality of openings 20 as shown in FIGS. 1 and 2. Each of the plurality of airfoils 22 has a cross sectional shape that varies in thickness from a leading end 24 to a trailing end 26 downstream of the leading end 24 of each of the plurality of airfoils 22. In general, each of the plurality of airfoils 22 increases gradually in thickness from the leading end 24 to a maximum thickness 28 between the leading end 24 and the trailing end 26 and then decreases gradually in thickness from the maximum thickness 28 to the trailing end 26.

In the illustrative embodiment, the plurality of airfoils 22 cooperate to define a velocity-increasing passageway 30 between each neighboring airfoil 22 as shown in FIGS. 2 and 3. The cross sectional shape of each airfoil 22 is configured to increase a velocity of air flowing though each velocity-increasing passageway 30 so that particles move past each airfoil 22 without adhering to the airfoils and accumulating overtime to block aperture 14. In some embodiments, other cross sectional shapes of the strips 22 may also define velocity-increasing passageways such as a diamond shape, for example.

Because of the cross sectional shape of each airfoil 22, each velocity-increasing passageway has a first area upstream of the maximum thickness 28 of the airfoils 22, a second area at the maximum thickness 28, and a third area downstream of the maximum thickness 28. The first area and the third area are both greater than the second area. The first area increases gradually from the leading end 24 of the airfoil 22 to the maximum thickness 28. The third area decreases gradually from the maximum thickness 28 of the airfoils 22 to the trailing end 26. The velocity of the air in each velocity-increasing passageway 30 is highest at the second area.

Each of the plurality of airfoils 22 is symmetrical about a central plane 32 passing through the leading end 24 and the trailing end 26 of each respective airfoil 22 as shown in FIG. 3. Accordingly, each airfoil 22 has an angle of incidence relative to an axis 15 passing through a center of the aperture 14 equal to about 0 degrees. In other words, the central plane 32 of each airfoil 22 is generally parallel with axis 15.

Each of the airfoils 22 has a length 34 extending between the leading end 24 and the trailing end 26 as shown in FIG. 3. The maximum thickness 28 is closer to the leading end 24 than the trailing end 26 so that the velocity of the air in each velocity-increasing passageway 30 rapidly increases from the leading end 24 to the point of maximum thickness 28 and then decreases velocity at a lower rate and/or over a longer distance downstream from the maximum thickness 28 to minimize pressure losses. In some embodiments, the maximum thickness 28 is within a range of about 5% to about 15% the length 34. In some embodiments, the maximum thickness 28 is within a range of about 8% to about 12% the length 34. In some embodiments, the maximum thickness 28 is about 10% the length 34. As used herein the term “about” means within 1%.

The leading end 24 is spaced a first distance 36 from the maximum thickness 28 while the trailing end 26 is spaced a second distance 38 from the maximum thickness 28. The first distance 36 is less than the second distance 38. In some embodiments, the first distance 36 is within a range of about 15% to about 35% the second distance 38. In some embodiments, the first distance 36 is within a range of about 20% to about 30% the second distance 38. In some embodiments, the first distance 36 is within a range of about 22% to about 28% the second distance 38. In some embodiments, the first distance 36 is about 25% the second distance 38.

The plurality of airfoils 22 includes a plurality of vertically-extending airfoils 40 and a plurality of horizontally-extending airfoils 42 that are arranged generally perpendicular to the plurality of vertically-extending airfoils 40 as shown in FIGS. 1, 4 and 5. The plurality of vertically-extending airfoils 40 and the plurality of horizontally-extending airfoils 42 cooperate to provide the grid 25 having generally square-shaped openings 20 at the leading end 24 of each airfoil 22. The leading end 24 of each vertically-extending airfoil 40 is spaced apart from the leading end 24 of each neighboring vertically-extending airfoil 40 by a distance of about 0.5 inches. Likewise, the leading end 24 of each horizontally-extending airfoil 42 is spaced apart from the leading end 24 of each neighboring horizontally-extending airfoil 42 by a distance of about 0.5 inches. In other embodiments, any suitable distance between leading ends 24 may be used. In some embodiments, the distance between the leading ends 24 of the vertically-extending airfoils 40 can be different from the distance between the leading ends 24 of the horizontally-extending airfoils 42.

