Underfloor air supply unit

Abstract

The invention relates to a floor underfloor air supply unit (100) for use in a raised floor system having a raised floor, an underfloor plenum space below the floor, and an indoor space above the floor. The unit has a housing (101) having a top surface (102) configured to be generally parallel to the raised floor, a first inlet (120) below the top surface of the housing and configured to receive plenum air VA from the plenum space, a second inlet (130) in the top surface and configured to receive air from the indoor space, and an outlet (140) in the top surface and configured to supply air to the indoor space. The unit further has a fan (150) for drawing air from the first and / or second inlets and supplying air to the outlet. The unit defines an air flow path from the second inlet to the outlet over which the air flow direction is reversed, such that the second inlet and the outlet are on the same side of the fan in the top surface. In one embodiment, the second inlet (130) and the outlet (140) are aligned in the X direction and adjacent in the Y direction, and the second inlet comprises two second inlets (131, 132) separated in the Y direction by a single outlet (140).

Description

Technical Field

[0001] This invention relates to an underfloor air supply unit suitable for installation in a raised access flooring system. Background Technology

[0002] Raised access floor systems typically consist of an array (usually square) of floor sections mounted on raised supports above the structural floor of the building below. The resulting gaps allow utilities such as electricity, water, and network cabling to be supplied to where they are needed.

[0003] Underfloor air supply units are known, and these units are typically configured to have the same footprint as square floor sections to facilitate integration into standard floor arrays. A standard industry size for floor sections is 600 mm x 600 mm. Underfloor air supply units can draw air supply from the void beneath the raised floor. This void air can be supplied from other parts of the building or from the exterior, and can be ambient air, or may have been treated or conditioned in some way, such as by heating or cooling, filtering, humidifying, or dehumidifying. The supply unit can receive void air through ductwork; however, ductwork may not be necessary if the entire void supplies air to one or more units in the system. These units can also draw indoor air supply from above the raised floor. This indoor air is typically ambient air taken directly from the room and not pretreated in any way. Therefore, the unit can supply void air, indoor air, and mixtures of both.

[0004] Therefore, a standard underfloor air supply unit has two inlets: one from the gap beneath the raised floor for gap air and one from the space above for indoor air; and an outlet leading to the space above the raised floor. Consequently, the top surface of the unit requires inlet and outlet openings for the indoor space above and below, typically covered by a grille. The openings in a standard unit are located at each end of a square unit (which can be considered the length in the X direction) and can span the entire width of the unit in the orthogonal direction (which can be considered the Y direction). The fan will be located in the middle of the unit, between the two openings. This arrangement means that the entire standard floor section, typically 600 mm x 600 mm, must be effectively opened and exposed to properly install the standard dual-outlet unit.

[0005] This requirement may affect the placement of standard double-hole floor units in a cellular floor system where the open floor area may be very limited, and where entire open 600 mm x 600 mm sections may be unavailable or few in number within a given cellular configuration. As an example, the placement of furniture or partitions may limit the available open floor area, making it impossible to install standard double-hole units.

[0006] Given these limitations, standard dual-aperture underfloor units may have to be placed in unsuitable locations that could affect system functionality and occupant comfort. For example, they could be placed under a table or other furniture that would impede airflow and thus system function, or directly under a chair that would cause discomfort. In such cases, the office layout may have to be altered to accommodate the standard unit, ultimately reducing the system's flexibility, which is one of the primary reasons for its use.

[0007] At least in preferred embodiments, the present invention aims to address problems associated with prior art underfloor air supply units, including one or more of the problems discussed above. Summary of the Invention

[0008] This invention provides an underfloor air supply unit for a raised access floor system, the system including a raised floor, a void space beneath the floor, and an interior space above the floor. The unit includes: a housing having a top surface configured to be generally parallel to the raised floor in use; a first inlet located below the top surface of the housing and configured to receive void air from the void space in use; a second inlet in the top surface and configured to receive air from the interior space in use; an outlet in the top surface and configured to supply air to the interior space in use; and a fan for drawing air from the first inlet and / or the second inlet and supplying air to the outlet in use, wherein the unit defines an airflow path from the second inlet to the outlet, the airflow direction being reversed along the airflow path such that the second inlet and the outlet are on the same side of the fan in the top surface.

