Air conditioner

Abstract

To suppress noise including not only noise generated on an outdoor unit side, but also noise generated when air passes through a duct and noise generated on an indoor unit side, during ventilation operation of an air conditioner.SOLUTION: An air conditioner 1 comprises a duct 60, an intake and exhaust fan 43, and a silencer 70. The duct 60 forms a transport path for air circulating between an outdoor unit 3 and an indoor unit 2. The intake and exhaust fan 43 circulates air in the duct 60. The silencer 70 is provided in the duct 60, and reduces sound propagating through the duct 60. The silencer 70 is also installed on the back surface of the indoor unit 2.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] This relates to an air conditioner in which an outdoor unit and an indoor unit are connected by a connecting pipe. [Background technology]

[0002] In recent years, air conditioners equipped with a ventilation function have become widespread. For example, the air conditioner disclosed in Patent Document 1 (JP Patent Publication 2004-69173 A) has a configuration in which an outdoor unit and an indoor unit are connected by a duct, and a ventilation fan mounted on the outdoor unit supplies outdoor air to the room or exhausts indoor air to the outside. Summary of the Invention [Problem to be solved by the invention]

[0003] In the above air conditioners, there is a risk that noise caused by the ventilation fan will propagate indoors through the duct, so a silencer is installed on the outdoor unit side to suppress the noise.

[0004] However, noise includes not only sound generated on the outdoor unit side, but also sound generated when air passes through the duct and sound generated on the indoor unit side, so there is a demand for soundproofing technology that can suppress noise including these sounds. [Means for solving the problem]

[0005] The air conditioner of a first aspect is an air conditioner in which an outdoor unit and an indoor unit are connected by a connecting pipe, and is provided with a duct, a fan, and a sound-reducing section. The duct forms a transport path for air circulating between the outdoor unit and the indoor unit. The fan circulates air within the duct. The sound-reducing section is provided in the duct and reduces sound propagating through the duct. The sound-reducing section is also installed on the rear surface of the indoor unit.

[0006] With this air conditioner, not only is sound transmitted through the duct to the indoor unit reduced, but sound transmitted through the duct with the indoor unit as the sound source is also reduced near the sound source, providing a high noise suppression effect.

[0007] An air conditioner according to a second aspect is the air conditioner according to the first aspect, wherein the sound reduction section is separable from the duct.

[0008] In this air conditioner, the sound reduction section and the duct are separate components, so that only the sound reduction section can be removed during maintenance, improving maintainability.

[0009] An air conditioner according to a third aspect is the air conditioner according to the first or second aspect, in which the sound reduction section is positioned outside the duct.

[0010] In this air conditioner, the internal space of the sound reduction section functions as an expansion chamber, attenuating the sound propagating through the duct.

[0011] An air conditioner according to a fourth aspect is the air conditioner according to the first or second aspect, wherein the sound reduction section is positioned inside the duct.

[0012] In this air conditioner, the sound reduction section fits inside the duct, making it suitable for installation in narrow spaces such as behind the indoor unit.

[0013] An air conditioner according to a fifth aspect is the air conditioner according to the first or second aspect, in which a duct is connected to one end or both ends of the sound reduction section. The cross-sectional area of ​​the air flow path in the sound reduction section is larger than the cross-sectional area of ​​the air flow path in the duct.

[0014] In this air conditioner, the internal space of the sound reduction section serves as an expansion chamber to attenuate sound.

[0015] An air conditioner according to a sixth aspect is the air conditioner according to any one of the first to fifth aspects, wherein the duct has a section extending from one end to the other end of a space sandwiched between opposing side surfaces of the indoor unit, and the sound reduction section is provided midway along the section.

[0016] In this air conditioner, sound that originates from the indoor unit as a sound source and propagates through the duct can be reduced near the sound source, thereby providing a high level of noise suppression effect.

[0017] An air conditioner according to a seventh aspect is the air conditioner according to any one of the first to fifth aspects, wherein the duct serves as both an intake duct and an exhaust duct. Air flows from the outdoor unit to the indoor unit through the intake duct. Air flows from the indoor unit to the outdoor unit through the exhaust duct.

