Duct units and displacement air conditioning systems

Abstract

To provide a replacement air conditioning system capable of efficiently cooling an area where a person exists, and a duct unit.SOLUTION: A duct unit can be attached to an air conditioner including an inlet capable of sucking indoor air, a heat exchanger capable of cooling the air sucked from the inlet by heat exchange, and a supply port capable of supplying the heat-exchanged air into a room. The duct unit includes an air return duct part and an air supply duct part. The air return duct part includes an air return outlet connectable to the inlet, an air return inlet located separately from the air return outlet, and an air return body part for connecting the air return outlet and the air return inlet. The air supply duct part includes an air supply inlet connectable to the supply port, an air supply outlet located separately from the air supply inlet and an air supply body part for connecting the air supply inlet and the air supply outlet. The air supply outlet is located on a downside with respect to the air return inlet in a state in which the duct unit is attached to the air conditioner such that the air return is connected to the inlet and the air supply let is connected to the supply port.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present disclosure relates to a duct unit and a displacement air conditioning system. [Background technology]

[0002] Air conditioners including an intake port, a heat exchanger, and a supply port are known (see, for example, International Publication No. 2017 / 090104 (Patent Document 1)). In the air conditioner described in Patent Document 1, the intake port draws in indoor air. The heat exchanger cools the air drawn in through the intake port by heat exchange. The supply port supplies the air that has undergone heat exchange in the heat exchanger into the room. In the air conditioner described in Patent Document 1, the supply port is located above the intake port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 090104 Summary of the Invention

[0004] The duct unit of the present disclosure is attachable to an air conditioner including an intake port capable of drawing in indoor air, a heat exchanger capable of cooling the air drawn in through the intake port by heat exchange, and a supply port capable of supplying the air heat-exchanged by the heat exchanger into the room. The duct unit includes a return air duct section and an intake air duct section. The return air duct section includes a return air outlet connectable to the intake port, a return air inlet located away from the return air outlet, and a return air main body connecting the return air outlet and the return air inlet. The intake air duct section includes an intake air inlet connectable to the supply port, an intake air outlet located away from the intake air inlet, and a supply air main body connecting the intake air inlet and the intake air outlet. When the duct unit is attached to the air conditioner so that the return air outlet is connected to the intake port and the intake air inlet is connected to the supply port, the intake air outlet is located below the return air inlet.

[0005] The displacement air conditioning system of the present disclosure includes an air conditioner and the above-described duct unit attached to the air conditioner. The air conditioner includes an intake port capable of drawing in indoor air, a heat exchanger capable of cooling the air drawn in through the intake port by heat exchange, and a supply port capable of supplying the air that has been heat exchanged by the heat exchanger into the room. In the duct unit, a return air outlet is connected to the intake port, and a supply air inlet is connected to the supply port. [Brief explanation of the drawings]

[0006] [Figure 1A] FIG. 1A is a perspective view of a displacement air conditioning system of the present disclosure. [Figure 1B] FIG. 1B is a perspective view of the air conditioner in the displacement air conditioning system shown in FIG. 1A. [Figure 1C] FIG. 1C is a perspective view of a support section and a return air duct section in the displacement air conditioning system shown in FIG. 1A. [Figure 1D] FIG. 1D is a perspective view of a support section and an intake air duct section in the displacement air conditioning system shown in FIG. 1A. [Figure 2] FIG. 2 is a left side view of the displacement air conditioning system shown in FIG. 1A. [Figure 3] FIG. 3 is a front view of the displacement air conditioning system shown in FIG. 1A. [Figure 4] FIG. 4 is a right side view of the displacement air conditioning system shown in FIG. 1A. [Figure 5] FIG. 5 is a cross-sectional view of a portion of the covering portion and the supply air duct portion in a displacement air conditioning system. [Figure 6] FIG. 6 is a perspective view of the air supply secondary chamber with the cover attached. [Figure 7] FIG. 7 is a perspective view of the air supply secondary chamber with the cover removed. [Figure 8] FIG. 8 is a front view of a modified displacement air conditioning system. [Figure 9] FIG. 9 is a front view of the air supply secondary chamber and the cover in the first position. [Figure 10] FIG. 10 is a front view of the air supply secondary chamber and the cover in the second position. DETAILED DESCRIPTION OF THE INVENTION

[0007] [Problem to be solved by this disclosure] Depending on the purpose of air conditioning, a duct unit may be attached to an air conditioner to create an air conditioning system comprising the air conditioner and the duct unit. The duct unit comprises a return air duct section and a supply air duct section. The outlet of the return air duct section is connected to the intake port. The inlet of the supply air duct section is connected to the supply port. In order for the air conditioning system to perform the same function as an air conditioner, the outlet of the supply air duct section is located above the inlet of the return air duct section.

[0008] When the air conditioning system described above is installed in a room with a high ceiling, the overhead space is also cooled. The overhead space is the space above the area where people are present. However, since there are no people in the overhead space, there is no need to cool it. Therefore, when the air conditioning system cools the overhead space, the air conditioning system consumes unnecessary energy. When the air conditioning system cools the overhead space, energy efficiency is low.

[0009] It is an object of the present disclosure to provide a displacement air conditioning system and a duct unit to be included therein that can efficiently cool occupied areas.

[0010] [Effects of this disclosure] The duct unit and displacement air conditioning system of the present disclosure can efficiently cool occupied areas.

[0011] [Description of the embodiments of the present disclosure] Embodiments of the present disclosure will be listed and described below. The duct unit of the present disclosure is attachable to an air conditioner including an intake port capable of drawing in indoor air, a heat exchanger capable of cooling the air drawn in through the intake port by heat exchange, and a supply port capable of supplying the air heat-exchanged by the heat exchanger into the room. The duct unit includes a return air duct section and an intake air duct section. The return air duct section includes a return air outlet connectable to the intake port, a return air inlet located away from the return air outlet, and a return air main body connecting the return air outlet and the return air inlet. The intake air duct section includes an intake air inlet connectable to the supply port, an intake air outlet located away from the intake air inlet, and a supply air main body connecting the intake air inlet and the intake air outlet. When the duct unit is attached to the air conditioner so that the return air outlet is connected to the intake port and the intake air inlet is connected to the supply port, the intake air outlet is located below the return air inlet.

[0012] The duct unit of the present disclosure can supply air that has been heat exchanged by a heat exchanger from the supply air outlet, allowing for efficient cooling of areas where people are present. A displacement air conditioning system can be easily configured by attaching the duct unit to an air conditioner so that the return air outlet is connected to the intake port and the supply air inlet is connected to the supply port.

[0013] In the above-described duct unit, when the duct unit is attached to an air conditioner, the supply air inlet may be located above the return air outlet. This duct unit can be attached to an air conditioner in which the supply port is located above the intake port.

[0014] In the above-described duct unit, when the duct unit is attached to an air conditioner, the air intake inlet may face the top surface of the air conditioner. This duct unit can be attached to an air conditioner whose supply port is located on the top surface.

[0015] In the above-described duct unit, when the duct unit is attached to an air conditioner, the air intake inlet may be located above the top surface of the air conditioner. This duct unit can be attached to an air conditioner whose supply port is located on the top surface.

