AIR-CONDITIONING SYSTEM, CONTROLLER FOR AIR-CONDITIONING APPARATUS, AND CONTROL METHOD FOR AIR-CONDITIONING APPARATUS

Abstract

An air-conditioning system includes an air-conditioning apparatus including indoor units, temperature detectors each of which detects a temperature of an associated one of zones into which an air-conditioning target space is divided in association with positions of the indoor units, a human detection sensor which detects whether each of the zones is a human presence zone where a person or persons are present or a human absence zone where no person is present, and a controller that causes the indoor unit in the human presence zone to perform cooling/heating operation, thereby causing a temperature detected by the temperature detector in the human presence zone to reach a set temperature. The controller causes the indoor unit in the human absence zone to perform air-sending operation, and determines the volume of air from the indoor unit in the human absence zone based on that in the human presence zone.

Description

TECHNICAL FIELD

The present disclosure relates to an air-conditioning system that conditions air in an air-conditioning target space, a controller for an air-conditioning apparatus, and a control method for the air-conditioning apparatus.

BACKGROUND ART

In the past, air-conditioning apparatuses that condition air in a large space where a lot of persons are present, such as an office building or a business office, have been known (see, for example, Patent Literature 1). An air-conditioning apparatus disclosed in Patent Literature 1 divides an air-conditioning target space into a plurality of control regions, classifies the plurality of control regions into a human presence control region where a person or persons are present and a human absence control region where no person is present, and controls the flow rate of refrigerant that flows in each of indoor units associated with the respective control regions. As a specific example, Patent Literature 1 describes that in the case of performing cooling operation, the air-conditioning apparatus sets a target indoor temperature for the human absence control region to a higher value than that for the human presence control region.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application Publication No. Hei 11-311437

SUMMARY OF INVENTION

Technical Problem

When the number of persons in the human presence control region or the amount of activity of a person in the human presence control region increases, an environmental load in the human presence control region increases. In this case, for example, the air-conditioning apparatus disclosed in Patent Literature 1 can be considered to increase the volume of air from an indoor unit in the human presence control region to increase the cooling capacity of the indoor unit, while keeping the cooling capacity of an indoor unit in the human absence control region at a reduced level. As a result, the amount of air convection between the human presence control region and the human absence control region increases, and air conditioning in the human absence control region is indirectly performed. Inevitably, the energy consumption of the air-conditioning apparatus increases.

The present disclosure is applied to solve the above problem, and relates to an air-conditioning system, a controller for an air-conditioning-apparatus, and a control method for the air-conditioning apparatus, which can reduce the energy consumption of the air-conditioning apparatus.

Solution to Problem

An air-conditioning system according to an embodiment of the present disclosure includes: an air-conditioning apparatus including a plurality of indoor units each configured to condition air in an air-conditioning target space; a plurality of temperature detectors each configured to detect a temperature of an associated one of a plurality of zones into which the air-conditioning target space is divided in association with positions of the plurality of indoor units; a human detection sensor configured to detect whether each of the plurality of zones is a human presence zone where a person or persons are present or a human absence zone where no person is present; and a controller configured to cause, in the human presence zone detected by the human detection sensor, the indoor unit in the detected human presence zone to perform cooling operation or heating operation, thereby causing a temperature detected by an associated one of the temperature detectors to reach a set temperature. The controller is configured to cause the indoor unit in the human absence zone detected by the human detection sensor to perform air-sending operation, and determine a volume of air from the indoor unit in the detected human absence zone based on a volume of air from the indoor unit in the human presence zone.

A controller for an air-conditioning apparatus, according to another embodiment of the present disclosure, is connected to the air-conditioning apparatus, a plurality of temperature detectors, and a human detection sensor. The air-conditioning apparatus includes a plurality of indoor units each configured to condition air in an air-conditioning target space. The plurality of temperature detectors are configured to detect a temperature of an associated one of a plurality of zones into which the air-conditioning target space is divided in association with positions of the plurality of indoor units. The human detection sensor is configured to detect whether a person or persons are present or no person is present in each of the plurality of zones or not. The controller is configured to: cause the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human presence zone where a person or persons are present to perform cooling operation or heating operation, thereby causing a temperature detected by the temperature detector in the human presence zone to reach a set temperature; and cause the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human absence zone where no person is present to perform air-sending operation, and determine a volume of air from the indoor unit in the human absence zone based on a volume of air from the indoor unit in the human presence zone.

A control method for an air-conditioning apparatus, according to still another embodiment of the present disclosure, is a method of controlling, using a controller, the air-conditioning apparatus. The air conditioning apparatus includes a plurality of indoor units each configured to condition air in an air-conditioning target space. The controller is connected to the air-conditioning apparatus, a plurality of temperature detectors, and a human detection sensor. The plurality of temperature detectors are each configured to detect a temperature of an associated one of a plurality of zones into which the air-conditioning target space is divided in association with positions of the plurality of indoor units. The human detection sensor is configured to detect whether a person or persons are present or no person is present in each of the plurality of zones. The control method includes: causing the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human presence zone where a person or persons are present to perform cooling operation or heating operation, thereby causing a temperature detected by the temperature detector in the detected human presence zone to reach a set temperature; and causing the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human absence zone where no person is present to perform air-sending operation, and determining a volume of air from the indoor unit in the detected human absence zone based on a volume of air from the indoor unit in the human presence zone.

Advantageous Effects of Invention

According to the embodiments of the present disclosure, the cooling operation or the heating operation is performed in the human presence zone, the air-sending operation is performed in the human absence zone, and the volume of air for the air-sending operation in the human absence zone is determined based on the volume of air for the cooling operation or the heating operation in the human presence zone. This reduces occurrence of air convection between the human presence zone and the human absence zone, thus reducing occurrence of indirect air conditioning in the human absence zone. As a result, the efficiency of air conditioning in the human presence zone is improved, thus reducing the energy consumption of the air-conditioning apparatus.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a configuration example of an air-conditioning system according to Embodiment 1.

FIG. 2 is a schematic external view of a configuration example of an indoor unit as illustrated in FIG. 1.

FIG. 3 is an enlarged schematic external view of an airflow direction louver as illustrated in FIG. 2.

FIG. 4 is a schematic plan view of an example of the arrangement of indoor units as illustrated in FIG. 1 in Embodiment 1.

