Duct Units and Displacement Air Conditioning Systems

Abstract

The duct unit can be attached to 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 heat-exchanged by the heat exchanger to the room. The duct unit includes a return air duct section and an air supply 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 section connecting the return air outlet and the return air inlet. The air supply duct section includes an air supply inlet connectable to the supply port, an air supply outlet located away from the air supply inlet, and a supply air main body section connecting the air supply inlet and the air supply outlet. When the duct unit is attached to the air conditioner such that the return air outlet is connected to the intake port and the air supply inlet is connected to the supply port, the air supply outlet is located below the return air inlet.

Description

[Technical field]

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

[0002] An air conditioner including an intake port, a heat exchanger, and a supply port is known (see, for example, International Publication WO 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 from the intake port by heat exchange. The supply port supplies the air that has been heat exchanged by the heat exchanger to 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 can be attached to 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 heat-exchanged by the heat exchanger to the room. The duct unit includes a return air duct section and an air supply 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 section connecting the return air outlet and the return air inlet. The air supply duct section includes an air supply inlet connectable to the supply port, an air supply outlet located away from the air supply inlet, and a main body section connecting the air supply inlet and the air supply outlet. When the duct unit is attached to the air conditioner such that the return air outlet is connected to the intake port and the air supply inlet is connected to the supply port, the air supply 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-mentioned 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 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 to 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 description 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 portion and an air supply duct portion in the displacement air conditioning system shown in FIG. 1A. [Diagram 2] FIG. 2 is a left side view of the displacement air conditioning system shown in FIG. 1A. [Diagram 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. [Diagram 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 replacement 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 PREFERRED EMBODIMENTS

[0007] [Problem that this disclosure aims to solve] Depending on the purpose of air conditioning, a duct unit is attached to an air conditioner, and an air conditioning system comprising an air conditioner and a duct unit is required. 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 above-mentioned air conditioning system is installed in a room with a high ceiling, the upper space is also cooled. The upper space is a space above the area where people are present. However, since there are no people in the upper space, there is no need to cool it. Therefore, when the air conditioning system cools the upper space, the air conditioning system consumes unnecessary energy. When the air conditioning system cools the upper space, energy efficiency is poor.

[0009] It is an object of the present disclosure to provide a displacement air conditioning system and a duct unit provided therewith 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] The embodiments of the present disclosure will be listed and described. The duct unit of the present disclosure can be attached to 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 heat-exchanged by the heat exchanger to the room. The duct unit includes a return air duct section and an air supply 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 section connecting the return air outlet and the return air inlet. The air supply duct section includes an air supply inlet connectable to the supply port, an air supply outlet located away from the air supply inlet, and a main body section connecting the air supply inlet and the air supply outlet. When the duct unit is attached to the air conditioner such that the return air outlet is connected to the intake port and the air supply inlet is connected to the supply port, the air supply outlet is located below the return air inlet.

[0012] According to the duct unit of the present disclosure, air that has been heat exchanged by a heat exchanger can be supplied from the supply air outlet, and areas where people are present can be efficiently cooled. 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-mentioned 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 suction port.

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

[0015] In the above-mentioned duct unit, when the duct unit is attached to an air conditioner, the air supply 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-mentioned duct unit, when the duct unit is attached to the 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 that 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. According to this duct unit, the air flow from the vertical pipe can be stabilized in the air supply secondary chamber. Therefore, stable air can be supplied from the air supply outlet into the room. As a result, the area where people are present can be efficiently cooled.

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

[0018] In the above-mentioned duct unit, the supply air secondary chamber may include a plate-like member having a plurality of through holes formed therein. The supply air 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 a turbulent flow.

[0019] In the above-mentioned duct unit, when the duct unit is attached to the air conditioner, the front portion may include a front surface where the supply air outlet is formed. The front surface may be made of a plate-like member having a plurality of through holes. With this duct unit, the area in front of the supply air secondary chamber can be efficiently cooled.

