Air conditioner

Abstract

This air conditioner comprises: a housing; a drain pan that is provided to the housing and receives drain water generated inside of the housing; a discharge device that is provided to the housing, has a drain port formed therein, and drains, through the drain port, the drain water collected in the drain pan; a water level detection device that detects that the drain water has reached a set water level above the drain port of the discharge device; and a control device. The water level detection device detects a plurality of set water levels, and the control device determines the presence or absence of a discharge failure of the discharge device on the basis of the amount of time until the water level detection device detects that the drain water has reached a set water level.

Description

air conditioner

[0001] The present disclosure relates to an air conditioner.

[0002] Conventionally, air conditioners that detect poor drainage are known. Poor drainage can occur, for example, due to a drain pipe clogged with biofilm or a pump malfunction in the drain device that discharges the drain water. When poor drainage occurs, the drain water level in the drain pan rises. Air conditioners are configured to stop operation when the drain water reaches a predetermined level in the drain pan. Therefore, when poor drainage occurs and the drain water level rises and reaches the predetermined level, the air conditioner is forced to shut down. In this case, unexpected maintenance, such as cleaning the drain pan and drain pipe, is required.

[0003] Therefore, a technology is known that detects the drain water level before the air conditioner is forced to stop operating, thereby alerting the user to the occurrence of a drainage problem. Patent Document 1 discloses an air conditioner with an ultrasonic water level detector installed above the drain pan. Patent Document 1 also discloses an air conditioner with a capacitance water level detector installed on the outer wall side of the drain pan. Both of these water level detectors detect continuous changes in the water level without contact.

[0004] Japanese Patent Application Laid-Open No. 2008-96002

[0005] In Patent Document 1, the occurrence of drainage failure is determined by continuously detecting the water level while the drain device is operating. Therefore, there is room for a simpler method to determine the occurrence of drainage failure.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an air conditioner that can determine whether or not a discharge failure has occurred in the discharge device in a simple manner.

[0007] The air conditioner of the present disclosure comprises a housing, a drain pan provided in the housing for receiving drain water generated inside the housing, a discharge device provided in the housing with a drain outlet formed therein for discharging drain water accumulated in the drain pan from the drain outlet, a water level detection device for detecting whether the drain water has reached a set water level above the drain outlet of the discharge device, and a control device, wherein the water level detection device detects multiple set water levels, and the control device determines whether or not the discharge device is failing to discharge properly based on the time it takes for the water level detection device to detect that the drain water has reached the set water level.

[0008] According to the present disclosure, the control device determines whether or not a discharge failure has occurred in the discharge device based on the time it takes for the water level detection device to detect that the drain water has reached a set water level. This allows the air conditioner to easily determine whether or not a discharge failure has occurred in the discharge device.

[0009] 1 is a refrigerant circuit diagram showing an air conditioner according to embodiment 1. FIG. 2 is a hardware configuration diagram of a control device according to embodiment 1. FIG. 3 is a schematic diagram showing the internal configuration of an indoor unit according to embodiment 1. FIG. 4 is a schematic diagram showing a water level detection device according to embodiment 1. FIG. 5 is a table for explaining the relationship between the detection pattern of the water level detection device according to embodiment 1 and the liquid level. FIG. 6 is a flowchart showing the operation of the control device according to embodiment 1. FIG. 7 is a diagram for explaining water level changes when drain water remains at the start of operation in embodiment 1. FIG. 8 is a diagram for explaining water level changes when no drain water remains at the start of operation in embodiment 1. FIG. 9 is an explanatory diagram showing water level changes when the drain water level decreases over time after operation of the air conditioner 1 is stopped in embodiment 1. FIG. 10 is a schematic diagram showing a water level detection device according to embodiment 2. FIG. 11 is a schematic diagram showing a water level detection device according to embodiment 3. FIG. 12 is a table for explaining the relationship between the detection pattern of the water level detection device according to embodiment 3 and the liquid level.

[0010] Hereinafter, an embodiment of an air conditioner 1 according to the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the embodiment described below. In addition, the dimensional relationships between components in the following drawings, including FIG. 1, may differ from the actual relationships. In addition, in the following description, terms indicating directions will be used as appropriate to facilitate understanding of the present disclosure. However, these terms are for the purpose of explaining the present disclosure and do not limit the present disclosure.

[0011] Embodiment 1. Figure 1 is a refrigerant circuit diagram showing an air conditioner 1 according to embodiment 1. The air conditioner 1 is a device that adjusts the temperature of air in an indoor space, and as shown in Figure 1, includes an outdoor unit 2 and an indoor unit 3. The outdoor unit 2 includes a compressor 5, a flow switching device 6, an outdoor heat exchanger 7, an outdoor blower 8, and an expansion valve 9. The indoor unit 3 includes an indoor heat exchanger 10, an indoor blower 11, a humidifier 12, and a control device 30.

[0012] A refrigerant circuit is formed by connecting a compressor 5, a flow switching device 6, an outdoor heat exchanger 7, an expansion valve 9, and an indoor heat exchanger 10 via refrigerant piping. The compressor 5 draws in low-temperature, low-pressure refrigerant, compresses it, and discharges it as high-temperature, high-pressure refrigerant. The compressor 5 is, for example, an inverter compressor with controllable capacity. The flow switching device 6 switches the direction of refrigerant flow in the refrigerant circuit and is, for example, a four-way valve. The outdoor heat exchanger 7 exchanges heat between, for example, outdoor air and the refrigerant. The outdoor heat exchanger 7 functions as a condenser during cooling operation and as an evaporator during heating operation. The expansion valve 9 is, for example, an electronic expansion valve with an adjustable opening, which reduces the pressure of the refrigerant and expands it.

[0013] The air conditioner 1 does not necessarily have to have the flow path switching device 6. In this case, the air conditioner 1 becomes a dedicated cooling machine or a dedicated heating machine.

[0014] The indoor heat exchanger 10 exchanges heat between, for example, indoor air and a refrigerant. The indoor heat exchanger 10 functions as an evaporator during cooling operation and as a condenser during heating operation. The indoor blower 11 is a device that sends indoor air to the indoor heat exchanger 10. The humidifier 12 humidifies the air blown out from the indoor unit 3. The humidifier 12 may be, for example, a steam type that heats water and humidifies it with steam, an evaporation type that humidifies it by blowing air over a filter containing water, or an ultrasonic type that converts water into fine particles using ultrasonic vibrations and releases them into the air, or a combination of these types.