FIG. 5 is a functional block diagram illustrating a configuration example of a controller in FIG. 1.

FIG. 6 is a hardware configuration diagram illustrating a configuration example of the controller as illustrated in FIG. 5.

FIG. 7 is a hardware configuration diagram illustrating another configuration example of the controller as illustrated in FIG. 5.

FIG. 8 is a flowchart of an example of an operation procedure of the air-conditioning system according to Embodiment 1.

FIG. 9 is a flowchart of an example of a specific operation procedure of the process of step S110 indicated in FIG. 8 in Embodiment 1.

FIG. 10 is a diagram illustrating an example of the volume of air from each of four indoor units as illustrated in FIG. 4 in the case where one of the indoor units performs cooling operation.

FIG. 11 is a schematic diagram illustrating air flows generated by the indoor units installed in two adjacent zones in a room as illustrated in FIG. 4.

FIG. 12 is a schematic plan view illustrating another example of the arrangement of the indoor units as illustrated in FIG. 1 in Embodiment 1.

FIG. 13 is a diagram illustrating an example of control over 12 indoor units as illustrated in FIG. 12 in the case where four of the indoor units perform the cooling operation.

FIG. 14 is a diagram illustrating an example of the control which is performed in the case where the four indoor units as illustrated in FIG. 4 have different air volume adjustment functions.

FIG. 15 is a schematic plan view illustrating an example of the arrangement of the indoor units as illustrated in FIG. 1 in Embodiment 2.

FIG. 16 is a flowchart indicating an example of a specific operation procedure of the process of step S110 indicated in FIG. 8 in Embodiment 2.

FIG. 17 is a schematic plan view illustrating another example of the arrangement of the indoor units as illustrated in FIG. 1, in Embodiment 2.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure will be described in detail with reference to the drawings. Regarding the embodiments, various specific settings will be described by way of example, and those descriptions are not limiting. In the embodiments according to the present disclosure, communication means one or both of wireless communication and wired communication. In the embodiments, communication may be a communication method in which wireless communication and wired communication are mixed. The communication method may be, for example, a communication method in which wireless communication is performed in a space and wired communication is performed in another space. Furthermore, a first device may communicate with a second device by wire, and the second device may communicate with the first device wirelessly. In addition, in order that the embodiments be more easily understood, arrows indicating three axes (X axis, Y axis, and Z axis) defining directions are added to some of the figures of the drawings.

Embodiment 1

A configuration of an air-conditioning system according to Embodiment 1 will be described. FIG. 1 is a block diagram illustrating a configuration example of the air-conditioning system according to Embodiment 1. As illustrated in FIG. 1, an air-conditioning system 1 includes an air-conditioning apparatus 3 that conditions air in an air-conditioning target space, and a controller 30 that controls the air-conditioning apparatus 3. The air-conditioning apparatus 3 includes an outdoor unit 10 and a plurality of indoor units 20-1 to 20-n. It should be noted that n is an integer greater than or equal to 2 and represents the number of indoor units. Each of the indoor units to 20-n conditions the air in the air-conditioning target space depending on which of operation modes is set. In each of the operation modes, an associated one of a cooling operation, a heating operation, a dehumidifying operation, an air-sending operation, etc., is performed. Each indoor unit may have a humidifying function or a moisturizing function.

The outdoor unit 10 includes a compressor 11, a four-way valve 12, a heat-source-side heat exchanger 13, and an outdoor fan 14. Each of the indoor units 20-1 to 20-n includes a load-side heat exchanger 21, an expansion valve 22, an indoor fan 23, and a temperature detector 24. In addition to the load-side heat exchanger 21, the expansion valve 22, the indoor fan 23, and the temperature detector 24, a human detection sensor 25 is provided in the indoor unit 20-2. The compressor 11 and the heat-source-side heat exchanger 13 are connected to the expansion valve 22 and the load-side heat exchanger 21 of each of the indoor units by refrigerant pipes 15, whereby a refrigerant circuit 40 in which refrigerant circulates is formed.

The compressor 11 sucks refrigerant, compresses the sucked refrigerant, and then discharges the compressed refrigerant. The compressor 11 is, for example, an inverter compressor whose capacity is variable. The four-way valve 12 changes the flow direction of refrigerant that flows in the refrigerant circuit 40. The expansion valve 22 reduces the pressure of the refrigerant to expand the refrigerant. The expansion valve 22 is, for example, an electronic expansion valve. The heat-source-side heat exchanger 13 is a heat exchanger that causes heat exchange to be performed between the refrigerant and outdoor air. The load-side heat exchanger 21 is a heat exchanger that causes heat exchange to be performed between the refrigerant and the air in the air-conditioning target space. The heat-source-side heat exchanger 13 and the load-side heat exchanger 21 are, for example, finned tube heat exchangers. The outdoor fan 14 is, for example, a propeller fan. The outdoor fan 14 changes the volume of air depending on an operating frequency. The indoor fan 23 is, for example, a cross-flow fan.

The controller 30 is connected to the temperature detector 24 and the human detection sensor 25 in each of the indoor units 20-1 to 20-n by signal lines (not illustrated), but may be wirelessly connected to these components. The controller 30 is connected to the compressor 11, the four-way valve 12, and the outdoor fan 14 by signal lines (not illustrated), but may be wirelessly connected to these components. The controller 30 is connected to the expansion valve 22 and the indoor fan 23 in each of the indoor units 20-1 to 20-n by signal lines (not illustrated), but may be wirelessly connected to these components.

FIG. 2 is a schematic external view illustrating a configuration example of the indoor unit as illustrated in FIG. 1. Although the following description concerning Embodiment 1 is made with respect to the case where the indoor units 20-1 to 20-n are four-way ceiling cassette type indoor units, the indoor units are not limited to the four-way ceiling cassette type indoor units. FIG. 2 illustrates an external appearance as the indoor unit 20-2 mounted on a ceiling is viewed from a region located obliquely below the indoor unit 20-2. The appearance configuration of the indoor unit 20-2 will be described with reference to FIG. 2. Since the appearance configurations of the other indoor units are the same as that of the indoor unit 20-2, their descriptions will be omitted

As illustrated in FIG. 2, the indoor unit 20-2 has a lower surface 29 that has a rectangular shape. The lower surface 29 has four air outlets 27a to 27d and an air inlet 26. The air inlet 26 is located in a central portion of the lower surface 29. At the air inlet 26, a lattice frame (not illustrated) is provided. The air outlets 27a to 27d are arranged around the air inlet 26 and extend along four sides of the air inlet 26.