[0018] In this air conditioner, the number of parts is reduced. [Brief description of the drawings]

[0019] [Figure 1] 1 is an external view of an air conditioner according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic diagram of an air conditioner. [Diagram 3] FIG. 2 is a schematic diagram of a humidification unit. [Figure 4] 4 is a diagram showing a schematic view of air flow passing through the moisture absorption rotor; FIG. [Diagram 5] FIG. 2 is a perspective view of the indoor unit as viewed from the rear. [Figure 6] FIG. 2 is a schematic cross-sectional view of the indoor unit. [Figure 7] FIG. 2 is a cross-sectional view along the longitudinal direction of the sound reducer. [Figure 8] 10 is a cross-sectional view taken along the longitudinal direction of a sound reducer according to a first modified example. FIG. [Figure 9] 13 is a cross-sectional view taken along the longitudinal direction of a sound reducer according to a second modified example. FIG. [Figure 10] FIG. 11 is a cross-sectional view taken along the longitudinal direction of a sound reducer according to a third modified example. [Figure 11A] FIG. 13 is a cross-sectional view taken along the longitudinal direction of a sound reducer according to a fourth modified example. [Figure 11B] FIG. 11B is a view taken along the arrow AA in FIG. 11A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] (1) Schematic configuration of air conditioner 1 Fig. 1 is an external view of an air conditioner 1 according to this embodiment. In Fig. 1, the air conditioner 1 is equipped with an indoor unit 2 and an outdoor unit 3. The indoor unit 2 is attached to a wall surface or the like inside a room, and the outdoor unit 3 is installed outside the room.

[0021] Fig. 2 is a schematic configuration diagram of an air conditioner 1. In Fig. 2, an indoor unit 2 and an outdoor unit 3 are connected by refrigerant pipes 31 and 32 to form a refrigerant circuit.

[0022] (1-1) Outdoor unit 3 The outdoor unit 3 has an air conditioning outdoor unit 5 and a humidifier unit 4. An air supply and exhaust duct 60 is provided between the outdoor unit 3 and the indoor unit 2. The duct 60 is used when supplying outdoor air and humidified air from the humidifier unit 4 to the indoor unit 2, and when exhausting indoor air to the outside.

[0023] The duct 60, together with a connection duct 61 provided so as to straddle the inside and outside of the outdoor unit 3, forms an air supply and exhaust path through which air passes.

[0024] (1-1-1) Air conditioning outdoor unit 5 1 and 2, the air conditioning outdoor unit 5 includes refrigerant circuit components and an outdoor casing 50 that houses the refrigerant circuit components.

[0025] 1, a cover 55 is attached to the right side plate 52 located on the right side of the outdoor casing 50. The cover 55 protects the liquid stop valve 27 and the gas stop valve .

[0026] The outdoor casing 50 accommodates a compressor 21, a four-way switching valve 22, an accumulator 23, an outdoor heat exchanger 24, and a motor-operated valve 25 as refrigerant circuit components.

[0027] The four-way switching valve 22 is connected to the discharge side of the compressor 21. The accumulator 23 is connected to the suction side of the compressor 21.

[0028] One end of the motor-operated valve 25 is connected to the outdoor heat exchanger 24 , and the other end is connected to one end of the indoor heat exchanger 11 via a filter 26 , a liquid shutoff valve 27 and a refrigerant pipe 32 .

[0029] In addition, the four-way switching valve 22 is connected to the other end of the indoor heat exchanger 11 via a gas shutoff valve 28 and a refrigerant piping 31.

[0030] The air conditioning outdoor unit 5 further has an outdoor fan 29. The outdoor fan 29 is a propeller fan, and is rotationally driven by an outdoor fan motor 29a. The outdoor fan 29 sends the air taken into the air conditioning outdoor unit 5 to the outdoor heat exchanger 24, and promotes heat exchange between the air and the refrigerant flowing inside the outdoor heat exchanger 24.

[0031] (1-1-2) Humidification unit 4 The humidification unit 4 has a humidification function, an air supply function, and an exhaust function. As shown in FIG. 2, the humidification unit 4 includes a moisture absorption rotor 41, a heater 42, an air supply / exhaust fan 43, a switching damper 44, and an adsorption fan 46.

[0032] The supply and exhaust fan 43 is disposed to the side of the moisture absorption rotor 41. The supply and exhaust fan 43 and the indoor unit 2 are connected by a connection duct 61 and a duct 60. The supply and exhaust fan 43 supplies air taken in from outside to the indoor unit 2. The supply and exhaust fan 43 also exhausts air sent from inside the room to the outside through an supply and exhaust port provided on the back of the humidification unit 4. A switching damper 44 switches between the supply and exhaust operations.