[0009] Void air can be supplied from other parts of the building or from the outside. Void air can be ambient air, or it may have been treated or conditioned in some way, such as by heating or cooling, filtering, humidifying, or dehumidifying. Void air can be supplied via ducting; however, if air is supplied to one or more units in the system throughout the void, ducting may not be necessary. Indoor air will typically be ambient air taken directly from the room and not pretreated in any way. Therefore, the unit can supply void air, indoor air, and mixtures of both.

[0010] The fan can selectively draw all air from either the first inlet or the second inlet, or a certain proportion of air from both inlets. In some embodiments, as discussed below, the unit has a "fully open" position where the first inlet is open and the second inlet is closed, such that all air is drawn from the first inlet (gap air). In a "fully closed" position, the second inlet is open, and air is drawn from the second inlet (indoor air). In a fully closed position, the first inlet may be closed, such that all air is drawn from the second inlet (indoor air), or the first inlet may be partially closed, such that at least some air is still drawn from the first inlet (gap air), for example, for ventilation purposes. Positions between fully open and fully closed are also possible. The unit may include devices such as dampers, as discussed below, to selectively control the air supply from the first and second inlets to the fan.

[0011] The unit, housing, and top surface can be considered to have a length in the X direction, a width in the Y direction, and a height in the Z direction. The unit can be designed to be assembled within a floor system or to provide a module for the floor system, such as a 600 x 600 mm module.

[0012] As described above, the unit reverses the airflow direction from the second inlet to the outlet, such that the second inlet and outlet are on the same side of the fan on the top surface. In prior art units, the airflow through the unit is typically (when considering length or the X direction) in only one direction, i.e., straight, from one end to the other, with the fan between the inlet and outlet. By reversing the direction in the airflow path, a more compact path, i.e., a shorter “footprint” in the X direction, can be achieved. The fan then does not need to be located between the inlet and outlet, allowing the inlet and outlet to be on the same side of the fan. The fan can be located at one end of the unit. Direction reversal can also occur within the fan itself. With the inlet and outlet on the same side of the fan on the top surface, a more compact arrangement is possible, allowing for a single grille and a smaller footprint. The inlet and outlet no longer need to be separated by fan gaps and can, for example, be adjacent to each other, as discussed below.

[0013] When considering the length of the unit or the X-direction, the airflow direction is reversed. The X-direction component of the airflow direction can be reversed at points or sections in the airflow path, allowing the second inlet and outlet to be on the same side of the fan.

[0014] Preferably, the turning angle of the airflow path is greater than 90 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees, or 180 degrees, preferably about 180 degrees or substantially 180 degrees, to reverse the airflow direction. Preferably, the turning angle of the airflow path in the X direction is greater than 90 degrees, so that there is a component in the X direction returning towards the original direction.

[0015] The airflow path will also deviate in at least one of the other directions (Y, Z, or both) to provide a path to the outlet. Therefore, preferably, the airflow path is reversed in the X direction and also deviates in at least one of the width (Y) and height (Z) directions.

[0016] Points or sections where the direction of airflow reverses can be located in the duct (e.g., bends, curves, elbows, etc.), or can be provided by or within a fan.

[0017] Therefore, in a preferred embodiment, the airflow path is configured to reverse direction within the fan. The fan can be configured to turn the airflow path substantially 180 degrees.

[0018] The fan inlet and outlet can be located on the same side of the fan (in length or X direction). The fan typically has a rotation axis. In a preferred embodiment, the axis is aligned in the Y direction, and the second inlet and outlet are located on the same side of the axis in the X direction.

[0019] As mentioned above, the fan can be located at the reversing point or a reversing point can be provided to facilitate changing the direction of airflow toward the outlet, and therefore the fan does not have to be located between the inlet and the outlet.

[0020] In a preferred embodiment, the airflow path is configured to supply air to a first layer in the unit before the airflow direction is reversed, and wherein, after the airflow direction is reversed, the airflow path is located in a second layer in the unit. The first layer may be lower than or higher than the second layer (in height or in the Z direction).

[0021] In a preferred embodiment, the unit further defines a second airflow path from the first inlet to the outlet, along which the airflow direction is also reversed. The airflow path from the second inlet to the outlet and the second airflow path from the first inlet to the outlet can be merged before reversing the direction. In this embodiment, the first and second inlets can be located on the same side of the fan in the X direction. If the first and second inlets are on opposite sides of the fan, the second airflow path is not reversible in direction.

