Ceiling cassette air conditioner

Abstract

The present invention provides a ceiling cassette air conditioner comprising: a hollow box-shaped main unit case having a bottom surface with a main unit inlet and a top panel opposite the bottom surface; and a blower having a fan and a fan case in which the fan is housed, the blower being disposed in the main unit case so that the central axis of the fan is orthogonal to the bottom surface of the main unit case. The fan case has: a bottom wall section provided with a first blower inlet and disposed beside the bottom surface of the main unit case in the direction of extension of the central axis; and a top wall section provided with a second blower inlet and disposed beside the top panel in the direction of extension of the central axis. A secondary airway connecting the outside and the second blower inlet is provided in the main unit case, and the blower is disposed so that the first blower inlet faces the main unit inlet and a gap is formed between the top wall section and the top panel to form part of the secondary airway and serve as an air intake pathway to the second blower inlet.

Description

Ceiling-mounted air conditioner

[0001] The present disclosure relates to a ceiling-mounted air conditioner equipped with a blower.

[0002] Generally, ceiling-mounted air conditioners are required to be thin. To achieve this, some air conditioners (hereinafter also referred to as indoor units) have a sirocco fan positioned within the housing with its rotation axis perpendicular to the air intake of the indoor unit's housing (see, for example, Patent Document 1). The air conditioner disclosed in Patent Document 1 is a floor-standing indoor unit that is placed on the floor indoors with the side of the housing with the air intake facing forward. In the indoor unit disclosed in Patent Document 1, the sirocco fan and the blower, which have a fan case, are configured to draw air only from the front, with the rear of the blower facing the rear wall of the housing.

[0003] Japanese Patent Application Laid-Open No. 2007-198641

[0004] However, in a configuration like the indoor unit disclosed in Patent Document 1, where the fan is positioned so that the rotation axis of the sirocco fan is perpendicular to the air inlet on the front of the housing and the fan draws air only through the front air inlet, the air inlet area is limited and pressure loss increases. As a result, the fan rotation speed must be increased to ensure sufficient airflow, which leads to increased noise from the air conditioner.

[0005] The present disclosure has been made against the background of the above-mentioned problems, and provides a ceiling-mounted air conditioner that can suppress noise deterioration due to the limited area of ​​the intake port, even when the blower is configured so that the fan's rotation axis is perpendicular to the intake port of the housing (also called the main case).

[0006] The ceiling-mounted air conditioner of the present disclosure comprises a hollow box-shaped main body case having a bottom surface with a main body intake port and a top plate facing the bottom surface, and a blower having a fan and a fan case in which the fan is housed, and arranged within the main body case so that the central axis of the fan is perpendicular to the bottom surface of the main body case, the fan case having a bottom wall portion having a first blower intake port and arranged on the side of the bottom surface of the main body case in the extension direction of the central axis, and an upper wall portion having a second blower intake port and arranged on the side of the top plate in the extension direction of the central axis, a secondary air passage connecting the outside and the second blower intake port is provided within the main body case, and the blower is arranged so that the first blower intake port faces the main body inlet and so that a gap is formed between the upper wall portion and the top plate that forms part of the secondary air passage and serves as a path for air to be sucked into the second blower intake port.

[0007] According to the present disclosure, in a ceiling-mounted air conditioner in which the blower is positioned so that the fan's rotation axis is perpendicular to the main body intake port of the main body case, it is possible to suppress noise deterioration due to the limited intake port area.

[0008] FIG. 5 is a schematic side view showing a state in which a ceiling-embedded air conditioner according to Embodiment 1 is installed in the ceiling space. FIG. 6 is a schematic perspective view of the ceiling-embedded air conditioner shown in FIG. 1 as seen from above. FIG. 7 is a schematic perspective view of the ceiling-embedded air conditioner shown in FIG. 1 as seen from below. FIG. 8 is a schematic perspective view of the ceiling-embedded air conditioner shown in FIG. 2 with the top plate removed. FIG. 9 is a schematic front view of the ceiling-embedded air conditioner shown in FIG. 2 with the controller removed. FIG. 10 is a schematic cross-sectional view showing the A-A cross section of FIG. 5. FIG. 11 is a diagram showing another example of the configuration of the blower unit mounting fixture shown in FIG. 6. FIG. 12 is a schematic perspective view of the ceiling-embedded air conditioner shown in FIG. 1 as seen from below.