[0033] Fig. 3 is a schematic diagram of the humidification unit 4. Fig. 4 is a schematic diagram showing the flow of air through the moisture absorption rotor 41. In Fig. 3 and Fig. 4, for ease of explanation, the air passage from the adsorption suction port 40b to the adsorption fan 46 is called the moisture absorption passage X, the air passage from the air supply / exhaust port 40c to the heater 42 is called the heat extraction passage Y, and the air passage from the heater 42 to the air supply / exhaust fan 43 is called the humidification passage Z.

[0034] In the humidification unit 4, the adsorption fan 46 is operated to take in outdoor air from the adsorption inlet 40b into the moisture adsorption passage X. The air Ax flowing through the moisture adsorption passage X passes through the first region Rx of the moisture adsorption rotor 41 facing the moisture adsorption passage X, and the moisture in the air Ax is absorbed in the first region Rx.

[0035] The air Ax passes through the adsorption fan 46 and is discharged to the front of the outdoor unit 3 through the adsorption air outlet 40a.

[0036] Furthermore, the humidification unit 4 takes in outdoor air from the supply / exhaust port 40c into the heat extraction passage Y by rotating the supply / exhaust fan 43. The air Ay flowing through the heat extraction passage Y passes through a second region Ry of the moisture absorption rotor 41 facing the heat extraction passage Y, and is then heated by the heater 42. The air Ay is heated by the heater 42 and becomes high-temperature air Az, which flows into the humidification passage Z. The high-temperature air Az passes through a third region Rz of the moisture absorption rotor 41 facing the humidification passage Z, and flows into the connecting duct 61.

[0037] The air Ay flowing through the heat extraction passage Y recovers heat from the second region Ry of the moisture absorption rotor 41 as it passes through the second region Ry, increasing its temperature, and is then further heated by the heater 42 to become high-temperature air Az. The high-temperature air Az flowing through the humidification passage Z absorbs moisture from the third region Rz of the moisture absorption rotor 41 as it passes through the third region Rz.

[0038] 4, the moisture absorbent rotor 41 rotates in the direction indicated by the arrow D, and passes through the moisture absorbent passage X, the humidification passage Z, and the heat extraction passage Y in that order. As a result, in the moisture absorbent rotor 41, the first region Rx of the moisture absorbent rotor 41 facing the moisture absorbent passage X, the third region Rz of the moisture absorbent rotor 41 facing the humidification passage Z, and the second region Ry of the moisture absorbent rotor 41 facing the heat extraction passage Y move sequentially.

[0039] The moisture adsorbed by the moisture adsorption rotor 41 from the air Ax in the moisture adsorption passage X is released by the high-temperature air Az heated by the heater 42, and the high-temperature air Az is humidified.

[0040] The supply and exhaust fan 43 sends the air that has passed through the moisture absorption rotor 41 to the indoor unit 2 via the supply and exhaust path. The air sent to the indoor unit 2 contains the moisture that was adsorbed by the moisture absorption rotor 41.

[0041] The air thus supplied from the humidifying unit 4 to the indoor unit 2 passes through the indoor heat exchanger 11 and is blown out into the room.

[0042] Moreover, by not operating the adsorption fan motor 46a or the heater 42, the air conditioner 1 can only supply air, taking in outdoor air without humidifying it and sending it to the indoor unit 2. The air conditioner 1 can also only exhaust indoor air to the outside.

[0043] (1-2) Indoor unit 2 Fig. 5 is a perspective view of the indoor unit 2 as viewed from the back, and Fig. 6 is a schematic cross-sectional view of the indoor unit 2. In Figs. 5 and 6, the indoor unit 2 includes an indoor heat exchanger 11, an indoor fan 12, a casing 14, an air filter 13, a drain pan 16, a horizontal flap 17, a humidifying duct 18, and a frame 19.

[0044] The indoor heat exchanger 11 is a fin-and-tube type heat exchanger having a heat transfer tube and a plurality of fins. The indoor heat exchanger 11 is disposed upstream of the indoor fan 12. The indoor fan 12 is a cross-flow fan, configured in a cylindrical shape, and provided with a large number of blades on its circumferential surface. The indoor fan 12 is driven to rotate by an indoor fan motor 12a, sucks indoor air into the interior of the indoor unit 2, and blows out the air into the room after heat exchange with the indoor heat exchanger 11. The drain pan 16 is disposed below the indoor heat exchanger 11. During cooling operation or dehumidification operation, condensation generated in the indoor heat exchanger 11 is received by the drain pan 16.