[0022] In a preferred embodiment, the second inlet and outlet are substantially adjacent to each other on the top surface of the unit. The second inlet and outlet do not necessarily need to be adjacent or directly adjacent, although they can be. There may at least be a partition wall, or there may be a relatively narrow partition / separation section forming part of the top surface, but adjacency should be distinguished from the prior art, in which the inlet and outlet are located at opposite ends of the unit (in the Y direction), separated by the distance required by the fan, and therefore they are not adjacent. Adjacency refers to when considered in a plan view, and this can be in either the X or Y direction.

[0023] As discussed above, positioning the second entrance and exit adjacent to each other (and preferably centrally located) frees up one or both ends of the unit for placing furniture, partitions, etc. The second entrance and exit may share a single grille, which may be a design similar to one of the grilles in the current dual-grille unit.

[0024] In a preferred embodiment, adjacent second inlet and outlet regions are combined to define a total second inlet / outlet region in the top surface of the housing. This region preferably extends less than the length of the top surface in the X direction, and preferably less than half the length, and more preferably between one-third and one-half the length, and still preferably approximately one-third of the length. This region may extend across less than, substantially all, or all of the width of the top surface in the Y direction, and / or may be substantially centered or oriented towards or on one side of the Y direction. This region may be substantially centered in the top surface in the X direction, or off-center, such as at one end of the top surface in the X direction or at one end of the top surface.

[0025] In a preferred embodiment, the second inlet and outlet are aligned in one of the X and Y directions and adjacent in the other. "Aligned" means that the inlet and outlet are generally aligned in the relevant directions. This can be relative to the centerline of the inlet and outlet, or, for example, relative to an edge. While the second inlet and outlet are aligned in one direction, they may or may not be coaxial in the other direction.

[0026] In one embodiment, the second inlet and outlet are aligned in the X direction. The second inlet and outlet may be adjacent in the Y direction. The combined width of the second inlet and outlet may substantially extend across the width of the top surface in the Y direction. The length of the second inlet and / or outlet in the X direction preferably extends less than the length of the top surface, and preferably less than half the length, and more preferably between one-third and one-half the length, and still preferably approximately one-third of the length. The second inlet and outlet may extend co-located in the X direction. The second inlet and / or outlet may each comprise a single inlet / outlet. In a preferred arrangement, the second inlet comprises two second inlets separated by a single outlet in the Y direction.

[0027] In another embodiment, the second inlet and outlet are aligned in the Y direction. The second inlet and outlet may be adjacent in the X direction. The width of the second inlet and / or outlet may extend substantially across the width of the top surface in the Y direction. The combined length of the second inlet and outlet in the X direction preferably extends less than the length of the top surface, and preferably less than half the length, and more preferably between one-third and one-half the length, and still preferably approximately one-third of the length. The second inlet and outlet may extend co-located in the Y direction. The second inlet and / or outlet may each comprise a single inlet / outlet. The second inlet and outlet may have substantially the same length in the X direction.

[0028] The unit preferably further includes a damper to selectively control the air supply from the first inlet and / or the second inlet to the fan. The damper can supply all air to the fan from either the first or the second inlet, or a specific proportion of air can be supplied from both inlets. The damper is preferably a plate or baffle whose position can be controlled by a motor. In some embodiments, the damper extends substantially across the width of the unit in the Y direction. The damper can guide air to the first layer discussed above.

[0029] The unit preferably further includes a heater for heating the air supplied to the outlet.

[0030] At least in preferred embodiments, the present invention addresses the requirement for underfloor air conditioning units (i.e., individual components of a larger underfloor air conditioning system) that can be installed in the infrastructure of a raised floor system utilizing 600 mm x 600 mm interlocking floor panels, without requiring a total effective open area of ​​600 mm x 600 mm floor panels to function correctly. Furthermore, within the total 600 mm x 600 mm area provided by the raised floor system infrastructure, a portion of the open area required for the normal operation of the underfloor unit can be adjusted along the X-axis or Y-axis depending on the orientation of the underfloor unit.

[0031] The present invention is advantageous in that the open floor area is limited such that the entire open area of ​​a 600 mm x 600 mm floor panel (in which industry standard 2-grid floor under-units can be installed) is unavailable or very little available. This situation is common in cellular spaces, where furniture and partition walls limit the open floor area, making it impossible to install standard 2-grid units.