[0015] The control device 30 controls the operation of the air conditioner 1. As will be described in detail later, the control device 30 determines whether or not a drainage problem has occurred inside the indoor unit 3 based on the detection results of the water level detection device 50. Here, the hardware configuration of the control device 30 will be described. FIG. 2 is a hardware configuration diagram of the control device 30 according to the first embodiment. The control device 30 includes, for example, a processor 71 such as a CPU and a memory 72. The processor 71 and the memory 72 are connected by a bus 73. The memory 72 may be a non-volatile or volatile semiconductor memory, or a removable recording medium. The control device 30 may also be configured using hardware such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0016] Returning to FIG. 1 , the air conditioner 1 has a display device 40 provided outside the outdoor unit 2 and the indoor unit 3. The display device 40 is, for example, a display provided on a remote control (not shown) for operating the indoor unit 3. The display device 40 displays whether or not there is a drainage problem occurring inside the indoor unit 3 based on instructions from the control device 30. The display device 40 may be a display medium on a cloud server. The display device 40 may also be a display provided separately from the remote control, or may indicate whether or not there is a drainage problem using an LED lamp or other device other than a display.

[0017] Next, the internal configuration of the indoor unit 3 will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing the internal configuration of the indoor unit 3 according to Embodiment 1. As shown in Fig. 3, the indoor unit 3 has, in addition to the indoor heat exchanger 10, the humidifier 12, and the control device 30, a drain pan 21, a discharge device 22, a drain pipe 23, and a water level detection device 50. The indoor heat exchanger 10, the humidifier 12, the control device 30, the drain pan 21, the discharge device 22, the drain pipe 23, and the water level detection device 50 are stored inside a housing 20 that forms the outer shell of the indoor unit 3.

[0018] The drain pan 21 is a dish-shaped container that receives drain water D generated inside the housing 20. The drain water D is, for example, condensed water generated in the indoor heat exchanger 10 and the humidifier 12. The drain pan 21 is, for example, approximately 50 mm deep, and is sloped so that its bottom becomes deeper toward the position facing the discharge device 22. This allows condensed water that falls into the drain pan 21 to be collected in the discharge device 22. The drain pan 21 is also recessed in a portion facing the drain outlet 22a of the discharge device 22. This recess is the deepest part of the drain pan 21. The drain pan 21 is provided below the indoor heat exchanger 10 and the humidifier 12.

[0019] The discharge device 22 is a pump that drains drain water D accumulated in the drain pan 21 and is provided above the drain pan 21. When the discharge device 22 is driven, the drain water D is sucked into the discharge device 22 and discharged from the inside of the discharge device 22 to the drain pipe 23. A drain outlet 22a is formed in the lower part of the discharge device 22. The drain outlet 22a is an opening through which the drain water D passes. When the water level of the drain water D accumulated in the drain pan 21 reaches a position higher than the position of the drain outlet 22a, the discharge device 22 drains the drain water D from the drain outlet 22a. The drain outlet 22a is disposed opposite a central depression of the drain pan 21. This allows the drain outlet 22a to be located at a shallow position without contacting the bottom portion of the drain pan 21, thereby enabling the drain water D collected near the discharge device 22 to be efficiently drained.

[0020] The drain pipe 23 is a pipe connected to the discharge device 22, and the outlet end is arranged outside the indoor unit 3. The drain water D discharged from the discharge device 22 flows inside the drain pipe 23 and is discharged outside the indoor unit 3.

[0021] The humidifier 12 is attached to, for example, a wall surface of the housing 20 .

[0022] The water level detection device 50 detects the water level of the drain water D at the location where it is installed. The water level detection device 50 is a float switch type (ON / OFF state switch) that uses two reed switches. The water level detection device 50 uses the two reed switches to detect when the drain water D has reached a set water level. The specific structure of the water level detection device 50 will be described later.

[0023] The water level detection device 50 is disposed adjacent to the discharge device 22 above the inclined portion of the drain pan 21. The water level detection device 50 is disposed within a range where the depth of the drain pan 21 is equal to or greater than a predetermined depth, excluding the recess facing the drain outlet 22a of the discharge device 22. As described above, because the bottom of the drain pan 21 is inclined, the deeper the drain pan 21, the greater the change in water level. By limiting the depth at which the water level detection device 50 is disposed to a depth equal to or greater than a predetermined depth, accurate water level measurement is possible. Furthermore, the possible locations for the water level detection device 50 exclude areas that do not collect drain water D to be drawn into the discharge device 22. This allows the water level detection result to be considered to reflect the discharge status of the drain water D by the discharge device 22. For example, the water level detection device 50 can be disposed along the path of drain water D flowing from the indoor heat exchanger 10 or the humidifier 12 toward the recess in the drain pan 21, as the target for water level detection. The water level detection device 50 transmits the detection result to the control device 30 .

[0024] FIG. 4 is a schematic diagram showing a water level detection device 50 according to the first embodiment. As shown in FIG. 4, the water level detection device 50 includes a float 51, a support 52, a first magnet 53a, a second magnet 53b, a first detection unit 54a, a second detection unit 54b, and side plates 55a and 55b. The float 51 is, for example, a cylindrical structure and is located at the bottom of the water level detection device 50. The water level detection device 50 includes a single float 51. The float 51 floats on drain water stored in the drain pan 21. To float on drain water, the float 51 may be hollow or may be made of a material with a density lower than that of water.

[0025] The support 52 is a frame-shaped structure whose lower end is fixed to the upper surface of the float 51. The support 52 supports the first magnet 53a and the second magnet 53b. The support 52 consists of rod-shaped vertical shafts 52a and 52b, an upper horizontal shaft 52c, and a lower horizontal shaft 52d. The vertical shafts 52a and 52b extend vertically, and their lower ends are fixed to the outer periphery of the float 51. The vertical shafts 52a and 52b face each other across the center on the upper surface of the float 51. The upper horizontal shaft 52c of the float 51 extends horizontally and connects the upper end of the vertical shaft 52a to the upper end of the vertical shaft 52b. The lower horizontal shaft 52d of the float 51 extends horizontally and connects the lower part of the vertical shaft 52a to the lower part of the vertical shaft 52b.

[0026] The first magnet 53a is provided on the upper horizontal shaft portion 52c, and the second magnet 53b is provided on the lower horizontal shaft portion 52d.