[0045] An intake port 14d and an exhaust port 14e are formed in the casing 14. In the air flow path from the intake port 14d to the exhaust port 14e, an air filter 13, an indoor heat exchanger 11, and an indoor fan 12 are arranged in this order from upstream.

[0046] A horizontal flap 17 is disposed at the air outlet 14e. The horizontal flap 17 changes the direction of the air blown out from the air outlet 14e to up or down.

[0047] The humidifying duct 18 passes between the inner surface of the side surface 14a of the casing 14 and the longitudinal end of the indoor heat exchanger 11, and is disposed so that its air outlet faces the indoor heat exchanger 11. During ventilation operation, the humidifying operation is stopped, and outside air is supplied from the humidifying unit 4 via the connecting duct 61, the duct 60, and the humidifying duct 18. When the indoor unit 2 is performing a humidifying operation, humidified outside air is blown out from the humidifying unit 4 via the connecting duct 61, the duct 60, and the humidifying duct 18.

[0048] 5 and 6, the frame 19 separates the indoor heat exchanger 11, the indoor fan 12, etc. into a front space, in which the indoor heat exchanger 11, the indoor fan 12, etc. are housed, from a rear space through which the duct 60 is routed. The rear space is formed by inclining the frame 19 from the center to the bottom end so that it bites into the front space.

[0049] (1-3) Sound attenuator 70 The air conditioner 1 further includes a sound reducer 70. The sound reducer 70 reduces a target sound by using a sound reducing structure or a sound reducing material, and is generally also called a muffler or silencer.

[0050] The sound reducer 70 is disposed on the rear surface of the indoor unit 2 in a state where it is connected to the duct 60, as shown in FIG.

[0051] Specifically, the sound reducer 70 is installed in the rear space of the casing 14 with one end connected to the end of the humidification duct 18 and the other end connected to the duct 60. In the present application, the sound reducer 70 mainly reduces the sound propagating through the duct 60.

[0052] 5, the duct 60 has a section 600 extending from one end to the other end of a space sandwiched between the opposing side surfaces 14a, 14b of the indoor unit 2. The sound reducer 70 is provided in the section 600.

[0053] Since the sound reducer 70 can be lengthened within the range that fits within the section 600, the longer it is set to be in the longitudinal direction, the greater the sound reduction effect becomes.

[0054] (2) Configuration of sound reducer 70 Fig. 7 is a cross-sectional view taken along the longitudinal direction of the sound reducer 70. In Fig. 7, the sound reducer 70 has a cylindrical outer shape. The sound reducer 70 has a casing 701 and a sound absorbing material 702.

[0055] (2-1) Casing 701 The casing 701 includes a first end 701a, a second end 701b, and a body 701c. The first end 701a, the second end 701b, and the body 701c are cylindrical. The first end 701a and the second end 701b protrude from the end face of the body 701c, and have an outer diameter smaller than that of the body 701c.

[0056] Since the first end 701a is connected to one end of the humidification duct 18, the first end 701a becomes the air outlet side of the sound reducer 70 during air supply, and the second end 701b becomes the air inlet side. Conversely, the first end 701a becomes the air inlet side of the sound reducer 70 during air exhaust, and the second end 701b becomes the air outlet side. The first end 701a and the second end 701b are inserted into the duct 60.

[0057] (2-2) Sound absorbing material 702 Sound absorbing material 702 is disposed inside casing 701. Sound absorbing material 702 is formed in a cylindrical shape. Sound absorbing material 702 has a through hole 702a with a circular cross section in the center. Through hole 702a is connected to duct 60. Air passes through through hole 702a when air is supplied or exhausted. Felt, urethane foam, etc. can be used as the material for sound absorbing material 702.

[0058] (2-3) Noise reduction effect of sound reducer 70 In the air conditioner 1 that sends outdoor air to the indoor unit 2, noise is generated in the supply and exhaust fan 43 that sends air to the indoor unit 2. This sound may propagate through the duct 60 and leak from the indoor unit 2 into the room.