In some embodiments, the airfoils 22 may be arranged in a different formation such that they extend in directions other than vertically and horizontally. For example, each airfoil 22 may be arranged or oriented at an angle between the vertical and horizontal directions. In yet another embodiment, the airfoils 22 may be arranged to lie at different angles relative to one another such that the plurality of airfoils 22 form openings 20 having a different shape, such as a diamond, triangle, parallelogram, etc.

The aperture 14 in the illustrative embodiment is circular in shape as shown in FIGS. 4 and 5. Some of the openings 20 in an outer periphery of the aperture 14 may have a different shape than openings 20 defined entirely by airfoils 22 due to being defined partially by the duct 18 or other structure defining aperture 14. In the illustrative embodiment, all openings 20 have maximum dimensions of at most 0.5 inches to meet regulations, however any suitable spacing may be used in other embodiments where regulations are different, for example.

The air inlet 10 may optionally include a screen cover 44 coupled to the duct mount 12 and/or the building and arranged upstream of the intake screen 16 as shown in FIGS. 1, 2, and 4. The screen cover 44 has a sloped top wall 46 and a pair of opposing side walls 48, 50. Lower ends of the top wall 46 and the side walls 48, 50 define an intake opening 52 that allows air to flow under the top wall 46 to the intake screen 16. The top wall 46 is arranged to lie at a downwardly sloping angle from the duct mount 12. In some embodiments, the top wall 46 is arranged to lie at an angle 47 within a range of about 20 degrees to about 60 degrees from a vertical plane extending across aperture 14.

The top wall 46 and the two side walls 48, 50 are configured to block falling particles such as rain, snow, ice, etc. from reaching the intake screen 16. Air is drawn toward intake screen 16 through intake opening 52 in a generally upward direction. As a result of the upward flow of air, some intake screens cause a region of stagnant air 54 downstream of the intake screen 16 within the duct 18 as shown in FIG. 17. The plurality of airfoils 22 included in the illustrative embodiment straighten the air passing through aperture 14 in the direction of the duct 18 to reduce the region of stagnant air 54, as shown in FIG. 6, compared to other intake screens that do not have airfoils 22 like the intake scree shown in FIG. 17. In this way, the plurality of airfoils 22 may reduce pressure losses caused by air inlet 10 with a cover 44. The plurality of airfoils 22 cause localized areas of high velocity within the velocity-increasing passageways 30 as suggested in FIG. 7.

Another embodiment of an air inlet 210 is shown in FIGS. 8-13. Air inlet 210 is similar to air inlet 10. Accordingly, similar reference numbers are used to reference similar features between air inlet 10 and air inlet 210. The disclosure of air inlet 10 is incorporated by reference for air inlet 210.

The air inlet 210 includes a duct mount 212 that is formed to define an aperture 214 and an intake screen 216 that is sized to span the aperture 214 as shown in FIGS. 8, 10, and 11. The duct mount 212 may have any shape, but, in the illustrative embodiment, has a square shape and is configured to mount to a duct 218 that leads to the air handling unit 100. The duct mount 212 may couple to the duct 218 or another structure around the duct 218 (i.e. the building) and positions the intake screen 216 relative to the duct 218. The aperture 214 formed in the duct mount 212 is circular in shape to match a shape of the duct 218, but, in other embodiments, may have a different shape (i.e. square, rectangular, triangular, etc.). The intake screen 216 also has a circular shape that corresponds with the aperture 214.

The intake screen 216 has a diameter that is greater than or equal to a diameter of the aperture 214 to extend all the way across the aperture 214. The intake screen 216 is illustratively embodied as a grid formed by a plurality of strips that define a plurality of openings 220 therebetween. The plurality of openings 220 are smaller than the aperture 214 to block large objects from entering the duct 218. In some embodiments, the duct mount 212 may be omitted and the intake screen 216 is attached directly to the duct 218 or the building.

