GB2577032A - A fan housing assembly - Google Patents
A fan housing assembly Download PDFInfo
- Publication number
- GB2577032A GB2577032A GB1810125.3A GB201810125A GB2577032A GB 2577032 A GB2577032 A GB 2577032A GB 201810125 A GB201810125 A GB 201810125A GB 2577032 A GB2577032 A GB 2577032A
- Authority
- GB
- United Kingdom
- Prior art keywords
- housing
- cowl
- diffuser
- defines
- assembly according
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000004519 manufacturing process Methods 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims abstract description 9
- 238000007666 vacuum forming Methods 0.000 claims description 16
- 239000004676 acrylonitrile butadiene styrene Substances 0.000 claims description 11
- 230000003014 reinforcing effect Effects 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- XECAHXYUAAWDEL-UHFFFAOYSA-N acrylonitrile butadiene styrene Chemical compound C=CC=C.C=CC#N.C=CC1=CC=CC=C1 XECAHXYUAAWDEL-UHFFFAOYSA-N 0.000 description 3
- 229920000122 acrylonitrile butadiene styrene Polymers 0.000 description 3
- 230000000712 assembly Effects 0.000 description 3
- 238000000429 assembly Methods 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 241001465754 Metazoa Species 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011152 fibreglass Substances 0.000 description 2
- 230000003068 static effect Effects 0.000 description 2
- 241000272496 Galliformes Species 0.000 description 1
- 230000004323 axial length Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D19/00—Axial-flow pumps
- F04D19/002—Axial flow fans
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
- F04D29/54—Fluid-guiding means, e.g. diffusers
- F04D29/541—Specially adapted for elastic fluid pumps
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/40—Casings; Connections of working fluid
- F04D29/52—Casings; Connections of working fluid for axial pumps
- F04D29/54—Fluid-guiding means, e.g. diffusers
- F04D29/541—Specially adapted for elastic fluid pumps
- F04D29/545—Ducts
- F04D29/547—Ducts having a special shape in order to influence fluid flow
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D29/00—Details, component parts, or accessories
- F04D29/70—Suction grids; Strainers; Dust separation; Cleaning
- F04D29/701—Suction grids; Strainers; Dust separation; Cleaning especially adapted for elastic fluid pumps
- F04D29/703—Suction grids; Strainers; Dust separation; Cleaning especially adapted for elastic fluid pumps specially for fans, e.g. fan guards
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F7/00—Ventilation
- F24F7/04—Ventilation with ducting systems, e.g. by double walls; with natural circulation
- F24F7/06—Ventilation with ducting systems, e.g. by double walls; with natural circulation with forced air circulation, e.g. by fan positioning of a ventilator in or against a conduit
- F24F7/065—Ventilation with ducting systems, e.g. by double walls; with natural circulation with forced air circulation, e.g. by fan positioning of a ventilator in or against a conduit fan combined with single duct; mounting arrangements of a fan in a duct
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2250/00—Geometry
- F05D2250/50—Inlet or outlet
- F05D2250/52—Outlet
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
Abstract
Disclosed is a fan housing assembly 110 suitable to be mounted on a building, which includes; a housing 112 with a fan mounting arrangement, a base portion 116 at a first end which can connect to a building, and a tubular portion 118 extending from the base portion, where a free end 120 of the tubular portion defines a second end of the housing, with the housing defining an airflow path from the first to the second end; a diffuser 138 positioned outside of the housing with a narrow end proximate the housing and a wider end away from the housing; a cowl 128 positioned to cover the second end of the diffuser with a gap between. The cowl may be continuously curved and circular in shape. The outer perimeter of the cowl may be co-planar with the second end of the diffuser. Also included is a method of manufacture of the fan housing assembly.
Description
(54) Title of the Invention: A fan housing assembly
Abstract Title: Fan housing assembly with diffuser (57) Disclosed is a fan housing assembly 110 suitable to be mounted on a building, which includes; a housing 112 with a fan mounting arrangement, a base portion 116 at a first end which can connect to a building, and a tubular portion 118 extending from the base portion, where a free end 120 of the tubular portion defines a second end of the housing, with the housing defining an airflow path from the first to the second end; a diffuser 138 positioned outside of the housing with a narrow end proximate the housing and a wider end away from the housing; a cowl 128 positioned to cover the second end of the diffuser with a gap between. The cowl may be continuously curved and circular in shape. The outer perimeter of the cowl may be co-planar with the second end of the diffuser. Also included is a method of manufacture of the fan housing assembly.