[0027] The first and second detection units 54a, 54b are magnetic detection elements such as reed switches. The first and second detection units 54a, 54b each have a rectangular parallelepiped shape that is elongated in the vertical direction. The first and second detection units 54a, 54b are located in an area surrounded by the vertical shafts 52a, 52b, the upper horizontal shaft 52c, and the lower horizontal shaft 52d of the support body 52. ​​The first and second detection units 54a, 54b are connected to each other. The first and second detection units 54a, 54b are arranged side by side in the vertical direction, with the first detection unit 54a located above the second detection unit 54b.

[0028] The first detection unit 54a faces the first magnet 53a in the vertical direction. When the first detection unit 54a is close to the first magnet 53a and is affected by the magnetic force from the first magnet 53a, the contacts of the first detection unit 54a are in the ON state (closed). On the other hand, when the first detection unit 54a is far from the first magnet 53a and is not affected by the magnetic force from the first magnet 53a, the contacts of the first detection unit 54a are in the OFF state (open). The first detection unit 54a has an internal switch portion (not shown) and a case that covers the switch portion to prevent the switch portion from being exposed and forms an outer shell.

[0029] The second detection unit 54b faces the second magnet 53b in the vertical direction. When the second detection unit 54b is close to the second magnet 53b and is affected by the magnetic force from the second magnet 53b, the contacts of the second detection unit 54b are in the ON state (closed). On the other hand, when the second detection unit 54b is far from the second magnet 53b and is not affected by the magnetic force from the second magnet 53b, the contacts of the second detection unit 54b are in the OFF state (open). The second detection unit 54b has an internal switch portion (not shown) and a case that covers the switch portion to prevent the switch portion from being exposed and forms an outer shell.

[0030] The side plates 55a and 55b are vertically thin plate-like structures that protrude horizontally from the case of the second detection unit 54b. The side plates 55a and 55b protrude in opposite directions in the horizontal direction. Although not shown, the case of the second detection unit 54b is fixed to the housing 20 via the side plates 55a and 55b. Therefore, when the drain water level changes, the positions of the first detection unit 54a and the second detection unit 54b do not change. On the other hand, the float 51 and the first magnet 53a and the second magnet 53b, which are indirectly fixed to the float 51 via the support 52, change position in accordance with changes in the drain water level. At this time, the distance between the first detection unit 54a and the first magnet 53a and the distance between the second detection unit 54b and the second magnet 53b also change. The positional relationship between the first detector 54a and the second detector 54b and the first magnet 53a and the second magnet 53b is adjusted so that the contact state changes at a preset water level.

[0031] The float 51 provided at the bottom of the water level detection device 50 floats on the drain water, so that the support body 52, the first magnet 53a and the second magnet 53b, the first detection portion 54a and the second detection portion 54b, and the side plate portions 55a and 55b are all kept out of contact with the drain water remaining in the drain pan 21. In other words, only the float 51 comes into contact with the drain water.

[0032] FIG. 5 is a table illustrating the relationship between the detection pattern and the liquid level of the water level detection device 50 according to the first embodiment. As shown in FIG. 5, the first detection unit 54a switches its contact when the drain water level is at a set water level L1. The contact of the first detection unit 54a is in an ON state when the water level is below the set water level L1 and is in an OFF state when the water level is equal to or greater than the set water level L1. On the other hand, the second detection unit 54b switches its contact when the drain water level is at a set water level L2. The contact of the second detection unit 54b is in an ON state when the water level is above the set water level L2 and is in an OFF state when the water level is equal to or less than the set water level L2. Here, the set water level L1 is set at a position higher than the drain outlet 22a of the discharge device 22, and the set water level L2 is set at a position higher than the set water level L1. The position of the set water level L2 is not particularly limited as long as it is equal to or less than the depth of the drain pan 21.

[0033] When the drain water level is shallower than the set water level L1, the float 51 and the first and second magnets 53a and 53b are located at a relatively low level. At this time, the contacts of the first detector 54a are in the ON state, and the contacts of the second detector 54b are in the OFF state. On the other hand, when the drain water level is deeper than the set water level L2, the float 51 and the first and second magnets 53a and 53b are located at a relatively high level. At this time, the contacts of the first detector 54a are in the OFF state, and the contacts of the second detector 54b are in the ON state. Furthermore, when the drain water level is above the set water level L1 and below the set water level L2, the float 51 and the first and second magnets 53a and 53b are located at a medium height. At this time, the contacts of the first detector 54a are in the OFF state, and the contacts of the second detector 54b are in the OFF state. In this way, the water level detection device 50 can detect when the drain water has reached a set water level. Furthermore, the water level detection device 50 can detect the drain water level in three stages by combining the connection states of the first detection unit 54a and the second detection unit 54b.

[0034] Returning to FIG. 3 , the control device 30 includes a water level output unit 31, a determination unit 32, and a transmission unit 33. The water level output unit 31, the determination unit 32, and the transmission unit 33 are realized by the processor 71 reading and executing a program stored in the memory 72. The water level output unit 31 receives the detection result of the water level detection device 50 and outputs it to the determination unit 32. The determination unit 32 determines whether a discharge failure, which reduces the discharge capacity of the discharge device 22, has occurred based on the output of the water level output unit 31. For example, if the water level output unit 31 outputs a signal indicating that a predetermined determination time has elapsed with the drain water D reaching the set water level, the determination unit 32 determines that a discharge failure has occurred in the discharge device 22. Furthermore, if the rate of change of the water level calculated from the output of the water level output unit 31 is less than a predetermined rate, the determination unit 32 determines that a discharge failure has occurred in the discharge device 22.

[0035] The transmitting unit 33 transmits the determination result of the determining unit 32 to an external display device 40. By checking the display device 40, the user can recognize whether or not a discharge problem has occurred. If a discharge problem has occurred, the user can carry out maintenance in accordance with the usage status of the air conditioner 1. Note that if the display device 40 is a display medium on a cloud server, the transmitting unit 33 may store the time when the discharge problem occurred in association with the water level data at that time.