At the air outlets 27a to 27d, airflow direction louvers 28a to 28d are provided to control the flow direction of air. In the configuration example as illustrated in FIG. 2, each of the airflow direction louvers 28a to 28d includes two rectangular flaps. Specifically, at the air outlet 27a, the airflow direction louver 28a is provided; at the air outlet 27b, the airflow direction louver 28b is provided; at the air outlet 27c, the airflow direction louver 28c is provided; and at the air outlet 27d, the airflow direction louver 28d is provided.

FIG. 3 is an enlarged schematic external view of the airflow direction louver as illustrated in FIG. 2. FIG. 3 is an enlarged view of the airflow direction louver 28a of the indoor unit 20-2. In FIG. 3, the angle of each of the two flaps of the airflow direction louver 28a relative to a reference plane that is parallel to the ceiling is indicated as a depression angle 8. Each of the two flaps of the airflow direction louver 28a has a rotary shaft 45. The rotary shaft 45 is connected to a driving unit (not illustrated). The driving unit (not illustrated) rotates the rotary shaft 45 to adjust the depression angle θ of the airflow direction louver 28a.

FIG. 4 is a schematic plan view illustrating an example of the arrangement of the indoor units as illustrated in FIG. 1 in Embodiment 1. In the example illustrated in FIG. 4, the number n of indoor units is four. FIG. 4 illustrates the arrangement of the indoor units 20-1 to 20-4 in a room RM1 that is an air-conditioning target space, as viewed downward from a region located above the ceiling of the room RM1.

The space in the room RM1 is divided into a plurality of zones Z11 to Z23 in association with the positions of the indoor units 20-1 to 20-4. FIG. 4 illustrates the case where the zones Z21 and Z23 are arranged on the assumption that indoor units are installed in regions in which actually, no indoor unit is installed at the ceiling. It is assumed herein that the zones Z11 to Z23 each have a square shape as viewed in plan view.

The temperature detectors 24 each detects a temperature of an associated one of the four zones arranged in association with the positions of the indoor units 20-1 to The temperature detector 24 in each of the indoor units 20-1 to 20-4 outputs a detection result to the controller 30. The temperature detector 24 is, for example, a temperature sensor, such as a thermistor.

The human detection sensor 25 detects, with respect to each of the plurality of zones, whether the zone is a human presence zone where a person or persons are present or a human absence zone where no person is present. The human detection sensor 25 is, for example, an infrared sensor. The human detection sensor 25 outputs, as a detection result, infrared image data which is data obtained by scanning the air-conditioning target space with infrared rays, to the controller 30. In the example illustrated in FIG. 1, the human detection sensor 25 is provided at the indoor unit 20-2; however, the human detection sensor 25 may be provided at a place other than the indoor unit 20-2. In other words, regarding the position of the human detection sensor it suffices that the human detection sensor 25 is provided at any position as long as the human detection sensor 25 can determine whether a person or persons are present in the entire air-conditioning target space or not.

FIG. 5 is a functional block diagram illustrating a configuration example of the controller as illustrated in FIG. 1. The controller 30 is, for example, a microcomputer. The controller 30 is connected to a remote control (not illustrated) with which a user inputs setting information on, for example, an operation mode and a set temperature, to the air-conditioning apparatus 3. The user may input setting information to the controller 30, using an information processing terminal including a personal digital assistant (PDA), such as a smartphone or a tablet, and a personal computer. As illustrated in FIG. 5, the controller 30 includes a refrigeration cycle controller 31, a zone determination module 32, an air-volume controller 33, and an airflow direction controller 34.

The zone determination module 32 holds a management table that includes information on the arrangement of the indoor units 20-1 to 20-4 and the positions of the zones Z11 to Z23 as indicated in FIG. 4. The management table stores information on the coordinates of each of the positions of the indoor units 20-1 to 20-4, information on the arrangement of zones associated with the positions of the indoor units, and zone information indicating whether each of the zones is the human presence zone or the human absence zone. For example, assuming that the indoor unit 20-1 is located at a reference position, the management table stores data on a distance Ly1 between the indoor unit 20-1 and the indoor unit 20-2 in a direction along the Y-axis indicated in FIG. 4. The management table stores data on a distance Lx1 between the indoor unit 20-2 and the indoor unit 20-3 in a direction indicated by an X arrow in FIG. 4 and data on a distance Ly1 between the indoor unit 20-2 and the indoor unit 20-4 in the direction indicated by the Y arrow in FIG. 4. The zone determination module 32 determines, at regular intervals, whether each of the zones is the human presence zone or the human absence zone, based on infrared image data from the human detection sensor 25. When the result of the above determination differs from the zone information stored in the management table, the zone determination module 32 updates the management table such that the zone information indicates the latest determination result. When the management table is updated, the zone determination module 32 transmits information on the updated management table to the refrigeration cycle controller 31 and the air-volume controller 33.

When receiving the information on the management table from the zone determination module 32, the refrigeration cycle controller 31 controls operation of the indoor unit installed in the human presence zone such that a temperature detected by the temperature detector 24 located in the human presence zone falls within a predetermined temperature range with reference to the set temperature.

When the temperature detected by the temperature detector 24 in the human presence zone is lower than the set temperature, the refrigeration cycle controller 31 controls the four-way valve 12 to cause the refrigerant discharged from the compressor 11 to flow to the load-side heat exchanger 21 in order that the indoor unit in the human presence zone perform the heating operation. When the temperature detected by the temperature detector 24 in the human presence zone is higher than the set temperature, the refrigeration cycle controller 31 controls the four-way valve 12 to cause the refrigerant discharged from the compressor 11 to flow to the heat-source-side heat exchanger 13 in order that the indoor unit in the human presence zone perform the cooling operation. The operation mode, such as a heating operation mode or a cooling operation mode, may be set by the user.