The intake screen 216 includes a plurality of airfoils 222 (or strips having an airfoil-shaped cross section) that extend across the aperture 214 and interconnect with one another to form a grid 225 defining the plurality of openings 220 as shown in FIGS. 8, 10, and 11. Each of the plurality of airfoils 222 has a cross sectional shape that varies in thickness from a leading end 224 to a trailing end 226 downstream of the leading end 224 of each of the plurality of airfoils 222. In general, each of the plurality of airfoils 222 increases gradually in thickness from the leading end 224 to a maximum thickness 228 between the leading end 224 and the trailing end 226 and then decreases gradually in thickness from the maximum thickness 228 to the trailing end 226.

In the illustrative embodiment, the plurality of airfoils 222 cooperate to define a velocity-increasing passageway 230 between each neighboring airfoil 222 as shown in FIGS. 8 and 9. The cross sectional shape of each airfoil 222 is configured to increase a velocity of air flowing though each velocity-increasing passageway 230 so that particles move past each airfoil 222 without adhering to the airfoils and accumulating overtime to block aperture 214.

Because of the cross sectional shape of each airfoil 222, each velocity-increasing passageway 230 has a first area upstream of the maximum thickness 228 of the airfoils 222, a second area at the maximum thickness 228, and a third area downstream of the maximum thickness 228. The first area and the third area are both greater than the second area. The first area increases gradually from the leading end 224 of the airfoil 222 to the maximum thickness 228. The third area decreases gradually from the maximum thickness 228 of the airfoils 222 to the trailing end 226. The velocity of the air in each velocity-increasing passageway 230 is highest at the second area.

Each of the plurality of airfoils 222 is angled and curved relative to an axis 15 of the aperture 14 as shown in FIGS. 8 and 9. Each airfoil 222 has an angle of incidence relative to the axis 15 passing through a center of the aperture 14 within a range of about 5 degrees to about 45 degrees to guide the air passing through aperture 214 toward the duct 218.

Each of the airfoils 222 has a length 234 extending between the leading end 224 and the trailing end 226 as shown in FIG. 9. The maximum thickness 228 is closer to the leading end 224 than the trailing end 226 so that the velocity of the air in each velocity-increasing passageway 230 rapidly increases from the leading end 224 to the point of maximum thickness 228 and then decreases velocity at a lower rate and/or over a longer distance downstream from the maximum thickness 228 to the trailing end 226 to minimize pressure losses. In some embodiments, the maximum thickness 228 is within a range of about 5% to about 15% the length 234. In some embodiments, the maximum thickness 228 is within a range of about 10% to about 14% the length 234. In some embodiments, the maximum thickness 228 is about 13% the length 234. As used herein the term “about” means within 1%.

The leading end 224 is spaced a first distance 236 from the maximum thickness 228 while the trailing end 226 is spaced a second distance 238 from the maximum thickness 228. The first distance 236 is less than the second distance 238. In some embodiments, the first distance 236 is within a range of about 15% to about 35% the second distance 238. In some embodiments, the first distance 236 is within a range of about 20% to about 30% the second distance 238. In some embodiments, the first distance 236 is within a range of about 20% to about 26% the second distance 238. In some embodiments, the first distance 236 is about 22% the second distance 238. As used herein the term “about” means within 1%.

The plurality of airfoils 222 includes a plurality of vertically-extending airfoils 240 and a plurality of horizontally-extending airfoils 242 that are arranged generally perpendicular to the plurality of vertically-extending airfoils 240 as shown in FIGS. 10 and 11. The plurality of vertically-extending airfoils 240 and the plurality of horizontally-extending airfoils 242 cooperate to provide the grid 225 having generally square-shaped openings 220 at the leading end 224 of each airfoil 222. The leading end 224 of each vertically-extending airfoil 240 is spaced apart from the leading end 224 of each neighboring vertically-extending airfoil 240 by a distance of about 0.5 inches. Likewise, the leading end 224 of each horizontally-extending airfoil 242 is spaced apart from the leading end 224 of each neighboring horizontally-extending airfoil 242 by a distance of about 0.5 inches. In other embodiments, any suitable distance between leading ends 224 may be used. In some embodiments, the distance between the leading ends 224 of the vertically-extending airfoils 240 can be different from the distance between the leading ends 224 of the horizontally-extending airfoils 242.