[0009] Hereinafter, an embodiment of a ceiling-mounted air conditioner according to the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. Furthermore, in the following drawings, including FIG. 1, the size relationships between the components may differ from the actual size relationships. Furthermore, in the following description, terms indicating directions are used as appropriate to facilitate understanding of the present disclosure. However, these terms are for the purpose of explaining the present disclosure and do not limit the present disclosure. Examples of terms indicating directions include "up," "down," "right," "left," "front," and "rear." Note that the same or corresponding parts in each drawing will be denoted by the same reference numerals.

[0010] Embodiment 1. Fig. 1 is a schematic side view showing a ceiling-mounted air conditioner according to embodiment 1 installed above the ceiling. Fig. 2 is a schematic perspective view of the ceiling-mounted air conditioner shown in Fig. 1 as viewed from above. Fig. 3 is a schematic perspective view of the ceiling-mounted air conditioner shown in Fig. 1 as viewed from below. In the figures, solid white arrows conceptually indicate air flow. The ceiling-mounted air conditioner is installed above the ceiling, draws in air from the space to be air-conditioned (room), heats or cools it, and supplies the air to the space to be air-conditioned through a ceiling opening 211o in a ceiling 200 via a duct or directly. Hereinafter, the ceiling-mounted air conditioner may be referred to as an indoor unit 100.

[0011] The indoor unit 100 is installed by being embedded in the ceiling 200 of the space to be air-conditioned. In the following description, the indoor unit 100 is defined as being installed within a dropped ceiling 210 as shown in FIG. 1 . The dropped ceiling 210 refers to an area where a portion of the ceiling 200 is lowered. When the dropped ceiling 210 is used as the installation space for the indoor unit 100, a larger installation space can generally be secured compared to when the indoor unit 100 is installed indoors. Furthermore, when the indoor unit 100 is installed above the ceiling, the intake port 10b and the exhaust port 10a can be set relatively freely by, for example, constructing ducts, which improves the interior design compared to room air conditioners installed indoors.

[0012] 1, a ceiling opening 211o is provided in a side portion 211 of the dropped ceiling 210, and a grill 6 is attached to the indoor side of the side portion 211 so as to cover the ceiling opening 211o. In the first embodiment, it is assumed that an inspection hatch is not provided in the dropped ceiling 210 (for example, the bottom portion 212) for the sake of the design of the ceiling 200.

[0013] The indoor unit 100 has a main body case 1 made of sheet metal that forms the outer shell. The main body case 1 is a rectangular parallelepiped box (see FIG. 2) with a hollow space formed inside. The main body case 1 is configured such that an air outlet 10a (see FIG. 2) is provided on a first surface S1, and an air inlet 10b (see FIG. 3) is provided on a second surface S2 different from the first surface S1. The first surface S1 and the second surface S2 of the main body case 1 are side surfaces that intersect at right angles. Hereinafter, the air inlet 10b of the main body case 1 may be referred to as the main body inlet.

[0014] The indoor unit 100 is configured so that the main body case 1 is suspended within a dropped ceiling 210 via multiple suspension bolts (not shown) installed vertically on beams or the like of a building. The indoor unit 100 is positioned so that a first surface S1 on which the air outlet 10a (see FIG. 2) of the main body case 1 is provided faces a ceiling opening 211o. The indoor unit 100 introduces indoor air A1 into the dropped ceiling 210 through the ceiling opening 211o and a grill 6 provided in a side portion 211 of the dropped ceiling 210, and takes in indoor air A2 that has flowed into the dropped ceiling 210 through an air inlet 10b into the main body case 1. The indoor unit 100 exchanges heat between the indoor air A2 taken into the main body case 1 and a refrigerant to generate conditioned air A3 whose temperature has been adjusted by cooling or heating, and then blows out the conditioned air A3 from the air outlet 10a of the main body case 1. The conditioned air A3 blown out from the air outlet 10a is blown into the room through the ceiling opening 211o provided in the side portion 211 of the dropped ceiling 210 and the grill 6. The conditioned air A4 blown out into the room cools or heats the room.

[0015] In the following, terms indicating directions ("up," "down," "right," "left," "front," or "rear") are defined as indicating directions when viewed from the front, with the second surface S2 of the indoor unit 100 being the bottom surface and the first surface S1 being the front surface. In the drawings, the arrow X direction indicates the width direction of the indoor unit 100, the arrow Y direction indicates the depth direction of the indoor unit 100, and the arrow Z direction indicates the height direction of the indoor unit 100.