[0016] In the above-described duct unit, when the duct unit is attached to an air conditioner, the air supply main body may include a vertical pipe extending in the height direction and an air supply secondary chamber connected to the lower end of the vertical pipe and located at a first end, which is the end closer to the air supply outlet. The cross-sectional area of ​​the internal space of the air supply secondary chamber in a direction perpendicular to the height direction may be larger than the cross-sectional area of ​​the internal space of the vertical pipe in a direction perpendicular to the height direction. An air supply outlet may be formed in the air supply secondary chamber. With this duct unit, the air flow from the vertical pipe can be stabilized within the air supply secondary chamber. Therefore, stable air can be supplied into the room from the air supply outlet. As a result, areas where people are present can be efficiently cooled.

[0017] In the above-described duct unit, when the duct unit is attached to an air conditioner, the secondary air intake chamber may include a front portion that is an area including the air intake outlet, and a rear portion that is connected to the opposite side of the front air intake outlet in the depth direction, which is the direction along which air is blown out from the air intake outlet. The lower end of the vertical pipe may be connected to the rear portion. In this duct unit, the front and rear portions are aligned in the depth direction. Therefore, the air flow that flows in the height direction in the vertical pipe can be changed to the depth direction in the secondary air intake chamber, thereby stabilizing the flow of air blown out from the air intake outlet.

[0018] In the above-described duct unit, the air supply secondary chamber may include a plate-shaped member having a plurality of through holes formed therein. The air supply outlet may be a plurality of through holes. With this duct unit, it is possible to prevent the air supplied through the plurality of through holes from becoming turbulent.

[0019] In the above-described duct unit, when the duct unit is attached to an air conditioner, the front portion may include a front surface where the air supply outlet is formed. The front surface may be made of a plate-like member with a plurality of through holes formed therein. This duct unit can efficiently cool the area in front of the secondary air supply chamber.

[0020] In the above-described duct unit, the air supply secondary chamber may have a rectangular parallelepiped shape. In this duct unit, the air supply secondary chamber has a simple configuration.

[0021] In the above-described duct unit, the vertical pipe may have an internal space whose cross-sectional area perpendicular to the height direction increases downward. The lower end of the vertical pipe may be connected to the rear. The air pressure in the vertical pipe can be reduced downward to suppress turbulence and send the air to the rear while regulating it. Therefore, air with suppressed turbulence can be sent from the rear to the front. As a result, air can be smoothly supplied from the air intake outlet to areas where people are present.

[0022] In the above-described duct unit, the air intake main body may include an air intake primary chamber located at a second end of the air intake main body closer to the air intake inlet. The air intake inlet may be formed in the air intake primary chamber. In this duct unit, the flow of air that has undergone heat exchange by the heat exchanger in the air intake primary chamber can be stabilized while the air is sent to the air intake outlet.

[0023] In the above-described duct unit, when the duct unit is attached to an air conditioner, the primary air supply chamber may be located above the top surface of the air conditioner. In the duct unit, the primary air supply chamber and the air conditioner can be aligned in the height direction. This allows the space between the primary air supply chamber and the air conditioner to be reduced, at least in the depth direction.

[0024] In the above-described duct unit, the first portion, which is at least a part of the intake duct, may be made of a material with lower thermal conductivity than metal. Air that has been heat exchanged (cooled) by a heat exchanger flows through the intake duct. If the first portion of the intake duct is made of metal, the first portion is likely to cool down due to the high thermal conductivity of metal. As a result, condensation may form on the outside of the first portion. However, in this duct unit, the first portion is made of a material with lower thermal conductivity than metal, so the first portion is less likely to cool down. As a result, condensation on the outside of the first portion can be suppressed. In addition, the air flowing through the first portion can be prevented from being heated by the air around the intake duct.

[0025] In the above-described duct unit, the second portion, which is at least a part of the intake duct portion, may be made of metal. The duct unit may further include a covering portion that covers the second portion and is made of a material with lower thermal conductivity than metal. Air that has been heat exchanged (cooled) by the heat exchanger flows through the intake duct portion. This air has a high relative humidity. Because the second portion of the intake duct portion is made of metal, the second portion is easily cooled due to the high thermal conductivity of metal. As a result, condensation may form on the outside of the second portion. However, in this duct unit, the covering portion that is made of a material with lower thermal conductivity than metal covers the second portion, thereby preventing condensation on the outside of the second portion. In addition, the air flowing through the second portion can be prevented from being heated by the air around the intake duct.

[0026] In the above-described duct unit, the intake duct portion may further include a cover that can open and close a first region that is a part of the intake outlet. According to this duct unit, by closing the first region with the cover, the area of ​​the intake outlet with the first region closed by the cover can be made smaller than the area of ​​the intake outlet with the first region open. This increases the velocity of the cool air supplied from the intake outlet. Increasing the velocity of the cool air generates turbulence around the intake outlet. The turbulence causes the cool air to mix with the warm air around the intake outlet. This makes it possible to create relatively uniformly cooled air around the intake outlet. As a result, the temperature of a specified space can be uniformly cooled. The specified space is, for example, a space up to 2.0 m in height from the floor.

[0027] On the other hand, if turbulence continues to occur around the air intake outlet (continues to create turbulence), the air in the area above where people are present (predetermined space) will mix with the air in the area where people are present (predetermined space), which will reduce the cooling efficiency of the air in the area where people are present.

[0028] Therefore, if the area where people are present is cooled evenly to a certain temperature and then the first area is opened, the speed of the air supplied from the intake air outlet will decrease. This will prevent the air from becoming turbulent. As a result, the air will not be stirred up unnecessarily. In other words, mixing of the air in the upper area and the air in the area where people are present is prevented, making displacement air conditioning more efficient.

[0029] In the above-described duct unit, the cover may be movable between a first position that opens the first area and a second position that closes the first area. In this duct unit, the first area can be reliably opened and closed by opening and closing the cover.

[0030] In the above-described duct unit, when the duct unit is attached to an air conditioner, the return air outlet may face the rear surface of the air conditioner. This duct unit can be attached to an air conditioner whose air inlet is located on the rear surface.

[0031] In the above-described duct unit, when the duct unit is attached to an air conditioner, the return air outlet may be located rearward in the depth direction from the rear surface of the air conditioner. This duct unit can be attached to an air conditioner whose intake port is located on the rear surface.

[0032] In the above-described duct unit, when the duct unit is attached to an air conditioner, the return air inlet may be located above the top surface of the air conditioner. With this duct unit, air above the top surface of the air conditioner can be drawn in through the return air inlet.

[0033] In the above-described duct unit, the return air main body may include a return air chamber located at a third end of the return air main body that is closer to the return air inlet. The return air chamber may have a return air inlet formed therein. In this duct unit, indoor air can be drawn in at a low speed through the return air inlet in the return air chamber.

[0034] In the above-described duct unit, the return air main body may further include a return air connecting pipe connected to the return air chamber. The return air connecting pipe may include a second connection area that is an area adjacent to the return air chamber. The area of ​​the return air inlet may be larger than the cross-sectional area of ​​the second connection area perpendicular to the direction in which the second connection area extends. This duct unit can slowly draw indoor air through the return air inlet while regulating the air flow in areas above the occupied area. This can suppress air turbulence in the occupied area. As a result, displacement air conditioning can be performed efficiently.

