GB2568131A

GB2568131A - Exhaust assemblies

Info

Publication number: GB2568131A
Application number: GB1813415.5A
Authority: GB
Inventors: Dare James; Lake Jason
Original assignee: Fantech Pty Ltd
Current assignee: Fantech Pty Ltd
Priority date: 2017-11-01
Filing date: 2018-08-16
Publication date: 2019-05-08
Anticipated expiration: 2038-08-16
Also published as: GB201813415D0; AU2018220078B2; GB2568131B; ZA201805776B; AU2018220078A1

Abstract

An exhaust assembly 100 comprises a casing 126 defining a chamber 28 to receive a fan 18. Fluid flow is induced by the fan toward the annular exhaust 38 between a first casing open end 130 and a second casing open end 131 as defined by one or more walls 131A, 131B, 131C. A convex fan cap 136 at the second casing open end covers the fan. The fan may comprise a motor 24 and an impeller 22 having a shroud 62 and a back plate 60 to engage with a base 12. Fluid flow may be guided by tapering of the walls or curved guiding vanes 158 radially extending from the fan cap. The fan cap may define an aperture for the fan, may be one piece moulded and may comprise a convex lid 48 for weather protection. The assembly is particularly suited for building ventilation systems.

Description

[0001] Described embodiments relate generally to exhaust assemblies, such as exhaust assemblies suitable for mounting on rooftops.

Background [0002] Exhaust assemblies are used in building ventilation systems to induce air circulation. Some exhaust assemblies are mounted external to buildings, on rooftops, for instance, to minimise noise and allow maintenance access.

[0003] Exhaust assemblies often comprise a housing or casing that houses a fan, comprising an electric motor and an impeller, for inducing an airflow from building ventilation systems to which they are coupled.

[0004] Various parameters are taken into account when designing exhaust assemblies. These parameters include the required fluid flow capacity and environmental factors, such as water ingress, and exposure to wind and sunlight. Bird and other animal proofing is also a factor which is taken under consideration. Importantly, in considering these factors, a design must balance any restriction to fluid flow through the exhaust assembly with the impact on the efficiency of the exhaust assembly when comparing the energy input into the assembly with the volume of fluid displaced through the exhaust assembly.

[0005] Throughout this specification the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

Summary [0007] Some embodiments relate to an exhaust assembly comprising: a casing defining a chamber, the casing comprising one or more walls extending between a first casing open end and a second casing open end the casing configured to receive a fan within the chamber, spaced apart from the one or more walls, the fan configured for inducing a fluid flow through the chamber between the first casing open end and the second casing open end; a fan cap disposed toward the second casing open end and arranged to cover the fan, the cap defining an annular exhaust between the one or more walls; wherein the fan cap comprises a substantially convex-shaped outer surface configured to cooperate with the one or more walls of the chamber to guide an induced fluid flow from the fan toward the annular exhaust.

[0008] Part of an inner surface of the one or more walls may be curved to taper from the second casing open end toward the first casing open end to guide fluid flow through the chamber toward the annular exhaust. The one or more walls may comprise: a substantially curved first wall portion extending from the second casing open end; and a substantially straight second wall portion extending from the first wall portion toward the first casing open end such that the casing tapers towards the first casing open end.

[0009] The exhaust assembly may further comprise one or more guide vanes disposed within the annular exhaust to guide fluid flow from the chamber through the annular exhaust. The one or more guide vanes may comprise a plurality of guide vanes arranged concentrically about the fan cap. The plurality of guide vanes may be coupled to each other by means of a coupling member. The one or more guide vanes may be curved but it is preferred that they be angled to guide fluid flow along a surface of the respective guide vane before exhausting through the annular exhaust. The one or more concentrically arranged guide vanes may comprise one or more ridges extending radially from a major surface of the respective guide vane to allow the guide vane to couple or engage with a neighbouring guide vane, the cap and/or the one or more wall of the casing.

[0010] The exhaust may comprise a fan provided within the chamber. The fan cap may extend radially from the fan. The fan may comprise a motor and an impeller. The impeller may comprise a back plate configured to cooperate with the cap base to convey fluid flow through the chamber toward the annular exhaust. The impeller may comprise a shroud defining an aperture through which fluid enters the fan and the shroud may be configured to convey fluid flow through the chamber toward the annular exhaust.

[0011] The fan cap may comprise a cap lid arranged to cooperate with a cap base to shield the cap base from precipitation or other environmental elements. The cap lid may comprise a substantially convex-shaped outer surface such that water falling on the cap lid is caused to run off the cap lid into the annular exhaust. The fan cap can comprise a one piece moulding constituting both a fan cap lid and a fan cap base. The fan cap may define a fan aperture for receiving at least part of the fan.