[0059] However, in this air conditioner 1, the sound generated by the supply and exhaust fan 43 is reduced by the sound reducer 70 provided on the back of the indoor unit 2 before it propagates indoors. The sound that enters the body 701c of the sound reducer 70 vibrates the sound absorbing material 702, converting the sound pressure into thermal energy, thereby achieving a sound-reduction effect. In addition, some of the sound travels while being reflected. In this way, while passing through the body 701c, the sound is reduced by the sound absorbing material 702, or is attenuated by repeated reflections. Therefore, in this air conditioner 1, the sound that travels from the outdoor unit 3 to the indoors is reduced.

[0060] (3) Features (3-1) In the air conditioner 1, a sound reducer 70 is provided in a duct 60, which is a transport path for air circulating between the outdoor unit 3 and the indoor unit 2. Since the sound reducer 70 is installed on the rear surface of the indoor unit 2, not only is the sound propagating to the indoor unit 2 via the duct 60 reduced, but also the sound propagating through the duct 60 with the indoor unit 2 as the sound source is reduced near the sound source. This provides a high effect in suppressing noise.

[0061] (3-2) In the air conditioner 1, the noise reducer 70 and the duct 60 are separate members, so that only the noise reducer 70 can be removed during maintenance, improving maintainability.

[0062] (3-3) In the air conditioner 1, the duct 60 is connected to one or both ends of the sound reducer 70, and the cross-sectional area of ​​the air flow path in the sound reducer 70 is larger than the cross-sectional area of ​​the air flow path in the duct 60.

[0063] (3-4) In the air conditioner 1, the duct 60 has a section 600 that extends from one end to the other end of the space sandwiched between the opposing side surfaces 14a and 14b of the indoor unit 2. The sound reducer 70 is provided in this section 600. Therefore, sound propagating through the duct 60 with the indoor unit 2 as the sound source is reduced near the sound source, resulting in a high noise suppression effect.

[0064] (3-5) In the air conditioner 1, the duct 60 serves as both an air supply duct and an exhaust duct, which contributes to a reduction in the number of parts.

[0065] (4) Modified sound reducer 7 uses a sound absorbing material 702, but is not limited to this. Below, the structures and sound reduction principles of modified sound reducers will be briefly described with reference to the drawings.

[0066] (4-1) First Modification Fig. 8 is a cross-sectional view along the longitudinal direction of a sound reducer 70' according to a first modified example. In Fig. 8, sound reducer 70' has the same configuration as sound reducer 70 in Fig. 7, except that sound absorbing material 702 is not built into the inside of casing 701.

[0067] The cross-sectional area of ​​the air flow path in the body 701c is larger than that of the duct 60, so the body 701c functions as an expansion chamber. Since sound is reflected at the point where the space expands / contracts, it interferes within the body 701c, resulting in a sound reduction effect. Therefore, in this air conditioner 1, the sound transmitted from the outdoor unit 3 to the room is reduced.

[0068] (4-2) Second Modification Fig. 9 is a cross-sectional view along the longitudinal direction of a sound reducer 71 according to a second modified example. In Fig. 9, sound reducer 71 is attached to the outer periphery of duct 60. A plurality of through holes 601 are provided in the portion of the outer periphery of duct 60 where sound reducer 71 is attached. Sound reducer 70 has a casing 711 and a sound absorbing material 712.

[0069] (4-2-1) Casing 711 The casing 711 includes a first end 711a, a second end 711b, and a body 711c. The first end 711a, the second end 711b, and the body 711c are cylindrical. The first end 711a and the second end 711b protrude from the end face of the body 711c, and the outer diameters thereof are smaller than that of the body 711c. The inner diameters of the first end 711a and the second end 711b are finished so as to fit with the outer diameter of the duct 60.

[0070] (4-2-2) Sound-absorbing material 712 Sound absorbing material 712 is disposed inside casing 711. Sound absorbing material 712 is formed in a cylindrical shape so as to surround duct 60. Therefore, sound absorbing material 712 has a through hole with a circular cross section formed in the center. The inner diameter of the through hole is finished to be equal to the inner diameters of first end 711a and second end 711b. Felt, urethane foam, etc. can be used as the material for sound absorbing material 702.

[0071] (4-2-3) Noise reduction effect of sound reducer 71 Sound waves propagating through duct 60 enter body 711c of sound reducer 70 from through-hole 601, vibrating sound-absorbing material 712 and converting sound pressure into thermal energy, thereby achieving a sound-reduction effect. While passing through duct 60 covered by body 711c, sound waves are silenced by sound-absorbing material 712. Therefore, in this air conditioner 1, the sound transmitted from the outdoor unit 3 to the room is reduced.