[0036] (Causes of Poor Discharge) One example of a cause of poor discharge is biofilm B. Biofilm B, also known as slime, is a complex aggregate of bacteria or mold, sticky polysaccharides metabolized by bacteria or mold, and airborne contaminants. Because biofilm B is viscous, if it adheres to and accumulates on the walls of the discharge device 22, drain pipe 23, or drain pan 21, drainage of the drain water D becomes impossible. Furthermore, if drain water D adheres to the first magnet 53a, the second magnet 53b, the first detection unit 54a, or the second detection unit 54b, the viscosity of the biofilm B contained in the drain water D can impede the smooth movement of the first magnet 53a and the second magnet 53b when the first magnet 53a and the first detection unit 54a, or the second magnet 53b and the second detection unit 54b, come close to each other. In this case, the water level detection device 50 may be unable to accurately detect the water level. In the present disclosure, in order to prevent such a decrease in the detection accuracy of the water level detection device 50, the water level detection device 50 is configured so that the drain water D comes into contact only with the float 51. Therefore, even if a highly viscous biofilm B forms in the drain pan 21, the biofilm B will not adhere to the first detection unit 54a and the second detection unit 54b or the first magnet 53a and the second magnet 53b. Therefore, in the air conditioner 1 of embodiment 1, the movement of the first magnet 53a and the second magnet 53b in response to changes in the water level is not hindered, and therefore a decrease in the detection accuracy of the water level detection device 50 can be prevented.

[0037] Here, using Figure 6, an outline of the flow of operations related to determining whether drain water is being discharged properly in the air conditioner 1 and displaying this to the user will be explained. Figure 6 is a flowchart showing the operation of the control device 30 according to the first embodiment. As shown in Figure 6, first, the water level detection device 50 monitors changes in the water level. If the water level detection device 50 does not detect a change in the water level (step S1: NO), it waits until a change in the water level is detected. If a change in the water level is detected (step S1: YES), the water level detection device 50 transmits the detection result to the control device 30 (step S2). Note that the water level detection device 50 may be configured to transmit the water level detection status to the control device 30 at regular intervals, regardless of whether a change in the water level is detected.

[0038] When the water level output unit 31 of the control device 30 receives the detection result from the water level detection device 50, the determination unit 32 of the control device 30 determines whether or not a discharge failure has occurred based on the detection result (step S3). If the determination unit 32 determines that a discharge failure has occurred (step S3: YES), the transmission unit 33 of the control device 30 instructs the display device 40 to display that a discharge failure has occurred (step S4). The display device 40, having received the instruction from the transmission unit 33, displays that a discharge failure has occurred (step S5). If the determination unit 32 determines that a discharge failure has not occurred (step S3: NO), the series of operations ends. Note that the transmission unit 33 of the control device 30 may also instruct the display device 40 to display that a discharge failure has not occurred.

[0039] (Changes in Water Level) As will be described below, the water level in the drain pan 21 can change depending on the operating conditions of the air conditioner 1 or the installation environment of the air conditioner 1 (for example, temperature and humidity), regardless of whether or not there is a discharge problem, and it may be difficult to maintain a stable water level. The determination unit 32 determines whether or not a discharge problem has occurred using a number of methods depending on the operating conditions of the air conditioner 1 or the installation environment of the air conditioner 1. First, fluctuations in the water level in the drain pan 21 due to changes in the operating conditions of the air conditioner 1 will be described. First, during cooling operation, drain water is generated from the indoor heat exchanger 10 or the humidifier 12. At this time, drain water is discharged by the discharge device 22, but because drain water is constantly generated, drain water is always present in the drain pan 21 during cooling operation.

[0040] When the operation of the discharge device 22 stops as a result of the air conditioner 1 being shut down, the drain water that was present in the drain pipe 23 while it was being pumped back up flows back into the drain pan 21. As a result, the drain water that was present in the drain pipe 23 is added to the drain water that was originally present on the drain pan 21, causing the level of drain water on the drain pan 21 to rise. After the air conditioner 1 is shut down, the drain water on the drain pan 21 gradually evaporates. If the air conditioner 1 is not restarted for an extended period of time, no drain water will be present on the drain pan 21. For this reason, the state of the drain pan 21 at the start of cooling operation can be divided into two states: one in which drain water is present despite evaporation, and one in which drain water has completely evaporated and is no longer present.

[0041] (Method for determining whether a discharge failure has occurred when drain water remains at the start of operation) Next, a method for determining whether a discharge failure has occurred will be described for each water level state at the start of operation of the air conditioner 1. First, a method for determining whether a discharge failure has occurred when drain water remains at the start of operation will be described. For example, if the time between the previous shutdown of the air conditioner 1 and the start of the current cooling operation of the air conditioner 1 is short and not much drain water has evaporated, drain water will remain in the drain pan 21 at the start of operation. As a determination operation under such conditions, the determination unit 32 performs the following determination operation when the drain water level at the start of operation is equal to or higher than the set water level L1 (the contacts of the first detection unit 54a are in the OFF state).

[0042] FIG. 7 is a diagram illustrating the change in the water level when drain water remains at the start of operation in the first embodiment. Note that FIG. 7 illustrates an example in which the drain water level exceeds the set water level L2. After the start of cooling operation, the discharge device 22 operates to discharge the drain water. When no discharge failure occurs, the amount of drain water discharged by the discharge device 22 is equal to or exceeds the amount of condensed water generated by the indoor heat exchanger 10 and the humidifier 12. Therefore, after the start of cooling operation, the drain water level remains generally stable at the drain outlet 22a. That is, when no discharge failure occurs, the contact of the first detection unit 54a switches from the OFF state to the ON state and then remains in the ON state.

[0043] When a discharge failure occurs, the water level may change in one of three possible patterns. In the first pattern P1a, the drainage speed of the discharge device 22 decreases, and the stable water level becomes higher than the set water level L1. In the first pattern P1a, the time it takes for the contact of the second detection unit 54b to change from the ON state to the OFF state is longer than when a discharge failure does not occur. Therefore, the determination unit 32 detects a discharge failure according to the following method in accordance with the first pattern P1a. That is, the determination unit 32 measures the time Tc2 required for the contact of the second detection unit 54b to change from the ON state to the OFF state after the discharge device 22 starts operating. Furthermore, the determination unit 32 calculates the time Tc2s required for the contact of the second detection unit 54b to change from the ON state to the OFF state after the discharge device 22 starts operating when a discharge failure does not occur. The time Tc2s here is calculated when the operating conditions or the installation environment of the air conditioner 1, as acquired by various sensors (not shown), are the same as those at the time Tc2 is measured. For example, the time required for switching the second detection unit 54b measured during actual operation of the air conditioner 1 is linked to the operating conditions or the installation environment of the air conditioner 1 and stored in advance, and the time Tc2s is set from these measured times so that it matches the operating conditions or the installation environment of the air conditioner 1 during control. Alternatively, a time calculated in advance through an experiment or the like may be used as a candidate for the time Tc2s instead of the actually measured time. The determination unit 32 then compares the time Tc2 with the time Tc2s, and if the time Tc2 is longer than the time Tc2s (Tc2 > Tc2s), determines that a discharge failure has occurred. Furthermore, the determination unit 32 compares the time Tc2 with the time Tc2s, and if the length of the time Tc2 is equal to or shorter than the time Tc2s (Tc2≦Tc2s), determines that no discharge failure has occurred.

