Air conditioning system, method for controlling air conditioning system, and program for controlling air conditioning system

Abstract

To provide an air conditioning system, a control method of the air conditioning system, and a control program of the air conditioning system capable of suppressing generation of dew condensation in a heat exchange element of a ventilation unit.SOLUTION: An air conditioning system includes: an indoor unit including an indoor heat exchanger; a ventilation unit for a heat exchange element for executing heat exchange between indoor air and outdoor air; and a humidity sensor for detecting the humidity of air toward the heat exchange element. The indoor unit is configured so as to execute a first dehumidifying operation started on the basis of a start instruction from a user and a second dehumidifying operation as a dew condensation suppression operation executed for suppressing dew condensation of the heat exchange element. The indoor unit controls the humidity of indoor air to a level lower than a first threshold when executing the first dehumidifying operation, and when the humidity of indoor air is a second threshold or more higher than the first threshold, executes the second dehumidifying operation so that the humidity of the indoor air becomes less than the second threshold.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to an air conditioning system, a control method for an air conditioning system, and a control program for an air conditioning system. [Background technology]

[0002] Patent Document 1 discloses a heat exchange ventilator that performs general ventilation by total heat exchange ventilation. This heat exchange ventilator includes a heat exchanger, a main body frame that supports the heat exchanger, and a liquid receiving member that is installed below the heat exchanger within the main body frame. In this heat exchange ventilator, water that adheres to the heat exchanger due to condensation drips toward the liquid receiving member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-144995 A Summary of the Invention [Problem to be solved by the invention]

[0004] Although the above-mentioned heat exchange ventilation device can treat water generated by condensation, no consideration has been given to suppressing the generation of condensation itself.

[0005] An object of the present disclosure is to provide an air conditioning system capable of suppressing the occurrence of condensation on a heat exchange element of a ventilation unit, a control method for an air conditioning system, and a control program for an air conditioning system. [Means for solving the problem]

[0006] The air conditioning system of the present disclosure includes an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges heat between indoor air and outdoor air, and a humidity sensor that detects the humidity of air heading toward the heat exchange element, the indoor unit is configured to perform a first dehumidification operation that starts based on a start instruction from a user, and a second dehumidification operation as a condensation suppression operation that is performed to suppress condensation on the heat exchange element, the indoor unit controls the humidity of the indoor air to be less than a first threshold during the first dehumidification operation, and when the humidity of the indoor air is equal to or greater than a second threshold higher than the first threshold, performs the second dehumidification operation so that the humidity of the indoor air is less than the second threshold. This air conditioning system can suppress condensation from occurring on the heat exchange element of the ventilation unit.

[0007] In the air conditioning system, the indoor unit may execute the second dehumidification operation when the humidity of the indoor air is equal to or higher than the second threshold and the humidity of the outdoor air is equal to or higher than a third threshold that is higher than the first threshold. According to this air conditioning system, it is possible to more suitably suppress the occurrence of condensation on the heat exchange element of the ventilation unit.

[0008] In the air conditioning system, the indoor unit may perform the second dehumidification operation when the humidity of the indoor air is equal to or higher than the second threshold value and the continuous operation time of the ventilation unit is equal to or longer than a first predetermined time. According to this air conditioning system, it is possible to more suitably suppress the occurrence of condensation on the heat exchange element of the ventilation unit.

[0009] The air conditioning system of the present disclosure includes an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges heat between indoor air and outdoor air, and a humidity sensor that detects the humidity of air heading toward the heat exchange element, the indoor unit is configured to perform a second dehumidification operation as a condensation suppression operation performed to suppress condensation on the heat exchange element, the condensation suppression operation is an operation that uses the indoor heat exchanger as an evaporator, and when an operation start condition of the indoor unit is satisfied while the operation of the indoor unit is stopped, the indoor unit starts up and starts the condensation suppression operation, the operation start condition includes at least one of a condition related to the humidity of the indoor air and a condition related to the humidity of the outdoor air. This air conditioning system can suppress condensation from occurring on the heat exchange element of the ventilation unit.

[0010] In the air conditioning system, the operation start condition may include both a condition related to the humidity of the indoor air and a condition related to the humidity of the outdoor air. According to this air conditioning system, it is possible to more suitably suppress the occurrence of condensation on the heat exchange element of the ventilation unit.

[0011] In the air conditioning system, the operation start condition may further include a condition related to a continuous operation time of the ventilation unit. According to this air conditioning system, it is possible to more suitably suppress the occurrence of condensation on the heat exchange element of the ventilation unit.

[0012] In the above air conditioning system, when the condensation suppression operation is being performed, the indoor unit may stop the condensation suppression operation when the time during which the indoor air humidity continues to be below the operation stop threshold reaches a second predetermined time, or when the time during which the condensation suppression operation is being performed reaches a third predetermined time. With this air conditioning system, the power consumption of the indoor unit can be reduced.

[0013] In the above air conditioning system, the ventilation unit may include a supply fan that supplies air into the room and an exhaust fan that exhausts air from the room, and the supply fan and the exhaust fan may be controlled so that the exhaust air volume is greater than the supply air volume when the indoor unit is performing the condensation suppression operation. With this air conditioning system, it is possible to more effectively suppress the occurrence of condensation on the heat exchange element of the ventilation unit.