[0012] The exhaust assembly may comprise a base for coupling the exhaust assembly to a ventilation system, the base comprising a first base open end and a second base open end to provide fluid communication between the ventilation system and the fan. The second base open end may engage with the fan such that fluid flow induced by the fan flows from the ventilation system through the base and into the fan.

[0013] The casing may be arranged relative to the base to define a drainage gap between the base and the casing to allow fluids that enter the chamber to drain from the exhaust assembly.

Brief Description of the Drawings [0014] Some embodiments will now be described by way of non-limiting examples with reference to the accompanying drawings.

[0015] Figure 1A shows a perspective view of an exhaust assembly, in accordance with some embodiments;

[0016] Figures IB and 1C show a side view of a cross section of the exhaust assembly of Figure 1A;

[0017] Figure 2 shows a perspective view of a cross section of an exhaust assembly, in accordance with some embodiments;

[0018] Figure 3 A shows a perspective view of an exhaust assembly in accordance with some embodiments;

[0019] Figure 3B shows a plan view of the exhaust assembly of Figure 3 A;

[0020] Figure 3C shows a sectioned side view of the exhaust assembly of Figure 3 A;

[0021] Figure 4A shows a plan view of a casing of the exhaust assembly of Figure 3 A;

[0022] Figure 4B shows a sectioned side view of the casing of Figure 4A [0023] Figure 5A shows a perspective view of a cap base of the exhaust assembly of

Figure 3A;

[0024] Figure 5B shows a underside view of the cap base of Figure 5A;

[0025] Figure 5C shows a side view of the cap base of Figure 5A;

[0026] Figure 5D shows a sectioned side view of the cap base of Figure 5A [0027] Figure 6A shows a plan view of a cap lid of the exhaust assembly of Figure 3A.

[0028] Figure 6B shows a side view of a cap lid of the exhaust assembly of Figure 6A.

[0029] Figure 7A shows a plan view of guide vanes of the exhaust assembly of Figure 3A;

[0030] Figure 7B shows a sectioned side view of the guide vanes of Figure 7A;

[0031] Figure 7C shows enlarged detailed view of the guide vane section marked B in

Figure 7B;

[0032] Figure 8A shows a perspective view of guide vanes of the exhaust assembly of

Figure 3A, in accordance with some embodiments;

[0033] Figure 8B shows a plan view of the guide vanes of Figure 8A;

[0034] Figure 8C shows a sectioned side view of the guide vanes of Figure 8B;

[0035] Figure 8D shows enlarged detailed view of the guide vane section marked A in

Figure 8B;

[0036] Figure 9A shows a simulated fluid flow through a concept design iteration of an exhaust assembly; and [0037] Figure 9B shows a simulated fluid flow through one embodiment of an exhaust assembly.

Description of Embodiments [0038] Described embodiments relate generally to exhaust assemblies, such as exhaust assemblies suitable for mounting on rooftops. Some embodiments are directed towards exhaust assemblies that provide for improved fluid flow.

[0039] For example, in some embodiments, the exhaust assembly comprises a fan cap base having a substantially convex-shaped outer surface which is configured to cooperate with one or more walls of a chamber of the exhaust assembly to guide an induced fluid flow from the fan toward an annular exhaust of the exhaust assembly. In contrast to known exhaust assemblies, where fan caps tend to hinder fluid flow through the exhaust assembly, the convexshaped outer surface of the fan cap base provides for improved fluid flow through the chamber of the exhaust assembly.

[0040] In some embodiments, inner walls of the casing may be configured to improve fluid flow through the exhaust assembly. For example, in some embodiments, one or more inner walls of the casing may be substantially curved and/or may taper from the annual exhaust towards an open end arranged for fluid communication with a building ventilation system to assist in conveying fluid through the casing from the building ventilation system to the annular exhaust. In some embodiments, an impeller of the fan may comprise a back plate configured to contribute or assist in improved conveying of fluid through the chamber toward the annular exhaust. In some embodiments, the exhaust assembly the comprises one or more guide vanes disposed within an annular exhaust defined between an inner surface of the casing and the fan cap to further guide and/or direct fluid flow from the chamber through the annular exhaust and from the exhaust assembly.

[0041] Referring now to Figures 1A and IB, the exhaust assembly 10 may be configured to induce fluid circulation within a building. For example, the exhaust assembly 10 may be arranged to cooperate with a duct element (not shown) of a building ventilation system (not shown) to provide fluid communication between an interior and exterior of the building.

[0042] The exhaust assembly 10 comprises a fan 18 for inducing a fluid flow through the exhaust assembly 10. For example, the fan 18 may comprise an impeller 22 and an electric motor 24. In some embodiments, the fan 18 may be a centrifugal fan or a mixed flow fan.