[0035] In the above-mentioned duct unit, the return air chamber may have a rectangular parallelepiped shape with an internal space. The return air chamber may have at least one opening as a return air inlet. In this duct unit, the area of ​​the return air inlet can be easily adjusted.

[0036] The above-mentioned duct unit may further include a frame portion that supports the primary air supply chamber when the duct unit is attached to the air conditioner. In this duct unit, the frame portion supports the primary air supply chamber, thereby ensuring reliable connection of the air supply inlet of the air supply duct portion to the supply port of the air conditioner.

[0037] In the above-described duct unit, when the duct unit is attached to the air conditioner, the frame portion may include an air supply support frame located above the top surface of the air conditioner and perpendicular to the height direction. The primary air supply chamber may be located on the upper surface of the air supply support frame. In this duct unit, the air supply support frame ensures that the primary air supply chamber and the air conditioner are aligned in the height direction. This reduces the space between the primary air supply chamber and the air conditioner, at least in the depth direction.

[0038] In the above-described duct unit, the return air main body may include a return air chamber located at a third end of the return air main body closer to the return air inlet. A return air inlet may be formed in the return air chamber. The duct unit may further include a frame portion that supports the return air chamber when the duct unit is attached to the air conditioner. With this duct unit, the frame portion supports the return air chamber, thereby enabling the return air outlet of the return air duct portion to be reliably connected to the air intake of the air conditioner.

[0039] In the above-described duct unit, when the duct unit is attached to the air conditioner, the frame portion may include a return air support frame that is located above the top surface of the air conditioner and perpendicular to the height direction. The return air chamber may be disposed on the upper surface of the return air support frame. In this duct unit, the return air support frame allows the return air chamber and the air conditioner to be aligned in the height direction. This reduces the space between the return air chamber and the air conditioner in the depth direction.

[0040] In the above-mentioned duct unit, the supply air main body may include a supply air primary chamber located at a second end of the supply air main body closer to the supply air inlet. A supply air inlet may be formed in the supply air primary chamber. The return air main body may include a return air chamber located at a third end of the return air main body closer to the return air inlet. A return air inlet may be formed in the return air chamber. The supply air primary chamber and the return air chamber may be aligned in the height direction. With this duct unit, the space between the return air chamber and the air conditioner can be reduced at least in the depth direction.

[0041] In the above-described duct unit, the return air chamber may be located above an upper surface of the supply air primary chamber. In this duct unit, air above the upper surface of the supply air primary chamber can be drawn in through the return air inlet.

[0042] In the above-described duct unit, a gap may be formed between the supply air primary chamber and the return air chamber. With this duct unit, it is possible to prevent the temperature of the air flowing through the supply air primary chamber from increasing due to contact between the supply air primary chamber and the return air chamber.

[0043] The above-described duct unit may further include a base. The air supply secondary chamber may be disposed on the base. In this duct unit, the air supply outlet of the air supply secondary chamber can be easily disposed on the base.

[0044] In the above-described duct unit, when the duct unit is attached to an air conditioner, the air conditioner and the secondary air supply chamber may be arranged on a common base. In this duct unit, the air conditioner and the secondary air supply chamber can be aligned on the base.

[0045] The displacement air conditioning system of the present disclosure includes an air conditioner and the above-described duct unit attached to the air conditioner. The air conditioner includes an intake port capable of drawing in indoor air, a heat exchanger capable of cooling the air drawn in through the intake port by heat exchange, and a supply port capable of supplying the air that has undergone heat exchange in the heat exchanger into the room. In the duct unit, a return air outlet is connected to the intake port, and a supply air inlet is connected to the supply port. In this displacement air conditioning system, air that has undergone heat exchange in the heat exchanger can be supplied from the supply air outlet, allowing for efficient cooling of areas where people are present. In other words, the displacement air conditioning system can efficiently perform displacement air conditioning.

[0046] [Details of the embodiment of the present invention] Next, embodiments of a duct unit and a displacement air conditioning system according to the present disclosure will be described with reference to FIGS. 1A to 7. FIG. 1A is a perspective view of a displacement air conditioning system according to the present disclosure. In FIG. 1A, the displacement air conditioning system is viewed from the front. FIG. 1B is a perspective view of an air conditioner in the displacement air conditioning system shown in FIG. 1A. In FIG. 1B, the air conditioner is viewed from the front. FIG. 1C is a perspective view of a support section and a return air duct section in the displacement air conditioning system shown in FIG. 1A. In FIG. 1B, the support section and the return air duct section are viewed from the front. FIG. 1D is a perspective view of a support section and a supply air duct section in the displacement air conditioning system shown in FIG. 1A. In FIG. 1D, the support section and the supply air duct section are viewed from the front. FIG. 2 is a left side view of the displacement air conditioning system shown in FIG. 1A. In FIG. 2, a portion of the displacement air conditioning system is shown in cross section. FIG. 3 is a front view of the displacement air conditioning system shown in FIG. 1A. FIG. 4 is a right side view of the displacement air conditioning system shown in FIG. 1A. Fig. 5 is a cross-sectional view of a portion of the supply air duct of a displacement air conditioning system. Fig. 6 is a perspective view of the supply air secondary chamber with the cover attached. Fig. 7 is a perspective view of the supply air secondary chamber with the cover removed. In the following drawings, the same or corresponding parts are given the same reference numerals and their descriptions will not be repeated.

[0047] (Embodiment) [Basic configuration of displacement air conditioning system 1] The replacement air conditioning system 1 performs replacement air conditioning on a room. In replacement air conditioning, the lower area of ​​the room where people are mainly present is air-conditioned (cooled). The lower area is, for example, within a range of 2.0 m above the floor of the room. In replacement air conditioning, the upper area located above the lower area does not need to be air-conditioned. The replacement air conditioning system 1 is placed on the floor of the room. As shown in FIG. 1A, the replacement air conditioning system 1 comprises an air conditioner 2 and a duct unit 3.

[0048] As shown in Figures 1B and 2, the air conditioner 2 includes an intake port 21, a heat exchanger 22, a fan 23, and a supply port 24. The intake port 21 (see Figure 2) is capable of drawing in indoor air. The heat exchanger 22 (see Figure 2) is capable of cooling the air drawn in from the intake port 21 by heat exchange. The fan 23 (see Figure 2) is capable of sending air toward the heat exchanger 22. The supply port 24 (see Figure 2) is capable of supplying the air that has undergone heat exchange by the heat exchanger 22 into the room.

[0049] 1A and 2, the duct unit 3 is attached to the air conditioner 2. In other words, the duct unit 3 can be attached to the air conditioner 2. The duct unit 3 includes a support portion 31, a return air duct portion 32, and a supply air duct portion 33.

[0050] The support portion 31 supports the return air duct portion 32 and the supply air duct portion 33.