Fig. 5
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Fig. 2
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Fig. 3
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Fig. 4
5/8
Fig. 5
6/8
125
Fig. 6
7/8
Fig. 7
8/8
Fig. 8
A Fan Housing Assembly
FIELD
The present teachings relate to a fan housing assembly; and to a method of manufacturing a fan housing assembly.
BACKGROUND
Roof fans used to extract air from buildings typically consist of a fan mounted within a housing, and an external weather cowl or hood provided over the fan/housing so as to prevent/minimise water ingress into a building structure.
Such roof fans are typically provided in the form of an axial fan or a centrifugal fan, or as a mixed flow combined fan. An axial fan is one which causes the air to flow through it in an axial direction (i.e. parallel to the shaft about which the blades rotate). In a centrifugal fan, air enters the fan axially and is then rotationally driven by the impellers so as to displace air radially.
Known axial fans use a deep square cowl, to prevent rain water ingress into a building. The design of known axial fans is detrimental to airflow, which creates energy losses and so results in reduced efficiency of the fan assembly, and therefore unnecessary energy consumption to achieve the required airflow.
The present teachings seek to overcome, or at least mitigate, one or more problems associated with the prior art.
SUMMARY
A first aspect provides a fan housing assembly for mounting to an external surface of a building structure, the assembly comprising:
a housing comprising a fan mounting arrangement for mounting a fan within the housing, a base portion at a first end thereof configured for connecting to an external surface of a building structure, and a tubular portion extending from said base portion, wherein a free end of the tubular portion defines a second end of the housing, wherein the housing defines an airflow path extending from the first end to the second end;
a diffuser defining a first end positioned proximate to the free end of the tubular portion, and a second end, opposing said first end, wherein the first end defines a first diameter and the second end defines a second diameter, larger than the first diameter, such that the diffuser tapers towards the first end thereof; and a cowl positioned so as to cover the second end of the diffuser and be spaced apart therefrom.
Covering the second end for the diffuser acts as a barrier to prevent water flowing directly into the axial end of the housing assembly. Air flowing through the housing will hit the inner surface of the cowl and be redirected out of the fan assembly. The provision of a diffuser at the free end of the housing works to reduce the angle through which the air must be re-directed to exit the housing assembly, thus reducing energy loss in the fan assembly.
The provision of a diffuser has also been found to minimise the recirculation of air within a fan housing assembly, which further improves efficiency of the flow of airflow therethrough.
The combination of an angled diffuser with a cowl has also been found further reduce the ingress of rain water into the fan assembly, compared to known fan assemblies.
The second end of the diffuser may be circular in end view.
The provision of a circular end of the diffuser (i.e. having a circular crosssection) has been found to improve the distribution of airflow flowing from the housing to outside of the housing assembly.
The diffuser may define a truncated cone.
This has been found to further improve the efficiency of airflow through the housing assembly.
An inner surface of the cowl defines a continuously curved surface.
Providing an inner surface of the cowl that is free from abrupt angles (i.e. a smooth internal surface) reduces the build-up of high pressure points underneath the cowl. This in turn reduces the slowing down of the airflow passing through the housing assembly compared to the standard known configurations, increasing the efficiency of the fan assembly.
The inner surface of the cowl optionally defines a concave curved surface extending from a centre point of the cowl to a perimeter of the cowl, wherein the concave curve has a radius of curvature that increases from a maximum at the centre point to a minimum at the perimeter.
Providing a gradual increase in the curvature has been found to further improve airflow through the housing assembly.
A perimeter of the cowl may be arranged to be substantially co-planar with the second end of the diffuser and radially spaced apart therefrom.
This arrangement of the diffuser and cowl provides an airflow outlet that is covered by the cowl, thus further reducing water ingress into the housing assembly.
The cowl optionally defines a perimeter thereof, and wherein the cowl perimeter defines a continuously curved surface.
This arrangement has been found to further improve the distribution of airflow within the housing assembly.
The cowl may be substantially is circular.
This arrangement has been found to further improve the distribution of airflow within the housing assembly.
Further, this arrangement, when coupled with a circular cover, has been found to improved flow within the assembly, and to reduce the build-up of high pressure regions therein, thus improving the efficient of airflow.