[0044] In the second pattern P2a, the drain water level is likely to rise because the discharge device 22 discharges zero drain water or the rate at which condensed water is generated from the indoor heat exchanger 10 and the humidifier 12 is greater than the rate at which the drain water is discharged by the discharge device 22. In the second pattern P2a, the output of the water level detection device 50 does not change. Therefore, the determination unit 32 determines that a drainage failure has occurred when the output of the water level detection device 50 does not change for a predetermined determination time corresponding to the second pattern P2a.

[0045] The third pattern P3a corresponds to a case in which the drainage capacity of the discharge device 22 is reduced, but the drain water is still discharged, and the drainage water level stabilizes at the drain outlet 22a after a longer period of time than when no discharge failure occurs. In the third pattern P3a, the time it takes for the contact of the first detection unit 54a to change from the ON state to the OFF state is longer than when no discharge failure occurs. Therefore, the determination unit 32 detects a discharge failure according to the third pattern P3a using the following method. Specifically, the determination unit 32 measures the time Tc1 required for the contact of the first detection unit 54a to change from the ON state to the OFF state after the discharge device 22 starts operating. Furthermore, the determination unit 32 calculates the time Tc1s required for the contact of the second detection unit 54b to change from the ON state to the OFF state after the discharge device 22 starts operating when no discharge failure occurs. The time Tc1s here is calculated when the operating conditions or the installation environment of the air conditioner 1 acquired by various sensors (not shown) are the same as those at the time Tc1 is measured. For example, the time required for switching the first detection unit 54a measured during actual operation of the air conditioner 1 is linked to the operating conditions or the installation environment of the air conditioner 1 and stored in advance, and the time Tc1s is set from these measured times so that the conditions match the operating conditions or the installation environment of the air conditioner 1 during control. Alternatively, a time calculated in advance through an experiment or the like may be used as a candidate for the time Tc1s instead of the actually measured time. The determination unit 32 then compares the time Tc1 with the time Tc1s, and if the time Tc1 is longer than the time Tc1s (Tc1 > Tc1s), determines that a discharge failure has occurred. Furthermore, the determination unit 32 compares the time Tc1 with the time Tc1s, and if the length of the time Tc1 is equal to or shorter than the time Tc1s (Tc1≦Tc1s), determines that no discharge failure has occurred.

[0046] (Detection of poor drainage when there is almost no drain water at the start of operation) Next, detection of poor drainage when there is almost no drain water at the start of operation will be described. For example, if there is a long period of time between the previous shutdown of the air conditioner 1 and the start of the current cooling operation of the air conditioner 1, the drain water in the drain pan 21 evaporates, leaving almost no drain water at the start of operation. As a determination operation under such conditions, the determination unit 32 performs the following determination operation when the drain water level at the start of operation is below the set water level L1 (the contacts of the first detection unit 54a are in the ON state).

[0047] FIG. 8 is a diagram illustrating the change in the water level when no drain water remains at the start of operation in the first embodiment. Note that FIG. 8 illustrates an example in which the drain water level is 0. After the start of cooling operation, the drain water is discharged when the drain water level reaches the height of the drain outlet 22a. When no discharge failure occurs, the amount of drain water discharged from the discharge device 22 is equal to or exceeds the amount of condensed water generated by the indoor heat exchanger 10 and the humidifier 12. Therefore, after the start of cooling operation, the drain water level is generally stable at the position of the drain outlet 22a. In other words, when no discharge failure occurs, the contact of the first detection unit 54a remains in the ON state.

[0048] If a discharge failure occurs, after the start of cooling operation, the discharge device 22 discharges no drain water, or the rate at which condensed water is generated from the indoor heat exchanger 10 and the humidifier 12 exceeds the rate at which the drain water is discharged. Therefore, as shown by the two dashed lines, condensed water generated from the indoor heat exchanger 10 and the humidifier 12 continues to accumulate in the drain pan 21, causing the drain water level to rise. As cooling operation continues, the drain water level eventually exceeds the set water level L1. Therefore, the determination unit 32 determines that a discharge failure has occurred if the time Tu1 required for the contact of the first detection unit 54a to change from the ON state to the OFF state after the discharge device 22 is operated is shorter than a predetermined time Tu1s (not shown). Furthermore, the determination unit 32 determines that a discharge failure has not occurred if the length of time Tu1 is equal to or longer than the predetermined time Tu1s. The time Tu1s is, for example, a time determined by experiments or the like for each operating state or installation environment of the air conditioner 1. The time Tu1s is set to a length that allows sufficient determination that a discharge failure has occurred when the time Tu1 falls below the time Tu1s.

[0049] Note that as cooling operation continues even after the drain water level exceeds the set water level L1, the drain water level eventually exceeds the set water level L2. Therefore, the determination unit 32 may determine that a discharge problem has occurred if the time Tu2 required from when the contact of the first detection unit 54a changes from an ON state to an OFF state until the contact of the second detection unit 54b changes from an OFF state to an ON state is shorter than a predetermined time Tu2s (not shown). In this case, the determination unit 32 determines that a discharge problem has not occurred if the length of time Tu2 is equal to or longer than the predetermined time Tu2s. The time Tu2s is, for example, a time determined by experiments or the like for each operating condition or installation environment of the air conditioner 1. The time Tu2s is set to a length sufficient to adequately determine that a discharge problem has occurred when the time Tu2 falls below the time Tu2s.

[0050] The determination unit 32 may also calculate whether or not a discharge failure has occurred based on the rate of rise of the water level instead of time Tu1 or time Tu2. In this case, the determination unit 32 calculates the rate of rise of the water level per unit time by dividing the difference in height between the set water level L2 and the set water level L1 by time Tu2. If the rate of rise of the water level is faster than a predetermined rate of rise, the determination unit 32 determines that a discharge failure has occurred.

[0051] (Detection of discharge failure after operation is stopped) Next, a description will be given of detection of the occurrence of discharge failure under conditions when operation of the air conditioner 1 is stopped. The determination unit 32 performs the following determination operation while the air conditioner 1 is stopped.