[0043] In some embodiments, the exhaust assembly 10 comprises a casing 26 defining a chamber 28 for receiving or housing the fan 18. The casing 26 may also be referred to as a wind band or a shell. The casing 26 may comprise one or more walls 31 extending between a first casing open end 30 and a second casing open end 32. The fan 18 may be positioned within the casing 26 and spaced apart from an inner surface of the wall 31 to allow fluid to be conveyed through the casing 26 from the first casing open end 30 to the second casing open end 32. For example, a fluid flow induced by the fan 18 within the casing 26 may cause fluid to flow or be drawn from the first casing open end 30, along a passage of the chamber 28 provided between the fan 18 and the inner surface of the wall 31, and to exit the casing 26 of the exhaust assembly 10 via the second casing open end 32.

[0044] The casing 26 may take the form of any suitable shape. In some embodiments, as shown in Figure IB, the wall 31 of the casing may be substantially curved or cylindrical. The wall 31 may comprises a first wall portion 31A extending from the second casing open end 32 which may be substantially curved and a second wall portion 3 IB which may be substantially straight and extend from the first wall portion 31A to the first casing open end 30. As shown in Figure IB, the width of the casing 26 may be narrower towards the first casing open end 30.

[0045] In other embodiments, such as the exhaust assembly 100 shown in Figure 2, the wall 131 of the casing 126 may taper from the second casing open end 132 towards the first casing open end 130. In other words, a first wall portion 131A extending from second casing open end 132 may be substantially straight and a second wall portion 13 IB may taper from the first wall portion 131A towards the first casing open end 130. In this way, the width of the casing 126 in proximity to the second casing open end 132 may be substantially uniform and may reduce or lessen towards the first casing open end 130. In some embodiments, and as shown in Figure 2, the casing 126 may comprise a third wall portion 131C extending between the second wall portion 13 IB and the first casing open end 130. The third wall portion 131C may be substantially straight, may taper outwardly, or may taper inwardly, at a similar angle or different angle to the taper of the second wall portion 13 IB. As shown in Figure 2, the exhaust assembly 100 may comprise similar features and elements to those of exhaust assembly 10 as depicted in Figures 1A and IB, and accordingly those similar features and elements are denoted by like numerals.

[0046] Referring again to Figures 1A and IB, in some embodiments, the exhaust assembly 10 comprises a fan cap or cap 36 for covering the fan 18. The cap 36 is arranged to be positioned over the fan 18 such that an annular gap or annular exhaust 38 is provided between the inner surface of the wall 31 of the casing 26 and the cap 36. For example, the cap 36 may be disposed at an upper surface of the fan 18 and may extend radially from the fan 18. The cap 36 may be disposed in close proximity to the second casing open end 32 and may be at least partially disposed within the chamber 28. In some embodiments, such as shown in Figure 3C, the exhaust assembly 200 comprises a cap 236 that is fully disposed within the casing 226. The cap 36 may be sized and arranged to form a cover for the fan 18. For example, the cap 36 may be physically dimensioned to at least partially shield the fan 18 from meteorological conditions, such as falling rain.

[0047] The cap 36 may be substantially spherical or disc-shaped. In some embodiments, the cap 36 is in the form a one piece moulded shell having a substantially hollow centre. In another form the cap 36 may comprise a cap base 40 and a cap lid 48. In this latter form the cap base 40 may be substantially arcuate and may be configured to contribute or assist in conveying fluid through the casing 26 and out of the annular exhaust 38. For example, the cap base 40 may be configured to arch into the chamber 28 of the casing 26 from the second casing open end 32. In some embodiments, the cap base 40 may comprise a substantially convexshaped outer surface 42, for example, that curves or bends inwards and upwards towards a cap lid 48, and may be configured to guide an induced fluid flow from the fan 18 toward the annular exhaust 38. As explained in more detail below with reference to Figures 9A and 9B, the exhaust assembly 10 comprising the cap base 40 provides for an improved flow of fluid through the casing 26 that is less impeded by the cap 36. An inner surface 44 of the cap base 40, may be substantially concave or may take any suitable form. As shown in the figures, in some embodiments, the cap base 140 may be substantially bowl shaped and may for example, comprise a substantially planer base section 143 and curved side walls 145. As best shown in Figure 2, the cap base 140 may define a fan aperture 146 for receiving or accommodating at least a part of the fan 18, such as the motor 24 or part thereof, for example.

[0048] Referring again to Figures 1A and IB, the cap 36 may comprise the cap lid 48 arranged to cooperate with the cap base 40. The cap lid 48 may be substantially arcuate or dome shaped. The cap lid 48 may a substantially convex-shaped outer surface, for example, that curves or bends inwards and/ or downwards towards the cap base 40. The cap lid 48 may arch towards the second casing open end 32. The cap lid 48 may project from the second casing open end 32, for example. In some embodiments, the cap base 40 and cap lid 42 cooperate top form a shell or disc, which may be substantially hollow. The cap lid 48 may be configured to shield the cap base 40 and/or the fan 18 from rain or other environmental elements, for example, by causing any water falling on the cap lid 48 to be redirected or caused to run off the cap lid 48 into the annular exhaust 38. As shown in Figure 3C, in some embodiments, the cap lid 248 may be arranged fully within the chamber 228 of the casing 226. Where the cap 36 is a one piece moulding it is shaped in the same way as the cap 36 which comprises the cap lid 48 and cap base 48 so that it functions in the same way as the two piece cap.