[0051] The return air duct section 32 can be referred to as an RA (Return Air) duct section. Hereinafter, the return air in components containing "return air" can be read as RA. As shown in FIGS. 1C and 2, the return air duct section 32 includes a return air outlet 321, a return air inlet 322, and a return air main body section 323. The return air outlet 321 is connected to the air intake 21 (see FIG. 2) of the air conditioner 2. In other words, the return air outlet 321 can be connected to the air intake 21. The return air inlet 322 is located away from the return air outlet 321. The return air main body section 323 connects the return air outlet 321 and the return air inlet 322.

[0052] The supply air duct section 33 can be referred to as an SA (Supply Air) duct section. Hereinafter, the supply air in components containing "supply air" can be read as SA. As shown in FIGS. 1D and 3, the supply air duct section 33 includes a supply air inlet 331 (see FIG. 3), a supply air outlet 332, and a supply air main body section 333. The supply air inlet 331 is connected to the supply port 24 of the air conditioner 2. In other words, the supply air inlet 331 is connectable to the supply port 24. The supply air outlet 332 is located away from the supply air inlet 331. The supply air main body section 333 connects the supply air inlet 331 and the supply air outlet 332.

[0053] [Details of Air Conditioning Unit 2 and Duct Unit 3] The air conditioner 2 and the duct unit 3 will be described in detail below. Hereinafter, the air conditioner 2 and the duct unit 3 will be described in detail "in a state where the duct unit 3 is attached to the air conditioner 2." Therefore, the phrase "in a state where the duct unit 3 is attached to the air conditioner 2" will be omitted.

[0054] [Air Conditioner 2 Details] As shown in FIGS. 1B, 2, and 3, the air conditioner 2 has a box shape. The air conditioner 2 has a lower surface 25, an upper surface 26, a front surface 27, a rear surface 28, two side surfaces 29 and 30, an intake connection pipe 211, and a supply connection pipe 241. As shown in FIGS. 2 and 3, the lower surface 25 is parallel to a horizontal plane S. The upper surface 26 is located away from the lower surface 25 in the height direction HD. The upper surface 26 forms the upper end of the air conditioner 2. As shown in FIGS. 1B and 3, the upper surface 26 includes the supply port 24. The front surface 27 is perpendicular to the horizontal plane S. As shown in FIG. 2, the rear surface 28 is located away from the front surface 27 (see FIGS. 1B and 3) in the depth direction DD of the air conditioner 2. The rear surface 28 forms the rear end of the air conditioner 2. The rear surface 28 includes the intake port 21. As shown in FIG. 3, each of the two side surfaces 29, 30 is perpendicular to the horizontal plane S. The two side surfaces 29, 30 are spaced apart from each other in the horizontal direction LD. As shown in FIG. 1B, the horizontal direction LD is perpendicular to the depth direction DD and the height direction HD. As shown in FIG. 2, the suction connection pipe 211 is joined to the outer periphery of the suction port 21 on the rear surface 28. The internal space of the suction connection pipe 211 communicates with the suction port 21. The suction connection pipe 211 extends in the depth direction DD. As shown in FIGS. 2 and 3, the supply connection pipe 241 is joined to the outer periphery of the supply port 24 on the top surface 26. The internal space of the supply connection pipe 241 communicates with the supply port 24. The supply connection pipe 241 extends in the height direction HD.

[0055] [Duct unit 3 details] 1C to 3, the support portion 31 includes a base 311 and a frame portion 312. In other words, the duct unit 3 includes the base 311.

[0056] [Base 311] As shown in FIGS. 1C and 1D, the base 311 is located at the lower end of the support portion 31. The base 311 is aligned along a horizontal plane S. The base 311 has a frame shape. As shown in FIG. 3, the base 311 may have a plate shape. The air conditioner 2 is placed on the base 311.

[0057] [Frame part 312] As shown in FIGS. 1C and 1D , the frame section 312 includes support columns 3121, 3122, 3123, and 3124, a return air support frame 313, and an intake air support frame 314. The support columns 3121, 3122, 3123, and 3124 extend in the height direction HD from the upper surface of the base 311. The support columns 3121, 3122, 3123, and 3124 are parallel to one another. The support columns 3121 and 3122 extend from the front end of the base 311. The support column 3121 extends from one end of the base 311 in the horizontal direction LD. The support column 3122 extends from the middle of the base 311 in the horizontal direction LD. The support columns 3123 and 3124 extend from the rear end of the base 311. The support pillar 3123 is located apart in the depth direction DD from the support pillar 3121. The support pillar 3124 is located apart in the depth direction DD from the support pillar 3122. The support pillar 3124 extends from the middle part of the base 311 in the lateral direction LD.

[0058] [Return air support frame 313] As shown in FIG. 1C , the return air support frame 313 is located at the upper end of the support part 31. The return air support frame 313 faces the base 311 in the height direction HD. The return air support frame 313 is joined to the upper ends of the support columns 3121, 3122, 3123, and 3124. Each of the four corners of the return air support frame 313 is attached to each of the support columns 3121, 3122, 3123, and 3124. The return air support frame 313 is perpendicular to the height direction HD. The return air support frame 313 is parallel to the horizontal plane S. The return air support frame 313 has a frame shape. The return air support frame 313 may be a plate-shaped return air support plate. As shown in FIGS. 2 and 3 , the return air support frame 313 is located above the upper surface 26 of the air conditioner 2. The return air support frame 313 is located away from the air conditioner 2 in the height direction HD.

[0059] [Air supply support frame 314] As shown in FIG. 1D , the supply air support frame 314 is located between the base 311 and the return air support frame 313 in the height direction HD. The supply air support frame 314 faces the return air support frame 313 in the height direction HD. The supply air support frame 314 overlaps with the return air support frame 313 in the height direction HD. The supply air support frame 314 is connected to the middle portions of the support columns 3121, 3122, 3123, and 3124 in the height direction HD. Each of the four corners of the supply air support frame 314 is attached to each of the support columns 3121, 3122, 3123, and 3124. The supply air support frame 314 is perpendicular to the height direction HD. The supply air support frame 314 is parallel to the horizontal plane S. The supply air support frame 314 has a frame shape. As shown in FIGS. 2 and 3 , the supply air support frame 314 is located above the top surface 26 of the air conditioner 2. The air supply support frame 314 is located away from the air conditioner 2 in the height direction HD.

[0060] [Return air duct section 32] 1C and 2, as described above, the return air duct unit 32 includes the return air main body unit 323. The return air main body unit 323 includes a return air chamber 324 and a return air connecting pipe 325.

[0061] [Return Air Chamber 324] The return air chamber 324 is located at a third end of the return air main body 323, which is closer to the return air inlet 322. The return air chamber 324 has a rectangular parallelepiped shape with an internal space. The return air chamber 324 has at least one opening as the return air inlet 322. For example, the return air chamber 324 has openings 3241, 3242, and 3243, which are open on three sides, as the return air inlet 322. In other words, the return air inlet 322 is formed in the return air chamber 324. The opening 3241 is located at the front end of the return air chamber 324 in the depth direction DD. The openings 3242 and 3243 are located at both ends of the return air chamber 324 in the lateral direction LD, respectively. A grill 3244 is provided in each of the openings 3241, 3242, and 3243. The openings 3241, 3242, 3243 are located above the top surface 26 (see FIG. 2) of the air conditioner 2. In other words, the return air inlet 322 is located above the top surface 26 of the air conditioner 2.