The cowl may comprise one or more reinforcing ribs thereon.
The base portion of the housing optionally comprises one or more stiffening ribs.
The diffuser may be provided as a separate component to the housing.
This allows the specific shape of the diffuser to be tailored to the shape of the cowl being used in a particular assembly.
The diffuser is optionally connected to the housing via one or more brackets.
The one or more brackets may be configured for mounting a cowl to the housing.
The tubular portion of the housing optionally defines a taper towards the second end of the housing.
A fan is optionally mounted to the fan mounting arrangement, wherein the fan is configured to propel air through the housing assembly along an axial airflow path.
A non-return valve is optionally provided within the housing.
Such a non-return valves helps to ensure that air is not drawn into the building through the housing assembly.
A second aspect provides a method of manufacturing a fan housing assembly according to any preceding claim, the method comprising the steps of:
a) vacuum forming a housing, the housing comprising a fan mounting arrangement for mounting a fan within the housing, a base portion at a first end thereof configured for connecting to an external surface of a building structure, and a tubular portion extending from said base portion, wherein a free end of the tubular portion defines a second end of the housing, wherein the housing defines an airflow path extending from the first end to the second end;
b) vacuum forming a diffuser defining a first end and a second end, opposing said first end, wherein the first end defines a first diameter and the second end defines a second diameter, larger than the first diameter, such that the diffuser tapers towards the first end thereof;
c) positioning the first end of the diffuser proximate the free end of the tubular portion of the housing;
d) vacuum forming a cowl; and
e) positioning said cowl so as to cover the second end of the diffuser and be spaced apart therefrom.
The housing and/or diffuser are optionally formed from acrylonitrile butadiene styrene (ABS).
Step a) may further comprise vacuum forming one or more stiffening ribs in the housing.
The cowl may be formed from acrylonitrile butadiene styrene (ABS).
Step d) may further comprise vacuum forming one or more stiffening ribs in the cowl.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments will now be described with reference to the accompanying drawings, in which:
Figure 1 is a side view of a fan assembly according to the prior art;
Figure 2 is a cross-sectional side view of the fan assembly of Figure 1;
Figure 3 is an exploded perspective view of the fan assembly of Figure 1;
Figure 4 is a side view of a fan assembly according to an embodiment;
Figure 5 is a cross-sectional side view of the fan assembly of Figure 4;
Figure 6 is an exploded perspective view of the fan assembly of Figure 4;
Figure 7 is a graph showing the efficiency of first configuration of the fan assemblies of Figures 1 and 4; and
Figure 8 is a graph showing the efficiency of second configuration of the fan assemblies of Figures 1 and 4.
DETAILED DESCRIPTION OF EMBODIMENT(S)
Referring firstly to Figures 1 to 3, a known fan housing assembly is illustrated and is indicated generally at 10.
The fan housing assembly 10 is formed from a housing 12 and a cowl 14, where the cowl 14 is positioned to cover a free (upper) end of the housing 12 to reduce water ingress.
The housing 12 incudes a base portion 16 at a first end thereof and a tubular portion 18 extending from said base portion 16. The base portion 16 is configured for connecting to an external surface of a building structure, typically a roof (not shown). The free end 20 of the tubular portion 18 defines a second end of the housing 12. The free end 20 of the tubular portion 18 (i.e. the second end of the housing 12) is circular.
The housing 12 includes a fan mounting in the form of a mounting ridge 22 in the base portion 16 for mounting a fan 24 having an impeller 25 within the housing 12. The fan 24 is mounted to the ridge 22 via a fan plate 26. The fan 24 is configured to propel air through the housing 12 along an axial airflow path (i.e. into the housing via the base portion 16, and out through free end of the tubular portion 18).
The cowl 14 is mounted to the fan assembly 10 and is positioned so as to cover the free end 20 of the tubular portion 18. Covering the free end 20 of the tubular portion 18 provides a physical barrier to prevent rain water flowing directly into the axial end of the housing 12. Provision of such a cowl disrupts the airflow and diverts airflow away from axial flow path, which reduces the efficiency of the fan assembly 10.
In order to provide an outlet for the airflow through the housing 12, an inner surface of the cowl 14 is spaced apart from the free end 20 of the tubular portion 18. The inner surface of the cowl 14 is spaced apart from the free end 20 of the tubular portion 18 both axially and radially.