In some embodiments, the airfoils 222 may be arranged in a different formation such that they extend in directions other than vertically and horizontally. For example, each airfoil 222 may be arranged or oriented at an angle between the vertical and horizontal directions. In yet another embodiment, the airfoils 222 may be arranged to lie at different angles relative to one another such that the plurality of airfoils 222 form openings 220 having a different shape, such as a diamond, triangle, parallelogram, etc.

The aperture 214 in the illustrative embodiment is circular in shape. Some of the openings 220 in an outer periphery of the aperture 214 may have a different shape than openings 220 defined entirely by airfoils 222 due to those peripheral airfoils 222 being defined partially by the duct 218 or other structure defining aperture 214. In the illustrative embodiment, all openings 220 have maximum dimensions of at most 0.5 inches to meet regulations, however any suitable spacing may be used in other embodiments where regulations are different, for example.

The air inlet 210 may optionally include a screen cover 244 coupled to the duct mount 212 and/or the building and arranged upstream of the intake screen 216 as shown in FIGS. 10 and 11. The screen cover 244 has a sloped top wall 246 and a pair of opposing side walls 248, 250. Lower ends of the top wall 246 and the side walls 248, 250 define an intake opening 252 that allows air to flow under the top wall 246 to the intake screen 216.

The top wall 246 and the two side walls 248, 250 are configured to block falling particles such as rain, snow, ice, etc. from reaching the intake screen 216. Air is drawn toward intake screen 216 through the intake opening 252 in a generally upward direction. As a result of the upward flow of air, some intake screens cause a region of stagnant air 254 downstream of the intake screen 216 within the duct 218 as shown in FIG. 15. The plurality of airfoils 222 included in the illustrative embodiment straighten the air passing through aperture 214 in the direction of the duct 218 to reduce the region of stagnant air 254, as shown in FIG. 12, compared to other intake screens that do not have airfoils 222 like the intake scree shown in FIG. 17. In this way, the plurality of airfoils 222 may reduce pressure losses caused by air inlet 210 with a cover 244. The plurality of airfoils 222 cause localized areas of high velocity within the velocity-increasing passageways 230 as suggested in FIG. 13.

Each of the airfoils 222 are angled so that the leading end 224 faces generally downwardly toward the intake opening 252 as shown in FIGS. 10-13. Such an arrangement tracks more closely with the airflow entering intake opening 252 and flowing through aperture 214 toward duct 218. Accordingly, the airfoils are configured to direct the airflow and straighten the airflow downstream of the intake screen 216.

In some embodiments, each airfoil may have a different angle of incidence. For example, a lowermost airfoil 260 may have a first angle of incidence of about 20 degrees while an uppermost airfoil 262 may have a second angle of incidence of about 10 degrees. Other airfoils 222 between the lowermost airfoil 260 and the uppermost airfoil 262 may have an angle of incidence between 10 and 20 degrees such that the angle of incidence of the airfoils decreases from the lowermost airfoil 260 to the uppermost airfoil 262. Each of the vertically-extending airfoils 240 have an angle of incidence of about 0 such that that are symmetrical about a central plane extending between the leading end 224 and the trailing end 226 of each vertically-extending airfoil 240.

Another embodiment of an air inlet 310 is shown in FIGS. 14 and 15. Air inlet 310 is similar to air inlet 10. Accordingly, similar reference numbers are used to reference similar features between air inlet 10 and air inlet 310. The disclosure of air inlet 10 is incorporated by reference for air inlet 310.

The air inlet 310 is configured for use with an exhaust system in a bathroom, for example. The air inlet includes a mount 312 and a plurality of square-shaped screen panes 322 interconnected by supports 323. Each screen pane 322 has an airfoil-shaped cross section as shown in FIG. 15. In other embodiments, the panes 322 can have a different shape such as circular, triangular, rectangular, etc.