[0016] 2, the main body case 1 is composed of a top plate 11 that forms the top surface, a right side plate 12 that forms the right side surface, a left side plate 13 that forms the left side surface, and a rear side plate 14 that forms the back surface (see FIG. 3). In addition, on the outside of the main body case 1, four hanging hardware 19 for hanging bolts are provided on both the left and right sides.

[0017] As shown in Fig. 3, the indoor unit 100 includes, within a main body case 1, a blower 2 that circulates indoor air, an indoor heat exchanger 9 that exchanges heat between the indoor air and a refrigerant, and the like. The refrigerant may be water, antifreeze, or any other refrigerant. The indoor unit 100 also includes a drain pan 15 that collects drain water generated in the indoor heat exchanger 9, and a drain pump 16 (see Fig. 4 described below) that discharges drain water accumulated inside the drain pan 15 to the outside. The indoor unit 100 also includes a controller 17 that controls functional components such as the blower 2 and the drain pump 16.

[0018] As shown in Figure 3, the blower 2 is disposed on the left side within the main body case 1, and the indoor heat exchanger 9 is disposed on the right side within the main body case 1. The drain pan 15 is disposed below the indoor heat exchanger 9 and constitutes the right portion of the bottom surface of the main body case 1 (i.e., the above-mentioned second surface S2). The left portion of the bottom surface of the main body case 1 is opened by the intake port 10b. The controller 17 is disposed in front of the blower 2 and is disposed on the left portion of the front surface of the main body case 1 (i.e., the above-mentioned first surface S1). The right portion of the front surface of the main body case 1 is opened by the air outlet 10a.

[0019] In the main body case 1, the suction port 10b may be provided on the top plate 11 constituting the upper surface, instead of on the bottom surface. In this case, the bottom plate is provided below the blower 2.

[0020] The indoor heat exchanger 9 is disposed on the right side and front side of the main body case 1, along the air outlet 10a. The indoor heat exchanger 9 has multiple gaps, and air flows through these gaps in the front-to-rear direction (direction of arrow Y). Therefore, the conditioned air A3 is blown out forward at the air outlet 10a. Hereinafter, the direction in which the conditioned air A3 is blown out at the air outlet 10a, i.e., the front-to-rear direction (direction of arrow Y), may be referred to as the blowing direction of the conditioned air A3.

[0021] The blower 2 includes a fan 23, a fan motor 24 that rotates the fan 23, and a fan case 20 that houses the fan 23 and the fan motor 24. Hereinafter, the fan 23 and the fan motor 24, which are the main operating parts of the blower 2, may be referred to as the blower unit 2x. The blower unit 2x is attached to the main body case 1. The attachment structure of the blower unit 2x to the main body case 1 will be described later. The blower 2 is, for example, a centrifugal blower, the fan 23 is, for example, a sirocco fan, and the fan case 20 has a spiral shape. The blower 2 is disposed horizontally within the main body case 1 so that the central axis Ax of the fan 23 is aligned in the height direction (direction of arrow Z), i.e., so that the central axis Ax of the fan 23 is perpendicular to the bottom surface of the main body case 1.

[0022] The fan case 20 is configured to be separable into two in the blowing direction (direction of arrow Y) of the conditioned air A3 described above, and has a first casing section 21 on the rear side that includes the blower outlet 20o (see FIG. 4 described below), and a second casing section 22 on the front side. For example, the first casing section 21 and the second casing section 22 of the fan case 20 are divided into front and rear sections by an imaginary plane that extends in the horizontal direction (direction of arrow X) and includes the central axis Ax of the fan 23. In other words, the blower 2 is configured so that the second casing section 22 can be removed from the first casing section 21 to expose the blowing section 2x inside the fan case 20.

[0023] The indoor unit 100 is connected to an outdoor unit (not shown) via connecting piping such as liquid piping and gas piping, and together with the outdoor unit, constitutes an air conditioning system. A compressor, flow switching device, outdoor heat exchanger, and pressure reducing device (not shown) of the outdoor unit are connected in sequence via piping to an indoor heat exchanger 9 of the indoor unit 100 to constitute a refrigerant circuit. Refrigerant circulates through the refrigerant circuit of the air conditioning system, thereby heating or cooling the space to be air-conditioned (room) in the indoor unit 100. The indoor heat exchanger 9 acts as an evaporator during cooling operation and as a condenser during heating operation.