[0062] The return air chamber 324 further has a return air chamber outlet 3245. The return air chamber outlet 3245 is located at the rear end of the return air chamber 324 in the depth direction DD. The return air chamber outlet 3245 faces the opening 3241 (see FIG. 1C ) in the depth direction DD. The return air chamber outlet 3245 is located away from the opening 3241 (see FIG. 1C ) in the depth direction DD.

[0063] The return air chamber 324 is supported by the return air support frame 313. In other words, the return air chamber 324 is supported by the frame part 312. The return air chamber 324 is disposed on the upper surface of the return air support frame 313. The openings 3241, 3242, 3243 are located above the upper surface of the return air support frame 313.

[0064] [Return air connection pipe 325] The return air connecting pipe 325 is connected to the return air chamber 324. The return air connecting pipe 325 has a first return air pipe 3251, a second return air pipe 3252, and a third return air pipe 3253. The first return air pipe 3251, the second return air pipe 3252, and the third return air pipe 3253 are arranged in this order in the return air connecting pipe 325.

[0065] The return air first pipe 3251 includes a second connection region 3254. The second connection region 3254 is a region adjacent to the return air chamber 324. The second connection region 3254 extends in the depth direction DD. A cross-sectional area of ​​the second connection region 3254 perpendicular to the direction in which the second connection region 3254 extends is smaller than an area of ​​the return air inlet 322. In other words, the area of ​​the return air inlet 322 is larger than a cross-sectional area of ​​the second connection region 3254 perpendicular to the direction in which the second connection region 3254 extends. The area of ​​the return air inlet 322 is the sum of the areas of the openings 3241, 3242, and 3243. The return air first pipe 3251 is located at the upper end of the return air connecting pipe 325. The return air first pipe 3251 has a bent portion. The bent portion has an arc shape in side view. One end of the return air first pipe 3251 faces forward. One end of the return air first pipe 3251 is connected to the return air chamber outlet 3245. The other end of the return air first pipe 3251 faces downward.

[0066] The return air third pipe 3253 is located at the lower end of the return air connecting pipe 325. The return air third pipe 3253 is a straight pipe. The return air third pipe 3253 runs along the depth direction DD. A return air outlet 321 is formed at one end of the return air third pipe 3253. That is, one end of the return air third pipe 3253 is connected to the intake port 21. The return air outlet 321 faces the rear surface 28 of the air conditioner 2. The return air outlet 321 is located rearward of the rear surface 28 of the air conditioner 2 in the depth direction DD.

[0067] The return air second pipe 3252 is located at the rear end of the return air connecting pipe 325. The return air second pipe 3252 connects the other end of the return air first pipe 3251 and the other end of the return air third pipe 3253. The return air second pipe 3252 is a straight pipe. The return air second pipe 3252 extends in the height direction HD. The return air second pipe 3252 is located on the rear side of the air conditioner 2 in the depth direction.

[0068] The material of the return air duct portion 32 is not limited. The return air duct portion 32 may be made of, for example, metal. Examples of metal include stainless steel, aluminum, and iron. The return air duct portion 32 may also be made of glass wool or polyvinyl chloride.

[0069] [Air supply duct part 33] 1D, 3, and 4, as described above, air intake duct portion 33 includes air intake main body portion 333. Air intake main body portion 333 includes air intake secondary chamber 334, air intake primary chamber 335, connecting pipe 3351, air intake connecting pipe 336, covering portion 337 (see FIG. 5), and cover 338 (see FIG. 6).

[0070] [Air supply secondary chamber 334] The supply air secondary chamber 334 is located at the first end. The first end is the end of the supply air main body 333 that is closer to the supply air outlet 332. The supply air outlet 332 is formed in the supply air main body 333. The supply air secondary chamber 334 is arranged on the base 311. The air conditioner 2 and the supply air secondary chamber 334 are arranged on a common base 311. The supply air secondary chamber 334 is aligned with a part of the return air main body 323 and the air conditioner 2 in the horizontal direction LD. The supply air secondary chamber 334 is located away from the side surface 30 of the return air main body 323 in the horizontal direction LD. The supply air secondary chamber 334 is located on the opposite side of the air conditioner 2 with respect to the support columns 3122, 3124 in the horizontal direction LD.

[0071] The air supply secondary chamber 334 has a depth direction DD. The depth direction DD is a direction along the direction in which air is blown out from the air supply outlet 332. The air supply secondary chamber 334 has a rectangular parallelepiped shape. The air supply secondary chamber 334 includes a front portion 3341 and a rear portion 3342. The front portion 3341 is located on the near side in the depth direction DD. The front portion 3341 is an area that includes the air supply outlet 332. In other words, the air supply outlet 332 is formed in the front portion 3341. The front portion 3341 includes a front surface 3343 and two side surfaces 3346A, 3346B.

[0072] The air supply secondary chamber 334 includes a plate-shaped member 3344. A plurality of through holes 3345 are formed in the member 3344. The member 3344 is, for example, a punched plate. The member 3344 constitutes a front surface 3343. The front surface 3343 is a surface in which the air supply outlet 332 is formed at a front portion 3341. In other words, the front surface 3343 is constituted by the plate-shaped member 3344 in which a plurality of through holes 3345 are formed. The air supply outlet 332 is the plurality of through holes 3345. Each of the plurality of through holes 3345 penetrates the member 3344 in the thickness direction. Both ends of the front surface 3343 in the lateral direction LD may be inclined surfaces. The inclined surfaces are planes perpendicular to the depth direction DD and inclined with respect to planes along the lateral direction LD and the height direction HD. The inclined surfaces are along the height direction HD. The inclined surfaces may also include the through holes 3345.

[0073] 4, the supply air outlet 332 is located below the return air inlet 322. The supply air secondary chamber 334 is located below the return air chamber 324 in the height direction HD. The supply air secondary chamber 334 is located below the return air support frame 313 and the supply air support frame 314 in the height direction HD.

[0074] Each of the two side surfaces 3346A and 3346B is connected to each of the two ends in the lateral direction LD of the front surface 3343. Each of the two side surfaces 3346A and 3346B extends in the depth direction DD and the height direction HD.

[0075] The rear part 3342 is connected to the side of the front part 3341 opposite to the air supply outlet 332. The rear part 3342 is connected to the rear end of the front part 3341 in the depth direction DD. The rear part 3342 is located on the rear side of the front part 3341. The upper end of the rear part 3342 is open.

[0076] [Air supply primary chamber 335] As shown in Figures 1D and 3, the air supply primary chamber 335 is located at the second end. The second end is the end of the air supply main body 333 that is closer to the air supply inlet 331. The air supply primary chamber 335 is located above the top surface 26 of the air conditioner 2 (see Figure 3). The air supply inlet 331 faces toward the top surface 26 of the air conditioner 2. The air supply inlet 331 is located above the top surface 26 of the air conditioner 2. The air supply inlet 331 is located above the return air outlet 321 (see Figure 2).