The cowl 14 includes a central portion 28, and four substantially linear perimeter walls 30 extending away from said central portion 28. As is clearly shown in Figure 2, the central portion is substantially square when viewed along the axial airflow path. The four perimeter walls 30 are arranged at an angle (illustrated at approximately 80°) to the central section 28, and at an angle of 90° to adjacent perimeter walls 30.
The angled regions between the central portion 28 and the perimeter walls 30, and between adjacent perimeter walls 30, result in the formation of high pressure regions. In particular, high pressure regions form in the upper corner regions underneath the cowl, indicated by the arrows H, which slow down airflow within the assembly 10, causing pressure losses in the air flow, lowering the efficiency of the fan assembly.
The distal ends of the four perimeter walls 30 form the perimeter edge 31 of the cowl 14. The perimeter of the cowl 14 is arranged to be substantially co-planar with the free end 20 of the tubular portion 18 and radially spaced apart therefrom. The four perimeter walls 30 of the cowl 14 restrict air flow from flowing out of the fan assembly 10.
In the arrangement of Figures 1 to 3, in order to flow out of the fan assembly 10, air is redirected through almost 180° (i.e. up, over and around the substantially upright wall of the tubular portion 18), as is illustrated by the arrow F. The relative geometries of the upstanding wall of the tubular portion 18 and the cowl 14 results in the recirculation of air back into the device around the radially outer surface of the tubular portion 18, indicated by the arrows R. This recirculation of air disrupts airflow out of the fan assembly 10, and so results in energy losses of the air flow, lowering the efficiency of the fan assembly.
A guard 34 is provided at the free end 20 of the tubular member 18. That is, a guard 34 is provided between the free end 20 of the tubular member 18 and the inner surface of the cowl 14 (i.e. in the axial spacing between the free end 20 of the tubular member 18 and the inner surface of the cowl 14). The guard 34 is provided as an annular guard, and intended to prevent animals (e.g. birds) from entering the assembly 10.
A butterfly valve (i.e. a non-return valve) 32 is provided within the housing 12 to prevent air from being drawn into a building via the fan assembly 10. The valve 32 is positioned at the free end 20 of the tubular portion 18. That is, the butterfly valve 32 is provided between the free end 20 of the tubular portion 18 and the guard 34.
It will be appreciated that in some arrangements, the guard 34 and/or the butterfly valve 32 may be omitted from the fan assembly 10.
The cowl 14 is secured to the housing via mounting brackets 36. The mounting brackets 36 are secured to a radially outer surface of the tubular portion 18 and to the inner surface of the cowl 14. Four mounting brackets 36 are provided in the arrangement shown. The mounting of the cowl 14 to the housing 12 secures both the butterfly valve 32 and the guard 34 in place within the fan assembly 10.
Referring now to Figures 4 to 6, a fan assembly according to an embodiment of the present teachings is illustrated and indicated generally at 110.
The fan housing assembly 110 is formed from a housing 112 and a cowl 114, where the cowl 114 is positioned to cover a free end of the housing 112 to reduce water ingress. The fan assembly 110 is able to be installed onto roofs having a pitch of up to 30°, and still able to achieve the reduction of water ingress.
The housing 112 incudes a base portion 116 at a first end thereof and a tubular portion 118 extending from said base portion 116. The base portion 116 is configured for connecting to an external surface of a building structure (not shown). The free end 120 of the tubular portion 118 defines a second end of the housing 112.
The free end 120 of the tubular portion 118 (i.e. the second end of the housing 112) is circular. In the illustrated embodiment, the tubular portion 118 of the housing 112 defines a taper towards the free end 120 thereof. The housing 112 (i.e. the base portion 116 coupled with the tubular portion 118) defines an axial airflow path extending from the first end to the second end of the housing 112.
The housing 112 includes a fan mounting in the form of a mounting ridge 122 in the base portion 116 for mounting a fan 124 having an impeller 125 within the housing 112. The fan 124 is mounted to the ridge 122 via a fan plate 126. The fan 124 is configured to propel air through the housing 112 along an axial airflow path (i.e. into the housing 112 via the base portion 116, and out of the housing 112 through free end 120 of the tubular portion 118).
The fan assembly 110 includes a diffuser 138 positioned proximate to the free end 120 of the tubular portion 118. The diffuser 138 defines a first end 140 and second end 142 opposing first end 140, and the first end 140 is positioned proximate the free end 120 of the tubular portion 118.