[0024] Fig. 4 is a schematic perspective view showing the ceiling-mounted air conditioner (indoor unit 100) shown in Fig. 2 with the top plate 11 removed. Fig. 5 is a schematic front view showing the ceiling-mounted air conditioner (indoor unit 100) shown in Fig. 2 with the controller 17 removed.

[0025] As shown in Fig. 4, the indoor unit 100 has a partition plate 7 and a guide wall 8 inside the main body case 1. The partition plate 7 is a rectangular plate-like member extending in the depth direction (direction of arrow Y) and divides the internal space of the main body case 1 into a side for the blower 2 and a side for the indoor heat exchanger 9. The left end of the indoor heat exchanger 9 is attached to the front portion of the right surface of the partition plate 7. Hereinafter, within the internal space of the main body case 1, the space to the left of the partition plate 7 in which the blower 2 is housed may be referred to as the blower housing space Sf, and the space to the right of the partition plate 7 in which the indoor heat exchanger 9 is housed may be referred to as the heat exchanger housing space Sh.

[0026] A through-hole air opening 7o is provided at the rear side of the partition plate 7. A blower outlet 20o of the fan case 20 is connected to the air opening 7o of the partition plate 7. Specifically, the peripheral edge of the blower outlet 20o in the first casing portion 21 of the fan case 20 is fixed with screws to the peripheral edge of the air opening 7o on the left face of the partition plate 7. Air is sent from the blower 2 into the heat exchanger housing space Sh through the air opening 7o provided at the rear side of the partition plate 7.

[0027] The guide wall 8 is provided at the rear of the heat exchanger housing space Sh within the main body case 1. The guide wall 8 guides air toward the indoor heat exchanger 9, which is disposed perpendicular to the partition plate 7. The guide wall 8 curves forward and extends from the rear end of the right surface of the partition plate 7 to the right end of the rear surface 9b of the indoor heat exchanger 9. The guide wall 8 slopes forward increasingly as it approaches the indoor heat exchanger 9, i.e., toward the right. The guide wall 8 extends rightward along the rear side panel 14 near the partition plate 7 and forward along the right side panel 12 near the indoor heat exchanger 9. Air sent from the blower 2 into the heat exchanger housing space Sh through the air outlet 7o, i.e., the airflow toward the right, is transformed by the guide wall 8 into a forward airflow and flows into the indoor heat exchanger 9.

[0028] Within the main body case 1, the blower 2 and the indoor heat exchanger 9 are arranged in the depth direction (arrow Y direction) such that the blower outlet 20o of the fan case 20 is located further back than the air inlet surface (i.e., the back surface 9b) of the indoor heat exchanger 9. When the inside of the main body case 1 is viewed from above, the blower 2 and the indoor heat exchanger 9 are arranged so that the surface on which the blower outlet 20o is formed intersects with the back surface 9b of the indoor heat exchanger 9. In other words, when the inside of the main body case 1 is viewed from above, the partition plate 7 provided with the air blowing opening 7o and the indoor heat exchanger 9 are arranged so that the partition plate 7 intersects with the back surface 9b of the indoor heat exchanger 9.

[0029] The first casing portion 21 of the fan case 20 at the rear side, which includes the blower outlet 20o, is fixed to the partition plate 7 and incorporated into the main body case 1. Specifically, the first casing portion 21 has a plate-shaped frame portion (not shown) around the blower outlet 20o, and this frame portion faces the left side surface of the partition plate 7 shown in FIG. 4 and is fixed with screws to the peripheral edge of the air opening 7o in the partition plate 7. The second casing portion 22 is attached to the first casing portion 21 and incorporated into the main body case 1.

[0030] As shown in Figures 3 and 4, fan case 20 has opposing top and bottom wall portions 20a and 20b, and a peripheral wall portion 20c connecting the outer peripheries of top and bottom wall portions 20a and 20b. Fan openings 20ao and 20bo are provided in top and bottom wall portions 20a and 20b, respectively. As described above, fan outlet 20o is provided in a portion of the outer periphery of fan case 20 (specifically, in the frame portion provided around fan outlet 20o of first casing portion 21). In a configuration in which intake port 10b is provided on the bottom surface of main case 1, when blower 2 is housed in main case 1, fan opening 20bo provided in bottom wall portion 20b of fan case 20 faces intake port 10b of main case 1 and functions as main blower intake port 20i. The blower 2 is disposed in the main body case 1 so that the blower outlet 20 o faces the blower opening 7 o of the partition plate 7 .