The refrigeration cycle controller 31 sets the state of the expansion valve 22 of the indoor unit in the human absence zone to a closed state. The refrigeration cycle controller 31 controls an operating frequency of the compressor 11, the operating frequency of the outdoor fan 14, and an opening degree of the expansion valve 22 of the indoor unit 20-2 to cause the temperature detected by the temperature detector 24 in the human presence zone to fall within the predetermined temperature range with reference to the set temperature. The refrigeration cycle controller 31 transmits air-volume control information to the air-volume controller 33 and the airflow direction controller 34. This air-volume control information includes information on an air volume set by the user and information indicating that the indoor unit in the human absence zone is caused to perform air-sending operation. The air-volume controller 33 controls an operating frequency of the indoor fan 23 of the indoor unit in the human presence zone on the basis of the air volume set by the user. In Embodiment 1, the indoor fan 23 included in each of the indoor units 20-1 to is configured such that the air volume can be changed in multiple levels, depending on the operating frequency. For example, the air volume levels are four levels, fL1 to fL4. The levels satisfy the relationship “fL1<fL2<fL3<fL4”.

The air-volume controller 33 causes the indoor unit in the human absence zone to perform the air-sending operation, and determines, based on the volume of air from the indoor unit in the human presence zone, the volume of air from the indoor unit in the human absence zone. For example, the air-volume controller 33 causes the volume of air from the indoor unit in the human absence zone to be larger than the volume of air from the indoor unit in the human presence zone. In the case where a plurality of human presence zones are present, the air-volume controller 33 determines the volume of air from the indoor unit in the human absence zone on the basis of the volume of air from the indoor unit in one of the human presence zones that is the closest to the human absence zone. The air-volume controller 33 may increase the volume of air from the indoor unit in the human absence zone, depending on the distance between the indoor unit in the human absence zone and the indoor unit in the human presence zone.

The airflow direction controller 34 determines the depression angle θ of the airflow direction louvers 28a to 28d at the air outlets 27a to 27d of the indoor unit in the human absence zone on the basis of the depression angle θ of the airflow direction louvers 28a to 28d at the air outlets 27a to 27d of the indoor unit in the human presence zone. For example, the airflow direction controller 34 sets the depression angle θ of the airflow direction louvers 28a to 28d at the air outlets 27a to 27d of the indoor unit in the human absence zone to the same angle as that of the airflow direction louvers 28a to 28d at the air outlets 27a to 27d of the indoor unit in the human presence zone. An example of hardware of the controller 30 as illustrated in FIG. 5 will be described. FIG. 6 is a hardware configuration diagram illustrating a configuration example of the controller as illustrated in FIG. 5. In the case where the various functions of the controller 30 are fulfilled by hardware, the controller 30 as illustrated in FIG. 5 includes a processing circuit 80 as illustrated in FIG. 6. The processing circuit 80 fulfills the functions of the refrigeration cycle controller 31, the zone determination module 32, the air-volume controller 33, and the airflow direction controller 34 which are provided as illustrated in FIG. 5.

In the case where the functions are fulfilled by hardware, the processing circuit 80 is, for example, a single-component circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a combination of those circuits and processors. The functions of the refrigeration cycle controller 31, the zone determination module 32, the air-volume controller 33, and the airflow direction controller 34 may be fulfilled by individual processing circuits 80. The functions of the refrigeration cycle controller 31, the zone determination module 32, the air-volume controller 33, and the airflow direction controller 34 may be fulfilled by a single processing circuit 80. Another example of the hardware of the controller 30 as illustrated in FIG. 5 will be described. FIG. 7 is a hardware configuration diagram illustrating another configuration example of the controller as illustrated in FIG. 5. In the case where the various functions of the controller 30 are fulfilled by software, the controller 30 as illustrated in FIG. 5 includes a processor 81, such as a central processing unit (CPU), and a memory 82, as illustrated in FIG. 7. The processor 81 and the memory 82 fulfill the functions of the refrigeration cycle controller 31, the zone determination module 32, the air-volume controller 33, and the airflow direction controller 34. FIG. 7 illustrates the processor 81 and the memory 82 which are connected by a bus 83 such that the processor 81 and the memory 82 can communicate with each other. In the case where the hardware of the controller 30 has a configuration as illustrated in FIG. 7, the memory 82 stores the management table. Furthermore, the memory 82 stores programs associated with flowcharts, which will be described later.

In the case where the functions are fulfilled by software, the functions of the refrigeration cycle controller 31, the zone determination module 32, the air-volume controller 33, and the airflow direction controller 34 are fulfilled by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and are stored in the memory 82. The processor 81 reads the programs stored in the memory 82 and runs the programs, thus fulfilling the functions.

As the memory 82, a nonvolatile semiconductor memory, such as a read-only memory (ROM), a flash memory, an erasable and programmable ROM (EPROM), or an electrically erasable and programmable ROM (EEPROM), is used. Also, as the memory 82, a volatile semiconductor memory, such as a random access memory (RAM), may be used. Furthermore, as the memory 82, for example, a removable recording medium, such as a magnetic disk, a flexible disk, an optical disc, a compact disc (CD), a MiniDisc (MD), or a digital versatile disc (DVD), may be used.

Operation of the controller 30 according to Embodiment 1 will be described. FIG. 8 is a flowchart of an example of the operation procedure of the air-conditioning system according to Embodiment 1. The controller 30 executes processes indicated in FIG. 8 at regular intervals. For convenience of explanation, of the plurality of zones in the air-conditioning target space, an arbitrary zone in which the indoor unit is installed is denoted by Zij, where i and j are integers greater than or equal to 1. Nx is a maximum value of i, and Ny is a maximum value of j.

The zone determination module 32 obtains infrared image data from the human detection sensor 25 (step S101). The zone determination module 32 determines whether or not it is necessary to update the management table held by the zone determination module 32 (step S102). For example, when the air-conditioning apparatus 3 is started by the user from an operation-stopped state in which the air-conditioning apparatus 3 is in a stopped state, the zone determination module 32 determines that it is necessary to update the management table held by the zone determination module 32. Also, in step S102, the zone determination module 32 determines whether or not the position of a human presence zone determined based on the obtained infrared image data coincides with that indicated by data stored in the management table held by the zone determination module 32. As the result of the above determination, when determining that the human presence zone is changed, the zone determination module 32 determines that it is necessary to update the management table, and the process proceeds to step S103. By contrast, when determining that the human presence zone is not changed, the zone determination module 32 determines that it is not necessary to update the management table, and the process proceeds to step S111. In step S103, the refrigeration cycle controller obtains temperature information from the temperature detector 24 in each of the indoor units 20-1 to 20-n and stores the obtained information in the management table held by the zone determination module 32. The zone determination module 32 sets 1 as i of the zone Zij and sets 1 as j of the zone Zij (step S104). A combination of i and j is represented as (i, j). With respect to the room RM1 as illustrated in FIG. 4, combinations of (i, j) are (1, 1), (1, 2), (2, 2), and (1, 3).