[0072] As described above, in the air conditioner 1 according to the second modified example, the sound reducer 71 is positioned outside the duct 60 and attenuates the sound propagating through the duct 60.

[0073] (4-3) Third Modification Fig. 10 is a longitudinal cross-sectional view of a sound reducer 71' according to a third modified example. In Fig. 10, sound reducer 71' has the same configuration as sound reducer 71 in Fig. 9, except that sound absorbing material 712 is not built into the inside of casing 711.

[0074] The sound propagating through the duct 60 is attenuated and reduced by interference when it enters the body 711c of the sound reducer 71' from the through hole 6a. In addition, resonance occurs between the duct 60 and the body 711c, creating a sound-deadening effect. Therefore, in this air conditioner 1, the sound transmitted from the outdoor unit 3 to the room is reduced.

[0075] As described above, in the air conditioner 1 according to the third modified example, the sound reducer 71' is located outside the duct 60, and the internal space of the sound reducer 71' functions as an extension chamber. Therefore, the sound propagating through the duct 60 is attenuated.

[0076] (4-4) Fourth Modification Fig. 11A is a cross-sectional view along the longitudinal direction of sound absorber 72 according to the fourth modified example. Fig. 11B is a view taken along the line AA in Fig. 11A. In Figs. 11A and 11B, sound absorber 72 is formed by closely contacting the outer peripheral surface of cylindrical sound absorbing material 722 with the inner peripheral surface of duct 60. Sound absorbing material 722 has through hole 722a with a circular cross section at its center. Air passes through through hole 722a when air is supplied or exhausted. Felt, urethane foam, etc. can be used as the material for sound absorbing material 722.

[0077] The sound propagating through the duct 60 and entering the sound attenuator 72 vibrates the sound absorbing material 722, converting the sound pressure into thermal energy. This provides a sound deadening effect. Also, part of the sound is attenuated as it is repeatedly reflected. Therefore, the sound propagating through the duct 60 is attenuated.

[0078] Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure described in the claims. [Explanation of symbols]

[0079] 1. Air conditioner 2 Indoor unit 3 Outdoor unit 14a Side 14b Side 30 Connecting piping 43 Intake and exhaust fan (fan) 60 Duct 70 Sound attenuator (sound attenuator) 70´ Sound attenuator (sound attenuator) 71 Sound attenuator (sound attenuator) 71´ Sound attenuator (sound attenuator) 72 Sound attenuator (sound attenuator) 600 Sections [Prior art documents] [Patent documents]

[0080] [Patent Document 1] JP 2004-69173 A

Claims

1. An air conditioner in which an outdoor unit (3) and an indoor unit (2) are connected by a connecting pipe (30), A duct (60) that forms a transport path for air flowing between the outdoor unit (3) and the indoor unit (2); A fan (43) for circulating air through the duct (60); A sound reduction section (70) provided in the duct (60) for reducing sound propagating through the duct (60); Equipped with The sound reduction unit is installed on the rear surface of the indoor unit (2). Air conditioner (1).

2. The sound-reducing portion (70) is separable from the duct (60). An air conditioner (1) as claimed in claim 1.

3. The sound reducing portion (70) is located outside the duct (60). An air conditioner (1) according to claim 1 or claim 2.

4. The sound reducing section (70) is located inside the duct (60). An air conditioner (1) according to claim 1 or claim 2.

5. The duct (60) is connected to one end or both ends of the sound reducing section (70), The cross-sectional area of ​​the air flow path in the sound reducing section (70) is larger than the cross-sectional area of ​​the air flow path in the duct (60). An air conditioner (1) according to claim 1 or claim 2.

6. The duct (60) has a section (600) extending from one end to the other end of a space sandwiched between both opposing side surfaces (14a, 14b) of the indoor unit (2), The sound reducing section (70) is provided midway through the section (600). An air conditioner (1) according to claim 1 or claim 2.

7. The duct (60) an air supply duct through which air passes from the outdoor unit (3) to the indoor unit (2); an exhaust duct through which air passes from the indoor unit (2) to the outdoor unit (3); Also serves as An air conditioner (1) according to claim 1 or claim 2.

Images