EP2592360B1

EP2592360B1 - An enclosure for a HVAC system

Info

Publication number: EP2592360B1
Application number: EP12192262.9A
Authority: EP
Inventors: Colin Biggs
Original assignee: Nuaire Ltd
Current assignee: Nuaire Ltd
Priority date: 2011-11-10
Filing date: 2012-11-12
Publication date: 2019-05-01
Anticipated expiration: 2032-11-12
Also published as: GB2496419B; EP2592360A3; GB201119439D0; EP2592360A2; GB2496419A

Description

The present invention relates to an enclosure for a HVAC system and in particular to a fan housing for use in a HVAC system.
Heating, ventilation and air conditioning (HVAC) systems are used in the built environment for assisting in the control of temperature and air quality. Such systems include machine components of the HVAC system such as fans, heaters and compressors, and ducting forming plenums to direct air throughout a building.
In industrial or commercial buildings such as offices or schools the ducting and enclosures containing machine components for a HVAC system are typically substantially contained within a void between a suspended ceiling and the structural ceiling of a room. Periodically it is required to access elements of the HVAC contained within plenums. To permit such access the enclosures forming the plenums commonly include removable base panels which are removed to access the interior of the enclosure. Unless significant work is required this access will be conducted through the framework of the suspended ceiling with one or more tiles having been removed.
It is firstly difficult to support and remove such an access panel from below, through a ceiling framework or otherwise, as the engineer must release the fastenings of the panel while simultaneously supporting the panel's weight. Furthermore, any removable access panel will typically be significantly larger than the tiles of a suspended ceiling and therefore once removed it is not possible to withdraw the panel through the framework of a suspended ceiling. Any work must therefore be carried out with the maintenance engineer attempting to support the panel, or as often happens the engineer will attempt to support the weight of the panel on the ceiling framework which can lead to damage of the frame work which is not designed to support such a load.
US 5 679 121 A describes an enclosure of an air conditioner including a filter-carrying access opening in form of a grill.
It is therefore desirable to provide an improved enclosure for a HVAC system which addresses the above described problems and/or which offers improvements generally.
According to the present invention there is provided an enclosure for a HVAC system as defined in the accompanying claims.
In an embodiment of the invention there is provided an enclosure for a HVAC system comprising at least one wall defining said enclosure; a fluid inlet; a fluid outlet; an access opening to permit access to the enclosure; a closure member for closing the access opening; a guide element for slidingly receiving and supporting the closure member. The guide element is movable between a first operative position in which it holds the closure member in a closed position to close the access opening and a second operative position in which the closure member is spaced from the access opening and wherein in the second operative position the closure member is able to slide in the guide member away from the access opening to permit access to the enclosure through the access opening. The closure member is preferably an access panel. By holding the panel in both the closed and open positions the guide member obviates the requirement for a person to hold and support the weight of the panel during removal, which can be hazardous when working overhead. In addition, the guide member permits the panel to slide way from the opening while still holding the panel, thereby solving the problem of how to support the panel while work through the access opening is conducted and avoiding the need to hazardously support the panel on a suspended ceiling framework.
The enclosure may further comprise locking means for locking the guide member in the first operative closed position. In an orientation where the panel moves to the open position under its own weight, it is desirable to lock the guide member in the closed position to prevent it returning to the open position when released under the weight of the panel.
The closure member may comprise a first sealing surface arranged cooperate with a corresponding second sealing surface on the enclosure to fluidly seal the opening when the closure member is in the closed position. Where the enclosure defines a fluid pathway is advantageous that the access panel is sealed in an airtight manner to prevent fluid losses. At least one of the closure member and the enclosure may include a sealing member arranged such that it is located between the first and second sealing surfaces to create a seal therebetween when the closure member is in the closed position.
The guide member may be arranged to move between the first and second operative positions in a direction substantially perpendicular to the opening and the closure member slides relative to the guide member in a direction substantially parallel to the opening. By sliding parallel to the opening the panel may be moved sideways within a ceiling void to the open position thereby avoid interference with the ceiling structure below.
The guide member may be arranged to move between the first and second operative positions in a substantially vertical direction and the closure member slides relative to the guide member in a substantially horizontal direction.
The walls of the enclosure may include a plurality of side walls and a top panel connected to a first edge of the side walls the opposing edges forming a perimeter defining the opening, and the closure member is a panel which in the closed position closes the opening and forms the base of the enclosure.
The guide member may comprise a pair of guide rails provided on opposing sides of the panel. Each guide rail may comprise at least one guide slot which receives a corresponding guide pin extending from the enclosure which guides the guide rails during movement between the first and second operative positions and acts as a stop member engaging with one end of the slots to locate and support the guide rails in the second operative position.
Each guide pin may comprise a shaft having a threaded portion which is received within a corresponding threaded portion of the enclosure and a locking head at the opposing end which is configured to engage and clamp the respective guide rail to lock it in the first operative position.
The guide rails may each comprise a side wall and a pair of projections extending inwardly towards the closure member from a face of the side wall defining a sliding channel for slidingly receiving the closure member and guide rails are arranged such that the side walls engage and are arranged parallel to a respective side wall of the enclosure.
The side wall of each guide rail may include at least two guide slots and the respective side wall to which they are connected each include at least two corresponding guide pins.
The enclosure and closure member may define a ducting member for a HVAC system.
In another embodiment of the invention there is provided an enclosure for a HVAC system comprising a plurality of walls defining an enclosure having a fluid inlet, a fluid outlet and an access opening to permit external access to the enclosure; a closure member for closing the access opening; a guide element connected to the enclosure to slidingly receive and support the closure member. The guide element is movable between a first operative position in which it holds the closure member in a closed position to close the opening and a second operative position in which the closure member is spaced from the opening and permitted to slide in the guide member to open the opening.
The present invention will now be described by way of example only with reference to the following illustrative figures in which:

Figure 1 shows an enclosure according to an embodiment of the invention;
Figure 2 shows the enclosure of Figure 1 in situ as part of a HVAC system;
Figure 3 shows an enlarged of the guide member and sliding panel arrangement;
Figure 4a shows a partial view of an enclosure according to an embodiment of the invention in the closed position;
Figure 4b shows a partial view of an enclosure according to an embodiment of the invention in the first open position; and
Figure 4c shows a partial view of an enclosure according to an embodiment of the invention in the second open position.

Referring to Figure 1 a fan chamber 1 for a HVAC system houses a fan for moving air through the system. The chamber 1 includes a plurality of panels defining upstanding side walls 2 and end walls 3, although the enclosure may be formed with only side walls and open end walls. Each side wall 2 connects at each end to the respective adjacent ends of the end walls 3 such that the side walls 2 and end walls 3 interconnect to define a boundary. A top panel 4 connects to the upper edges 5 of the side walls 2 and end walls 3 to close and seal the walls from above. The top panel 4, side walls 2 and end walls 3 are secured to each other by rivets, or any other suitable permanent fixing means. The side walls 2, end walls 3 and top panel 4 define an open base enclosure 7, with the lower edges 9 of the side walls 2 and end walls 3 forming a perimeter defining an opening 6 to the enclosure. A base panel 8 is provided to close the opening 6.
An air inlet duct 10 is formed in a first end wall 3 at a first end of the chamber 1 and an air outlet duct 12 is formed in a second end wall 3 at the opposing end of the chamber 1. A fan 14 is housed within the chamber 1 and an air channel is defined through the chamber 1 from the inlet duct 10 to the inlet of the fan 14, and outwardly from the outlet of the fan 14 to the outlet duct 12. The fan 14 is driven by an electric motor contained in a motor housing 16 mounted to the side wall 2 of the chamber 1.
Brackets 18 are secured to each side wall 2 for mounting the chamber 1 to a support structure. As shown in Figure 2 the fan chamber 1 may be suspended from a ceiling through the attachment of support cables 20 to the brackets 18 which are then mounted to the ceiling or other overhead structure. Ducting pipes 22 are connected to the inlet duct 10 and the outlet duct 12 to convey air to and from the chamber 1 respectively. In a typical building structure the chamber 1 and ducting 22 will be typically be supported from the structural ceiling in this manner with a suspended ceiling framework structure being supported at a position below the chamber 1, with the suspended ceiling and structural ceiling defining a void therebetween within which the HVAC system of which the chamber 1 and ducting 22 for a part is housed.
In the event of malfunction of the fan 14 or for the purpose of period service, it is necessary to be able to access the fan 14 within the chamber 1. As such access is required from below where the chamber is ceiling mounted, chamber fans of the prior art typically include a base panel which is screwed in position to the rest of the enclosure, rather than being permanently fixed with rivets. This enables the base panel to be removed by unfastening the screws to release the panel. However, once removed the weight of the panel must be supported and the panel cannot be lowered through the suspended ceiling frame structure. Even if the frame of the ceiling were not present, supporting a panel overhead in this manner even if only during initial removal presents a hazard, particularly as where the panel is insulated and therefore has a significant weight.
To obviate the requirement for a maintenance engineer to support the weight of the base panel 8 on removal, the base panel 8 is slideably mounted to the enclosure 7 defined by the side 2 end 3 walls and the top panel 4 enabling it to be slid to an open position as shown in Figure 2, in which the base panel 8 has been slid to one side to an opening position to enable access to the fan 14 within the chamber 1 from below. The base panel 8 is slidingly mounted to the side walls 2 by guide rails 22 which are provided on either side of the panel, as will be described in further detail below. The base panel 8 includes recessed handles to facilitate the sliding of the panel 8 while minimising the depth of the arrangement and avoiding projecting handles which may catch against other elements or structures present in the ceiling void.
The base panel 8 forms part of an air channel within the chamber 1, as can be seen in Figure 2. Air enters the chamber 1 through the inlet duct 10 and an air channel 25 is defined between the base panel 8 and an internal panel 26. The air channel 25 directs the air to the inlet 28 of the fan 14. To avoid losses a sealed air tight mating arrangement between the base panel 8 and the enclosure 7 is required. However, an airtight sealed engagement between the enclosure 7 and the base panel 8 would inhibit sliding movement of the base panel 8 relative to the enclosure 7. Therefore the panel 8 is arranged to be moved between a first position in which it is in sealed engagement with the enclosure 7 and a second position in which it is spaced from the enclosure 7 and free to slide in the guide rails 22.