[0031] 4, the controller 17 has a control board (not shown) that controls each functional component, a control box 17c that houses the control board and each wiring, and a lid 17a that prevents moisture or dust from inside the ceiling 200 from entering the inside of the controller 17. The controller 17 has, for example, a rectangular parallelepiped shape, and the rectangular plate-like lid 17a can be attached and detached with screws or the like to the rectangular parallelepiped control box 17c that is open on the front side.

[0032] In Fig. 4, the controller 17 is disposed in front of the blower 2 and is detachably fixed to the main body case 1. The controller 17 forms part of the front side of the left section of the outer shell of the indoor unit 100. The controller 17 is disposed so that the lid 17a is located on the front side. The lid 17a is disposed on the left side of the front surface (first surface S1) of the main body case 1, and the upper, left, and lower side surfaces of the control box 17c are disposed on the upper, left, and lower side surfaces of the front side of the left section of the main body case 1. In other words, in Fig. 4, when the controller 17 is removed from the main body case 1, an opening 10c (see Fig. 5) is formed in part of the front side of the left section of the outer shell of the indoor unit 100.

[0033] 1, 4, and 5, when performing maintenance on the indoor unit 100 (for example, inspection, cleaning, or part replacement), a worker can reach in through the ceiling opening 211o, which is opened by removing the grill 6 provided in the dropped ceiling 210, to easily perform maintenance on the controller 17 and the blower 2. The controller 17 is provided on the front surface (first surface S1) of the main body case 1 where the air outlet 10a is provided, i.e., on the side surface opposite the ceiling opening 211o, and when the controller 17 is removed from the main body case 1, an opening 10c is formed in front of the blower 2. Therefore, the blower 2 can be accessed through the ceiling opening 211o and the opening 10c.

[0034] 4 and 5 , the controller 17 is defined as being positioned to close the opening 10c of the main body case 1 to allow easy access to the controller 17 during maintenance, but the positioning of the controller 17 relative to the main body case 1 is not limited to the above. The controller 17 may be positioned somewhere other than the front of the main body case 1, or may be positioned inside the main body case 1. In this case, the opening 10c on the front of the main body case 1 is closed by a member separate from the controller 17.

[0035] Fig. 6 is a schematic cross-sectional view showing the A-A cross section of Fig. 5. Fig. 6 illustrates a state in which the opening 10c shown in Fig. 5 is closed by the controller 17. Note that Fig. 6 does not illustrate the internal structure of the controller 17. The solid white arrow, the dashed white arrow, and the dashed arrow all represent airflow.

[0036] 6, motor body 24a of fan motor 24 is attached by blower attachment fixture 3 to the inside of the surface of main body case 1 opposite to the surface on which suction port 10b is provided. In embodiment 1, suction port 10b is provided on the bottom surface of main body case 1, so blower 2x is attached to the inner surface of top plate 11.

[0037] In addition, in the case 1, the air inlet 10b is provided on the top plate 11, and if a bottom plate is provided below the blower 2, the blower section 2x is attached to this bottom plate of the case 1.

[0038] The air passage formed within the main body case 1 and the mounting structure of the fan motor 24 on the top plate 11 will be described in detail below with reference to FIGS. 1, 3, 4 and 6. FIG.

[0039] As described with reference to Figures 3 and 4, blower 2 has blower openings 20ao, 20bo provided in top wall 20a and bottom wall 20b of fan case 20, allowing it to draw air from both the upper and lower sides. As shown in Figure 6, a gap G through which air flows is formed between top plate 11 of main case 1 and top wall 20a of fan case 20. Specifically, within main case 1 (particularly, blower housing space Sf), suction paths Fi1, Fi2 are provided below and above blower 2, respectively. Furthermore, suction port 10b on the bottom surface of main case 1 has a larger opening area than blower opening 20bo in bottom wall 20b of fan case 20.

[0040] In the following, the blower opening 20bo provided in the bottom wall portion 20b of the fan case 20, which faces the bottom surface on which the intake port 10b of the main body case 1 is provided, may be referred to as the first blower intake port, and the blower opening 20ao provided in the upper wall portion 20a may be referred to as the second blower intake port.