[0052] 9 is an explanatory diagram showing changes in the drain water level when the drain water level decreases over time after the air conditioner 1 is stopped in Embodiment 1. When the discharge device 22 stops operating as the air conditioner 1 is stopped, the drain water that was present in the drain pipe 23 during pumping flows back into the drain pan 21. As a result, the drain water that was present in the drain pipe 23 is added to the drain water that was accumulating on the drain pan 21 while the discharge device 22 was operating, and the drain water level in the drain pan 21 rises after the discharge device 22 is stopped.

[0053] When a drainage problem does not occur, the drain water level remains lower than the set water level L1 even after backflow occurs. Then, as time passes after the discharge device 22 is stopped, the drain water level decreases. Here, the decrease in the drain water level is due to evaporation of the drain water caused by the extended shutdown time of the air conditioner 1. As shown in FIG. 9 , the discharge device 22 may be operated independently of the air conditioner 1. In this case, the operation of the discharge device 22 may decrease the drain water level. The function of operating the discharge device 22 independently of the air conditioner 1 is intended to detect drainage problems in advance before the air conditioner 1 is operated. In this case, the time from when the air conditioner 1 is stopped to when the discharge device 22 alone starts operating is preset and stored in the control device 30. Apart from the example shown in FIG. 9 , when the air conditioner 1 is restarted, the discharge device 22 operates, causing the drain water level to decrease. Thus, when a drainage problem does not occur, the contact of the first detection unit 54a remains in the ON state.

[0054] When a drainage problem occurs, before the discharge device 22 is shut down, the drain water level is higher than the drain outlet 22a but has not yet reached the set water level L1. When the discharge device 22 is shut down, the drain water backflows, causing the drain water level to rise above the set water level L1. The contacts of the first detection unit 54a of the water level detection device 50 remain in the OFF state until the drain water level decreases and returns to the set water level L1. The higher the water level before the discharge device 22 is shut down, the longer the time it takes for the drain water level to reach the set water level L1 after decreasing. Therefore, the determination unit 32 detects a drainage problem using the following method. That is, the determination unit 32 determines that a drainage problem has occurred if the time Td1 required for the contacts of the first detection unit 54a to change from the OFF state to the ON state after the water level decreases after the air conditioner 1 is shut down (after the time T has elapsed since the air conditioner 1 was shut down) is longer than a predetermined time Td1s (not shown). Furthermore, the determination unit 32 determines that a discharge failure has not occurred if the length of the time Td1 is equal to or shorter than a predetermined time Td1s. The time T is the time when the water level is expected to start decreasing after the air conditioner 1 stops operating, and is set in advance taking into consideration the function of operating the drain water evaporation or discharge device 22 independently of the air conditioner 1. The time Td1s is a time determined, for example, by experiments for each operating condition or installation environment of the air conditioner 1. The time Td1s is set to a length that allows sufficient determination that a discharge failure has occurred when the time Td1 exceeds the time Td1s.

[0055] Note that the drain water level may exceed the set water level L2 before the discharge device 22 stops operating. Therefore, the determination unit 32 may determine that a discharge failure has occurred if the time Td2 required from when the contact of the second detection unit 54a changes from an ON state to an OFF state until the contact of the first detection unit 54b changes from an OFF state to an ON state is longer than a predetermined time Td2s (not shown). In this case, the determination unit 32 determines that a discharge failure has not occurred if the length of the time Td2 is equal to or shorter than the predetermined time Td2s. The time Td2s is, for example, a time determined by experiments or other methods for each operating condition or installation environment of the air conditioner 1. The time Td2s is set to a length sufficient to adequately determine that a discharge failure has occurred when the time Td2 exceeds the time Td2s.

[0056] The determination unit 32 may also calculate the presence or absence of a discharge failure based on the rate at which the water level falls, instead of the time Td1 or Td2. In this case, the determination unit 32 calculates the rate at which the water level rises per unit time by dividing the difference in height between the set water level L2 and the set water level L1 by the time Td2. If the rate at which the water level falls is slower than a predetermined rate, the determination unit 32 determines that a discharge failure has occurred.

[0057] The determination unit 32 also determines that a discharge failure has occurred when the contact of the first detection unit 54a remains in the OFF state for a predetermined determination time.

[0058] It is also possible to determine whether a discharge problem has occurred by limiting the conditions to only when the air conditioner 1 starts operating, only when it is operating continuously, or only when it is stopped. Furthermore, it is also possible to determine whether a discharge problem has occurred under two conditions, that is, when the air conditioner 1 starts operating and when it is stopped, and each operating state can be freely combined.

[0059] As described above, according to the first embodiment, the control device 30 determines whether or not there is a discharge problem in the discharge device 22 based on the time it takes for the water level detection device 50 to detect that the drain water has reached the set water level. Therefore, the air conditioner 1 can determine whether or not there is a discharge problem in the discharge device 22 using a simple method.

[0060] Embodiment 2. Figure 10 is a schematic diagram showing a water level detection device 50A according to embodiment 2. As shown in Figure 10, embodiment 2 differs from embodiment 1 in the configuration of the water level detection device 50A. In embodiment 2, parts that are common to embodiment 1 are given the same reference numerals and their description will be omitted, and the description will focus on the differences from embodiment 1.

[0061] In the second embodiment, the first detector 54Aa has a rectangular parallelepiped shape elongated in the horizontal direction, and the first magnet 53Aa corresponding to the first detector 54Aa is provided on the vertical shaft 52a. When the first detector 54Aa is close to the first magnet 53Aa and is affected by the magnetic force from the first magnet 53Aa, the contacts are in the ON state (closed). At this time, the first detector 54Aa faces the first magnet 53Aa horizontally. On the other hand, when the first detector 54Aa is far from the first magnet 53Aa and is not affected by the magnetic force from the first magnet 53Aa, the contacts are in the OFF state (open). At this time, the first detector 54Aa does not face the first magnet 53Aa either vertically or horizontally. The first detector 54Aa has an internal switch (not shown) and a case that covers the switch and forms an outer shell to prevent the switch from being exposed. The relationship between the detection pattern and the liquid level of the water level detecting device 50A according to the second embodiment is the same as that described with reference to FIG. 5 in the first embodiment.

[0062] According to the second embodiment, similar to the first embodiment, the control device 30 determines whether or not there is a discharge failure in the discharge device 22 based on the time taken for the water level detection device 50A to detect that the drain water has reached the set water level. Therefore, the air conditioner 1A can determine whether or not there is a discharge failure in the discharge device 22 using a simple method.