The zone determination module 32 determines whether or not the zone Zij is the human presence zone, based on the infrared image data from the human detection sensor 25 (step S105). In this case, it is assumed that Zij=Z11. The zone determination module 32 transmits the result of the determination to the refrigeration cycle controller 31 and the air-volume controller 33. When the zone determination module 32 determines that the zone Zij is the human presence zone, the refrigeration cycle controller 31 causes the indoor unit installed in the zone Zij to perform the cooling operation or the heating operation (step S106). The refrigeration cycle controller 31 controls the air-conditioning apparatus 3 such that the temperature detected by the temperature detector 24 in the human presence zone approaches the set temperature.

When it is determined in step S105 that the zone Zij is the human absence zone, the refrigeration cycle controller 31 closes the expansion valve 22 of the indoor unit installed in the zone Zij to cause the indoor unit to perform the air-sending operation (step S107). The air-volume controller 33 causes the indoor fan 23 of the indoor unit in the zone Zij to operate. The zone determination module 32 determines whether or not a condition where i=Nx and j=Ny is satisfied (step S108). When determining that the condition where i =Nx and j=Ny is not satisfied, the zone determination module 32 changes the value of i or j and determines the next zone Zij (step S109), and the process returns to step S105. When it is determined in step S108 that the condition where i=Nx and j=Ny is satisfied and the operation modes in all the zones Zij in which the indoor units are installed are determined, the process by the air-volume controller 33 proceeds to step S110. Where Zhk is an arbitrary human absence zone, in step S110, the air-volume controller 33 controls the volume of air from the indoor unit in the human absence zone Zhk on the basis of the volume of air from the indoor unit in the human presence zone.

A specific example of the process of step S110 will be described later.

After the process of step S110 by the air-volume controller 33 ends, the refrigeration cycle controller 31 determines whether or not the set temperature for the human presence zone is changed by the user (step S111). When determining that the set temperature for the human presence zone is changed by the user, the process by the refrigeration cycle controller 31 returns to step S103. The refrigeration cycle controller 31 changes details of control over the air-conditioning apparatus 3 on the basis of the changed set temperature. When determining in S111 that the set temperature for the human presence zone is not changed, the refrigeration cycle controller 31 ends the process.

The process of step S110 as indicated in FIG. 8 by the air-volume controller 33 will be described in detail. FIG. 9 is a flowchart of an example of a specific operation procedure of the process of step S110 as indicated in FIG. 8 in Embodiment 1.

The zone determination module 32 refers to the management table and calculates, with respect to the indoor unit in each of the human absence zones Zhk, a distance L between the indoor unit in the human absence zone Zhk and the indoor unit in the human presence zone (step S201). In the case where a plurality of human presence zones are present, the zone determination module 32 calculates, with respect to the indoor units in each of the human absence zones Zhk, the distances L between the indoor unit in the human absence zone Zhk and the indoor units in the human presence zones. The zone determination module 32 stores, with respect to the indoor unit in each of the human absence zones Zhk, the calculated distance L in the management table.

The air-volume controller 33 refers to the management table and determines whether or not a plurality of human presence zones are present (step S202). When determining that only one human presence zone is present, the air-volume controller 33 determines whether or not the distances L between the indoor units in the human absence zones Zhk and the indoor unit in the human presence zone are equal to each other (step S203). When determining that the distances L between the indoor units in the human absence zones Zhk and the indoor unit in the human presence zone are equal to each other, the air-volume controller 33 sets the volume of air from the indoor unit in each of the human absence zones Zhk to a value greater than the volume of air from the indoor unit in the human presence zone (step S204). By contrast, when determining that the distances L between the indoor units in the human absence zones Zhk and the indoor unit in the human presence zone are not equal to each other, the air-volume controller 33 sets the volume of air from the indoor unit in each of the human absence zones Zhk to a value that is greater than the volume of air from the indoor unit in the human presence zone and that depends on an associated one of the distances L (step S205).

When determining in step S202 that a plurality of human presence zones are present, the air-volume controller 33 determines, with respect to each of the human absence zones Zhk, one of the indoor units in the human presence zones that is separated from the indoor unit in the human absence zone Zhk by a shortest distance Lmin which is the shortest one of the distances between the indoor unit in the human absence zone Zhk and the indoor units in the human presence zones (step S206). Also, with respect to each of the human absence zones Zhk, the air-volume controller 33 sets the volume of air from the indoor unit in the human absence zone Zhk to a value that is greater than the volume of air from the indoor unit separated from the indoor unit in the human absence zone Zhk by the shortest distance Lmin and that depends on the shortest distance Lmin (step S207). In steps S205 and S207, the air-volume controller 33 increases the operating frequency of the indoor fan 23 of the indoor unit in each human absence zone Zhk to increase the volume of air from the indoor unit. As described above, the volume of air from the indoor unit in each of the human absence zones is set based on the present volume of air in the cooling operation or the heating operation of the indoor unit in the human presence zone and the distance L between the indoor unit in the human absence zone and the indoor unit in the human presence zone.

A specific example of control that is performed by the controller 30 according to the flowcharts indicated in FIGS. 8 and 9 will be described on the assumption that the air-conditioning target space is the room RM1 as illustrated in FIG. 4. It is assumed that, of the zones Z11 to Z23 as illustrated in FIG. 4, the zone Z12 is a human presence zone, and the zones Z11, Z21, Z22, Z13, and Z23 are human absence zones. The following description is made with respect to the case where the indoor unit 20-2 in the zone Z12, which is the human presence zone, performs the cooling operation; however, the indoor unit 20-2 may perform the heating operation.

FIG. 10 is a diagram illustrating an example of the volume of air from each of the four indoor units as illustrated in FIG. 4 in the case where one of the four indoor units performs the cooling operation. In Embodiment 1, each of the indoor units 20-1 to 20-4 can change the volume of air to be sent, in four stages; that is, change the level of the volume of the air to four air volume levels, fL1 to fL4, as indicated in FIG. 10. The air volume levels fL1 to fL4 satisfy the relationship “fL1<fL2<fL3<fL4”.