[0014] In the air conditioning system, when the indoor unit is performing the condensation suppression operation, the air supply fan may be stopped and the exhaust fan may be driven. With this air conditioning system, power consumption of the ventilation unit can be reduced.

[0015] In the air conditioning system, when the condensation suppression operation is performed by the indoor unit, a notification may be given that the condensation suppression operation has been performed. According to this air conditioning system, convenience is improved.

[0016] The control method of the air conditioning system of the present disclosure is a control method of an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges heat between indoor air and outdoor air, and a humidity sensor that detects the humidity of air heading toward the heat exchange element, the indoor unit is configured to perform a first dehumidification operation that starts based on a start instruction from a user, and a second dehumidification operation as a condensation suppression operation that is performed to suppress condensation on the heat exchange element, and includes causing the indoor unit to perform the first dehumidification operation so that the humidity of the indoor air is less than a first threshold, and causing the indoor unit to perform the second dehumidification operation so that the humidity of the indoor air is less than the second threshold when the humidity of the indoor air is equal to or greater than a second threshold that is higher than the first threshold. This control method of the air conditioning system can suppress condensation from occurring on the heat exchange element of the ventilation unit.

[0017] The control program for an air conditioning system according to the present disclosure is a control program for an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element for exchanging heat between indoor air and outdoor air, and a humidity sensor for detecting the humidity of air heading toward the heat exchange element, the indoor unit being configured to execute a first dehumidification operation that starts based on a start instruction from a user, and a second dehumidification operation as a condensation suppression operation that is executed to suppress condensation on the heat exchange element, and causes a computer to execute a process of causing the indoor unit to execute the first dehumidification operation so that the humidity of the indoor air is less than a first threshold, and a process of causing the indoor unit to execute the second dehumidification operation so that the humidity of the indoor air is less than the second threshold when the humidity of the indoor air is equal to or greater than a second threshold that is higher than the first threshold. According to the control program for the air conditioning system, it is possible to suppress condensation from occurring on the heat exchange element of the ventilation unit.

[0018] The control method of the air conditioning system of the present disclosure is a control method of an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges heat between indoor air and outdoor air, and a humidity sensor that detects the humidity of air heading toward the heat exchange element, the indoor unit is configured to perform a second dehumidification operation as a condensation suppression operation performed to suppress condensation on the heat exchange element, the condensation suppression operation is an operation using the indoor heat exchanger as an evaporator, and includes starting the indoor unit to cause the indoor unit to start the condensation suppression operation when an operation start condition of the indoor unit is satisfied while the operation of the indoor unit is stopped, the operation start condition includes at least one of a condition related to the humidity of the indoor air and a condition related to the humidity of the outdoor air. According to this control method of the air conditioning system, it is possible to suppress the occurrence of condensation on the heat exchange element of the ventilation unit.

[0019] The control program for an air conditioning system according to the present disclosure is a control program for an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element for exchanging heat between indoor air and outdoor air, and a humidity sensor for detecting the humidity of air moving toward the heat exchange element, the indoor unit being configured to execute a second dehumidification operation as a condensation suppression operation executed to suppress condensation on the heat exchange element, the condensation suppression operation being an operation using the indoor heat exchanger as an evaporator, and including having a computer execute a process of starting the indoor unit and causing the indoor unit to start the condensation suppression operation when an operation start condition of the indoor unit is satisfied while the operation of the indoor unit is stopped, the operation start condition including at least one of a condition related to the humidity of the indoor air and a condition related to the humidity of the outdoor air. According to the control program for the air conditioning system, it is possible to suppress condensation from occurring on the heat exchange element of the ventilation unit. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram showing a schematic configuration of an air conditioning system according to an embodiment; [Diagram 2] FIG. 2 is a diagram illustrating a schematic configuration of a system control unit. [Diagram 3] 5 is a flowchart showing an example of a procedure for condensation suppression control. [Figure 4] 6 is a flowchart showing an example of a processing procedure for fan drive control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the present embodiment will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and the same description will not be repeated.

[0022] <1. Air conditioning system configuration> FIG. 1 is a diagram showing a schematic configuration of an air conditioning system 10 of this embodiment. The air conditioning system 10 is applied to any building. The building is, for example, an individual house, an apartment building, or a commercial facility. The air conditioning system 10 includes an air conditioner 20 and a ventilation unit 50. The air conditioner 20 includes an indoor unit 30 and an outdoor unit 40. The indoor unit 30 is installed, for example, in the attic of the building. The outdoor unit 40 is installed outdoors. The ventilation unit 50 is installed, for example, in the attic of the building. The ventilation unit 50 performs, for example, general ventilation. In the air conditioning system 10, a refrigerant circuit RC is configured by the indoor unit 30 and the outdoor unit 40.

[0023] The indoor unit 30 includes an indoor heat exchanger 31, an indoor fan 32, a temperature sensor 33, a humidity sensor 34, an electric expansion valve 35, and a control device 36. The indoor heat exchanger 31, the indoor fan 32, the temperature sensor 33, the humidity sensor 34, and the electric expansion valve 35 are accommodated in a housing 30A.