[0063] As explained in the second embodiment, the range of the water level detected by the water level detection device 50A can be adjusted by changing the location where the first magnet 53Aa is fixed to the support body 52 to a location different from that in the first embodiment. For example, since the position where the first magnet 53Aa is provided in the second embodiment is lower than the position where the first magnet 53a is provided in the first embodiment, the set water level L1 in the second embodiment is higher than the set water level L1 in the first embodiment.

[0064] Embodiment 3. Figure 11 is a schematic diagram showing a water level detection device 50B according to embodiment 3. In embodiment 3, the configuration of the water level detection device 50B differs from embodiment 1. In embodiment 3, parts that are common to embodiment 1 are given the same reference numerals and their description will be omitted, and the description will focus on the differences from embodiment 1.

[0065] The first magnet 53Ba and the second magnet 53Bb are provided at the lower corners of the support body 53. Specifically, the first magnet 53Ba is provided at the connection between the vertical shaft portion 52a and the lower horizontal shaft portion 52d. The second magnet 53Bb is provided at the connection between the vertical shaft portion 52b and the lower horizontal shaft portion 52d. The first magnet 53Ba and the second magnet 53Bb have a rectangular parallelepiped shape that is elongated in the vertical direction.

[0066] The first detection unit 54Ba and the second detection unit 54Bb are magnetic detection elements such as reed switches. The first detection unit 54Ba and the second detection unit 54Bb are both rectangular parallelepipeds elongated in the horizontal direction. The first detection unit 54Ba and the second detection unit 54Bb are located in an area surrounded by the vertical shafts 52a and 52b, the upper horizontal shaft 52c, and the lower horizontal shaft 52d of the support body 52. ​​The first detection unit 54Ba and the second detection unit 54Bb are connected to each other by side plates 55Ba and 55Bb. The first detection unit 54Ba and the second detection unit 54Bb are arranged side by side in the vertical direction, with the second detection unit 54Bb located above the first detection unit 54Ba.

[0067] When the first detector 54Ba is close to the first magnet 53Ba and is affected by the magnetic force of the first magnet 53Ba, the contacts are in the ON state (closed). At this time, the first detector 54Ba faces the first magnet 53Ba horizontally. On the other hand, when the first detector 54Ba is far from the first magnet 53Ba and is not affected by the magnetic force of the first magnet 53Ba, the contacts are in the OFF state (open). At this time, the first detector 54Ba does not face the first magnet 53Ba either vertically or horizontally. The first detector 54Ba has an internal switch portion (not shown) and a case that covers the switch portion to prevent the switch portion from being exposed and forms an outer shell.

[0068] When the second detection unit 54Bb is close to the second magnet 53Bb and is affected by the magnetic force of the second magnet 53Bb, the contacts are in the ON state (closed). At this time, the second detection unit 54Bb faces the second magnet 53Bb horizontally. On the other hand, when the second detection unit 54Bb is far from the second magnet 53Bb and is not affected by the magnetic force of the second magnet 53Bb, the contacts are in the OFF state (open). At this time, the second detection unit 54Bb does not face the second magnet 53Bb either vertically or horizontally. The second detection unit 54Bb has an internal switch portion (not shown) and a case that forms an outer shell and covers the switch portion so that the switch portion is not exposed.

[0069] The switch portion of the first detection unit 54Ba is disposed on the first magnet 53Ba side in the case so that it is affected only by the first magnet 53Ba of the opposing first magnet 53Ba and second magnet 53Bb. Similarly, the switch portion of the second detection unit 54Bb is disposed on the second magnet 53Bb side in the case so that it is affected only by the second magnet 53Bb of the opposing first magnet 53Ba and second magnet 53Bb.

[0070] The side plate 55Ba is a horizontally thin plate-like structure that connects the case of the first detection unit 54Ba and the case of the second detection unit 54Bb at one horizontal end. The side plate 55Bb is a horizontally thin plate-like structure that connects the case of the first detection unit 54Ba and the case of the second detection unit 54Bb at the other end opposite the one horizontal end. Although not shown, the first detection unit 54Ba and the second detection unit 54Bb are fixed to the housing 20 via the side plate 55Ba and 55Bb. Therefore, when the drain water level changes, the positions of the first detection unit 54Ba and the second detection unit 54Bb do not change. On the other hand, the float 51 and the first magnet 53Ba and the second magnet 53Bb, which are indirectly fixed to the float 51 via the support 52, change position in accordance with changes in the drain water level. At this time, the distance between the first detector 54Ba and the first magnet 53Ba and the distance between the second detector 54Bb and the second magnet 53Bb also change. The positional relationship between the first detector 54Ba and the second detector 54Bb and the first magnet 53Ba and the second magnet 53Bb is adjusted so that the state of the contacts changes at a preset water level.

[0071] The first magnet 53Ba corresponding to the first detector 54Ba is provided at the position where the vertical shaft 52a and the lower horizontal shaft 52d are connected, i.e., at the bottom of the support 52, unlike in the first embodiment. Therefore, the contacts of the first detector 54Ba are switched to the OFF state when the water level is relatively low, and the contacts are switched to the ON state when the water level is relatively high. That is, the first detector 54Ba in the third embodiment has a contact switching opposite to that in the first embodiment. Furthermore, the second detector 54Bb, which is located higher than the first detector 54Ba, has a contact that is switched to the ON state when the water level is higher than that of the first detector 54Ba. In other words, when the drain water level rises and the float 51 and the first magnet 53Ba and second magnet 53Bb rise, the first detection unit 54Ba and the first magnet 53Ba approach each other before the second detection unit 54Bb and the second magnet 53Bb, and therefore the contacts of the first detection unit 54Ba switch to the ON state before the contacts of the second detection unit 54Bb.

[0072] FIG. 12 is a table illustrating the relationship between the detection pattern and the liquid level of the water level detection device 50B according to the third embodiment. As shown in FIG. 12, the first detection unit 54Ba switches its contact when the drain water level is at a set level L1. The contact of the first detection unit 54Ba is in an OFF state when the drain water level is below the set level L1 and in an ON state when the drain water level is equal to or greater than the set level L1. On the other hand, the second detection unit 54Bb switches its contact when the drain water level is at a set level L2. The contact of the second detection unit 54Bb is in an ON state when the drain water level is above the set level L2 and in an OFF state when the drain water level is equal to or less than the set level L2. Here, the set water level L1 is set at a position higher than the drain outlet 22a of the discharge device 22, and the set water level L2 is set at a position higher than the set water level L1. The position of the set water level L2 is not particularly limited as long as it is equal to or less than the depth of the drain pan 21.