[0032] Units that meet the above requirements can utilize the partial open area of ​​a 600 mm x 600 mm section of a raised access floor system, while industry standard 2 grid units cannot.

[0033] This invention specifically relates to an underfloor air conditioning unit that achieves the full functionality of a standard two-grid unit while using a single grid of the same type as the standard two-grid unit. This grid is positionally adjustable along an axis of a 600 mm x 600 mm section of the raised floor system, allowing installation in spaces with limited open floor area where the standard two-grid unit may not be installed, or where its installation method is detrimental to the overall function of the underfloor air conditioning system, or where its installation method is detrimental to occupant comfort. The single-grid underfloor unit can be installed in a 600 mm x 600 mm floor section with only partially open area; therefore, the same 600 mm x 600 mm section can be partially covered by furniture or partition walls.

[0034] At least in the preferred embodiments, the following provide some additional features and advantages of the invention:

[0035] • Air is recirculated and supplied to the raised access floor space above via a single exposed grille, the same size as the individual grilles on an industry-standard unit that requires two grilles.

[0036] • The visual footprint above the floor is smaller (single grille).

[0037] • Due to the layout of the internal structure, the floor space underneath is smaller. This reduces the amount of material used and increases placement flexibility (under a partition wall, where it would be impossible to place two standard grid units without compromising functionality).

[0038] • The grid arrangement within a 600 x 600 tile can be adjusted (this is not possible for a standard 2-grid unit).

[0039] • Units can be placed directly adjacent to each other without compromising functionality.

[0040] • The chassis is constructed such that the unit is divided into two distinct lower and upper sections, with partition walls parallel to the top and bottom of the unit. A fan compartment is located at one end of the unit, separate from and open to both the upper and lower sections. The chassis encloses the internal volume of the unit and is therefore airtight except for designated areas for inlets and outlets.

[0041] • The indoor inlet and fan outlet areas are adjacent to each other along the area covered by a single air grille. The inlet and outlet areas are open and located on the top surface of the upper section of the unit.

[0042] • Two indoor entrance sections are located on either side of a single fan outlet section, which is separated by a non-permeable partition perpendicular to the top of the unit and is part of the unit chassis construction.

[0043] • The floor entry area is located on the lower half of one of the side facades, which is parallel to the longitudinal direction of the individual air grille. This allows for the formation of a direct path from the lower unit section into the floor void for air to pass through.

[0044] • The centrifugal fan assembly is fixed inside the unit on the side opposite the air inlet under the floor in the fan room.

[0045] • The fan is oriented so that air is drawn from the interior of the bottom section of the unit and discharged into the top section of the unit by turning the air 180 degrees from its original direction of travel.

[0046] • Inside, the bottom section of the unit is open, allowing air to be drawn directly from the underfloor inlet into the centrifugal fan assembly, where it is then discharged to the top section of the unit.

[0047] • The aforementioned fan outlet area, covered by a single air grille, is located in the top section of the unit and has a direct air path to the centrifugal fan assembly.

[0048] • The indoor inlet area adjacent to the fan outlet area leads to the lower section of the unit, so air can move directly from the top of the unit (circulated air) to the lower section of the unit.

[0049] • The damper is installed parallel to the orientation of the underfloor inlet across the entire opening width of the lower section of the unit.

[0050] • The damper is actuated by a motor and has two final positions: fully “open” and fully “closed”.

[0051] • The damper is rectangular in shape and is attached to the unit housing via two opposing and concentric rotary joints positioned near the ends of the short sides of the rectangular damper. These joints are placed near the top surface of the lower section of the unit, so that the damper rotates around the rotary joints under tension from the motor or under gravity to block or open the interior area of ​​the lower section of the unit.

[0052] • In the fully “open” position, the motor engages, causing the damper to rotate clockwise under tension from the motor. The damper rotates until it contacts the top surface of the lower section of the unit. At this point, the damper is parallel to and directly adjacent to the top surface of the lower section.

[0053] • In this open position, the damper seals against the top surface of the lower section of the unit, separating the two indoor air intake areas from the lower section of the unit and preventing air from moving from the top of the unit to the lower section.

[0054] • In this open position, the path from the underfloor inlet through the lower section of the unit to the centrifugal fan assembly is fully open to allow for the passage of conditioned air.