[0024] The indoor heat exchanger 31 is used for heat exchange between the indoor air and the refrigerant. The indoor heat exchanger 31 functions as an evaporator or a condenser of the refrigerant. The indoor fan 32 supplies the indoor air to the indoor heat exchanger 31.

[0025] The temperature sensor 33 detects the temperature in the room. The humidity sensor 34 detects the humidity of the air in the room. The humidity of the air detected by the humidity sensor 34 includes the humidity of the air flowing toward the heat exchange element 54 of the ventilation unit 50. The motorized expansion valve 35 reduces the pressure of the refrigerant.

[0026] The control device 36 includes a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc., and controls components such as the indoor fan 32 in response to information processing. The control device 36 is connected to be able to communicate with a control device 48 of the outdoor unit 40 and a control device 55 of the ventilation unit 50. The communication between the control device 36 and the control device 48 and the control device 55 is wireless communication or wired communication. The control device 36 constitutes a part of a system control unit 70 (see FIG. 2).

[0027] The outdoor unit 40 includes a compressor 41, a four-way switching valve 42, an outdoor heat exchanger 43, an accumulator 44, an outdoor fan 45, a temperature sensor 46, a humidity sensor 47, and a control device 48.

[0028] The compressor 41 compresses the refrigerant. The outdoor heat exchanger 43 is used for heat exchange between the outdoor air and the refrigerant. The outdoor heat exchanger 43 functions as an evaporator or a condenser of the refrigerant. The outdoor fan 45 supplies the outdoor air to the outdoor heat exchanger 43.

[0029] The four-way switching valve 42 switches the refrigerant circuit RC between a cooling cycle state and a heating cycle state. In the cooling cycle state, the outdoor heat exchanger 43 functions as a condenser, and the indoor heat exchanger 31 functions as an evaporator. In the heating cycle state, the outdoor heat exchanger 43 functions as an evaporator, and the indoor heat exchanger 31 functions as a condenser.

[0030] The accumulator 44 separates the refrigerant liquid mixed in the vapor generated by the evaporator. The temperature sensor 46 detects the outdoor temperature. The humidity sensor 47 detects the humidity of the outdoor air. The humidity of the air detected by the humidity sensor 47 includes the humidity of the air heading toward the heat exchange element 54 of the ventilation unit 50.

[0031] The control device 48 includes a CPU, RAM, ROM, etc., and controls components such as the compressor 41, the four-way switching valve 42, and the outdoor fan 45 in accordance with information processing. The control device 48 constitutes a part of the system control unit 70 (see FIG. 2).

[0032] In the air conditioner 20, the indoor heat exchanger 31, the compressor 41, the four-way switching valve 42, the outdoor heat exchanger 43, the electric expansion valve 35, and the accumulator 44 are connected in a circular configuration to form a refrigerant circuit RC.

[0033] The ventilation unit 50 includes a housing 51 , an intake fan 52 , an exhaust fan 53 , a heat exchange element 54 , a control device 55 , a storage device 56 , and a remote control 57 .

[0034] Housing 51 is, for example, box-shaped, and houses supply air fan 52, exhaust fan 53, and heat exchange element 54. Housing 51 includes an outside air inlet 51A, an indoor supply air port 51B, an exhaust air inlet 51C, and an exhaust air outlet 51D.

[0035] Air flowing from the outside into the housing 51 passes through the outside air intake port 51A. An intake pipe 81 that takes in the outside air into the housing 51 is connected to the outside air intake port 51A. Air that has been heat exchanged by the heat exchange element 54 passes through the indoor air supply port 51B. A supply pipe 82 that supplies the air that has been heat exchanged by the heat exchange element 54 to the room is connected to the indoor air supply port 51B. Air flowing from the room into the housing 51 passes through the exhaust air intake port 51C. An intake pipe 83 that takes in the indoor air to the housing 51 is connected to the exhaust air intake port 51C. Air that has been heat exchanged by the heat exchange element 54 passes through the exhaust air outlet 51D. An exhaust pipe 84 that exhausts the air that has been heat exchanged by the heat exchange element 54 to the outside of the room is connected to the exhaust air outlet 51D.

[0036] Air supply fan 52 is installed near indoor air supply port 51B. When air supply fan 52 is driven, an air flow path is formed in housing 51 through outdoor air inlet 51A, heat exchange element 54, and indoor air supply port 51B in that order.

[0037] Exhaust fan 53 is installed near exhaust outlet 51D. By driving exhaust fan 53, a flow path is formed in housing 51 through which air flows in this order from exhaust inlet 51C, through heat exchange element 54, and through exhaust outlet 51D.

[0038] The heat exchange element 54 exchanges temperature and humidity between the outside and the inside of the room. The heat exchange element 54 is, for example, a stationary heat exchange element. The heat exchange element 54 is a cross-flow type. The heat exchange element 54 may be a counter-flow type.

[0039] The control device 55 includes a CPU, RAM, ROM, etc., and controls components such as the supply air fan 52 and the exhaust fan 53 in response to information processing. The control device 55 measures a continuous operation time, which is the time during which the ventilation unit 50 operates continuously. The control device 55 transmits information relating to the measured continuous operation time to the control device 36.