[0077] The air supply primary chamber 335 has a rectangular parallelepiped shape. The air supply primary chamber 335 has a lower surface 3353, an upper surface 3354, and two side surfaces 3355 and 3356. The air supply inlet 331 is formed in the lower surface 3353. For example, the air supply inlet 331 is formed in the center of the lower surface 3353. The end (peripheral end) of the lower surface 3353 contacts the upper surface of the air supply support frame 314. In this way, the air supply primary chamber 335 is supported by the air supply support frame 314.

[0078] The upper surface 3354 is located away from the return air support frame 313 in the height direction HD. The supply air primary chamber 335 is located below the lower surface of the return air chamber 324. In other words, the return air chamber 324 is located above the upper surface 3354 of the supply air primary chamber 335. The supply air primary chamber 335 and the return air chamber 324 are aligned in the height direction HD. A gap is formed between the supply air primary chamber 335 and the return air chamber 324.

[0079] As shown in FIG. 3 , the side surfaces 3355 and 3356 each connect the lower surface 3353 and the upper surface 3354 in the height direction HD. The side surface 3356 is located at one end of the air supply primary chamber 335 in the horizontal direction LD. The side surface 3355 is located away from the side surface 3356 in the horizontal direction LD. The side surface 3355 is located between the support columns 3121 and 3122 as viewed in the depth direction DD. As shown in FIG. 1D , the side surface 3355 is located between the two side surfaces of the return air chamber 324 as viewed in the height direction HD. The side surface 3355 is located between the two side surfaces 29 and 30 of the air conditioner 2 as viewed in the height direction HD.

[0080] The connecting pipe 3351 is located between the upper surface 26 of the air conditioner 2 and the lower surface 3353 of the air supply primary chamber 335. Specifically, the connecting pipe 3351 is located between the upper end of the supply connecting pipe 241 and the lower surface 3353 of the air supply primary chamber 335. The connecting pipe 3351 is surrounded by the air supply support frame 314 in the depth direction DD and the lateral direction LD. The connecting pipe 3351 is located between the side surfaces 3356 and 3355 when viewed in the height direction HD. The connecting pipe 3351 extends in the height direction HD. The connecting pipe 3351 connects the air supply inlet 331 and the supply port 24. In other words, the air supply inlet 331 is connected to the supply port 24 via the connecting pipe 3351. The internal space of the connecting pipe 3351 communicates with the internal space of the supply connecting pipe 241. The internal space of the connecting pipe 3351 communicates with the internal space of the air supply primary chamber 335. The internal space of the connecting pipe 3351 is narrower than the internal space of the air supply primary chamber 335. In other words, the air supply primary chamber 335 has an internal space wider than the internal space of the connecting pipe 3351. In the present disclosure, the internal dimension of the connecting pipe 3351 in the height direction HD is smaller than the internal dimension of the air supply primary chamber 335 in the height direction HD. The internal dimension of the connecting pipe 3351 in the horizontal direction LD is smaller than the internal dimension of the air supply primary chamber 335 in the horizontal direction LD. The internal dimension of the connecting pipe 3351 in the depth direction DD is smaller than the internal dimension of the air supply primary chamber 335 in the depth direction DD.

[0081] [Air supply connection pipe 336] The air supply connecting pipe 336 connects the air supply secondary chamber 334 and the air supply primary chamber 335. The air supply connecting pipe 336 includes a first air supply pipe 3361, a second air supply pipe 3362, and a third air supply pipe 3363. The first air supply pipe 3361 is located at one end of the air supply connecting pipe 336. The first air supply pipe 3361 is connected to the air supply primary chamber 335. One end of the first air supply pipe 3361 is connected to a side surface 3355 of the air supply primary chamber 335. One end of the first air supply pipe 3361 opens to the side. The first air supply pipe 3361 has an arc shape when viewed in the height direction HD. The other end of the first air supply pipe 3361 opens to the rear.

[0082] The third air supply pipe 3363 is located at the other end of the air supply connection pipe 336. The third air supply pipe 3363 extends in the height direction HD. The lower end of the third air supply pipe 3363 is connected to the rear part 3342 of the secondary air supply chamber 334. The third air supply pipe 3363 is, for example, a tapered pipe. The internal space of the third air supply pipe 3363 has a cross-sectional area that increases downward. The third air supply pipe 3363 includes a rear wall 3363A, a front wall 3363B, and two side walls 3363C and 3363D. As shown in FIG. 4 , the rear wall 3363A extends along the height direction HD. The front wall 3363B faces the rear wall 3363A in the depth direction DD. An extension line of the front wall 3363B intersects with an extension line of the rear wall 3363A above the front wall 3363B. The distance from the rear wall 3363A to the front wall 3363B in the depth direction DD increases downward. Two side walls 3363C and 3363D connect the rear wall 3363A and the front wall 3363B, respectively. The two side walls 3363C and 3363D are parallel to each other.

[0083] The second air supply pipe 3362 extends along the height direction HD. The second air supply pipe 3362 is a straight pipe. The upper end of the second air supply pipe 3362 is connected to the other end of the first air supply pipe 3361. The lower end of the second air supply pipe 3362 is connected to the upper end of the third air supply pipe 3363. The internal space of the second air supply pipe 3362 has a constant cross-sectional area throughout the height direction HD. The second air supply pipe 3362 and the third air supply pipe 3363 form a vertical pipe 3364. In other words, the vertical pipe 3364 includes the second air supply pipe 3362 and the third air supply pipe 3363. The vertical pipe 3364 extends in the height direction HD. The lower end of the third air supply pipe 3363 is connected to the rear portion 3342. The cross-sectional area of ​​the internal space of the vertical pipe 3364 in the direction perpendicular to the height direction HD is smaller than the cross-sectional area of ​​the internal space of the air supply secondary chamber 334 in the direction perpendicular to the height direction HD. In other words, the cross-sectional area of ​​the internal space of the air supply secondary chamber 334 in the direction perpendicular to the height direction HD is larger than the cross-sectional area of ​​the internal space of the vertical pipe 3364 in the direction perpendicular to the height direction HD.

[0084] The above-described air supply secondary chamber 334, air supply primary chamber 335, connecting pipe 3351, and air supply connecting pipe 336 constitute second portion 339. For example, at least one of air supply secondary chamber 334, air supply primary chamber 335, connecting pipe 3351, and air supply connecting pipe 336 may constitute second portion 339. The material of second portion 339 is not limited. Second portion 339 may be made of, for example, metal. Examples of metal include stainless steel, aluminum, and iron. Second portion 339 may also be made of glass wool or vinyl chloride.

[0085] [Covering part 337] 5, covering portion 337 covers second portion 339. Covering portion 337 is disposed in contact with the outer surface of second portion 339. Covering portion 337 is made of a material having lower thermal conductivity than metal. Examples of materials having lower thermal conductivity than metal include glass wool and resin foam.