For the room RM1 as illustrated in FIG. 4, in steps S105 to S107 indicated in FIG. 8, the refrigeration cycle controller 31 causes the indoor unit 20-2 to perform the cooling operation, and the air-volume controller 33 causes the indoor units 20-1, 20-3, and 20-4 to perform the air-sending operation. In the process of step S201 indicated in FIG. 9, the zone determination module 32 refers to the management table, and calculates, with respect to each of the indoor units in the human absence zones Zhk, the distance L between the indoor unit in the human absence zone Zhk and the indoor unit 20-2 in the zone Z12. Referring to FIG. 4, combinations of (h, k) are (1, 1), (2, 2), and (1, 3). The distance L between the indoor unit 20-1 and the indoor unit 20-2 is the distance Ly1, the distance L between the indoor unit 20-2 and the indoor unit 20-3 is the distance Lx1, and the distance L between the indoor unit 20-2 and the indoor unit 20-4 is the distance Ly1. In this case, Lx1=Ly1.

Since it is determined in step S202 that only the zone Z12 is the human presence zone, in step S203, he air-volume controller 33 determines whether the distances L between the indoor units in the human absence zones Zhk and the indoor unit in the human presence zone are equal to each other or not. In the above case, since the distances L between the indoor units in the human absence zones Zhk and the indoor unit in the human presence zone are equal to each other, in the process of step S204, the air-volume controller 33 sets the level of the volume of air from the indoor unit in each of the human absence zones Zhk to a level higher than that of the volume of air from the indoor unit 20-2 in the human presence zone. In the example illustrated in FIG. 10, because the level of the volume of air from the indoor unit 20-2 in the zone Z12 is the air volume level fL1, the level of the volume of air from each of the indoor units in the human absence zones Zhk is set to the air volume level fL2, which is higher than the air volume level fL1 for the indoor unit 20-2, by the air-volume controller 33. FIG. 11 is a schematic diagram illustrating air flows generated by the indoor units installed in two adjacent zones in the room as illustrated in FIG. 4. Also, FIG. 11 is a schematic side view of the space in the zones Z12 and Z22 in FIG. 4, as viewed in the direction along the Y-axis. As illustrated in FIG. 11, air blown from the air outlets 27b and 27d of the indoor unit 20-2 in the zone Z12, which is the human presence zone, flows in the space in the zone Z12 and is then sucked into the air inlet 26 of the indoor unit 20-2. Air blown from the air outlets 27b and 27d of the indoor unit 20-3 in the zone Z22, which is the human absence zone, flows in the space in the zone Z22 and is then sucked into the air inlet 26 of the indoor unit 20-3. The volume of air from the air outlet 27b of the indoor unit 20-3 in the zone Z22 is larger than that from the air outlet 27d of the indoor unit 20-2 in the zone Z12. This reduces occurrence of leakage of a cooling air flow in the human presence zone therefrom into the human absence zone, thus reducing occurrence of air convection between the human presence zone and the human absence zone that are adjacent.

Although the above description is made regarding the indoor unit 20-3 in the zone Z22 as illustrated in FIG. 4, with reference to FIG. 11, the same is true of the indoor units and 20-4 in the other human absence zones. Accordingly, it is also possible to reduce occurrence of the leakage of a cooling air flow in the zone Z12, which is the human presence zone, therefrom into the zones Z11, Z22, and Z13, which are the human absence zones, in the arrangement illustrated in FIG. 4. As a result, the cooling air flows can be trapped in the human presence zone.

Furthermore, it is assumed that the direction of air from the indoor unit 20-2 is a depression angle e12, and the direction of air from the indoor unit 20-3 is a depression angle e22. In the example illustrated in FIG. 11, the depression angles e12 and e22 satisfy the relationship “e12=e22”. When the relationship “e12=e22” is satisfied, a cooling air flow blown from the air outlet 27d of the indoor unit 20-2 and an air flow blown from the air outlet 27b of the indoor unit 20-3 collide with each other and then flow parallel to each other and toward a floor surface. Thus, the air flow in the human absence zone forms an air curtain perpendicular to the floor surface (in the direction along the Z-axis) at the boundary between the human presence zone and the human absence zone, thereby reducing occurrence of leakage of the cooling air flow in the human presence zone into the human absence zone.

The airflow direction controller 34 may adjust, depending on the operation mode of the indoor unit in the human presence zone, the depression angle θ corresponding to the direction of air from the indoor unit in the human presence zone and the depression angle θ corresponding to the direction of air from the indoor unit in the human absence zone. For example, when the operation mode of the indoor unit 20-2 is the heating operation mode, the airflow direction controller 34 adjusts the airflow direction louvers 28a to 28d of the indoor unit 20-2 such that the depression angle e12 approaches 90 degrees. That is, the airflow direction controller 34 controls the indoor unit 20-2 such that warm air is blown vertically downward from the indoor unit 20-2. In this case, the airflow direction controller 34 adjusts the airflow direction louvers 28a to 28d of the indoor unit 20-3 such that the depression angle e22 also approaches 90 degrees. By contrast, when the operation mode of the indoor unit 20-2 is the cooling operation mode, the airflow direction controller 34 adjusts the airflow direction louvers 28a to 28d of the indoor unit 20-2 such that the depression angle e12 approaches 0 degrees. That is, the airflow direction controller 34 controls the indoor unit 20-2 such that cooling air is blown horizontally from the indoor unit 20-2. In this case, the airflow direction controller 34 adjusts the airflow direction louvers 28a to 28d of the indoor unit 20-3 such that the depression angle e22 also approaches 0 degrees. Whichever of the heating operation mode and the cooling operation mode is set, an air flow in the human absence zone forms an air curtain perpendicular to the floor surface at the boundary between the human presence zone and the human absence zone, thereby reducing occurrence of leakage of an air flow in the human presence zone therefrom into the human absence zone.