[0020] In the above duct unit, the secondary air intake chamber may have a rectangular parallelepiped shape. In this duct unit, the secondary air intake chamber has a simple structure.

[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 arranging 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 intake air outlet to areas where people are present.

[0022] In the above-mentioned 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 air that has been heat exchanged by the heat exchanger in the air intake primary chamber can be sent to the air intake outlet while stabilizing the flow of the air.

[0023] In the above-mentioned duct unit, when the duct unit is attached to the 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 makes it possible to reduce the space between the primary air supply chamber and the air conditioner at least in the depth direction.

[0024] In the above-mentioned duct unit, the first portion, which is at least a part of the intake air duct, may be made of a material having a lower thermal conductivity than metal. Air that has been heat exchanged (cooled) by a heat exchanger flows through the intake air duct. When the first portion of the intake air 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 having a 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, it is possible to suppress the air flowing through the first portion from being heated by the air around the intake air duct.

[0025] In the above-mentioned 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 having 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. Since 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 occur on the outside of the second portion. However, in this duct unit, the covering portion made of a material having lower thermal conductivity than metal covers the second portion, so condensation on the outside of the second portion can be suppressed. In addition, the air flowing through the second portion can be suppressed from being heated by the air around the intake duct.

[0026] In the above-mentioned duct unit, the intake duct section may further include a cover capable of opening and closing 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 speed of the cold air supplied from the intake outlet. Increasing the speed of the cold air generates turbulence around the intake outlet. The turbulence causes the cold air to mix with the warm air around the intake outlet. Therefore, it is possible to create relatively uniformly cooled air around the intake outlet. As a result, it is possible to uniformly cool the temperature of a specified space. The specified space is, for example, a space with a height of up to 2.0 m from the floor surface.

[0027] On the other hand, if turbulence continues to occur around the intake air outlet (continues to create turbulence), the air in the upper area above the area 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 decreases. This prevents the air from becoming turbulent. Therefore, the air is not unnecessarily stirred up. In other words, mixing of the air in the upper area and the air in the area where people are present is prevented, making the displacement air conditioning more efficient.

[0029] In the above-mentioned 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-mentioned duct unit, when the duct unit is attached to the 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 suction port is located on the rear surface.

[0031] In the above-mentioned 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-mentioned duct unit, when the duct unit is attached to the 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 sucked in through the return air inlet.

[0033] In the above-mentioned 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 be formed with a return air inlet. In this duct unit, indoor air can be sucked in at a low speed through the return air inlet in the return air chamber.

[0034] In the above-mentioned duct unit, the return air main body may further include a return air connection pipe connected to the return air chamber. The return air connection 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. According to this duct unit, it is possible to regulate the air flow in the area above the area in which people are present in the room while sucking in indoor air from the return air inlet at a low speed. This makes it possible to suppress air turbulence in the area in which people are present. 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 having a space therein. 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 comprise 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 enabling the air supply inlet of the air supply duct portion to be reliably connected to the supply port of the air conditioner.

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

[0038] In the above-mentioned duct unit, the return air main body may include a return air chamber located at a third end of the return air main body, which is an end 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 intake port of the air conditioner.

[0039] In the above-mentioned 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 upper 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 chamber and the air conditioner can be aligned in the height direction by the return air support frame. Therefore, the space between the return air chamber and the air conditioner in the depth direction can be reduced.

[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-mentioned 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 sucked in through the return air inlet.

[0042] In the above-mentioned duct unit, a gap may be formed between the supply air primary chamber and the return air chamber. In this duct unit, it is possible to suppress an increase in temperature of the air flowing through the supply air primary chamber due to contact between the supply air primary chamber and the return air chamber.

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

[0044] In the above-mentioned duct unit, when the duct unit is attached to the air conditioner, the air conditioner and the secondary air supply chamber may be disposed 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 replacement air conditioning system of the present disclosure includes an air conditioner and the above-mentioned 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 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 to 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 replacement air conditioning system, air that has been heat exchanged by the heat exchanger can be supplied from the supply air outlet, and an area where people are present can be efficiently cooled. In other words, the replacement air conditioning system can efficiently perform replacement air conditioning.