[0040] The storage device 56 is configured, for example, by a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory). The storage device 56 is communicatively connected to the control device 55 via, for example, a bus. The storage device 56 stores a control program. The control program is configured by one or more programs. The control device 55 controls various components by executing the control program.

[0041] The remote control 57 is installed, for example, indoors. The user switches between starting and stopping the operation of the ventilation unit 50 by operating the remote control 57. The user can set the operation time of the ventilation unit 50, etc. by operating the remote control 57.

[0042] The air conditioner 20 further includes a remote control 60. The user operates the remote control 60 to, for example, switch the operation mode of the air conditioner 20. The operation modes of the air conditioner 20 that can be switched by the user operating the remote control 60 include, for example, a cooling operation, a heating operation, and a first dehumidification operation. When the cooling operation is performed, the indoor temperature drops to a temperature set by the user. When the heating operation is performed, the indoor temperature rises to a temperature set by the user. When the first dehumidification operation is performed, the indoor humidity drops. In the first dehumidification operation, the humidity of the indoor air is controlled to be less than a first threshold value XA. The first threshold value XA is a humidity value that is set so that the user does not feel uncomfortable when spending time indoors. The first threshold value XA is, for example, 65%. The first threshold value XA is preferably 55%. The first threshold value XA is more preferably 45%.

[0043] The operation modes of the air conditioner 20 further include a second dehumidification operation as a condensation suppression operation executed to suppress condensation on the heat exchange element 54. The system control unit 70 (see FIG. 2) of the air conditioner 20 executes condensation suppression control to automatically execute the second dehumidification operation when an operation start condition is satisfied. Details of the condensation suppression control will be described later. Note that, hereinafter, the second dehumidification operation may be referred to as a condensation suppression operation.

[0044] When the air conditioner 20 is in cooling operation, first dehumidification operation, or second dehumidification operation, the refrigerant circuit RC is in a cooling cycle state. In the cooling cycle state, the four-way switching valve 42 is in the state shown by the solid line in Fig. 1. In the cooling cycle state, the refrigerant discharged by the compressor 41 flows through the four-way switching valve 42, the outdoor heat exchanger 43, the motorized expansion valve 35, the indoor heat exchanger 31, the four-way switching valve 42, and the accumulator 44 in that order.

[0045] When the air conditioner 20 is in heating operation, the refrigerant circuit RC is in a heating cycle state. In the heating cycle state, the four-way valve 42 is in the state shown by the dashed line in Fig. 1. The refrigerant discharged by the compressor 41 flows through the four-way valve 42, the indoor heat exchanger 31, the motorized expansion valve 35, the outdoor heat exchanger 43, the four-way valve 42, and the accumulator 44 in that order.

[0046] 2 is a diagram for explaining an outline of the system control unit 70. The system control unit 70 includes a control device 36 and a control device 48.

[0047] The control device 36 acquires the detection results of the temperature sensor 33 and the humidity sensor 34. The control device 36 controls the indoor fan 32 and the motorized expansion valve 35 based on all or part of the detection results of the temperature sensor 33 and the humidity sensor 34. The control device 36 receives a signal indicating a user's instruction from the remote control 60. The control device 36 transmits a signal to the remote control 60 that controls the display state of a screen (not shown) of the remote control 60. When the air conditioner 20 starts the second dehumidification operation, the control device 36 transmits a first signal to the control device 55 (see FIG. 1). When the air conditioner 20 stops the second dehumidification operation, the control device 36 transmits a second signal to the control device 55.

[0048] The control device 48 acquires the detection results of the temperature sensor 46 and the humidity sensor 47. The control device 48 controls the compressor 41, the four-way switching valve 42, and the outdoor fan 45 based on all or part of the detection results of the temperature sensor 46 and the humidity sensor 47.

[0049] The system control unit 70 is communicatively connected to a storage device 71. The storage device 71 is configured, for example, by a non-volatile memory such as an EEPROM. The storage device 71 stores a control program 71A. The control program 71A is configured by one or more programs. The control device 36 and the control device 48 control various components by executing the control program 71A.

[0050] <2. Condensation prevention control> In the condensation suppression control, when the operation start condition is satisfied, the system control unit 70 of the air conditioner 20 executes the condensation suppression operation so that the humidity of the indoor air is less than the second threshold value XB. When the operation start condition is satisfied, the air conditioner 20 stops the cooling operation and executes the condensation suppression operation even if the air conditioner 20 is executing the cooling operation. When the operation start condition is satisfied in the case where the air conditioner 20 is in the operation stop state, the air conditioner 20 starts up and executes the condensation suppression operation. The second threshold value XB is a value set for suppressing condensation of the heat exchange element 54. The second threshold value XB is higher than the first threshold value XA. The second threshold value XB is, for example, 90%. The second threshold value XB is preferably 80%. The second threshold value XB is more preferably 70%. The operation stop state of the air conditioner 20 includes a state in which the power is off by, for example, transmitting an operation stop instruction from the remote control 60. In another example, the operation-stopped state of the air conditioner 20 includes a state in which the power is on but the operation of the compressor 41 is temporarily stopped due to, for example, thermo-off.