The first end 140 of the diffuser 138 defines a first diameter, and the second end 142 of the diffuser 138 defines a second diameter. The second diameter is larger than the first diameter, such that the diffuser 138 tapers towards the first end thereof. Put another way, the diffuser 138 broadens or widens in the direction towards the second end 142 thereof. In the exemplary embodiment shown, the angle of the taper is approximately 45° to the axial air flow path, but it will be appreciated that this taper angle may vary between 30° and 60°, for example between 35° and 55°.
In order to flow out of the fan assembly 110, air needs to flow through the diffuser 138, and then through the radial spacing between the cowl 114 and the diffuser 138. The outwardly angled diffuser 138 works to reduce the angle through which the air must be re-directed to exit the fan assembly 110, as is illustrated by the arrow F'. The inclusion of the diffuser also helps to reduce the occurrence of recirculation of air around the fan assembly 110, which further improves efficiency of the flow of airflow therethrough. Further, the provision of the diffuser has been found to reduce the build-up of dynamic pressure within the housing, by converting it into static pressure (i.e. static regain), which further improves the efficiency of the fan assembly 110.
In the illustrated embodiment, the second end 142 of the diffuser 138 is substantially circular. Having a circular end of the diffuser 138 has been found to improve the distribution of airflow through the fan assembly 110.
In the exemplary arrangement shown, the diffuser defines a truncated cone. This has been found to improve the efficiency of airflow through the housing assembly. It will be appreciated that, in alternative arrangements, the side walls of the diffuser 138 may define a curved, rather than linear, surface.
The cowl 114 is mounted to the fan assembly 110 and is positioned so as to cover the second end 142 of the diffuser 138. Covering the end of the diffuser 138 provides a physical barrier to prevent rain water flowing directly into the axial end of the housing 112.
Following flowing axially through the housing 112 and diffuser 138, the air encounters the inner surface of the cowl 114, which disrupts the airflow and diverts airflow away from the axial flow path.
In order to reduce disruption to the airflow, the inner surface of the cowl 114 is provided as a smooth (e.g. a continuously curved) surface. Put another way, the inner surface of the cowl 114 is free from abrupt angles or corners. This has been found to reduce the formation of high pressure regions within the fan assembly 110, which increases the efficiency of the fan assembly 110.
In the exemplary illustrated embodiment, the inner surface of the cowl 114 defines a concave curved surface. Said concave curve extends from a centre point of the cowl 114 to the perimeter 131 of the cowl 114. The concave curve has a radius of curvature that increases from a maximum (e.g. a planar surface having an infinite radius) at the centre point, to a minimum at the perimeter 131.
The cowl 114 includes a central portion 128 and a perimeter wall portion 130. In the illustrated arrangement, the perimeter wall 130, and so the perimeter edge 131, define a continuously curved (e.g. circular) surface. The perimeter edge 131 of the cowl 114 is arranged to be substantially co-planar with the second end 142 of the diffuser 138, and radially spaced apart therefrom.
In order to provide an outlet for the airflow through the housing 112, an inner surface of the cowl 114 is spaced apart from the second end 142 of the diffuser 138. Put another way, the inner surface of the cowl 114 is spaced apart from the second end 142 of the diffuser 138 in both an axial and a radial direction.
In order to provide the spacing in the radial direction between the cowl 114 and diffuser 138, the diameter of the radially inner surface of the cowl 114 is typically arranged to be between 55-60% larger than the diameter of the radially outer surface of the second end 142 of the diffuser 138. In some arrangements, it will be appreciated that the diameter of the radially inner surface of the cowl 114 is typically arranged to be between 50-68% larger than the diameter of the radially outer surface of the second end 142 of the diffuser 138.
As previously discussed, the perimeter edge 131 of the cowl 114 is arranged to be substantially co-planar with the second end 142 of the diffuser 138. In such arrangements, the spacing in the axial direction between the diffuser 138 and the cowl 114 is generally defined by the depth of the cowl 114. It will be appreciated that the depth of the cowl 114 will be varied to suit the size of the fan assembly 110, and may be between 25-40% of the overall height of the fan assembly 110, for example between 30-35% of the overall height of the fan assembly 110.