[0046] [Details of the embodiment of the present invention] Next, an embodiment of the duct unit and the replacement air conditioning system of the present disclosure will be described with reference to FIG. 1A to FIG. 7. FIG. 1A is a perspective view of the replacement air conditioning system of the present disclosure. In FIG. 1A, the replacement air conditioning system is viewed from the front. FIG. 1B is a perspective view of an air conditioner in the replacement 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 replacement 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 replacement 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 replacement air conditioning system shown in FIG. 1A. In FIG. 2, a part of the replacement air conditioning system is shown in a cross-sectional view. FIG. 3 is a front view of the replacement air conditioning system shown in FIG. 1A. FIG. 4 is a right side view of the replacement air conditioning system shown in FIG. 1A. Fig. 5 is a cross-sectional view of a portion of the supply air duct of the 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 replacement air conditioning system 1] The replacement air conditioning system 1 performs replacement air conditioning on a room. In replacement air conditioning, the lower area in 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 Fig. 1B and Fig. 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 Fig. 2) is capable of drawing in indoor air. The heat exchanger 22 (see Fig. 2) is capable of cooling the air drawn in from the intake port 21 by heat exchange. The fan 23 (see Fig. 2) is capable of sending air toward the heat exchanger 22. The supply port 24 (see Fig. 2) is capable of supplying the air that has been heat exchanged 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 a RA (Return Air) duct section. Hereinafter, the return air in the members including "return air" can be read as RA. As shown in Fig. 1C and Fig. 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 intake port 21 (see Fig. 2) of the air conditioner 2. In other words, the return air outlet 321 can be connected to the intake port 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 a SA (Supply Air) duct section. Hereinafter, the supply air in the members including "supply air" can be read as SA. As shown in FIG. 1D and FIG. 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 can be connected 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 conditioner 2 and duct unit 3] The air conditioner 2 and the duct unit 3 will be described in detail. Hereinafter, the air conditioner 2 and the duct unit 3 will be described in detail "in a state in which the duct unit 3 is attached to the air conditioner 2." Therefore, the phrase "in a state in which the duct unit 3 is attached to the air conditioner 2" will be omitted.

[0054] [Air conditioner 2 details] As shown in FIG. 1B, FIG. 2, and FIG. 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, 30, a suction connection pipe 211, and a supply connection pipe 241. As shown in FIG. 2 and FIG. 3, the lower surface 25 is parallel to the 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 FIG. 1B and FIG. 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 FIG. 1B and FIG. 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 suction 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 lateral direction LD. As shown in FIG. 1B, the lateral 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 at the rear surface 28. The internal space of the suction connection pipe 211 is connected to the suction port 21. The suction connection pipe 211 extends in the depth direction DD. As shown in FIG. 2 and FIG. 3, the supply connection pipe 241 is joined to the outer periphery of the supply port 24 at the upper surface 26. The internal space of the supply connection pipe 241 is connected to the supply port 24. The supply connection pipe 241 extends in the height direction HD.

[0055] [Details of Duct Unit 3] 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 Fig. 1C and Fig. 1D, the base 311 is located at the lower end of the support part 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 disposed on the base 311.