[0041] As shown in Fig. 6 , of the air drawn into main body case 1 through suction port 10b on the bottom surface of main body case 1 (room air A2 shown in Fig. 1 ), air passing through approximately the center of suction port 10b (indicated by the outline arrow) is drawn into blower 2 through lower blower opening 20bo of blower 2 via lower suction path Fi1 within main body case 1. On the other hand, of the air drawn into main body case 1 through suction port 10b on the bottom surface of main body case 1 (room air A2 shown in Fig. 1 ), air passing through the outer periphery of suction port 10b (indicated by the dashed arrow) flows outward along bottom wall 20b of fan case 20, rises along the outer surface of peripheral wall 20c, and then is drawn into blower 2 through upper suction path Fi2 through upper blower opening 20ao of blower 2, as shown by the dashed arrow. That is, in the blower 2, the blower opening 20ao provided in the upper wall 20a of the fan case 20 and covered by the top plate 11 also functions as an auxiliary blower inlet 20i (see FIG. 3).

[0042] Thus, within the main body case 1, there are formed a main air passage Pm connecting the air inlet 10b on the bottom surface of the main body case 1 with the fan opening 20bo on the lower side of the blower 2, and a first sub-air passage Ps1 longer than the main air passage Pm connecting the air inlet 10b on the bottom surface of the main body case 1 with the fan opening 20ao on the upper side of the blower 2. The blower 2 and the main body case 1 are configured so that more air flows through the main air passage Pm than through the first sub-air passage Ps1. The proportion of air drawn into the main body case 1 that flows through the main air passage Pm or the first sub-air passage Ps1 is determined by the length of the first sub-air passage Ps1 relative to the length of the main air passage Pm, the size of the gap provided on the outside of the peripheral wall 20c, the size of the gap G between the top plate 11 and the upper wall 20a, and the size of the opening area of ​​the air inlet 10b relative to the opening area of ​​the fan opening 20bo.

[0043] If the size of the gap G between the top plate 11 and the upper wall portion 20a is too small, it becomes difficult to draw air through the fan opening 20ao, and noise may be generated when trying to pass air through a narrow space. Therefore, it is advisable to set a limit on the size of the gap G so that a certain amount of air can be drawn through the fan opening 20ao. For example, to suppress noise generation, it is advisable for the size of the gap G to be 40 mm or more.

[0044] The mounting structure of the fan motor 24 on the top plate 11 will now be described. In Fig. 6, the motor body 24a is fixed to the top plate 11 by a blower unit mounting fixture 3, such as bolts 31. As shown in Figs. 4 and 6, a plurality of legs 24b are provided on the outer periphery of the upper end of the motor body 24a, and these legs 24b are fixed to, i.e., suspended from, the top plate 11 by the blower unit mounting fixture 3. The blower unit mounting fixture 3 is disposed so as to form a gap G, which serves as the suction path Fi2, between the top plate 11 and the upper wall portion 20a.

[0045] The structure of the blower mounting fixture 3 for attaching the motor main body 24a to the top plate 11 is not limited to the above structure, and may be any structure that forms a gap G that serves as the suction path Fi2 between the fan case 20 and the surface of the main body case 1 opposite to the surface on which the suction port 10b is provided.

[0046] FIG. 7 is a diagram showing another example of the configuration of the blower unit attachment fixture 3 shown in FIG. 6 . The blower unit attachment fixture 3 shown in FIG. 7 is configured so that the blower unit 2x can be pulled out forward. Specifically, the blower unit attachment fixture 3 includes a plate-shaped motor base 33 to which the motor main body 24a is fixed and a rail 32 that supports the motor base 33 so that it can slide forward and backward (in the direction of arrow Y). The rail 32 is fixed to the top plate 11. In this case, to prevent the entire suction path Fi2 from being blocked, the motor base 33 is positioned with a gap between it and the upper wall portion 20a of the fan case 20, or so that it covers only a portion of the blower opening 20ao of the upper wall portion 20a.

[0047] Figure 8 is a schematic perspective view of the ceiling-mounted air conditioner (indoor unit 100) shown in Figure 1, as viewed from below. In the main body case 1, one or more auxiliary openings 40 are provided in the side panels that connect the peripheral edges of the top panel 11 and the bottom surface (particularly, the side panels that separate the fan housing space Sf from the outside of the indoor unit 100, such as the left side panel 13 or the rear side panel 14). In Figure 8, two auxiliary openings 40 are provided, one on the left side of the rear side panel 14 and one on the left side panel 13. Each auxiliary opening 40 has an opening area smaller than the air inlet 10b of the main body case 1 (see Figure 6).