The cowl 114, diffuser 138, and the housing 112 are formed from acrylonitrile butadiene styrene (ABS). In order to increase the rigidity of the ABS cowl 114, reinforcing ribs (or stiffening ribs) 146 are provided thereon. In the illustrated arrangement, the ribs 146 are provided as four radial ribs 148 coupled with a circumferential reinforcing ring 150. The housing 112 is formed from acrylonitrile butadiene styrene (ABS). In order to increase the rigidity of the base portion 116 of the ABS housing 114, reinforcing ribs (or stiffening ribs) 152 are provided on both the base portion 116 and the tubular portion 118. In order to increase the rigidity of the tubular portion 118 of the ABS housing 114, reinforcing features are provided on the tubular portion 118. The reinforcing features are provided as scalloped regions 154 circumferentially spaced around the tubular portion 118. It will be appreciated that the cowl 114, diffuser 138, and the housing 112 may be manufactured using vacuum forming, which is an efficient way of manufacturing articles of this type.
In alternative arrangements, one or more of the cowl 114, the diffuser and/or the housing 112 may be formed from glass reinforced plastic (GRP), or any other suitable material, such as pressed sheet metal. In such arrangements, it will be appreciated that the reinforcing features on the housing 112 may be omitted.
A guard 134 is provided at the free end 120 of the tubular member 120. That is, a guard 134 is provided between the free end 120 of the tubular member 118 and the inner surface of the cowl 114 (i.e. in the axial spacing between the free end 120 of the tubular member 118 and the inner surface of the cowl 114). The guard 134 is provided as an annular guard, and intended to prevent animals from entering the assembly 110. It will be appreciated that in some arrangements, the fan assembly 110 may not include a guard 134.
A butterfly valve (i.e. a non-return valve) 132 is provided within the housing 112 to prevent air from being drawn into a building via the fan assembly 110. The valve 132 is positioned at the free end 120 of the tubular portion 118. That is, the butterfly valve 132 is provided between the free end 120 of the tubular portion 118 and the guard 134. It will be appreciated that in some arrangements, the fan assembly 110 may not include a butterfly valve 132.
In the illustrated embodiment, the diffuser 138 is provided as a separate component to the housing 112. The fan assembly 110 includes one or more brackets 136. The brackets 136 are provided to secure both the diffuser 138 and the cowl 114 to the housing 112. Specifically, the mounting brackets 136 are secured to the radially outer surface of the tubular portion 118, to the radially outer surface of the diffuser 138, and to the inner surface of the cowl 114. Four mounting brackets 136 are provided in the arrangement shown. However, in alternate arrangements, any suitable number of mounting brackets may be used. The mounting of the diffuser 138 and cowl 114 to the housing 112 also secures both the butterfly valve 132 and the guard 134 in place within the fan assembly 110.
It will be appreciated that, in alternative arrangements, the diffuser 138 and housing 112 may be integrally formed, and the brackets 136 will be secured between the cowl 114 and the housing 112, as described with reference to Figures 1 to 3.
The arrangement disclosed in Figures 4 to 6 has been found to result in an increase in efficiency of the fan assembly. The results of the testing are shown in Figures 7 and 8 for cowls 14, 114 having diameters of 400mm and 500mm, respectively. As can be seen from both Figures 7 and 8, the arrangement of the embodiment illustrated in Figures 4 to 6 results in increased efficiency across the entire range of flow rates tested, and has been shown to produce an increase in efficiency of up to 18% and 12% respectively.
The embodiment of Figures 4 to 6 has been disclosed as incorporating an axial fan 124. It will be appreciated that, in alternative arrangements, the fan may be provided in the form of a mixed flow or centrifugal fan. In such arrangements, the mixed flow fan or centrifugal fan is again mounted to base portion of the housing. It will be appreciated that the axial length of the housing will be adjusted to accommodate the mixed flow fan or centrifugal fan, as required. In arrangements incorporating a mixed flow fan, air will flow through said mixed flow fan, and be propelled out of the housing along a substantially diagonal flow path.
Although the teachings have been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope as defined in the appended claims.
Claims (25)
1) A fan housing assembly for mounting to an external surface of a building structure, the assembly comprising:
a housing comprising a fan mounting arrangement for mounting a fan within the housing, a base portion at a first end thereof configured for connecting to an external surface of a building structure, and a tubular portion extending from said base portion, wherein a free end of the tubular portion defines a second end of the housing, wherein the housing defines an airflow path extending from the first end to the second end;
a diffuser defining a first end positioned proximate to the free end of the tubular portion, and a second end, opposing said first end, wherein the first end defines a first diameter and the second end defines a second diameter, larger than the first diameter, such that the diffuser tapers towards the first end thereof; and a cowl positioned so as to cover the second end of the diffuser and be spaced apart therefrom, wherein the cowl comprises an inner surface extending from a centre point of the cowl to a perimeter of the cowl such that the perimeter of the cowl defines a perimeter of the inner surface, and wherein the inner surface of the cowl defines a continuously curved surface.