[0055] • In the fully “closed” position, the motor is disengaged, and the damper rotates counterclockwise under gravity until it contacts the minimum mechanical opening stop of the unit. At this point, the damper spans between the top and bottom surfaces of the lower section of the unit.

[0056] • In this closed position, the indoor entrance area in the upper section of the unit opens to the lower section of the unit, so recirculated air from above the unit can be freely transferred to the lower section of the unit.

[0057] • In this closed position, the path from the underfloor inlet through the lower section of the unit to the centrifugal fan assembly is partially blocked to prevent the passage of conditioned air.

[0058] • The "open" damper position corresponds to the unit being in "supply air mode," and the "closed" damper position corresponds to the unit being in "recirculation mode." These two modes are the basis for how the unit regulates indoor conditions.

[0059] • Because the sections for indoor inlets and fan outlets are directly adjacent to each other, a single grille is used to achieve both "supply" and "recirculation" modes. Attached Figure Description

[0060] Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

[0061] Figure 1 shows a schematic side view of a conventional underfloor air supply unit supplying air to the indoor space above in air supply mode;

[0062] Figure 2 shows the conventional underfloor air supply unit of Figure 1 supplying recirculated air to the indoor space above in recirculation mode;

[0063] Figure 3 shows a schematic plan view and an example plan view of a conventional underfloor air supply unit;

[0064] Figure 4 A plan view of the underfloor air supply unit according to the present invention is shown;

[0065] Figure 5A It shows Figure 4 A cross-sectional view of the underfloor air supply unit along line AA;

[0066] Figure 5B It shows Figure 4 A cross-sectional view taken along line BB of the underfloor air supply unit;

[0067] Figure 5C It shows Figure 4 A cross-sectional view taken along line CC of the underfloor air supply unit;

[0068] Figure 6A It shows Figure 4 A plan view of the underfloor air supply unit in recirculation mode;

[0069] Figure 6B It shows Figure 6A A cross-sectional view of the underfloor air supply unit along line AA;

[0070] Figure 7A It shows Figure 4 A plan view of the underfloor air supply unit in air supply mode;

[0071] Figure 7B It shows Figure 7A A cross-sectional view of the underfloor air supply unit along line AA;

[0072] Figure 8 Schematic plan views and example plan views of the underfloor air supply unit according to the present invention are shown; and

[0073] Figures 9A to 9D Examples of different second inlet and outlet configurations according to the present invention are shown. Detailed Implementation

[0074] Figures 1 and 2 show schematic diagrams of a conventional underfloor air supply unit 10 located in a raised raised floor system. The floor system includes a raised floor R, which is mounted on a raised support (not shown) above the structural floor S of the building. A gap V is formed between the two floor layers.

[0075] The underfloor air supply unit 10 is located in the void V and has a top surface 11 that is parallel to and generally coplanar with the raised floor R. The unit includes: a first inlet 12 below the top surface and receiving void air VA from the void space; a second inlet 13 in the top surface and receiving indoor air RA from the indoor space (FIG. 2); and an outlet 14 in the top surface supplying air SA to the indoor space. The unit 10 also includes: a fan 15 for driving air to the outlet 14; and an optional heater 16 between the fan and the outlet for heating the air.

[0076] The second inlet 13 and outlet 14 are fitted with grilles to prevent entry into the unit's interior and to provide a safe surface in the raised floor should someone stand on or walk on the unit. The second inlet 13, outlet 14, and grilles are located at opposite ends of the unit (i.e., along the length of the unit in the X direction), as can be seen in Figures 1 and 2, with the fan positioned between the second inlet and outlet. The second inlet 13, outlet 14, and grilles typically extend the entire width of the unit in the Y direction.

[0077] The damper 17 controls the air supply to the fan. In Figure 1, the unit is in supply air mode, with the damper 17 in the raised position, allowing the interstitial air VA received through inlet 12 from the interstitial space to be supplied as supply air SA to the upper indoor space. In Figure 2, the unit is in recirculation mode, with the damper 17 in the lowered position, allowing the indoor air RA from the upper indoor space to be optionally recirculated back into the indoor space via heater 16 as supply air SA. In recirculation mode, the damper can be configured to allow a small amount of interstitial air VA to pass through, ensuring that the supply air SA includes a certain amount of fresh air.