[0086] [Cover 338] As shown in FIGS. 6 and 7, the cover 338 can open and close a first region 3321 (see FIG. 7). The first region 3321 is a plurality of air supply outlets 332 located in an upper portion among the plurality of air supply outlets 332. The cover 338 is movable between a state where it is detached from the front surface 3343 (see FIG. 7) and a state where it is attached to the front surface 3343 (see FIG. 6). As shown in FIG. 7, when the cover 338 is detached from the front surface 3343, the first region 3321 and the second region 3322 are open. The second region 3322 is a region of the plurality of air supply outlets 332 that is below the first region 3321. As shown in FIG. 6, when the cover 338 is attached from the front surface 3343, the cover 338 closes the first region 3321. Even when the cover 338 is attached from the front surface 3343, the second region 3322 is open. Therefore, the second region 3322 is always open. The cover 338 extends along both the height direction HD and the lateral direction LD.

[0087] The air supply main body 333 further includes two guide plates 3347 (see FIG. 7) and 3348 (see FIG. 6). As shown in FIG. 7, the guide plate 3347 is disposed at the front end of the side surface 3346A of the front portion 3341. As shown in FIG. 6, the guide plate 3348 is disposed at the front end of the side surface 3346B of the front portion 3341. Each of the two guide plates 3347 and 3348 extends along the height direction HD. When the cover 338 is attached to the front surface 3343, both ends of the cover 338 in the lateral direction LD fit into the two guide plates 3347 and 3348, respectively. As shown in FIG. 7, the cover 338 can be detached from the guide plates 3347 and 3348 and removed from the front surface 3343. Two handles 3349 are provided on the cover 338.

[0088] [Assembly of the displacement air conditioning system 1 and installation of the duct unit 3 to the air conditioner 2] The assembly of the replacement air conditioning system 1 will now be described. The base 311 is placed on the floor of the room where replacement air conditioning is desired. As shown in FIG. 1A, the air conditioner 2 is placed on the top surface of the base 311. The frame section 312 is attached to the base 311. In this way, the support section 31 is prepared. Alternatively, the support section 31 may be prepared with the frame section 312 attached to the base 311 in advance, and the air conditioner 2 may be placed on the top surface of the base 311 on the support section 31.

[0089] The return air duct section 32 and the supply air duct section 33 are attached to the air conditioner 2, and as shown in FIGS. 1C and 1D, the return air duct section 32 and the supply air duct section 33 are supported by the support section 31. As shown in FIG. 2, the return air outlet 321 is connected to the intake port 21 of the air conditioner 2. Specifically, the return air third pipe 3253 and the intake connecting pipe 221 are joined. The return air chamber 324 is placed on the upper surface of the return air support frame 313. The supply air inlet 331 is connected to the supply port 24 of the air conditioner 2. The connecting pipe 3351 is inserted into the supply air support frame 314, and the connecting pipe 3351 and the supply connecting pipe 241 are joined. The supply air primary chamber 335 is placed on the upper surface of the supply air support frame 314. As a result, the duct unit 3 is attached to the air conditioner 2 so that the return air outlet 321 is connected to the intake port 21 and the supply air inlet 331 is connected to the supply port 24. In other words, the displacement air conditioning system 1 is assembled.

[0090] [Implementation of indoor displacement air conditioning using displacement air conditioning system 1] In the replacement air conditioning system 1, the cover 338 is removed from the front face 3343 as shown in FIG. 7. Before replacement air conditioning of the room is performed by the replacement air conditioning system 1, the cover 338 is attached to the front face 3343 as shown in FIG. 6. The air conditioner 2 is driven. As shown in FIG. 2, indoor air passes from the return air inlet 322 through the return air main body 323 and is drawn into the air conditioner 2 through the return air outlet 321 and the intake port 21. The drawn air is cooled by heat exchange with the heat exchanger 22. The cooled air passes through the supply port 24, the supply air inlet 331 and the supply air main body 333, and is supplied to the lower area from the supply air outlet 332 of the second area 3322.

[0091] When the temperature of the lower area drops to, for example, 26°C or below, cover 338 is removed from front surface 3343 as shown in Figure 7. The velocity of the air supplied from air supply outlet 332 then becomes lower than the velocity of the air when cover 338 was removed from front surface 3343. Replacement air conditioning by replacement air conditioning system 1 then continues.

[0092] [Variations] 1A, first portion 340, which is at least a part of air supply duct portion 33, may be made of a material having lower thermal conductivity than metal. The arrangement and configuration of first portion 340 are the same as those of second portion 339 described above.

[0093] Modified examples of the duct unit and displacement air conditioning system will be described below with reference to Figure 8. Figure 8 is a front view of a modified displacement air conditioning system. As shown in Figure 8, the support part 31 may further include a second cover 34 and a third cover 35. The second cover 34 is disposed in front of the air conditioner 2 and the air supply primary chamber 335 (see Figure 1A). The second cover 34 is attached to the supports 3121 and 3122 (see Figure 1A). The second cover 34 can expose the air conditioner 2 and the air supply primary chamber 335. The third cover 35 is disposed in front of the vertical pipe 3364 (see Figure 1A). The third cover 35 covers a portion of the vertical pipe 3364.

[0094] Modified examples of the duct unit and displacement air conditioning system will be described with reference to Figures 9 and 10. Figure 9 is a front view of the supply air secondary chamber and the cover positioned in a first position. Figure 10 is a front view of the supply air secondary chamber and the cover positioned in a second position. As shown in Figures 9 and 10, the cover 338 includes a plurality of horizontal plates 3381 and two vertical plates 3382. The horizontal plates 3381 have a lattice shape. The horizontal plates 3381 are spaced apart from each other in the height direction HD. Each of the horizontal plates 3381 extends in the horizontal direction LD. Each of the two vertical plates 3382 is connected to each of both ends of the cover 338 in the horizontal direction LD. Each of the two vertical plates 3382 extends in the height direction HD.

[0095] As shown in Fig. 10, the supply air outlets 332 in the first region 3321 are positioned apart from one another in the height direction HD. As shown in Fig. 9, when the cover 338 is positioned in the first position, the supply air outlets 332 in the first region 3321 overlap with and close multiple horizontal plates 3381. In other words, the cover 338 closes the supply air outlets 332 in the first region 3321. As shown in Fig. 10, when the cover 338 is positioned in the second position, the supply air outlets 332 in the first region 3321 are open. In this modification, the cover 338 is positioned on the front surface 3343 regardless of whether the cover 338 is positioned in the first position or the second position.

[0096] Although not shown, the supply air inlet 331 may be directly connected (directly coupled) to the supply port 24. The return air outlet 321 may be directly connected (directly coupled) to the intake port 21.