Another embodiment of an air inlet 410 is shown in FIG. 16. Air inlet 410 is similar to air inlet 10. Accordingly, similar reference numbers are used to reference similar features between air inlet 10 and air inlet 410. The disclosure of air inlet 10 is incorporated by reference for air inlet 410.

The air inlet 410 includes a duct mount 412, a cover 444, and an intake screen 416 coupled to the cover 444. The intake screen 416 may be substantially similar to intake screen 16, 216, or 316 but is coupled to lower ends of a top panel 446 and side panels 448, 450 of the cover 444.

The present disclosure is related to fresh air inlet transitions that get installed in the exterior of a home and connect to the inlet duct of a fresh air system or air handling unit. The air inlet may be installed in a hole in a wall to a building. The air inlet includes a bird screen (i.e. an intake screen) which may include up to 0.5 square inch openings, ⅛ square inch openings, ¼ square inch openings, or any other size openings. Some screens may collect debris on surfaces surrounding or defining the openings as air passes therethrough.

In some embodiments, the duct mount 12 could be connected to a straight duct section or an elbow duct for a soffit application. In some embodiments, air inlet can include a different metal cap or plastic cap over the intake screen to offer different models, orientation, and colors. The air inlet 10, 210, 310, 410 can be formed with various manufacturing additives (molded in or coated) to decrease surface friction of the surfaces of the air inlet 10 and block debris from adhering to the surfaces. These additives may include: anti-static (cationic antistatic additives), Teflon coatings (i.e. PTFE—Polytetrafluoroethylene), silicone coatings, ceramic coatings (Sol-gel), etc.

Claims

1. An air inlet for a building structure having an air handling unit, the air inlet comprising: a duct mount configured to couple to a duct and defining an aperture that opens into the duct to direct air into the building structure toward the air handling unit, andan intake screen having a plurality of airfoils extending across the aperture and configured to increase a velocity of air passing between each of the airfoils to minimize formation of debris deposits on or around the plurality of airfoils.

2. The air inlet of claim 1, wherein each of the airfoils has a length extending from a leading end of each airfoil to a trailing end of each airfoil, and wherein each airfoil having a first thickness at the leading end, a second thickness at the trailing end, and a third thickness at between the leading end and the trailing end, the third thickness being greater than the first thickness and the second thickness to provide a velocity-increasing passageway between each of the airfoils.

3. The air inlet of claim 2, wherein a maximum thickness of each airfoil is located a first distance from the leading end and a second distance from the trailing end, the second distance being greater than the first distance.

4. The air inlet of claim 3, wherein the plurality of airfoils has a first plurality of airfoils that extend across the aperture in a first direction and a second plurality of airfoils that extend across the aperture in a second direction perpendicular to the first direction.

5. The air inlet of claim 4, wherein the first plurality of airfoils and the second plurality of airfoils are each arranged so that an angle of incidence of each airfoil is about 0 degrees relative to an axis extending through a center of the aperture.

6. The air inlet of claim 4, wherein the length of the first plurality of airfoils is greater than the length of the second plurality of airfoils.

7. The air inlet of claim 2, wherein the first plurality of airfoils are each arranged so that a first angle of incidence of the first plurality of airfoils is about 0 degrees relative to an axis extending through a center of the aperture, and the second plurality of airfoils are each arranged so that a second angle of incidence of the second plurality of airfoils is within a range of about 5 degrees to about 45 degrees relative to the axis.

8. The air inlet of claim 7, further comprising a screen cover having a sloped top wall and a pair of opposing side walls, lower ends of the top wall and the side walls define an intake opening that allows air to flow under the top wall to the intake screen, and the second plurality of airfoil are angled to extend downwardly toward the intake opening.

9. The air inlet of claim 1, wherein each of the plurality of airfoils comprises a square-shaped pane and the air inlet further comprises a plurality of supports interconnecting each of the square-shaped panes and the duct mount to one another.