The following will describe the arrangement between the panel 8 and one of the guide rails 22. The same description applies to the opposing guide rail 22 and opposing side of the panel 2. As shown in Figure 3, the side wall 2 and base panel 8 are double skin panels having inner and outer walls or 'skins' which may have an acoustic and/or thermally insulating material provided therebetween. The end walls 3 and upper panel 4 may comprise a similar double skin construction. The guide rail 22 is mounted to the side wall 2 and the opposing guide rail is mounted to the respective opposing side wall 2 in a similar manner. The guide rail 22 includes a main body portion forming a side wall 29 which is arranged parallel to the side wall 2 and in use is substantially vertically oriented. A projection 30 extends inwardly towards the enclosure 7 and base panel 8 from the lower edge 31 of the wall 29 forming flange defining lower runner, and extends along the length of the wall 29 along its lower edge.
A second projection 32 extends inwardly from the wall 29 forming a flange defining an upper runner at a vertically spaced position above the lower runner 30. The second projection 32 extends along the length of the wall 29 parallel to the lower runner 30. The lower 30 and upper 32 runners define a channel 34 having a width substantially equal to the thickness of the panel 8 for receiving panel 8 in a sliding fashion. The channel is toleranced in such a way that sufficient gap is provided between the inner surfaces of the channel and the upper and lower surfaces of the panel 8 to permit unhindered sliding of the panel 8 within the channel.
In the closed position as shown in Figure 3 the panel 8 is held adjacent the lower edge of the 9 of the side wall 2 and is spaced from the lower edge 9 by the flange defined by the second projection 32. The second projection 32 stops short of the inner edge 38 of the side wall 2 with the portion of the lower edge 9 between the end of the second projection 32 and the inner edge 38 defining an upper sealing surface 40. The portion of the panel 8 immediately below the upper sealing surface defines a second sealing surface 42. A seal 36 is provided between the upper and lower sealing surfaces 40, 42 which is compressed between the two surfaces to create a seal therebetween when the panel 8 is in the closed position. The seal 36 extends entirely around the periphery of the opening 6. In the enclosure shown in Figures 1 and 2 end walls 3 are provided which define an inwardly located inlet 10 and outlet 12. The end walls 3 overhang and extend downwardly to the lower face of panel 8 and in the closed position abut the ends of the panel 8. Therefore a sealing flange is secured to the inner face of each of the end walls 3 at a position level with the upper surface of the panel 8 as a continuation of the sealing surface defined by the lower edges 9 of the side walls 2. The seal 36 extends around and is secured to the lower surface of the end flange and in the closed position is compressed between the upper surface of the panel 8 and the lower surface of the panel 8 with the portion of the panel 8 beneath the flange defining another portion of the panel's sealing surface. It will be appreciated that while the seal 36 is described as being secured to the enclosure 7 it could alternatively be secured to the upper surface of the panel 8 and brought into engagement with the enclosure in the closed position. Where no end walls 3 are required, such as where the enclosure is a straight through ducting member having open ends, a bridging member may be provided across the ends of the enclosure between the side walls to structurally space the side walls when the panel is in the open position and to define a sealing surface at the ends of the enclosure when the panel is in the closed position.
The guide rail 22 is held in the closed position by a socket cap screw 44. The socket cap screw 44 comprises a shaft 46 having a threaded distal end which extends through a slot 47 in the side wall 29 of the guide rail 22. A threaded sleeve (not shown) is provided within the side wall 2 which is secured to at least the outer skin. The threaded sleeve is required due to the void between the inner and outer skins of the side wall 2.
The proximal end of the shaft 46 comprises a cylindrical unthreaded section which is received within the slot 47 and a head 50 having a diameter greater that the shaft 46 and greater than the width of the slot 47. The head 50 is configured to receive an Allen key tool, although any alternative fixing means suitable for engaging the guide rail 22 and licking it in position may be used. As the screw 44 is tightened the head engages the side wall 29 and clamps the side wall 29 of the guide rail 22 against the side wall 2. Additional screws 44 and slot 47 arrangements are provided along the length of the guide rail 22 which fasten and operate in the same manner. The clamping engagement of the screws 44 is against the guide rail 22 is sufficient to hold the guide rail 22 and the panel 8 it supports in the closed raised position. Preferably additional screws are provided through the base of the panel 8 to screw the panel to the enclosure 7 once the panel is in the closed position, with the screws 44 acting to temporarily hold the panel in the closed position while the additional screws are fastened through the base. Any other means of fixedly securing the panel 8 may be alternatively or additionally utilised. It is however contemplated that the screws 44 may be configured to act to independently hold the panel in the closed position without the requirement for additional screws.