The airflow direction controller 34 may determine the depression angle θ corresponding to the direction of air from the indoor unit in the human absence zone on the basis of the distance L between the indoor unit in the human absence zone and one of the indoor units in the human presence zones that is the closest to the indoor unit in the human absence zone. For example, the airflow direction controller 34 determines the depression angle θ corresponding to the direction of air from the indoor unit in the human absence zone such that the greater the distance L, the smaller the depression angle θ. As a result, even when the distance L is great, an air flow produced by the air-sending operation in the human absence zone easily reaches the human presence zone.

Next, as another specific example, it will be described how the controller 30 controls the indoor units in a room RM2 as illustrated in FIG. 12. FIG. 12 is a schematic plan view illustrating another example of the arrangement of the indoor units as illustrated in FIG. 1 in Embodiment 1. In the example illustrated in FIG. 12, the number n of indoor units is 12. FIG. 12 illustrates the arrangement of the indoor units 20-1 to in the room RM2, which is an air-conditioning target space, as viewed from a region above a ceiling of the room RM2. Of the zones Z11 to Z34, the zones Z11, Z12, Z23, and Z14 are human presence zones, and the other eight zones are human absence zones.

It is assumed that the zones as illustrated in FIG. 12 each have a square shape as viewed in plan view. As illustrated in FIG. 12, Ly1 is the distance L between the indoor units in the two zones Z11 and Z12 that are adjacent to each other in the direction along the Y-axis, and Lx1 is the distance L between the indoor units in the two zones Z11 and Z21 that are adjacent to each other in the direction along the X-axis. The distances Lx1 and Ly1 satisfy the relationship “Lx1=Ly1”. In FIG. 12, indication of the distances Lx1 between the other indoor units in the direction along the X-axis and the distances Ly1 between the other indoor units in the direction along the Y-axis is omitted.

Furthermore, where Lxy is the distance L between the indoor unit in the zone Z11 and the indoor unit in the zone Z22 located on an extension of a diagonal line of the zone Z11, that is, located in an oblique direction from the zone Z11, the distances Lxy, Lx1, and Ly1 satisfy the relationship “Lxy²=Lx1²+Ly1²”, that is, “Lxy=Lx1×√2=Ly1×√2”.

For the room RM2 as illustrated in FIG. 12, in steps S105 to S107 indicated in FIG. 8, the refrigeration cycle controller 31 causes the indoor units 20-1, 20-4, 20-8, and 20-10 perform the cooling operation, and the air-volume controller 33 causes the other eight indoor units including the indoor unit 20-2 to perform the air-sending operation.

In the process of step S201 indicated in FIG. 9, the zone determination module 32 refers to the management table and calculates, with respect to each of the indoor units in the human absence zones Zhk, the distance L between the indoor unit in the human absence zone Zhk and the indoor unit in the human presence zone. In the example illustrated in FIG. 12, combinations of (h, k) are (2, 1), (3, 1), (2, 2), (3, 2), (1, 3), (3, 3), (2, 4), and (3, 4).

Since it is determined in step S202 that a plurality of human presence zones are present, in step S206, the air-volume controller 33 specifies, with respect to each of the human absence zones Zhk, one of the indoor units in the human presence zones that is separated from the indoor unit in the human absence zone Zhk by a shortest distance Lmin which is the shortest one of the distances L between the indoor units in the human presence zones and the indoor unit in the human absence zone. For example, it is assumed that the human absence zone Zhk to be controlled is the zone Z21. In this case, it is determined in step S206 that the indoor unit which is separated from the indoor unit in the human absence zone by the shortest distance Lmin is the indoor unit (Lmin=Lx1). In the case where, as described above, the zone Z21 is the human absence zone Zhk to be controlled, in step S207, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-2 to a level that is higher than that of the volume of air from the indoor unit 20-1 and that depends on the shortest distance

Lmin. When the level of the volume of air from the indoor unit 20-1 is the air volume level fL2, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-2 to the air volume level fL3, which is higher by one level than the air volume level fL2, because the shortest distance Lmin=Lx1 is the shortest one of the above distances between the indoor units.

FIG. 13 is a diagram illustrating an example of the control over each of the 12 indoor units as illustrated in FIG. 12 in the case where four of the indoor units perform the cooling operation. The volume of air from each of the indoor units in the human absence zones other than the zone Z21 will be described. It is assumed that, as indicated in FIG. 13, the level of the volume of air from each of the indoor units 20-1 and is set to the air volume level fL2, and the level of the volume of air from each of the indoor units 20-8 and 20-10 is set to the air volume level fL1. For the zone Z31, the indoor unit in the human presence zone that is separated from the indoor unit in the zone Z31 by the shortest distance Lmin is the indoor unit 20-1, and the shortest distance Lmin=2×Lx1. Since the shortest distance Lmin>Lx1, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-3 to the air volume level fL4, which is higher by one level than the air volume level fL3 which is set in the case where the shortest distance Lmin=Lx1.

For the zone Z22, the indoor units in the human presence zones that are separated from the indoor unit in the zone Z22 by the shortest distance Lmin are the indoor units 20-4 and 20-8, and the shortest distance Lmin=Lx1=Ly1. The level of the volume of air from the indoor unit 20-4 is the air volume level fL2, which is higher than the air volume level fL1 for the indoor unit 20-8. Therefore, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-5 to the air volume level fL3, which is higher by one level than the air volume level fL2 for the indoor unit 20-4.

For the zone Z32, the indoor unit in the human presence zone that is separated from the indoor unit in the zone Z32 by the shortest distance Lmin is the indoor unit 20-8, and the shortest distance Lmin =Lx1×√2. Although the shortest distance Lmin>Lx1, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-6 to the air volume level fL3 since the level of the volume of air from the indoor unit is the air volume level fL1.

For the zone Z13, the indoor units in the human presence zones that are separated from the indoor unit in the zone Z13 by the shortest distance Lmin are the indoor units 20-4, 20-8, and 20-10, and the shortest distance Lmin=Lx1=Ly1. The level of the volume of air from the indoor unit 20-4 is the air volume level fL2, which is higher than the air volume level fL1 for the indoor units 20-8 and 20-10. Therefore, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-7 to the air volume level fL3, which is higher by one level than the air volume level fL2 for the indoor unit 20-4.

For the zone Z33, the indoor unit in the human presence zone that is separated from the indoor unit in the zone Z33 by the shortest distance Lmin is the indoor unit 20-8, and the shortest distance Lmin=Lx1. Since the shortest distance Lmin=Lx1 and the level of the volume of air from the indoor unit 20-8 is the air volume level fL1, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-9 to the air volume level fL2, which is higher by one level than the air volume level fL1 for the indoor unit 20-8.