[0049] As shown in Figures 1A and IB, in some embodiments, the exhaust assembly 10 comprises one or more guide vanes 58 disposed within the annular exhaust 38 to guide fluid flow from the chamber 28 through the annular exhaust 38 and from the exhaust assembly 10. The one or more guide vanes 58 may comprise a plurality of guide vanes 58 arranged concentrically about the cap 36. The guide vanes 58 may be coupled to each other, for example, by one or more members 59, disposed about the guide vanes, extending radially from an outermost guide vane 58 to an innermost guide vane 58. In some embodiments, the guide vanes 58 may be secured in place within the annular exhaust 38 by coupling the guide vanes 58 or the one or more members 59 to the casing 26 and/or the cap 36. In some embodiments, the guide vanes 58 may be configured to plug into the annular gap and are held in positon by friction. For example, the outermost vane guide 58 may frictionally engage with the inner surface of the wall 31 and the innermost guide vane 58 may frictionally engage with cap 36. The guide vanes 58 may be curved or angled to guide fluid flow along the surface or curvature of the vane before exhausting through the annular exhaust 38. Alternatively, as seen in Figure 2, the guide vanes 158 may be straight and may be substantially parallel to the wall 131 of the casing 126. The number of vanes provided may depend on the dimensions of the annular exhaust 38. The guide vanes 58 may mitigate bird and other animal ingress into the chamber 28 of the casing 26. The guide vanes 58 may mitigate exposure of the fan 18 to meteorological conditions. For example, the guide vanes 58 may guide falling precipitation onto the inner surface of the wall 31 instead of falling onto the fan 18.

[0050] In some embodiments, as shown in Figures 8A to 8D, one or more of the concentrically arranged guide vanes 858 may comprises one or more ridges or ribs 870 extending or projecting radially from an inner or outer major surface of the respective guide vane 858 to allow the guide vane to couple or engage with a neighbouring guide vane, the cap 36 and/or the inner surface of the wall(s) 31 of the casing 26. The one or more ridges 870 may be disposed about the major surface of the respective guide vane in a spaced apart manner. For example, in some embodiments, the innermost guide vane 858-1 comprises one or more ridges 870 extending radially from an inner major surface of the innermost guide vane 858-1 towards the cap 36 to allow the innermost guide vane 858-1, and in some embodiments, thereby all of the guides vanes 858, to couple to or engage with the cap 36. Similarly, in some embodiments, an outermost guide vane 858-2 comprises one or more ridges 870 extending radially from an outer major surface of the outermost guide vane 858-2 towards the inner wall of the casing 26 to allow the outermost guide vane 858-2 To engage with the inner wall of the casing 26.

[0051] In some embodiments, the one or more ridges 870 may extend at least partially, and in some embodiments fully, along the radial thickness of the one or more guide vanes 858. The ridges 870 may be substantially saddle or v-shaped. the one or more ridges 870 of neighbouring guide vanes 858 may be aligned and configured to engage with one another. The ridges 870 of neighbouring guide vanes 858 may be arranged to frictionally engage with one another and/or may be secured together using one or more respective rivets 872. The one or more ridges 870 of the innermost guide vane 858-1 may, for example, couple to the cap 36 by means of one or more respective rivets 872.

[0052] In some embodiments, the one or more ridges 870 are formed by bending or shaping one or more sections of the guide vanes 858. For example, the ridges 870 may be formed from or composed of the same material as that which forms the guide vanes 858. Alternatively, the one or more ridges 870 may be disposed on the major surfaces of the guide vanes and may be composed of any suitable material, including that of the guide vanes 858.

[0053] In some embodiments, the exhaust assembly 10 comprises a base 12 for coupling the exhaust assembly 10 to one or more components of a building ventilation system, such as ducting elements (not shown). The base 12 may comprise a first base open end 14 and a second base open end 16 to provide fluid communication between the interior of the building to which the base 12 is coupled and the fan 18 within the casing 26. The first base open end 14 may be configured to engage or connect with the building ventilation system, or other ducting elements. As shown in Figure 1A, for example, the first base open end 14 may be substantially square or rectangular in shape in order to engage with square or rectangular ducting. Alternatively the first base open end 14 may be substantially circular in shape in order to engage with cylindrical ducting. A rectangular or square shaped first base open end 14 may also be arranged to engage with a cylindrical ducting element.