The opening method of the panel 8 is represented in Figures 4a-4c. In Figure 4a the panel is shown in the closed position. Due to the frictional engagement between the panel 8 and the seal 36 the panel 8 is unable to slide within the guide rail 22 in the closed position. The slot 47 is therefore substantially vertically oriented, or at least oriented away from a plane parallel with the opening, to permit the panel 8 to slide away from the closed position when the screws 44 are released. As the screws 44 are released the guide rail 22 is no longer clamped to the side wall 2 and is free to move relative thereto. The screws 44 act as guide pins sliding relative to the guide rail 22 within the slots 47. The slots 47 constrain and guide the movement of the guide rail 22 as it moves away from the closed position. In the arrangement shown in the Figure 3 in which the enclosure 7 is mounted overhead with the panel 8 located on the lower edge, this movement is in the downward direction.
The enclosure may be mounted in alternative orientations in which the panel is not downwardly facing. For example the enclosure may be wall mounted with the panel 8 in a substantially vertical orientation, in which case the movement away from the opening would be in a substantially horizontal direction away from the vertical plane of the opening. Therefore it should be appreciated that the term 'downwardly' should not be considered as limiting or as an absolute direction, and instead means only in a downwards direction relative to the opening above it. It is also contemplated that the guide rail 22 may be hinged at one end such that one end pivots while the second end slides away from the opening guided by a curved rather than straight slot 47.
The length of the slot 47 defines the distance from the opening to which the panel 8 may be moved. As the guide rail 22 slides downwardly the upper end 52 of the slot 47 closest to the opening 6 acts as stop. Once the end 52 slides into engagement with the screw 44 the guide rail is prevented from moving further away from the opening 6 and the panel 8 is held in this position by the guide rail 22. The position of the panel 8 in the furthest spaced location from the opening 6 defines the first open position of the panel in which the panel is aligned with but spaced from the opening 6 as shown in Figure 4b. The arrangement shown in Figures 1 and 2 including overhanging end walls 3 the length of the slot 47 is selected such that the panel 8 is able to move away from the opening a sufficient distance to clear the lower edge of the end walls 3, which is a distance greater than the thickness of the panel 8. In an embodiment without such end wall abutment a spacing of this distance is not required as no end wall clearance is necessary.
Once moved to the first open position the panel 8 is spaced from the opening and no longer constrained by the frictional action of the seal 36. As such the panel 8 is free to slide within the channel 34 of the guide 22 to a second open position in which the panel is no longer aligned with the opening 6 i.e. the panel 8 is laterally offset from the opening as shown in Figure 4c. With the panel 8 having been slid away from the opening either partially or fully access is permit from beneath into the opening 6. Preferably the panel 8 slides away from the opening 6 to open the opening 6 in a direction and orientation parallel to the opening 6. Advantageously the panel 8 is supported in a suspended position away from the opening in both first and second open position, meaning that an engineer is not required to support the weight of the panel 8 at any time.
To close the opening 6 the opening method is repeated in reverse, with the panel 8 being slid from the second open position to the first open position and then lifted to the closed position where it is momentarily held while the screws 44 are tightened. Due to the lateral support provided by the screws 44 within the guide slots 47 minimal effort is required to support the panel during this operation. Once the screws 44 are tightened the panel 8 remains held in the closed position with the panel 8 urged against the seal 36, allowing the engineer to proceed with applying and tightening the fixing screws through the lower surface of the panel.
Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection for the features of the invention as defined in the appended claims.
It will be appreciated that in further embodiments various modifications to the specific arrangements described above and shown in the drawings may be made. For example, reference herein to a plurality of walls should not be taken as requiring discrete and separate wall members. The term plurality of walls may for example refer to discrete sections of a continuous single wall such as the upper, lower and side quadrants of a cylindrical pipe wall. The term walls refers only to an enclosure defining member or members and is not limited for example to planar members or panels.