[0057] [Frame part 312] As shown in FIG. 1C and FIG. 1D, the frame portion 312 includes columns 3121, 3122, 3123, and 3124, a return air support frame 313, and an intake air support frame 314. Each of the columns 3121, 3122, 3123, and 3124 extends from the upper surface of the base 311 in the height direction HD. Each of the columns 3121, 3122, 3123, and 3124 is parallel to each other. Each of the columns 3121 and 3122 extends from the front end of the base 311. The column 3121 extends from one end of the base 311 in the horizontal direction LD. The column 3122 extends from the middle part of the base 311 in the horizontal direction LD. Each of the columns 3123 and 3124 extends from the rear end of the base 311. The support pillar 3123 is located away from the support pillar 3121 in the depth direction DD. The support pillar 3124 is located away from the support pillar 3122 in the depth direction DD. The support pillar 3124 extends from a middle portion 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 pillars 3121, 3122, 3123, and 3124. Each of the four corners of the return air support frame 313 is attached to each of the pillars 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 return air support plate having a plate shape. As shown in FIG. 2 and FIG. 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 parts of the pillars 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 pillars 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 FIG. 2 and FIG. 3, the supply air support frame 314 is located above the upper surface 26 of the air conditioner 2. The air supply support frame 314 is positioned 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 section 32 includes the return air main body section 323. The return air main body section 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 an end closer to the return air inlet 322. The return air chamber 324 has a rectangular parallelepiped shape with a space inside. 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 chamber 324 has the return air inlet 322 formed therein. 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 arranged in each of the openings 3241, 3242, and 3243. The openings 3241, 3242, and 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 includes 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 an 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. The cross-sectional area of ​​the second connection region 3254 perpendicular to the direction in which the second connection region 3254 extends is smaller than the area of ​​the return air inlet 322. In other words, the area of ​​the return air inlet 322 is larger than the 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 connection pipe 325. The return air first pipe 3251 has a bent portion. The bent portion has a circular arc shape in a 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 is 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 connection 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 at the rear 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 is made of, for example, a metal. Examples of metals include stainless steel, aluminum, and iron. The return air duct portion 32 may be made of glass wool or polyvinyl chloride.

[0069] [Air supply duct section 33] 1D, 3 and 4, as described above, the air supply duct portion 33 includes the air supply main body portion 333. The air supply main body portion 333 includes the air supply secondary chamber 334, the air supply primary chamber 335, a connecting pipe 3351, an air supply connecting pipe 336, a covering portion 337 (see FIG. 5), and a 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 an 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 disposed on the base 311. The air conditioner 2 and the supply air secondary chamber 334 are disposed 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 lateral 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 lateral direction LD. The supply air secondary chamber 334 is located on the opposite side of the air conditioner 2 with respect to the pillars 3122, 3124 in the lateral direction LD.

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

[0072] The air supply secondary chamber 334 includes a plate-like member 3344. A plurality of through holes 3345 are formed in the member 3344. The member 3344 is, for example, a punching 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 a plate-like member 3344 in which a plurality of through holes 3345 are formed. The air supply outlet 332 is a 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 horizontal direction LD may be inclined surfaces. The inclined surfaces are surfaces perpendicular to the depth direction DD and inclined with respect to a surface along the horizontal 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 both 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 Fig. 1D and Fig. 3, the supply air primary chamber 335 is located at the second end. The second end is the end of the supply air main body 333 that is closer to the supply air inlet 331. The supply air primary chamber 335 is located above the top surface 26 of the air conditioner 2 (see Fig. 3). The supply air inlet 331 faces the top surface 26 of the air conditioner 2. The supply air inlet 331 is located above the top surface 26 of the air conditioner 2. The supply air inlet 331 is located above the return air outlet 321 (see Fig. 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, 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. An 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, each of the side surfaces 3355 and 3356 connects 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 supply air 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 column 3121 and the support column 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 supply air primary chamber 335. Specifically, the connecting pipe 3351 is located between the upper end of the supply connection pipe 241 and the lower surface 3353 of the supply air primary chamber 335. The connecting pipe 3351 is surrounded by the supply air 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 as seen in the height direction HD. The connecting pipe 3351 extends in the height direction HD. The connecting pipe 3351 connects the supply air inlet 331 and the supply port 24. That is, the supply air inlet 331 is connected to the supply port 24 via the connecting pipe 3351. The internal space of the connecting pipe 3351 is connected to the internal space of the supply connection pipe 241. The internal space of the connecting pipe 3351 is connected to the internal space of the supply air 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 connection pipe 336 connects the air supply secondary chamber 334 and the air supply primary chamber 335. The air supply connection pipe 336 includes an air supply first pipe 3361, an air supply second pipe 3362, and an air supply third pipe 3363. The air supply first pipe 3361 is located at one end of the air supply connection pipe 336. The air supply first pipe 3361 is connected to the air supply primary chamber 335. One end of the air supply first pipe 3361 is connected to a side surface 3355 of the air supply primary chamber 335. One end of the air supply first pipe 3361 opens to the side. The air supply first pipe 3361 has an arc shape when viewed in the height direction HD. The other end of the air supply first 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 is aligned 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 each connect the rear wall 3363A and the front wall 3363B. The two side walls 3363C and 3363D are parallel to each other.