2) An assembly according to claim 1, wherein the second end of the diffuser is circular in end view.
3) An assembly according to claim 2, wherein the diffuser defines a truncated cone.
4) An assembly according to any preceding claim, wherein the inner surface of the cowl defines a concave curved surface extending from a centre point of the cowl to a perimeter of the cowl,
5) An assembly according to claim 4, wherein the concave curve has a radius of curvature that continuously increases from a maximum at the centre point to a minimum at the perimeter.
6) An assembly according to any preceding claim, wherein a perimeter of the cowl is arranged to be substantially co-planar with the second end of the diffuser and radially spaced apart therefrom to define an airflow outlet therebetween.
7) An assembly according to any preceding claim, wherein the cowl defines a perimeter thereof, and wherein the cowl perimeter defines a continuously curved surface.
8) An assembly according to claim 7, wherein the cowl perimeter is substantially circular.
9) An assembly according to any preceding claim, wherein the cowl comprises one or more reinforcing ribs thereon.
10) An assembly according to any preceding claim, wherein the base portion of the housing comprises one or more stiffening ribs.
11) An assembly according to any preceding claim, wherein the diffuser is provided as a separate component to the housing.
12) An assembly according to claim 11, wherein the diffuser is connected to the housing via one or more brackets.
13) An assembly according to claim 12, wherein the one or more brackets are configured for mounting a cowl to the housing.
14) An assembly according to any preceding claim, wherein the tubular portion of the housing defines a taper towards the second end of the housing.
15) An assembly according to any preceding claim, wherein a fan is mounted to the fan mounting arrangement, wherein the fan is configured to propel air through the housing assembly along an axial airflow path.
16) An assembly according to any preceding claim, wherein a non-return valve is provided within the housing.
17) A fan housing assembly for mounting to an external surface of a building structure, the assembly comprising:
a housing comprising a fan mounting arrangement for mounting a fan within the housing, a base portion at a first end thereof configured for connecting to an external surface of a building structure, and a tubular portion extending from said base portion, wherein a free end of the tubular portion defines a second end of the housing, wherein the housing defines an airflow path extending from the first end to the second end;
a diffuser in the form of a duct defining a first end positioned proximate to the free end of the tubular portion, a second end axially spaced apart from said first end, and a curved or linear side wall extending between the first end and the second end, wherein the second end is downstream of the first end such that air flows through the diffuser from the first end to the second end along the airflow path, wherein the first end defines a first diameter and the second end defines a second diameter larger than the first diameter, such that the diameter of the diffuser increases in a direction towards the second end; and a cowl positioned so as to cover the second end of the diffuser, the cowl defining a continuously curved perimeter surface, wherein the perimeter of the cowl is arranged to be substantially co-planar with the second end of the diffuser and radially spaced apart therefrom to define an airflow outlet therebetween.
18) An assembly according to claim 17, wherein the cowl comprises an inner surface covering the second end of the diffuser, and wherein substantially all of the inner surface of the cowl defines a continuously curved surface.
19) An assembly according to claim 17 or claim 18, wherein the inner surface of the cowl defines a concave curved surface extending from a centre point of the cowl to a perimeter of the cowl, wherein the concave curve has a radius of curvature that continuously increases from a maximum at the centre point to a minimum at the perimeter.
20) An assembly according to any one of claims 17 to 19, wherein the cowl perimeter is substantially circular.
21) A method of manufacturing a fan housing assembly according to any preceding claim, the method comprising the steps of:
a) vacuum forming a housing, the housing comprising a fan mounting arrangement for mounting a fan within the housing, a base portion at a first end thereof configured for connecting to an external surface of a building structure, and a tubular portion extending from said base portion, wherein a free end of the tubular portion defines a second end of the housing, wherein the housing defines an airflow path extending from the first end to the second end;
b) vacuum forming a diffuser defining a first end and a second end, opposing said first end, wherein the first end defines a first diameter and the second end defines a second diameter, larger than the first diameter, such that the diffuser tapers towards the first end thereof;
c) positioning the first end of the diffuser proximate the free end of the tubular portion of the housing;
d) vacuum forming a cowl; and
e) positioning said cowl so as to cover the second end of the diffuser and be spaced apart therefrom.