[0048] The auxiliary opening 40 is a knockout hole formed by punching out a knockout portion (not shown) that is provided in the side panel of the main body case 1 at the time of shipping the indoor unit 100. At the time of shipping the indoor unit 100, for example, a groove with a thin wall thickness, multiple notches, or multiple grooves is provided on the outer periphery of the knockout portion of the main body case 1, and it is configured so that whether or not to provide the auxiliary opening 40 can be selected when installing the indoor unit 100.

[0049] When the auxiliary opening 40 is provided, a second sub-air passage Ps2 is formed inside the main body case 1, connecting the auxiliary opening 40 in the side panel of the main body case 1 to the upper fan opening 20ao of the fan 2. Here, the air flow in the second sub-air passage Ps2 will be described. As indicated by the dashed arrow, the fan 2 draws air into the main body case 1 through the auxiliary opening 40 in the side panel of the main body case 1. The air drawn into the main body case 1 through the auxiliary opening 40 rises along the outer surface of the peripheral wall 20c of the fan case 20 and is then drawn into the fan 2 through the upper fan opening 20ao of the fan 2 via the upper suction path Fi2, as indicated by the dashed arrow in FIG. 6 . Hereinafter, the first sub-air passage Ps1 and the second sub-air passage Ps2, which connect the outside with the fan opening 20ao, may be referred to as the sub-air passage without any particular distinction.

[0050] As described above, the ceiling-mounted air conditioner (indoor unit 100) according to Embodiment 1 includes a hollow box-shaped main body case 1 having a bottom surface with a main body air inlet (air inlet 10b) and a top plate 11 facing the bottom surface, and a blower 2. The blower 2 has a fan 23 and a fan case 20 that houses the fan 23, and is disposed within the main body case 1 so that the central axis Ax of the fan 23 is perpendicular to the bottom surface of the main body case 1. The fan case 20 includes a bottom wall portion 20b that is provided with a first blower air inlet (fan opening 20bo) and is positioned on the bottom side of the main body case 1 in the extension direction of the central axis Ax, and an upper wall portion 20a that is provided with a second blower air inlet (fan opening 20ao) and is positioned on the top plate 11 side in the extension direction of the central axis Ax. A sub-air passage (for example, first sub-air passage Ps1 or second sub-air passage Ps2) that connects the outside with the second fan inlet (fan opening 20ao) is provided inside main body case 1. Fan 2 is arranged so that the first fan inlet faces the main body inlet and so that a gap G is formed between upper wall 20a and top plate 11, which constitutes part of the sub-air passage and serves as air intake path Fi2 to the second fan inlet.

[0051] As described above, the blower 2 is provided with a first blower suction port and a second blower suction port, and a sub-air passage (e.g., a first sub-air passage Ps1 or a second sub-air passage Ps2) is provided within the main body case 1, connecting the outside with the second blower suction port (blower opening 20ao). The blower 2 is positioned so that the first blower suction port faces the main body suction port, and a gap G is formed between the upper wall portion 20a and the top plate 11, forming part of the sub-air passage and serving as an air intake path Fi2 to the second blower suction port. Therefore, because the blower 2 is provided with not only the first blower suction port but also the second blower suction port, the suction port area of ​​the blower 2 is larger than that of a conventional blower suction port, thereby reducing pressure loss. Furthermore, the reduced pressure loss allows for a sufficient airflow without increasing the fan rotation speed, thereby suppressing noise deterioration due to an increase in the fan rotation speed.

[0052] The main body suction port (suction port 10b) has a larger opening area than the first fan suction port (fan opening 20bo). Inside the main body case 1, a first sub-air passage Ps1 is provided as a sub-air passage through which a portion of the air drawn into the main body case 1 from the main body suction port by the fan 2 is drawn into the second fan suction port (fan opening 20ao) via the suction path Fi2.

[0053] As a result, even if the main body case 1 has only one opening that functions as an intake port, air can easily enter not only the blower opening 20bo but also the first sub-air passage Ps1 that connects to the blower opening 20ao, thereby more reliably achieving the effect of suppressing noise deterioration.

[0054] The main body case 1 also has a side panel (e.g., the left side panel 13 or the rear side panel 14 in FIG. 8 ) that connects the peripheral edges of the bottom surface and the top panel 11. The side panel is provided with an auxiliary opening 40 having an opening area smaller than the main body suction port (suction port 10b). Inside the main body case 1, a second auxiliary air passage Ps2 is provided as a secondary air passage through which air drawn into the main body case 1 from the auxiliary opening 40 by the blower 2 is drawn into the second blower suction port (suction port 20ao) via the suction path Fi2.