[0054] The second base open end 16 is configured to cooperate with the fan 18 to allow fluid to be drawn from the interior of a building to which the exhaust assembly 10 is coupled, through the base 12 and into the fan 18. The second base open end 16 and the fan 18 may be engaged and in some embodiments, substantially sealingly engaged, with one another such that fluid being drawn from the interior of the building is funnelled through the base 12 and into the fan 18. For example, the base 12 may constrict or reduce in cross section from the first base open end 14 to the second base open end 16 forming a base neck 15 for engaging the fan 18 and base shoulder 17. The base 12 may comprise one or more bosses 19 to support the casing 26, which may, for example, be disposed on the base shoulder 17. The casing 26 may be arranged relative to the base 12 to define a drainage gap 34 between the base 12 and the casing 26 to allow fluids that enter the chamber 28, usually through the second casing open end 32, such as precipitation, to drain from the exhaust assembly 10.

[0055] With reference to Figures 3C, in some embodiments, the exhaust assembly 200 may comprise a mounting frame 254 for mounting the fan (not shown) to the casing 226 and/or to the base 212. The frame 254 may comprise brackets or struts 256. The fan 18 may be suspended from the frame 254. The cap 236 may be mounted on the frame 254. The cap base 240 may engage with the frame 254. For example, the base feet 252 disposed on the cap base 240 may be received within apertures (not shows) defined within the frame 254.

[0056] Referring again to Figures 1A and IB, in some embodiments, the impeller 22 of the fan 18 may comprise a back plate 60 configured to contribute or assist in conveying fluid through the chamber 28 toward the annular exhaust 38. The back plate 60 may be arranged relative to the cap 36 to assist in limiting or restricting fluid flow between the cap 36and the back plate 60. The back plate 60 may be angled toward the cap 36 to guide fluid flow toward the outer surface 42 of the cap base 40 and the annular exhaust 38. In some embodiments, the back plate 60 may be a substantially disk shaped plate.

[0057] The fan 18 may comprise a shroud 62 for engaging the fan 18 with the duct element (not shown) and/or the base 12. The shroud 62 may engage substantially sealingly with the duct element and/or the second base open end 16 to assist in directing fluid flow from the duct element or the base 12 into the impeller 22. The shroud 62 may be configured to guide fluid flow toward the annular exhaust 38. The shroud 62 may extend away and flare from the second base open end 16 toward the casing wall 31 and/or the annular exhaust 36. The impeller 22 may comprise blades 64 disposed between the back plate 60 and the shroud 62. The blades 64 may be shaped to direct fluid flow towards the annular exhaust 38.

[0058] The annular exhaust 38 may be disposed substantially aligned with the fluid flow discharged from the fan 18 such that the fluid is directed toward the annular exhaust 38. The cap 36, 136 may be arranged within the chamber 28 in order to limit the available space for fluid flow discharged from the fan 18 to recirculate within the chamber 28, between the cap 36, 136, and the back plate 60, for example. Recirculation of fluid within the chamber 28 may result in the formation of vortices and/or undesirable back pressures.

[0059] The exhaust assembly may comprise one or more electrical connections or be configured to facilitate electrical connection of the fan to an electrical supply.

[0060] For exemplary purposes, an installation process for some embodiments of an exhaust assembly 10 is described. The exhaust assembly 10 may be erected on a rooftop to cooperate with a duct element (not shown) of a building ventilation system (not shown) to provide fluid communication between an interior and exterior of the building. The ducting of ventilation systems often terminate in a plinth (not shown) or similar structure in order to accommodate and receive an exhaust assembly. During installation, for some embodiments, the base 12 is arranged on the plinth to provide fluid communication between the building ventilation system and the fan. Alternatively, in some embodiments the plinth or structure may be configured to receive a fan 18 without providing a base 12. In such instances the casing may be mounted on the plinth or alternatively on the rooftop.

[0061] In use, when the fan 18 is activated, it induces a fluid flow from the interior of the building, through the building ventilation system and through the base 12 (if present), and into the chamber 28 of the casing 26 via the second base open end 16. In some embodiments, as depicted in Figure 1C, fluid may be drawn into the chamber 28 substantially along axis Y, and into the fan 18. Fluid is expelled or discharged from the fan 18 and directed towards the one or more walls 31 of the casing 26 and is encouraged or directed to flow towards the annular exhaust 38 by one or more of the shape of the inner surface of the one or more walls 31, the back plate 60 of the fan 18, the shape of the cap base 40 and the guide vanes 58. In some instances, however, some fluid may egress from the chamber 28 through the first casing open end 30 between the casing 26 and the basel2.

[0062] In some embodiments, the fan 18 may discharge the fluid received from the second base open end 16 at an offset angle X relative to axis Y. The offset angle X may be between about 30 degrees and about 90 degrees. The offset angle X may be between about 70 degrees and about 40 degrees. The offset angle X may, for example, as seen in Figure 1C, be about 60 degrees.