[0051] The operation start conditions for the condensation prevention operation include a condition related to the humidity of the indoor air, a condition related to the humidity of the outdoor air, and a condition related to the continuous operation time of the ventilation unit 50. The condition related to the humidity of the indoor air is satisfied when the humidity of the indoor air detected by the humidity sensor 34 is equal to or higher than the second threshold value XB.

[0052] The condition regarding the humidity of the outdoor air is satisfied when the humidity of the indoor air detected by the humidity sensor 47 is equal to or higher than the third threshold value XC. The third threshold value XC is higher than the first threshold value XA. The third threshold value XC may be the same as or different from the second threshold value XB. Even if the humidity of the indoor air is high, if the humidity of the outdoor air is low, condensation is unlikely to occur on the heat exchange element 54. The higher the humidity of the indoor air and the humidity of the outdoor air are, and the smaller the difference between the humidity of the indoor air and the humidity of the outdoor air is, the more likely condensation is to occur on the heat exchange element 54. For this reason, it is preferable that the third threshold value XC is the same value as the second threshold value XB or a value close to the second threshold value XB.

[0053] The condition regarding the continuous operation time of the ventilation unit 50 is satisfied when the continuous operation time of the ventilation unit 50 measured by the control device 55 is equal to or longer than a first predetermined time TA. The first predetermined time TA is a time when condensation is predicted to occur on the heat exchange element 54. The first predetermined time TA is, for example, 48 hours.

[0054] When the air conditioning device 20 is performing the condensation suppression operation in the condensation suppression control, the air conditioning device 20 stops the condensation suppression operation when the operation stop condition is satisfied. The operation stop condition is satisfied, for example, when the time during which the indoor air humidity continues to be lower than the operation stop threshold value XZ reaches a second predetermined time TB. The time during which the indoor air humidity continues to be lower than the operation stop threshold value XZ is measured by the control device 36. The operation stop threshold value XZ is preferably the same value as the second threshold value XB or a value lower than the second threshold value XB. The operation stop threshold value XZ may be a value higher than the second threshold value XB. The second predetermined time TB is a time during which the indoor air humidity continues to be low, thereby suppressing the occurrence of condensation on the heat exchange element 54. The second predetermined time TB is, for example, 4 hours.

[0055] When the air conditioning system 10 executes the condensation suppression operation in the condensation suppression control, it notifies that the condensation suppression operation has been executed. The timing for notifying that the condensation suppression operation has been executed is when the condensation suppression operation is started, while the condensation suppression operation is being executed, or when the condensation suppression operation is stopped. The air conditioning system 10 notifies that the condensation suppression operation has been executed, for example, by turning on a lamp provided in the indoor unit 30. The air conditioning system 10 may notify that the condensation suppression operation has been executed, for example, by turning on a lamp provided in the housing 51 of the ventilation unit 50. The air conditioning system 10 may notify that the condensation suppression operation has been executed by transmitting information to a mobile terminal of a user. The air conditioning system 10 may notify that the condensation suppression operation has been executed, by transmitting information to at least one of the remote control 57 of the ventilation unit 50 and the remote control 60 of the air conditioning device 20. When the air conditioning device 20 is in an operation stop state, it is highly likely that no user is present in the room. For this reason, when the air conditioning system 10 is started from a stopped state and executes the condensation suppression operation, it is preferable to notify the user that the condensation suppression operation has been executed by transmitting information to the user's mobile terminal.

[0056] <3. Fan drive control> The control device 55 of the ventilation unit 50 executes fan drive control in parallel with the condensation suppression control executed by the system control unit 70 of the air conditioning device 20. In the fan drive control, when the control device 55 receives a first signal transmitted from the control device 36, the control device 55 controls the supply air fan 52 and the exhaust fan 53 so that the exhaust air volume from the room is greater than the supply air volume to the room. When the control device 55 receives the first signal, for example, the control device 55 stops the supply air fan 52 and drives the exhaust fan 53 so that the rotation speed is higher than before the first signal is received. When the control device 55 receives the first signal, for example, the control device 55 may stop the supply air fan 52 and drive the exhaust fan 53 so that the rotation speed before the first signal is maintained. When the control device 55 receives a second signal, the control device 55 returns the drive states of the supply air fan 52 and the exhaust fan 53 to the states before the first signal is received.

[0057] <4. Condensation suppression control processing procedure> An example of a procedure for condensation suppression control will be described with reference to Fig. 3. The system control unit 70 repeatedly executes condensation suppression control at predetermined time intervals, regardless of whether the air conditioning device 20 is operating or not.

[0058] In step S11, the control device 36 determines whether the humidity of the indoor air is equal to or higher than the second threshold value XB. If the determination in step S11 is positive, the control device 36 executes the process of step S12. If the determination in step S11 is negative, the control device 36 executes the process of step S11 again.

[0059] In step S12, the control device 36 determines whether the humidity of the outdoor air is equal to or higher than the third threshold value XC. If the determination in step S12 is positive, the system control unit 70 executes the process of step S13. If the determination in step S13 is negative, the system control unit 70 executes the process of step S11 again.