[0083] The second air intake pipe 3362 is aligned along the height direction HD. The second air intake pipe 3362 is a straight pipe. The upper end of the second air intake pipe 3362 is connected to the other end of the first air intake pipe 3361. The lower end of the second air intake pipe 3362 is connected to the upper end of the third air intake pipe 3363. The internal space of the second air intake pipe 3362 has a uniform cross-sectional area throughout the height direction HD. The second air intake pipe 3362 and the third air intake pipe 3363 form a vertical pipe 3364. That is, the vertical pipe 3364 includes the second air intake pipe 3362 and the third air intake pipe 3363. The vertical pipe 3364 extends in the height direction HD. The lower end of the third air intake 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-mentioned air supply secondary chamber 334, air supply primary chamber 335, connecting pipe 3351, and air supply connecting pipe 336 constitute the second part 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 the second part 339. The material of the second part 339 is not limited. The second part 339 is made of, for example, a metal. Examples of metals include stainless steel, aluminum, and iron. The second part 339 may be made of glass wool or polyvinyl 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 FIG. 6 and FIG. 7, the cover 338 can open and close the first region 3321 (see FIG. 7). The first region 3321 is a plurality of air supply outlets 332 located in the upper part among the plurality of air supply outlets 332. The cover 338 can move between a state where it is removed 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 removed 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 lower than 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 is aligned in 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 is aligned along the height direction HD. When the cover 338 is attached to the front surface 3343, each of the two end portions of the cover 338 in the lateral direction LD fits into each of the two guide plates 3347 and 3348. As shown in FIG. 7, the cover 338 is 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 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 upper surface of the base 311. The frame part 312 is attached to the base 311. In this way, the support part 31 is prepared. Alternatively, the support part 31 may be prepared with the frame part 312 attached to the base 311 in advance, and the air conditioner 2 may be placed on the upper surface of the base 311 on the support part 31.

[0089] The return air duct section 32 and the supply air duct section 33 are attached to the air conditioner 2, and the return air duct section 32 and the supply air duct section 33 are supported by the support section 31 as shown in FIG. 1C and FIG. 1D. 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 connection 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 connection pipe 3351 is inserted into the supply air support frame 314, and the connection pipe 3351 and the supply connection 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 replacement air conditioning using replacement air conditioning system 1] In the replacement air conditioning system 1, as shown in Fig. 7, the cover 338 is removed from the front surface 3343. Before replacement air conditioning of the room is performed by the replacement air conditioning system 1, the cover 338 is attached to the front surface 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 sucked into the air conditioner 2 from the return air outlet 321 and the intake port 21. The sucked 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 region 3322.

[0091] When the temperature of the lower area falls to, for example, 26° C. or lower, cover 338 is removed from front surface 3343 as shown in Fig. 7. Then, the velocity of air supplied from air supply outlet 332 becomes lower than the velocity of air when cover 338 was removed from front surface 3343. Replacement air conditioning by replacement air conditioning system 1 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 a 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] The modified example of the duct unit and the replacement air conditioning system will be described below with reference to FIG. 8. FIG. 8 is a front view of the replacement air conditioning system of the modified example. As shown in FIG. 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 FIG. 1A). The second cover 34 is attached to the supports 3121 and 3122 (see FIG. 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 FIG. 1A). The third cover 35 covers a part of the vertical pipe 3364.