[0078] Figure 3 shows a schematic and example plan view of a conventional underfloor air supply unit. The standard floor module is 600 mm x 600 mm. Grilles for the second inlet and outlet are located at opposite ends of the unit (i.e., along the length of the unit in the X direction). They essentially extend across the entire width of the unit in the Y direction. The example plan view shows some floor modules obstructed by partition walls and furniture, thus preventing conventional underfloor units from being located in these positions.

[0079] Now refer to Figure 4 , Figure 5A , Figure 5B and Figure 5C A floor-mounted air supply unit according to an embodiment of the present invention is described. Figure 5A , Figure 5B and Figure 5C They are shown respectively Figure 4 The cross-sectional views of the elements along lines AA, BB, and CC.

[0080] The underfloor air supply unit 100 has a housing 101, which includes a top surface 102 that, when in use within a gap V, will be parallel to and generally coplanar with the raised floor R.

[0081] A first inlet 120 is located below the top surface 102 and receives void air from the void space. A second inlet 130 is located in the top surface to receive indoor air, and an outlet 14 is located in the top surface to supply air to the indoor space. Unit 10 also includes a fan 150 for driving air to the outlet 140, the fan having a motor 151 and two impellers 152. A heater 160 is disposed between the fan 150 and the outlet 140 for heating the air as needed. A damper 170 controls the air supply to the fan, and its position is controlled by means of a motor 171, which can shorten or lengthen the belt 172 to move the damper between a supply air mode and a recirculation mode, and the position between the two modes is also possible.

[0082] In the illustrated embodiment, the second inlet 130 includes two inlets 131 and 132, which are separated in the Y direction by an outlet 140. Indoor air is received at the upper level of the unit by inlets 131 and 132, and this air is guided by a damper 170 to the lower level of the unit, where it is supplied to the fan impeller 152. Inlets 131 and 132 are trapezoidal in plan due to angled baffles 103 provided at the upper level, which guide the airflow from the impeller to the outlet 140. Control electronics may be located in compartment 104.

[0083] Figure 6A and Figure 6B It shows Figure 4 A plan view and a cross-sectional view of the underfloor air supply unit in recirculation mode. The damper 170 is in a lowered position, thus preventing or at least partially restricting the entry of interstitial air VA into the unit via the first inlet 120. The damper 170 guides indoor air RA from the second inlet 130 through the upper layer 105 to the lower layer 106, where the air enters the impeller 152. Within the impeller, the airflow path is turned 180 degrees in the X direction and also flows back from the lower layer 106 to the upper layer 105. An angled baffle 103 in the upper layer guides air from the impeller through the heater 160 to the outlet 140.

[0084] Figure 7A and Figure 7B It shows Figure 4A plan view and a cross-sectional view of the underfloor air supply unit in air supply mode. The damper 170 is in the raised position, thus preventing indoor air RA from entering the unit via the second inlet 130. The damper 170 allows gap air VA from the first inlet 120 (located in the lower layer 106 of the unit) to be passed to the impeller 152. Within the impeller, the airflow path again turns 180 degrees in the X direction and is also passed from the lower layer 106 to the upper layer 105. An angled baffle 103 in the upper layer guides air from the impeller via the heater 160 to the outlet 140.

[0085] Figure 8 Schematic and example plan views of an underfloor air supply unit according to the present invention are shown. Compared with the conventional air supply unit shown in FIG3, it can be seen that, due to the presence of a single grille G positioned inwardly from each end in the X direction, the unit of the present invention can be used even if the floor module is partially blocked by a partition wall or furniture.

[0086] Figures 9A to 9D Examples of different second inlet and outlet configurations according to the present invention are shown. Figure 9A and Figure 9B In this configuration, the second inlet 130 and outlet 140 are aligned in the Y direction and adjacent in the X direction. Figure 9B In the middle, there is a dividing section between the second entrance and the exit (indicated by a shaded line). Figure 9C and Figure 9D In this configuration, the second inlet 130 and outlet 140 are aligned in the X direction and adjacent in the Y direction. Figure 9D In the middle, there are two exits 140, which are separated by a second entrance 130.