[0073] When the drain water level is shallower than the set water level L1, the float 51, the first magnet 53Ba, and the second magnet 53Bb are located at a relatively low level. At this time, the contacts of the first detection unit 54Ba are in the OFF state, and the contacts of the second detection unit 54Bb are in the OFF state. On the other hand, when the drain water level is deeper than the set water level L2, the float 51, the first magnet 53Ba, and the second magnet 53Bb are located at a relatively high level. At this time, the contacts of the first detection unit 54Ba are in the ON state, and the contacts of the second detection unit 54Bb are in the ON state. Furthermore, when the drain water level is equal to or greater than the set water level L1 and equal to or less than the set water level L2, the float 51, the first magnet 53Ba, and the second magnet 53Bb are located at a medium height. At this time, the contacts of the first detection unit 54Ba are in the ON state, and the contacts of the second detection unit 54Bb are in the OFF state. Thus, in the third embodiment as well, the water level detection device 50B can detect that the drain water has reached the set water level. Furthermore, by combining the connection states of the first detection unit 54Ba and the second detection unit 54Bb, the water level detection device 50B can detect the drain water level in three stages.

[0074] According to the third embodiment, similar to the first embodiment, the control device 30 determines whether or not there is a discharge failure in the discharge device 22 based on the time it takes for the water level detection device 50B to detect that the drain water has reached the set water level. Therefore, the air conditioner 1B can determine whether or not there is a discharge failure in the discharge device 22 using a simple method.

[0075] The above is a description of the embodiments of the present disclosure, but the present disclosure is not limited to the configurations of the above embodiments and various modifications are possible within the scope of the technical concept. For example, the first and second embodiments may be combined to enable detection of three set water levels.

[0076] As described in the first embodiment, the amount of drain water present in the drain pan 21 is affected by the operating conditions and the installation environment of the air conditioner 1, and therefore may not always be constant and may not maintain a stable water level. For this reason, the ON / OFF outputs of the first detection unit 54a and the second detection unit 54b of the water level detection device 50 may frequently switch. In consideration of this, the determination unit 32 may measure the number of times the ON / OFF outputs of the first detection unit 54a and the second detection unit 54b switch, compare the measured number with a preset threshold value, and determine whether drainage is unnecessary. Specifically, the determination unit 32 determines that poor drainage may have occurred if the number of times the ON / OFF outputs of the first detection unit 54a and the second detection unit 54b switch is greater than the preset number. Instead of the number of times, the frequency indicating the number of times the ON / OFF output is switched per unit time, or the probability of the ON / OFF output being switched per unit time may be compared with the threshold value.

[0077] DESCRIPTION OF SYMBOLS 1 Air conditioner, 2 Outdoor unit, 3 Indoor unit, 5 Compressor, 6 Flow path switching device, 7 Outdoor heat exchanger, 8 Outdoor blower, 9 Expansion valve, 10 Indoor heat exchanger, 11 Indoor blower, 12 Humidifier, 20 Housing, 21 Drain pan, 22 Discharge device, 22a Drain outlet, 23 Drain pipe, 30 Control device, 31 Water level output unit, 32 Determination unit, 33 Transmitting unit, 40 Display device, 50, 50A, 50B Water level detection device, 51 Float, 52 Support, 52a, 52b Vertical shaft portion, 52c Upper horizontal shaft portion, 52d Lower horizontal shaft portion, 53a, 53Aa, 53Ba First magnet, 53b, 53Bb Second magnet, 54a, 54Aa, 54Ba First detection unit, 54b, 54Bb Second detection unit, 55a, 55b, 55Ba, 55Bb Side plate unit, 71 Processor, 72 Memory, 73 Bus.

Claims

1. An air conditioner comprising: a housing; a drain pan provided in the housing for receiving drain water generated inside the housing; a discharge device provided in the housing and having a drain outlet formed therein, which discharges drain water accumulated in the drain pan from the drain outlet; a water level detection device for detecting whether the drain water has reached a set water level above the drain outlet of the discharge device; and a control device, wherein the water level detection device detects a plurality of the set water levels, and the control device determines whether or not there is a discharge problem with the discharge device based on the time it takes for the water level detection device to detect that the drain water has reached the set water level.

2. The air conditioner as described in claim 1, wherein the water level detection device comprises: a float located at the bottom of the water level detection device and floating on drain water accumulated in the drain pan; a support provided on an upper part of the float; a first magnet provided on the support; a second magnet provided on the support; a first detection unit whose contact point is switched by the magnetic force of the first magnet; and a second detection unit whose contact point is switched by the magnetic force of the second magnet.

3. The air conditioner described in claim 2, wherein the support body comprises two vertical shaft portions extending vertically, an upper horizontal shaft portion connecting the upper portions of the two vertical shaft portions and extending horizontally, and a lower horizontal shaft portion connecting the lower portions of the two vertical shaft portions and extending horizontally, the first magnet being provided on the upper horizontal shaft portion, and the second magnet being provided on the lower horizontal shaft portion.

4. The air conditioner described in claim 2, wherein the support comprises two vertical shaft portions extending vertically, an upper horizontal shaft portion connecting the upper portions of the two vertical shaft portions and extending horizontally, and a lower horizontal shaft portion connecting the lower portions of the two vertical shaft portions and extending horizontally, the first magnet being provided on one of the two vertical shaft portions, and the second magnet being provided on the lower horizontal shaft portion.

5. The air conditioner described in claim 2, wherein the support comprises two vertical shaft portions extending vertically, an upper horizontal shaft portion connecting the upper portions of the two vertical shaft portions and extending horizontally, and a lower horizontal shaft portion connecting the lower portions of the two vertical shaft portions and extending horizontally, the first magnet is provided at a portion where one of the two vertical shaft portions and the lower horizontal shaft portion are connected, and the second magnet is provided at a portion where the other of the two vertical shaft portions and the lower horizontal shaft portion are connected.

6. An air conditioner as claimed in any one of claims 1 to 5, wherein the drain pan is formed with an inclined portion which becomes lower toward a position opposite the discharge device, and the water level detection device is disposed above the inclined portion.

7. An air conditioner as described in any one of claims 1 to 6, wherein the control device determines whether or not there is a discharge problem with the discharge device based on the time between when the water level detection device detects that the drain water has reached one of the multiple set water levels and when it detects that the drain water has reached the other of the multiple set water levels.

8. An air conditioner as claimed in any one of claims 1 to 7, wherein the control device determines whether or not there is a discharge defect in the discharge device based on the number of times, frequency or probability that the water level detection device detects that the set water level has been reached.

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