[0094] The modified example of the duct unit and the displacement air conditioning system will be described with reference to Figs. 9 and 10. Fig. 9 is a front view of the supply air secondary chamber and the cover located in the first position. Fig. 10 is a front view of the supply air secondary chamber and the cover located in the second position. As shown in Figs. 9 and 10, the cover 338 includes a plurality of horizontal plates 3381 and two vertical plates 3382. The plurality of horizontal plates 3381 have a lattice shape. The plurality of horizontal plates 3381 are located apart from each other in the height direction HD. Each of the plurality of 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 each other in the height direction HD. As shown in Fig. 9, when the cover 338 is in the first position, the supply air outlets 332 in the first region 3321 overlap with and close the horizontal plates 3381. That is, the cover 338 closes the supply air outlets 332 in the first region 3321. As shown in Fig. 10, when the cover 338 is in the second position, the supply air outlets 332 in the first region 3321 are open. In this modification, the cover 338 is disposed on the front surface 3343 regardless of whether the cover 338 is in the first position or the second position.

[0096] Although not shown, the supply air inlet 331 may be directly connected (connected) to the supply port 24. The return air outlet 321 may be directly connected (connected) 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 by the claims, not the above description, and 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 Fan 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 supply duct 331 Air intake 332 Air supply 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 Information board 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 3rd Cover DD Depth direction HD Height direction LD Horizontal 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 includes an air supply primary chamber located at a second end of the air supply main body that is closer to the air supply inlet, The air supply primary chamber is formed with the air supply inlet, a frame portion that supports the air supply primary chamber when the duct unit is attached to the air conditioner, When the duct unit is attached to the air conditioner, the frame portion is located above an upper surface of the air conditioner and includes an air supply support frame that is perpendicular to the height direction, The air intake primary chamber is disposed on the upper surface of the air intake support frame.

2. 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 return air main body includes 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 is formed with the return air inlet, The duct unit further includes a frame portion that supports the return air chamber when the duct unit is attached to the air conditioner, When the duct unit is attached to the air conditioner, the frame portion is located above the upper surface of the air conditioner and includes a return air support frame that is perpendicular to the height direction, a duct unit, the return air chamber being disposed on an upper surface of the return air support frame.

3. 3. 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.

4. 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.

5. 3. 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.

6. When the duct unit is attached to the air conditioner, the air supply main body is a vertical pipe extending in a height direction; an air intake secondary chamber connected to a lower end of the vertical pipe and located at a first end that is an end closer to the air intake outlet; a cross-sectional area of ​​an internal space of the air supply secondary chamber in a direction perpendicular to the height direction is larger than a cross-sectional area of ​​an internal space of the vertical pipe in the direction perpendicular to the height direction, 3. The duct unit according to claim 1, wherein the air supply outlet is formed in the air supply secondary chamber.

7. When the duct unit is attached to the air conditioner, the air supply secondary chamber is 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 duct unit according to claim 6 , wherein a lower end of the vertical pipe is connected to the rear portion.

8. the air supply secondary chamber includes a plate-like member having a plurality of through holes formed therein; The duct unit according to claim 7 , wherein the air supply outlets are the plurality of through holes.

9. 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 7 , wherein the front surface is formed of a plate-like member having a plurality of through holes formed therein.

10. The duct unit according to claim 6 , wherein the air supply secondary chamber has a rectangular parallelepiped shape.

11. The vertical pipe has an internal space whose cross-sectional area perpendicular to the height direction increases downward, The duct unit according to claim 7 , wherein a lower end of the vertical pipe is connected to the rear portion.

12. The duct unit according to claim 1 or 2, wherein the air supply duct portion further includes a cover that can open and close a first region that is a part of the air supply outlet.

13. The duct unit according to claim 2 , wherein the frame portion supports the primary air supply chamber when the duct unit is attached to the air conditioner.

14. 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; 3. The duct unit according to claim 1 or 2, 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