[0060] In step S13, the control device 36 determines whether or not the continuous operation time of the ventilation unit 50 is equal to or longer than the first predetermined time TA based on the signal transmitted from the control device 55. If the determination in step S13 is positive, the control device 36 executes the process of step S14. If the determination in step S13 is negative, the control device 36 executes the process of step S11 again.

[0061] In step S14, the system control unit 70 executes the condensation prevention operation. The control device 36 transmits a first signal to the control device 55 of the ventilation unit 50. In step S15, the control device 36 notifies the user that the condensation prevention operation has been executed.

[0062] In step S16, the control device 36 determines whether the time during which the indoor air humidity continues to be less than the operation stop threshold XZ has reached a second predetermined time TB. If the determination in step S16 is positive, the control device 36 executes the process of step S17. If the determination in step S16 is negative, the control device 36 executes the process of step S16 again.

[0063] In step S17, the system control unit 70 stops the condensation prevention operation. The control device 36 transmits a second signal to the control device 55.

[0064] <5. Processing procedure for fan drive control by ventilation unit> An example of a processing procedure of fan drive control executed by the control device 55 of the ventilation unit 50 will be described with reference to Fig. 4. The control device 55 always executes fan drive control, for example, while the ventilation unit 50 is in operation. The control device 55 starts fan drive control, for example, in response to an operation start instruction being transmitted from the remote control 57. The control device 55 ends fan drive control, for example, in response to an operation stop instruction being transmitted from the remote control 57.

[0065] In step S21, control device 55 drives supply air fan 52 and exhaust fan 53 to have preset rotational speeds for ventilation.

[0066] In step S22, the control device 55 determines whether or not the first signal has been received, i.e., whether or not the air conditioning device 20 has started the second dehumidification operation. If the determination in step S22 is positive, the control device 55 executes the process of step S23. If the determination in step S22 is negative, the control device 55 executes the process of step S22 again. In step S23, the control device 55 stops the supply air fan 52.

[0067] In step S24, the control device 55 judges whether or not the second signal has been received, i.e., whether or not the air conditioning device 20 has stopped the second dehumidification operation. If the judgment in step S24 is positive, the control device 55 executes the process of step S25. If the judgment in step S25 is negative, the control device 55 executes the process of step S24 again.

[0068] In step S25, controller 55 restores the driving states of supply air fan 52 and exhaust air fan 53 to the states before receiving the first signal.

[0069] In step S26, the control device 55 determines whether or not an operation stop instruction has been received from the remote control 57. If the determination in step S26 is positive, the control device 55 ends the fan drive control. If the determination in step S26 is negative, the control device 55 executes the process of step S22 again.

[0070] According to the air conditioning system 10, when the operation start condition is satisfied, the air conditioner 20 executes the condensation suppression operation. This reduces the humidity of the air in the room. The ventilation unit 50 takes in dry air from the room, so that the occurrence of condensation on the heat exchange element 54 is suppressed.

[0071] According to the air conditioning system 10, the operation start conditions include both a condition related to the humidity of the indoor air and a condition related to the humidity of the outdoor air, so that the occurrence of condensation on the heat exchange element 54 can be more suitably suppressed.

[0072] Even if the humidity of the indoor air is high, if the continuous operation time of the ventilation unit 50 is short, condensation may not occur on the heat exchange element 54. According to the air conditioning system 10, the operation start condition includes a condition related to the continuous operation time of the ventilation unit 50, so that the occurrence of condensation on the heat exchange element 54 can be more suitably suppressed.

[0073] When the operation stop condition is satisfied, the air conditioner 20 stops the condensation suppression operation, which allows the power consumption of the air conditioner 20 to be reduced.

[0074] When control device 55 receives the first signal transmitted from control device 36, control device 55 controls intake air fan 52 and exhaust air fan 53 so that the amount of exhaust air from the room is greater than the amount of intake air to the room. This makes it possible to more effectively prevent condensation from occurring on heat exchange element 54.

[0075] In the fan drive control, when the ventilation unit 50 receives the first signal, it stops the air supply fan 52. Therefore, the power consumption of the ventilation unit 50 can be reduced.

[0076] When the condensation suppression operation is executed in the condensation suppression control, the air conditioning system 10 notifies the user that the condensation suppression operation has been executed, thereby improving convenience.

[0077] According to the air conditioning system 10, the air conditioner 20 executes the condensation suppression operation under circumstances where condensation may occur on the heat exchange element 54, so that the ventilation unit 50 can be kept in operation. Since ventilation of the room can be continuously performed, the air in the room can be kept in a hygienic state.

[0078] <6. Variations> The above-described embodiments are examples of forms that the air conditioning system, the control method for the air conditioning system, and the control program for the air conditioning system according to the present disclosure may take, and are not intended to limit the forms. The air conditioning system, the control method for the air conditioning system, and the control program for the air conditioning system according to the present disclosure may take forms different from those exemplified in the embodiments. One example of such a form is a form in which part of the configuration of the embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to the embodiment. Below are some examples of modified embodiments.