10. An air inlet for a building structure having an air handling unit, the air inlet comprising: a duct mount configured to couple to a duct and defining an aperture that opens into the duct to direct air into the building structure toward the air handling unit, andan intake screen configured to span the aperture, the intake screen having a plurality of strips each having leading end and a trailing end spaced downstream from the leading end,wherein a cross section of each strip defines a first thickness at the leading end, a second thickness at the trailing end, and a third thickness at between the leading end and the trailing end, the third thickness being greater than the first thickness and the second thickness to provide a velocity-increasing passageway between each of the strips to increase a velocity of air within each velocity-increasing passageway so that formation of debris deposits on or around the plurality of strips is minimized.

11. The air inlet of claim 10, wherein the cross section of each strip of the plurality of strips is an airfoil-shaped cross section.

12. The air inlet of claim 10, wherein the plurality of strips comprises a first plurality of airfoils that extend across the aperture in a first direction and a second plurality of airfoils that extend across the aperture in a second direction perpendicular to the first direction, and wherein the first plurality of airfoils and the second plurality of airfoils are each arranged so that an angle of incidence of each airfoil is about 0 degrees relative to an axis extending through a center of the aperture.

13. The air inlet of claim 10, wherein the plurality of strips has a first plurality of airfoils that extend across the aperture in a first direction and a second plurality of airfoils that extend across the aperture in a second direction perpendicular to the first direction.

14. The air inlet of claim 13, wherein the first plurality of airfoils are each arranged so that a first angle of incidence of the first plurality of airfoils is about 0 degrees relative to an axis extending through a center of the aperture, and the second plurality of airfoils are each arranged so that a second angle of incidence of the second plurality of airfoils is within a range of about 5 degrees to about 45 degrees relative to the axis.

15. The air inlet of claim 13, wherein the length of the first plurality of airfoils is greater than the length of the second plurality of airfoils.

16. The air inlet of claim 10, further comprising a screen cover having a sloped top wall and a pair of opposing side walls, lower ends of the top wall and the side walls define an intake opening that allows air to flow under the top wall to the intake screen, and the second plurality of airfoil are angled to extend downwardly toward the intake opening.

17. An air inlet for a building structure having an air handling unit, the air inlet comprising: a duct mount configured to couple to a duct and defining an aperture that opens into the duct to direct air into the building structure toward the air handling unit,a cover coupled to the duct mount and comprising a top wall and a pair or side walls spaced apart from one another, lower ends of the top wall and each side wall cooperating to at least partially define an intake opening, andan intake screen configured to span the intake opening, the intake screen having a plurality of strips each having a leading end and a trailing end spaced downstream from the leading end,wherein a cross section of each strip defines a first thickness at the leading end, a second thickness at the trailing end, and a third thickness at between the leading end and the trailing end, the third thickness being greater than the first thickness and the second thickness to provide a velocity-increasing passageway between each of the strips to increase a velocity of air within each velocity-increasing passageway so that formation of debris deposits on or around the plurality of strips is minimized.

18. The air inlet of claim 17, wherein the cross section of each strip of the plurality of strips is an airfoil-shaped cross section.

19. The air inlet of claim 17, wherein the plurality of strips comprises a first plurality of airfoils that extend across the aperture in a first direction and a second plurality of airfoils that extend across the aperture in a second direction perpendicular to the first direction, and wherein the first plurality of airfoils and the second plurality of airfoils are each arranged so that an angle of incidence of each airfoil is about 0 degrees relative to an axis extending through a center of the aperture.

20. The air inlet of claim 17, wherein the plurality of strips comprises a first plurality of airfoils that extend across the aperture in a first direction and a second plurality of airfoils that extend across the aperture in a second direction perpendicular to the first direction, and wherein the first plurality of airfoils are each arranged so that a first angle of incidence of the first plurality of airfoils is about 0 degrees relative to an axis extending through a center of the aperture, and the second plurality of airfoils are each arranged so that a second angle of incidence of the second plurality of airfoils is within a range of about 5 degrees to about 45 degrees relative to the axis.