[0063] Provided below, in Table 1, are examples of dimensions for a casing 226 depicted in Figures 3A to 3C, 4A and 4B, as may be incorporated in some embodiments. The dimensions are in millimetres and are provided for illustrative purposes only. The physical size of the casing 226 may vary for various applications and embodiments. Various example dimensions of exhaust assemblies 200 in each table are used in conjunction with the dimensions of the coinciding example model number in Tables 2 to 4.

Example Model	A (mm)	B (mm)	C (mm)	E (mm)
1	190	300	270	55
2	245	351	270	55
3	360	500	375	80
4	455	632	500	85

Table 1. Exemplary dimensions relating to various models of the casing depicted in Figures 3A to 3C and Figures 4A and 4B [0064] With reference to Figure 4B, dimension A is the radius of the first casing open end 230. Dimension B is the radius of the second casing open end 232. Dimension C is the longitudinal dimension of the casing wall 231 A. Dimension E is the dimension of the linear section, neck or collar of the second wall portion 23 IB. These dimensions also describe the curvature of the first wall portion 231 A, as the curvature follows part of an ellipse with dimensions that can be determined from dimensions A, B and C.

[0065] Provided below, in Table 2, are examples of dimensions for a top cap base 240 depicted in Figures 3C, 5A and 5B, as may be incorporated in some embodiments. The dimensions are in millimetres and are provided for illustrative purposes only. The physical size of the cap base 240 may vary for various applications and embodiments. Various example dimensions of exhaust assemblies 200 in each table are used in conjunction with the dimensions of the coinciding example model number in Tables 1, 3 and 4.

Example Model	A (mm)	B (mm)	C (mm)	D (mm)	E (mm)	F (mm)	G (mm)
1	75	190	10	70	65	171.4	327
2	75	241.5	20	90	80	271.4	436
3	85	355	20	110	93	325.9	656.4
4	125	451	20	140	120	521	836

Table 2. Example dimensions relating to multiple models of the cap base depicted in Figures 3C and Figures 5A to 5D [0066] With reference to Figures 5B, 5C and 5D, dimension A is the semi-minor axis of the ellipse defining the curvature of the outer surface 242 of the top cap base 240. Dimension B is the outer radius of the cap base 240 as well as the semi-major axis of the ellipse defining the curvature of the outer surface 242. Dimension C is the width of a top cap lid engaging lip 250. Dimension D is the height of a base foot 252. Dimension E is the height of the top cap base 240. Dimension F is the diameter of the circular fan aperture 246 and Dimension G is the diameter of the circle upon which base feet 252 are disposed and spaced on the cap base 240.

[0067] Provided below, in Table 3, are examples of dimensions for a top cap lid 248 depicted in Figures 3A to 3C, 6A and 6B, as may be incorporated into some embodiments. The dimensions are in millimetres and are provided for illustrative purposes only. The physical size of the top cap lid 248 may vary for various applications and embodiments. Various example dimensions of exhaust assemblies 200 in each table are used in conjunction with the dimensions of coinciding example model number in Tables 1, 2 and 4.

Example Model	A (mm)	B (mm)
1	190	40
2	241.5	50
3	355	60
4	451	70

Table 3. Example dimensions relating to multiple models of the cap lid depicted in Figures 3A to 3C and Figures 6A and 6B [0068] With reference to Figure 6A dimension A is the radius of circular cap lid 248 as well as the length of the semi-major axis of the ellipse defining the curvature of cap lid 248. With reference to Figure 6B dimension B is the length of the semi minor axis of the ellipse defining the curvature of the dome of the cap lid 248.

[0069] Provided below, in Table 4, are examples of dimensions for guide vanes as seen in Figures 3A to 3C, 7A to 7C, as may be incorporated into some embodiments. The dimensions are in millimetres and are provided for illustrative purposes only. The physical size of the guide vanes 258 may vary for various applications and embodiments. Various example dimensions of exhaust assemblies 200 in each table are used in conjunction with the dimensions of coinciding example model numbers in Tables 1 to 3.

Example Model	A (mm)	B (mm)	C (mm)	D (mm)
1	205	230	265	70
2	255	280	317.5	50
3	375	410	455	60
4	470	505	550	70

Table 4. Example dimensions relating to multiple models of the guide vanes depicted in Figures 3A to 3C and Figures 7A to 7C [0070] With reference to Figures 7B and 7C, dimension A, B and C are possible radii of various guide vanes 258. For Example Model 4, a fourth guide vane is provided as the dimensions of the second casing open end 232 require the use of an additional guide vane 258.

[0071] As seen in Figure 7C, for example, curvatures of multiple vanes may be arrange to substantially follow the radius of evenly spaced concentric circles.