Claims

An enclosure (1) for a HVAC system comprising:
at least one wall (2) defining said enclosure;

a fluid inlet (10);

a fluid outlet (12);

an access opening (6) to permit access to the enclosure;

a closure member (8) for closing the access opening; and

a guide element slidingly receiving and supporting the closure member;

wherein the guide element is movable between a first operative position in which it holds the closure member in a closed position to close the access opening and a second operative position in which the closure member is spaced from the access opening and wherein in the second operative position the closure member is able to slide relative to the guide element away from the access opening to permit access to the enclosure through the access opening.
An enclosure according to claim 1 further comprising locking means (44,46,47,50) for locking the guide element in the first operative position.
An enclosure according to claim 1 or 2 wherein the closure member comprises a first sealing surface arranged to cooperate with a corresponding second sealing surface on the enclosure to fluidly seal the opening when the closure member is in the closed position.
An enclosure according to claim 3 wherein at least one of the closure member (8) and the enclosure (1) includes a sealing member arranged such that it is located between the first and second sealing surfaces to create a seal therebetween when the closure member is in the closed position.
An enclosure according to any preceding claim wherein the guide element is arranged to move between the first and second operative positions in a direction substantially perpendicular to the opening and the closure member slides relative to the guide element in a direction substantially parallel to the opening.
An enclosure according to claim 5 wherein the guide element is arranged to move between the first and second operative positions in a substantially vertical direction and the closure member (8) slides relative to the guide element in a substantially horizontal direction.
An enclosure according to any preceding claim wherein the enclosure is defined by a plurality of walls (2,3).
An enclosure according to claim 7 wherein the walls of the enclosure include a plurality of side walls (2) and a top panel (4) connected to a first edge of the side walls the opposing edges forming a perimeter defining the opening, and the closure member is a panel which in the closed position closes the opening and forms the base of the enclosure.
An enclosure according to any preceding claim wherein the guide element comprises a pair of guide rails (22) provided on opposing sides of the panel,
An enclosure according to claim 9 wherein each guide rail (22) comprises at least one guide slot (47) which receives a corresponding guide pin extending from the enclosure which guides the guide rails (22) during movement between the first and second operative positions and acts as a stop member engaging with one end of the at least one slot to locate and support the guide rails in the second operative position.
An enclosure according to claim 10 wherein each guide pin comprises a shaft (46) having a threaded portion which is received within a corresponding threaded portion of the enclosure and a locking head at the opposing end which is configured to engage and clamp the respective guide rail to lock it in the first operative position.
An enclosure according to claim 11 wherein the guide rails (22) each comprise a side wall and a pair of projections (32) extending inwardly towards the closure member from a face of the side wall defining a sliding channel for slidingly receiving the closure member and guide rails are arranged such that the side walls engage and are arranged parallel to a respective side wall of the enclosure.
An enclosure according to claim 12 wherein the side wall of each guide rail (22) includes at least two guide slots (47) and the respective side wall to which they are connected each include at least two corresponding guide pins.
An enclosure according to claim 13 wherein the enclosure and closure member define a ducting member for a HVAC system.
An enclosure according to any preceding claim wherein the guide element is mounted to the enclosure.