[0079] <6-1> In the above embodiment, the humidity of the indoor air is detected by the humidity sensor 34 of the indoor unit 30, but the method of detecting the humidity of the indoor air can be changed arbitrarily. The humidity of the indoor air may be detected by a humidity sensor installed in the housing 51 of the ventilation unit 50 near the exhaust air inlet 51C. In another example, the humidity of the indoor air may be detected by a humidity sensor installed at an arbitrary position in the room. In this modified example, the humidity sensor transmits the detection result to the control device 36, for example, at predetermined time intervals.

[0080] <6-2> In the above embodiment, the humidity of the outdoor air is detected by the humidity sensor 47 of the outdoor unit 40, but the method of detecting the humidity of the outdoor air can be changed as desired. The humidity of the outdoor air may be detected by a humidity sensor installed in the housing 51 of the ventilation unit 50 near the outdoor air inlet 51A. In another example, the humidity of the outdoor air may be detected by a humidity sensor installed at any position outside.

[0081] <6-3> In the above embodiment, the operation start conditions in the condensation suppression control included a condition related to the indoor air humidity, a condition related to the outdoor air humidity, and a condition related to the continuous operation time of the ventilation unit 50. The operation start conditions may include only a condition related to the outdoor air humidity. In this modification, steps S11 and S13 shown in FIG. 3 are omitted in the condensation suppression control. The operation start conditions may include only a condition related to the indoor air humidity or a condition related to the outdoor air humidity. In this modification, steps S11 or S12 and step S13 shown in FIG. 3 are omitted in the condensation suppression control.

[0082] <6-4> The condition related to the humidity of the indoor air in the operation start condition can be changed arbitrarily. The condition related to the humidity of the indoor air may be satisfied, for example, when the humidity of the indoor air detected by the humidity sensor 34 is equal to or higher than a fourth threshold value XD. The fourth threshold value XD is a value determined based on, for example, the indoor temperature and the continuous operation time of the ventilation unit 50. The higher the indoor temperature is, the lower the fourth threshold value XD is. The longer the continuous operation time of the ventilation unit 50 is, the lower the fourth threshold value XD is. The control device 36 updates the fourth threshold value XD from time to time based on a predetermined relational expression including the indoor temperature and the continuous operation time of the ventilation unit 50 as parameters. The control device 36 executes the process of step S11 of the condensation suppression control based on the fourth threshold value XD.

[0083] <6-5> The operation stop condition can be changed arbitrarily. For example, the operation stop condition may be satisfied when the time during which the air conditioning device 20 is performing the condensation suppression operation reaches a third predetermined time TC. The third predetermined time TC is the time when it is predicted that the humidity of the air in the room will decrease to a level at which the occurrence of condensation on the heat exchange element 54 can be suppressed.

[0084] <6-6> In the above embodiment, the operation modes of the air conditioner 20 included the cooling operation, the heating operation, the first dehumidification operation, and the condensation suppression operation, but at least one of the heating operation and the first dehumidification operation can be omitted.

[0085] <6-7> In the above embodiment, the control device 36 notifies that the condensation suppression operation has been performed, but it may also notify that the condensation suppression operation has ended.

[0086] <6-8> Although ventilation unit 50 stops driving supply air fan 52 in step S22 of the fan drive control, supply air fan 52 may be driven so that the rotation speed of supply air fan 52 is lower than the rotation speed of exhaust fan 53.

[0087] <6-9> In the above embodiment, there is no limitation on the shape of the indoor unit 30. The indoor unit 30 may be, for example, a ceiling-suspended type or a wall-mounted type.

[0088] <6-10> In the above embodiment, there is no limitation on the shape of the ventilation unit 50. The ventilation unit 50 may be, for example, a ceiling-suspended type, or an exposed installation type that is installed at any location in the room.

[0089] <6-11> In the above embodiment, the air conditioning apparatus 20 includes one indoor unit 30 and one outdoor unit 40. The number of indoor units 30 and outdoor units 40 included in the air conditioning apparatus 20 is not limited to this. The air conditioning apparatus 20 may include, for example, one outdoor unit 40 and multiple indoor units 30.

[0090] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. [Explanation of symbols]

[0091] 10: Air conditioning system 30: Indoor unit 31: Indoor heat exchanger 34: Humidity sensor 48: Humidity sensor 50: Ventilation unit 52: Intake fan 53: Exhaust fan 54: Heat exchange element 71A: Control program

Claims

1. an indoor unit including an indoor heat exchanger; a ventilation unit including a heat exchange element for exchanging temperature and humidity between the outside and the inside of the room; a humidity sensor for detecting the humidity of air flowing toward the heat exchange element; The indoor unit includes: The control system is configured to execute a first dehumidification operation that is started based on a start instruction from a user and controls the humidity of the indoor air to be less than a first threshold value, and a second dehumidification operation that is started when the humidity of the indoor air is equal to or greater than a second threshold value that is higher than the first threshold value and serves as a condensation suppression operation for suppressing condensation on the heat exchange element, The second dehumidification operation is An air conditioning system that controls the humidity of the air in the room so that it is less than the second threshold value.