[0072] With reference to Figure 9A, a simulated fluid flow is shown within an early design iteration of an exhaust assembly which does not include a cap base 40. As can been seen in the model, this arrangement may impede airflow through the assembly, and may lead to recirculation of air within a cavity above the fan 18, thereby resulting in a less effective exhaust assembly. In comparison, Figure 9B shows a simulated fluid flow of an exhaust assembly according to some embodiments, wherein the exhaust assembly comprises a cap base having a substantially convex-shaped outer surface configured to guide an induced fluid flow from the fan toward the annular exhaust. As depicted, the fluid flow through the chamber is much less impeded by the cap with reduced recirculation of air within the cavity above the fan, resulting in an improved air flow through the chamber and overall improved exhaust assembly. As shown, the inner walls 31 of the casing 26 of the exhaust assembly of Figure 9B contribute to the improved fluid flow through the chamber.

[0073] Furthermore and as shown in Figure 9B, the size of an area between the base second open end and the casing first open end, may contribute to air recirculation within the chamber. As seen when Figure 9A and 9B is viewed in comparison, by providing the casing with a relatively narrower first open end, formation of vortices within the chamber may be reduced by adjusting the size of the area between the base second open end and the casing first 5 open end. The diameter of the base second open end may be between about 50% to about 80% of the diameter of the first casing open end. The diameter of the cap may be between about 60% and about 90% of the diameter of the second casing open end.

[0074] It will be appreciated by persons skilled in the art that numerous variations and/or 10 modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

CLAIMS:

Claims

CLAIMS:

1. An exhaust assembly comprising:

a casing defining a chamber, the casing comprising one or more walls extending between a first casing open end and a second casing open end the casing configured to receive a fan within the chamber, spaced apart from the one or more walls, the fan configured for inducing a fluid flow through the chamber between the first casing open end and the second casing open end;

a fan cap disposed toward the second casing open end and arranged to cover the fan, the cap defining an annular exhaust between the one or more walls;

wherein the fan cap comprises a substantially convex- shaped outer surface configured to cooperate with the one or more walls of the chamber to guide an induced fluid flow from the fan toward the annular exhaust.

2. The exhaust assembly of claim 1 wherein at least part of an inner surface of the one or more walls is curved to taper from the second casing open end toward the first casing open end to guide fluid flow through the chamber toward the annular exhaust.

3. The exhaust assembly of either claim 1 or claim 2 wherein the one or more walls comprises:

a substantially curved first wall portion extending from the second casing open end;and a substantially straight second wall portion extending from the first wall portion toward the first casing open end such that the casing tapers towards the first casing open end.

4. The exhaust assembly of any one of the preceding claims, further comprising one or more guide vanes disposed within the annular exhaust to guide fluid flow from the chamber through the annular exhaust.

5. The exhaust assembly of claim 4, wherein the one or more guide vanes comprise a plurality of guide vanes arranged concentrically about the fan cap.

6. The exhaust assembly of claim 5, wherein the plurality of guide vanes are coupled to the fan cap.

7. The exhaust assembly of any one of claims 4 to 6, wherein the one or more guide vanes are curved or angled to guide fluid flow along a surface of the respective guide vane before exhausting through the annular exhaust.

8. The exhaust assembly of claim 4 or 5, wherein one or more of the concentrically arranged guide vanes comprises one or more ridges extending radially from a major surface of the respective guide vane to allow the guide vane to couple or engage with a neighbouring guide vane, the cap and/or the one or more wall of the casing.

9. The exhaust assembly of any one of the preceding claims, further comprising a fan provided within the chamber.

10. The exhaust assembly of claim 9, wherein the fan cap extends radially from the fan.

11. The exhaust assembly of claim 9 or 10, wherein the fan comprises a motor and an impeller.

12. The exhaust assembly of claim 10, wherein the impeller comprises aback plate configured to cooperate with the cap base to convey fluid flow through the chamber toward the annular exhaust.

13. The exhaust assembly of either claim 10 or 11, wherein the impeller comprises a shroud defining an aperture through which fluid enters the fan and being configured to convey fluid flow through the chamber toward the annular exhaust.

14. The exhaust assembly of any one of the preceding claims, wherein the fan cap comprises a cap lid arranged to cooperate with a cap base to shield the cap base from precipitation or other environmental elements.

15. The exhaust assembly of claim 14, wherein the cap lid comprises a substantially convex-shaped outer surface such that water falling on the cap lid is caused to run off the cap lid into the annular exhaust.

16. The exhaust assembly of any one of claims 1 to 13, wherein the fan cap comprises a one piece moulding.

17. The exhaust assembly of any one of the preceding claims, wherein the fancap defines a fan aperture for receiving at least part of the fan.

18. The exhaust assembly of any one of the preceding claims, comprising a base for coupling the exhaust assembly to a ventilation system, the base comprising a first base open end and a second base open end to provide fluid communication between the ventilation system and the fan.