[0097] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined not by the above description but by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0098] 1. Displacement air conditioning system 2. Air conditioners 21 Intake port 211 Suction connection pipe 22 Heat exchanger 23 Fans 24 supply port 241 Supply Connection Pipe 25 Bottom side 26 Top side 27 Front 28 Rear 29,30 Side 3 Duct unit 31 Support part 311 Base 312 Frame section 3121,3122,3123,3124 Post 313 Return air support frame 314 Air supply support frame 32 Return air duct section 321 Return air outlet 322 Return air inlet 323 Return air main body 324 Return Air Chamber 325 Return air connection pipe 33 Air intake duct 331 Air intake 332 Air intake outlet 333 Air supply main body 334 Secondary Air Supply Chamber 335 Primary Air Supply Chamber 336 Air supply connection pipe 337 Covering part 338 Cover 339 Part 2 340 Part 1 3241,3242,3243 aperture 3244 Grill 3245 Return air chamber outlet 3251 Return Air Pipe No. 1 3252 Return Air Pipe No. 2 3253 Return Air Pipe No. 3 3254 Second Connection Area 3321 First area 3322 Second area 3341 Front 3342 rear 3343 Front 3344 Materials 3345 Through hole 3346A,3346B Side 3347,3348 Signboard 3349 Handle 3351 Connecting pipe 3353 Bottom surface 3354 Top surface 3355,3356 Side 3361 Air supply pipe 1 3362 Air supply pipe 2 3363 Air supply pipe 3 3363A Back wall 3363B Front wall 3363C,3363D side wall 3364 Vertical pipe 3381 Horizontal board 3382 Vertical board 34 Second Cover 35 Third Cover DD Depth direction HD Height direction LD horizontal direction S horizontal plane

Claims

1. A duct unit that can be attached to an air conditioner, the duct unit including: an intake port that can take in indoor air; a heat exchanger that can cool the air taken in from the intake port by heat exchange; and a supply port that can supply the air that has been heat exchanged by the heat exchanger into the room, a return air duct section including a return air outlet connectable to the intake port, a return air inlet located away from the return air outlet, and a return air main body section connecting the return air outlet and the return air inlet; an air intake duct section including an air intake inlet connectable to the supply port, an air intake outlet located away from the air intake inlet, and an air intake main body section connecting the air intake inlet and the air intake outlet, When the duct unit is attached to the air conditioner so that the return air outlet is connected to the intake port and the supply air inlet is connected to the supply port, the supply air outlet is located below the return air inlet, The air supply main body portion is an air supply primary chamber located at an end of the air supply main body that is closer to the air supply inlet; an air supply secondary chamber located at an end of the air supply main body that is closer to the air supply outlet; an air supply connecting pipe connecting the air supply primary chamber and the air supply secondary chamber, The air supply primary chamber is formed with the air supply inlet, The air supply outlet is formed in the air supply secondary chamber, When the duct unit is attached to the air conditioner, the air supply secondary chamber a front portion that is a region including the air intake outlet; a rear portion connected to the front portion on the opposite side to the air supply outlet in a depth direction that is a direction along the air blowing direction from the air supply outlet, The air supply connection pipe is a vertical pipe extending in a height direction and connected to the air supply secondary chamber; an air intake first pipe connected to the vertical pipe and the air intake primary chamber; a lower end of the vertical pipe is connected to the rear portion; the first air supply pipe includes a portion extending along the depth direction, and a rear end of the portion is opened rearward, When the duct unit is attached to the air conditioner, the front portion is aligned with the air conditioner in a lateral direction perpendicular to the depth direction and the height direction, The rear portion of the duct unit is aligned with the return air main body portion in the lateral direction.

2. The duct unit according to claim 1 , wherein the supply air inlet is located above the return air outlet when the duct unit is attached to the air conditioner.

3. The duct unit according to claim 1 , wherein the air intake inlet faces an upper surface of the air conditioner when the duct unit is attached to the air conditioner.

4. The duct unit according to claim 1, wherein the air intake inlet is located above an upper surface of the air conditioner when the duct unit is attached to the air conditioner.

5. 2. The duct unit according to claim 1, wherein a cross-sectional area of ​​the internal space of the air supply secondary chamber in a direction perpendicular to the height direction is larger than a cross-sectional area of ​​the internal space of the vertical pipe in the direction perpendicular to the height direction.

6. the air supply secondary chamber includes a plate-like member having a plurality of through holes formed therein; The duct unit according to claim 1 , wherein the air supply outlets are the plurality of through holes.

7. When the duct unit is attached to the air conditioner, the front portion includes a front surface on which the air supply outlet is formed, The duct unit according to claim 6 , wherein the front surface is formed of a plate-like member having a plurality of through holes formed therein.

8. The duct unit according to claim 1 , wherein the air supply secondary chamber has a rectangular parallelepiped shape.

9. The duct unit according to claim 1 , wherein the vertical pipe has an internal space whose cross-sectional area perpendicular to the height direction increases downward.

10. A duct unit attachable to an air conditioner, comprising: an intake port capable of drawing in indoor air; a heat exchanger capable of cooling the air drawn in from the intake port by heat exchange; and a supply port capable of supplying the air that has been heat exchanged by the heat exchanger into the room, a return air duct section including a return air outlet connectable to the intake port, a return air inlet located away from the return air outlet, and a return air main body section connecting the return air outlet and the return air inlet; an air intake duct section including an air intake inlet connectable to the supply port, an air intake outlet located away from the air intake inlet, and an air intake main body section connecting the air intake inlet and the air intake outlet, When the duct unit is attached to the air conditioner so that the return air outlet is connected to the intake port and the supply air inlet is connected to the supply port, the supply air outlet is located below the return air inlet, The air supply main body portion is an air supply primary chamber located at an end of the air supply main body that is closer to the air supply inlet; an air supply secondary chamber located at an end of the air supply main body that is closer to the air supply outlet; an air supply connecting pipe connecting the air supply primary chamber and the air supply secondary chamber, The air supply primary chamber is formed with the air supply inlet, The air supply outlet is formed in the air supply secondary chamber, When the duct unit is attached to the air conditioner, the air supply secondary chamber a front portion that is a region including the air intake outlet; a rear portion connected to the front portion on the opposite side to the air supply outlet in a depth direction that is a direction along the air blowing direction from the air supply outlet, The air supply connection pipe is a vertical pipe extending in a height direction and connected to the air supply secondary chamber; an air intake first pipe connected to the vertical pipe and the air intake primary chamber; a lower end of the vertical pipe is connected to the rear portion; the first air supply pipe includes a portion extending along the depth direction, and a rear end of the portion is opened rearward, the first air supply pipe further includes a third portion that is arc-shaped when viewed in the height direction, A duct unit in which the third portion is connected to a side surface of the primary air supply chamber facing in a horizontal direction perpendicular to the depth direction and the height direction, and to a front end of the portion.

11. 11. The duct unit according to claim 1 or claim 10, wherein, when the duct unit is attached to the air conditioner, the primary air supply chamber is located above an upper surface of the air conditioner.

12. 11. The duct unit according to claim 1 or claim 10, wherein a first portion, which is at least a part of the air supply duct portion, is made of a material having lower thermal conductivity than metal.

13. the second portion, which is at least a part of the air supply duct portion, is made of metal; The duct unit according to claim 1 or 10, further comprising a covering portion that covers the second portion and is made of a material having lower thermal conductivity than the metal.

14. The duct unit according to claim 1 or 10, wherein the air supply duct portion further includes a cover that is capable of opening and closing a first region that is a part of the air supply outlet.

15. an air conditioner including an intake port capable of drawing in indoor air, a heat exchanger capable of cooling the air drawn in from the intake port by heat exchange, and a supply port capable of supplying the air that has been heat exchanged by the heat exchanger into the room; 11. The duct unit according to claim 1 or 10, which is attached to the air conditioner, wherein the return air outlet is connected to the intake port and the supply air inlet is connected to the supply port; and A displacement air conditioning system comprising:

Images