2. The air conditioning system according to claim 1 , wherein the indoor unit performs the second dehumidification operation when the humidity of the indoor air is equal to or higher than the second threshold and the humidity of the outdoor air is equal to or higher than a third threshold that is higher than the first threshold.

3. 3. The air conditioning system according to claim 1, wherein the indoor unit performs the second dehumidification operation when the humidity of the air in the room is equal to or higher than the second threshold value and the continuous operation time of the ventilation unit is equal to or longer than a first predetermined time.

4. an indoor unit including an indoor heat exchanger; a ventilation unit including a heat exchange element for exchanging temperature and humidity between the outside and the inside of the room; a humidity sensor for detecting the humidity of air flowing toward the heat exchange element; The indoor unit is configured to perform a second dehumidification operation as a condensation suppression operation performed to suppress condensation on the heat exchange element, The condensation suppression operation is an operation in which the indoor heat exchanger is used as an evaporator, When the indoor unit is in a stopped state and an operation start condition for the indoor unit is satisfied, the indoor unit starts up and starts the condensation suppression operation, The operation start condition includes at least one of a condition related to the humidity of the air in the room and a condition related to the humidity of the air outside the room, and further includes a condition related to a continuous operation time of the ventilation unit. Air conditioning system.

5. The air conditioning system according to claim 4 , wherein the operation start condition includes both a condition related to the humidity of the indoor air and a condition related to the humidity of the outdoor air.

6. The air conditioning system according to any one of claims 1 to 5, wherein, when the indoor unit is performing the condensation suppression operation, the indoor unit stops the condensation suppression operation when the time during which the humidity of the indoor air continues to be below the operation stop threshold reaches a second predetermined time, or when the time during which the condensation suppression operation is being performed reaches a third predetermined time.

7. The ventilation unit includes an intake fan that supplies air into the room and an exhaust fan that exhausts air from the room, The air conditioning system according to any one of claims 1 to 6, wherein the supply air fan and the exhaust fan are controlled so that the exhaust air volume is greater than the supply air volume when the indoor unit is performing the condensation suppression operation.

8. The air conditioning system according to claim 7 , wherein, when the indoor unit is performing the condensation suppression operation, the exhaust fan is controlled to be driven in a state in which the supply air fan is stopped.

9. The air conditioning system according to any one of claims 1 to 8, wherein, when the condensation suppression operation is performed by the indoor unit, a notification is given that the condensation suppression operation has been performed.

10. A control method for an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges temperature and humidity between the outside and the inside of the room, and a humidity sensor that detects the humidity of air flowing toward the heat exchange element, comprising: The indoor unit is configured to execute a first dehumidification operation that is started based on a start instruction from a user and controls the humidity of the indoor air to be less than a first threshold, and a second dehumidification operation that is started when the humidity of the indoor air is equal to or greater than a second threshold that is higher than the first threshold and serves as a condensation suppression operation that is executed to suppress condensation on the heat exchange element, causing the indoor unit to perform the second dehumidification operation so that the humidity of the indoor air is less than the second threshold value.

11. A control program for an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges temperature and humidity between the outside and the inside of the room, and a humidity sensor that detects the humidity of air flowing toward the heat exchange element, The indoor unit is configured to execute a first dehumidification operation that is started based on a start instruction from a user and controls the humidity of the indoor air to be less than a first threshold, and a second dehumidification operation that is started when the humidity of the indoor air is equal to or greater than a second threshold that is higher than the first threshold and serves as a condensation suppression operation that is executed to suppress condensation on the heat exchange element, and causing the indoor unit to perform the second dehumidification operation so that the humidity of the indoor air becomes less than the second threshold value.

12. A control method for an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges temperature and humidity between the outside and the inside of the room, and a humidity sensor that detects the humidity of air flowing toward the heat exchange element, comprising: The indoor unit is configured to perform a second dehumidification operation as a condensation suppression operation performed to suppress condensation on the heat exchange element, The condensation suppression operation is an operation in which the indoor heat exchanger is used as an evaporator, When an operation start condition of the indoor unit is satisfied while the operation of the indoor unit is stopped, starting the indoor unit and causing the indoor unit to start the condensation suppression operation, The operation start condition includes at least one of a condition related to the humidity of the air in the room and a condition related to the humidity of the air outside the room, and further includes a condition related to a continuous operation time of the ventilation unit. A method for controlling an air conditioning system.

13. A control program for an air conditioning system including an indoor unit including an indoor heat exchanger, a ventilation unit including a heat exchange element that exchanges temperature and humidity between the outside and the inside of the room, and a humidity sensor that detects the humidity of air flowing toward the heat exchange element, The indoor unit is configured to perform a second dehumidification operation as a condensation suppression operation performed to suppress condensation on the heat exchange element, The condensation suppression operation is an operation in which the indoor heat exchanger is used as an evaporator, When an operation start condition of the indoor unit is satisfied while the operation of the indoor unit is stopped, the method includes causing a computer to execute a process of starting the indoor unit and causing the indoor unit to start the condensation suppression operation, The operation start condition includes at least one of a condition related to the humidity of the air in the room and a condition related to the humidity of the air outside the room, and further includes a condition related to a continuous operation time of the ventilation unit. Air conditioning system control program.

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