19. The exhaust assembly of either claim 15 or 16, wherein the casing is arranged relative to the base to define a drainage gap between the base and the casing to allow fluids that enter the chamber to drain from the exhaust assembly.

Intellectual Property Office

Application No: GB 1813415.5 Examiner: Mr Simon Keohane

Claims searched: 1-20 Date of search: 26 November 2018

Patents Act 1977: Search Report under Section 17

Documents considered to be relevant:

Category Relevant to claims Identity of document and passage or figure of particular relevance X 1-3, 9-15 & 17-18 US 2805615 A (LOREN COOK) see figure 2 and column 2 lines 8-21. X 1-3, 9-15 & 17-18 DE 10118226 Cl (TURBO LUFTTECHNIK) see figure 1 & 2 and EPODOC abstract & WPI abstract, Acc. No. 2002-445612. X 1-3, 9-15 & 17-18 GB 895566 A (ISEL ISAAC SOLZMAN) see figure 2 and page 2 lines 31-70. X 1-3, 9-15 & 17-18 GB 321808 A (ADAMCIKAS & MAS SERA) see figures 1 & 2, EPODOC abstract and page 1 lines 44-71.

19. The exhaust assembly of claim 16, wherein the second base open end engages with the fan such that fluid flow induced by the fan flows from the ventilation system through the base and into the fan.

20. The exhaust assembly of either claim 16 or 17, wherein the casing is arranged relative to the base to define a drainage gap between the base and the casing to allow fluids that enter the chamber to drain from the exhaust assembly.

29 03 19

Amendments to claims have been filed as follows

CLAIMS:

5 1. An exhaust assembly comprising:

a casing defining a chamber, the casing comprising one or more walls extending between a first casing open end and a second casing open end the casing configured to receive a fan within the chamber, spaced apart from the one or more walls, the fan configured for inducing a fluid flow through the chamber between the 10 first casing open end and the second casing open end;

the fan cap comprising a substantially convex-shaped outer surface configured to cooperate with the one or more walls of the chamber to guide an induced fluid flow from the 15 fan toward the annular exhaust;

one or more guide vanes disposed within the annular exhaust to guide fluid flow from the chamber through the annular exhaust.

2. The exhaust assembly of claim 1 wherein at least part of an inner surface of the one or

20 more walls is curved to taper from the second casing open end toward the first casing open end to guide fluid flow through the chamber toward the annular exhaust.

25 a substantially curved first wall portion extending from the second casing open end;and a substantially straight second wall portion extending from the first wall portion toward the first casing open end such that the casing tapers towards the first casing open end.

4. The exhaust assembly of any preceding claim, wherein the one or more guide vanes comprise a plurality of guide vanes arranged concentrically about the fan cap.

5. The exhaust assembly of claim 4, wherein the plurality of guide vanes are coupled to 35 the fan cap.

29 03 19

6. The exhaust assembly of any preceding claim, wherein the one or more guide vanes are curved or angled to guide fluid flow along a surface of the respective guide vane before exhausting through the annular exhaust.

7. The exhaust assembly of any preceding claim, wherein one or more of the concentrically arranged guide vanes comprises one or more ridges extending radially from a major surface of the respective guide vane to allow the guide vane to couple or engage with a neighbouring guide vane, the cap and/or the one or more wall of the casing.

8. The exhaust assembly of any preceding claim, further comprising a fan provided within the chamber.

9. The exhaust assembly of claim 8, wherein the fan cap extends radially from the fan.

10. The exhaust assembly of claim 8 or 9, wherein the fan comprises a motor and an impeller.

11. The exhaust assembly of claim 9, wherein the impeller comprises aback plate

20 configured to cooperate with the cap base to convey fluid flow through the chamber toward the annular exhaust.

12. The exhaust assembly of either claim 9 or 10, wherein the impeller comprises a shroud defining an aperture through which fluid enters the fan and being configured to convey fluid

25 flow through the chamber toward the annular exhaust.

13. The exhaust assembly of any preceding claim, wherein the fan cap comprises a cap lid arranged to cooperate with a cap base to shield the cap base from precipitation or other environmental elements.

14. The exhaust assembly of claim 13, wherein the cap lid comprises a substantially convex-shaped outer surface such that water falling on the cap lid is caused to run off the cap lid into the annular exhaust.

29 03 19

15. The exhaust assembly of any one of claims 1 to 12, wherein the fan cap comprises a one piece moulding.

16. The exhaust assembly of any preceding claim, wherein the fancap defines a fan aperture 5 for receiving at least part of the fan.

17. The exhaust assembly of any preceding claim, comprising a base for coupling the exhaust assembly to a ventilation system, the base comprising a first base open end and a second base open end to provide fluid communication between the ventilation system and the

10 fan.

18. The exhaust assembly of claim 15, wherein the second base open end engages with the fan such that fluid flow induced by the fan flows from the ventilation system through the base and into the fan.