22) A method according to claim 21, wherein the housing and/or diffuser are formed from acrylonitrile butadiene styrene (ABS).
23) A method of manufacturing a fan housing assembly according to claim 21 or claim 22, wherein step a) further comprises vacuum forming one or more stiffening ribs in the housing.
24) A method according to any one of claims 21 to 23, wherein the cowl is formed from acrylonitrile butadiene styrene (ABS).
25) A method of manufacturing a fan housing assembly according to any one of claims 21 to 24, wherein step d) further comprises vacuum forming one or more stiffening ribs in the cowl.
Intellectual
Property
Office
Application No: GB1810125.3
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1810125.3A GB2577032B (en) | 2018-06-20 | 2018-06-20 | A fan housing assembly |
| NZ754673A NZ754673A (en) | 2018-06-20 | 2019-06-19 | A Fan Housing Assembly |
| AU2019204277A AU2019204277B2 (en) | 2018-06-20 | 2019-06-19 | A Fan Housing Assembly |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1810125.3A GB2577032B (en) | 2018-06-20 | 2018-06-20 | A fan housing assembly |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201810125D0 GB201810125D0 (en) | 2018-08-08 |
| GB2577032A true GB2577032A (en) | 2020-03-18 |
| GB2577032B GB2577032B (en) | 2020-09-23 |
Family
ID=63042759
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1810125.3A Active GB2577032B (en) | 2018-06-20 | 2018-06-20 | A fan housing assembly |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU2019204277B2 (en) |
| GB (1) | GB2577032B (en) |
| NZ (1) | NZ754673A (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2641987A (en) * | 1951-02-09 | 1953-06-16 | Joseph N Burgan | Ventilator |
| US2684621A (en) * | 1952-12-05 | 1954-07-27 | Loren Cook Company | Attic ventilator |
| GB968355A (en) * | 1961-12-08 | 1964-09-02 | Bryce Harold Miller | Ventilating device |
| SU1620685A1 (en) * | 1988-12-07 | 1991-01-15 | А. А. Михайлов и Л. А. Ступина | Roof-mounted fan |
| KR100927325B1 (en) * | 2009-07-24 | 2009-11-19 | 이화랑 | Wingless safety fans |
| US20150086349A1 (en) * | 2013-07-30 | 2015-03-26 | Radha Krishna Ganesh | Powered ventilators |
| CN107620721A (en) * | 2017-10-18 | 2018-01-23 | 浙江金盾风机股份有限公司 | A kind of double blast cap axial-flow roof ventilators |
-
2018
- 2018-06-20 GB GB1810125.3A patent/GB2577032B/en active Active
-
2019
- 2019-06-19 AU AU2019204277A patent/AU2019204277B2/en not_active Ceased
- 2019-06-19 NZ NZ754673A patent/NZ754673A/en not_active IP Right Cessation
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2641987A (en) * | 1951-02-09 | 1953-06-16 | Joseph N Burgan | Ventilator |
| US2684621A (en) * | 1952-12-05 | 1954-07-27 | Loren Cook Company | Attic ventilator |
| GB968355A (en) * | 1961-12-08 | 1964-09-02 | Bryce Harold Miller | Ventilating device |
| SU1620685A1 (en) * | 1988-12-07 | 1991-01-15 | А. А. Михайлов и Л. А. Ступина | Roof-mounted fan |
| KR100927325B1 (en) * | 2009-07-24 | 2009-11-19 | 이화랑 | Wingless safety fans |
| US20150086349A1 (en) * | 2013-07-30 | 2015-03-26 | Radha Krishna Ganesh | Powered ventilators |
| CN107620721A (en) * | 2017-10-18 | 2018-01-23 | 浙江金盾风机股份有限公司 | A kind of double blast cap axial-flow roof ventilators |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2019204277B2 (en) | 2021-12-16 |
| AU2019204277A1 (en) | 2020-01-16 |
| NZ754673A (en) | 2022-04-29 |
| GB2577032B (en) | 2020-09-23 |
| GB201810125D0 (en) | 2018-08-08 |
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