Claims

1. An underfloor air supply unit for a raised raised floor system, the system comprising a raised floor, a gap space beneath the floor, and an indoor space above the floor, the unit comprising: A housing having a top surface configured to be substantially parallel to the raised floor during use. A first inlet, located below the top surface of the housing and configured to receive void air from the void space during use. A second inlet, located in the top surface and configured to receive air from the interior space during use. An outlet, located on the top surface and configured to supply air to the interior space during use, and A fan, in use, is used to selectively draw air from the first and second inlets and supply air to the outlet. The unit defines an airflow path from the second inlet to the outlet, with the airflow direction reversed along the airflow path, such that the second inlet and the outlet are on the same side of the fan on the top surface.

2. The air supply unit as described in claim 1, wherein, The airflow path is turned at an angle greater than 90 degrees, 100 degrees, 110 degrees, 120 degrees, 130 degrees, 140 degrees, 150 degrees, 160 degrees, 170 degrees or 180 degrees in the length (X) direction of the unit, preferably about 180 degrees or substantially 180 degrees, to reverse the airflow direction.

3. The air supply unit as described in claim 2, wherein, The airflow path deviates in at least one of the width (Y) direction and the height (Z) direction.

4. The air supply unit as claimed in any of the preceding claims, wherein, The airflow path is configured to reverse direction within the fan.

5. The air supply unit as described in claim 4, wherein, The fan inlet and outlet are located on the same side of the fan (in the length or X direction).

6. The air supply unit as claimed in any of the preceding claims, wherein, The airflow path is configured to supply air to a first layer in the unit before the airflow direction is reversed, and wherein the airflow path is located in a second layer in the unit after the airflow direction is reversed.

7. The air supply unit as described in claim 6, wherein, The first layer is lower than the second layer (in height or Z direction), or the first layer is higher than the second layer (in height or Z direction).

8. The air supply unit as claimed in any of the preceding claims, wherein, The unit further defines a second airflow path from the first inlet to the outlet, in which the airflow direction is reversed.

9. The air supply unit as described in claim 8, wherein, Before the direction is reversed, the airflow path from the second inlet to the outlet and the second airflow path from the first inlet to the outlet are merged together.

10. The air supply unit as claimed in any of the preceding claims, wherein, The second inlet and the outlet are substantially adjacent to each other on the top surface of the unit.

11. The air supply unit as claimed in claim 10, wherein, The adjacent second inlet and outlet regions are combined to define a total second inlet / outlet region in the top surface of the housing, wherein the extension of the region is less than the length of the top surface in the X direction, and preferably less than half of the length, and further preferably between one-third and one-half of the length, and still preferably about one-third of the length.

12. The air supply unit as claimed in claim 11, wherein, The region extends substantially across the entire width of the top surface in the Y direction.

13. The air supply unit as described in claim 11 or 12, wherein, The region is located substantially centrally in the top surface in the X direction, or at one end of the top surface in the X direction.

14. The air supply unit as claimed in any of the preceding claims, wherein, The second inlet and the outlet are aligned in one of the X and Y directions and adjacent in the other of the X and Y directions.

15. The air supply unit as claimed in claim 14, wherein, The second inlet and the outlet are aligned in the X direction and adjacent in the Y direction.

16. The air supply unit as claimed in claim 15, wherein, The combined width of the second inlet and the outlet extends substantially across the width of the top surface in the Y direction.

17. The air supply unit as described in claim 15 or 16, wherein, The length of the second inlet and the outlet in the X direction is less than the length of the top surface in the X direction, and preferably less than half of the length, and more preferably between one-third and one-half of the length, and still preferably about one-third of the length.

18. The air supply unit as described in any one of claims 15 to 17, wherein, The second inlet includes two second inlets separated by a single outlet in the Y direction. The air supply unit as claimed in claim 14, wherein the second inlet and the outlet are aligned in the Y direction and adjacent in the X direction.

19. The air supply unit as claimed in claim 18, wherein, The second inlet and the outlet extend substantially across the width of the top surface in the Y direction.

20. The air supply unit as described in claim 18 or 19, wherein, The combined length of the second inlet and the outlet in the X direction is less than the length of the top surface in the X direction, and preferably less than half of the length, and more preferably between one-third and one-half of the length, and still preferably about one-third of the length.

21. The air supply unit as claimed in any of the preceding claims, further comprising a damper for selectively controlling the air supply from the first inlet and / or the second inlet to the fan.

22. The air supply unit as claimed in any of the preceding claims, further comprising a heater for heating the air supplied to the outlet.

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