[0055] This increases the number of openings that function as suction ports in the main body case 1, thereby increasing the suction port area of ​​the main body case 1. This further reduces pressure loss and further improves the effect of suppressing noise deterioration.

[0056] Furthermore, the auxiliary opening 40 in the side panel (for example, the left panel 13 or the rear panel 14 in FIG. 8) is a knockout hole formed by punching out a knockout portion provided in the side panel. This allows the user to choose whether or not to provide the auxiliary opening 40 depending on the environment of the installation location of the indoor unit 100, improving versatility.

[0057] The present disclosure is not limited to the above-described embodiment, and modifications can be made as appropriate without departing from the spirit of the present disclosure. For example, while an example using a sirocco fan as the fan 23 has been described, the present disclosure is not limited to this, and other types of fans such as turbo fans can be used in the same manner. Furthermore, in the first embodiment, the blower 2 is horizontally placed, and the indoor unit 100 is configured to draw air from below, but the blower 2 may be vertically placed, and the indoor unit 100 may draw air from the rear.

[0058] 1 Main body case, 2 Blower, 2x Blower unit, 3 Blower unit mounting fixture, 6 Grill, 7 Partition plate, 7o Blower opening, 8 Guide wall, 9 Indoor heat exchanger, 9b Back, 10a Outlet, 10b Inlet, 10c Opening, 11 Top plate, 12 Right side plate, 13 Left side plate, 14 Rear plate, 15 Drain pan, 16 Drain pump, 17 Controller, 17a Lid, 17c Control box, 19 Hanging hardware, 20 Fan case, 20a Upper wall, 20ao Blower opening, 20b Bottom wall, 20bo Blower opening, 20c Peripheral wall, 20i Blower inlet, 20o Blower outlet, 21 First casing part, 22 Second casing part, 23 Fan, 24 Fan motor, 24a motor body, 24b legs, 31 bolt, 32 rail, 33 motor base, 40 auxiliary opening, 100 indoor unit, 200 ceiling, 210 ceiling, 211 side portion, 211o ceiling opening, 212 bottom portion, A1 indoor air, A2 indoor air, A3 conditioned air, A4 conditioned air, Ax central axis, Fi1 suction path, Fi2 suction path, G gap, Pm main air path, Ps1 first sub-air path, Ps2 second sub-air path, S1 first surface, S2 second surface, Sf blower accommodating space, Sh heat exchanger accommodating space.

Claims

1. A ceiling-embedded air conditioner, comprising: a hollow box-shaped main body case having a bottom surface provided with a main body suction port and a top plate facing the bottom surface; a blower having a fan and a fan case for housing the fan, the blower being disposed in the main body case such that a central axis of the fan is orthogonal to the bottom surface of the main body case; the fan case having a bottom wall portion provided with a first blower suction port and disposed on the side of the bottom surface of the main body case in a extending direction of the central axis, and an upper wall portion provided with a second blower suction port and disposed on the side of the top plate in the extending direction of the central axis; a sub-air passage communicating the outside with the second blower suction port being provided in the main body case; and the blower being disposed such that the first blower suction port faces the main body suction port, and a gap is formed between the upper wall portion and the top plate to constitute a part of the sub-air passage and to serve as an air suction path to the second blower suction port.

2. The ceiling-embedded air conditioner according to claim 1, wherein the main body suction port has an opening area larger than that of the first blower suction port; and a first sub-air passage is provided in the main body case as the sub-air passage, and a part of the air sucked into the main body case from the main body suction port by the blower is sucked into the second blower suction port through the suction path.

3. The ceiling-embedded air conditioner according to claim 1 or 2, wherein the main body case has side plates connecting peripheral edges of the bottom surface and the top plate; an auxiliary opening portion having an opening area smaller than that of the main body suction port is provided in the side plates; and a second sub-air passage is provided in the main body case as the sub-air passage, and the air sucked into the main body case from the auxiliary opening portion by the blower is sucked into the second blower suction port through the suction path.

4. The ceiling-embedded air conditioner according to claim 3, wherein the auxiliary opening portion of the side plate is a knockout hole formed by punching out a knockout portion provided in the side plate.

Images