For the zone Z24, the indoor units in the human presence zones that are separated from the indoor unit in the zone Z24 are the indoor units 20-8 and 20-10, and the shortest distance Lmin=Lx1=Ly1. The shortest distance Lmin=Lx1=Ly1, and the level of the volume of air from each of the indoor units 20-8 and 20-10 is the air volume level fL1. Therefore, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-11 to the air volume level fL2, which is higher by one level than the air volume level fL1 for the indoor units 20-8 and 20-10.

For the zone Z34, the indoor unit in the human presence zone that is separated from the indoor unit in the zone Z34 by the shortest distance Lmin is the indoor unit 20-8, and the shortest distance Lmin=Lx1×√2. Although the level of the volume of air from the indoor unit 20-8 is the air volume level fL1, the air-volume controller 33 sets the level of the volume of air from the indoor unit 20-12 to the air volume level fL3 since the shortest distance Lmin>Lx1.

For example, in the case where the volume of air from an indoor unit in a human presence zone is the air volume level fL1, the air-volume controller 33 sets the level of the volume of air from an indoor unit in a human absence zone adjacent to the above human presence zone to the air volume level fL2. In the case where a human absence zone is located diagonally from the human presence zone, the air-volume controller 33 sets the level of the volume of air from the indoor unit in the human absence zone to the air volume level fL3. In the case where no human presence zone is present around or adjacent to the human absence zone, the air-volume controller 33 sets the level of the volume of air from the indoor unit in the human absence zone to the air volume level fL4.

The air-volume controller 33 determines the volume of air from the indoor unit in the human absence zone on the basis of the distance between the indoor unit in the human absence zone and the indoor unit in the human presence zone. As described above with reference to FIG. 13, in the case where a plurality of human presence zones are present and the volumes of air from the indoor units in the human presence zones are different from each other, the air-volume controller 33 determines the volume of air from the indoor unit in the human absence zone on the basis of the volume of air from the indoor unit in one of the human presence zones that is the closest to the human absence zone.

In the air-conditioning system 1, the air-sending operation of an indoor unit in a human absence zone located around a human presence zone reduces the probability that air adjusted in temperature by a cooling/heating operation or the heating operation of an indoor unit in the human presence zone will flow to the space in the human absence zone. It is therefore possible to efficiently air-condition a zone where a person or persons are present, in a large indoor space. Even if a plurality of human presence zones are present as illustrated in FIG. 12, it is possible to trap air in each of the human presence zones.

Although the above description is made with reference to FIG. 10, regarding the case where the indoor units 20-1 to 20-4 have the same air volume adjustment function, the indoor units 20-1 to 20-4 may have different air volume adjustment functions. FIG. 14 is a diagram illustrating an example of the control which is performed in the case where the four indoor units as illustrated in FIG. 4 have different air volume adjustment functions. The zone Z12 is a human presence zone, and the zones Z11, Z22, and Z13 are human absence zones.

As illustrated in FIG. 14, the volume of air from the indoor unit in each zone can be changed in three stages, that is, it can be changed to the three air volume levels fL1 to fL3; however, even in the case where the air volume levels set for the indoor units in the zones are the same as each other, the volumes of air from the indoor units in the zones are different from each other. In the example illustrated in FIG. 14, the level of the volume of air in the cooling operation of the indoor unit 20-2 in the zone Z12 is the air volume level fL1. In order for the indoor unit 20-1 in the zone Z11 and the indoor unit 20-3 in the zone Z22 to obtain a larger volume of air than the volume of air from the indoor unit 20-2 in the case where the level of the volume of air from the indoor unit 20-2 is the air volume level fL1, it suffices that the levels of the volumes of air from the indoor unit 20-1 in the zone Z11 and the indoor unit 20-3 in the zone Z22 are set to the air volume level fL2. On the other hand, in order for the indoor unit 20-4 in the zone Z13 to obtain a larger volume of air than the volume of air from the indoor unit 20-2 in the case where the level of the volume of air from the indoor unit 20-2 is the air volume level fL1, the volume of air from the indoor unit 20-4 in the zone Z13 may be set at the air volume level fL1. As described above, even in the case where the indoor units have different air volume adjustment functions, it suffices that the air-volume controller 33 controls the indoor units such that the volume of air from the indoor unit in the human absence zone is larger than the volume of air from the indoor unit in the human presence zone.

The indoor units 20-1 to 20-n may have, as an operation mode, a ventilation mode in which ventilation operation is performed to cause indoor air to flow out from an indoor space to the outside and cause outdoor air to flow into the indoor space. For example, in the ventilation mode, the air-volume controller 33 switches the state of a ventilation opening (not illustrated) located in the indoor unit, from a closed state to an opened state. During the cooling operation or the heating operation of the indoor unit in a human presence zone, the indoor units in human absence zones located around the human presence zone perform the ventilation operation for a predetermined period of time at regular intervals. Thus, it is possible to indirectly air out the human presence zone because of air exchange to let out air in the human presence zone and take outdoor air into the human presence zone. As a result, the temperature variation of the air in the human presence zone is smaller than that in the case where the human presence zone is directly ventilated, and clean air can thus be provided in in the human presence zone.

In the case of directly ventilating the human presence zone, the air-volume controller 33 switches the state of the ventilation opening (not illustrated) in the indoor unit in the human presence zone from the closed state to the opened state. However, in this case, the air-volume controller 33 may stop the rotation of the indoor fans 23 of the indoor units in the human absence zones. Thus, during cooling of the human presence zone, high-temperature outdoor air can be prevented from flowing into the human absence zones, thus reducing an increase in temperature of the air in the human absence zones. On the other hand, during heating of the human presence zone, low-temperature outdoor air can be prevented from flowing into the human absence zones, thus reducing a decrease in temperature of the air in the human absence zones. In such a manner, it is possible to reduce an increase or a decrease in temperature of the air in the human absence zones, and thus reduce an increase in air conditioning load in the human presence zone even when air flows from the human absence zones into the human presence zone. As a result, it is possible to further improve the effect of reducing the energy consumption of the air-conditioning apparatus 3.

The air-conditioning system 1 according to Embodiment 1 includes the air-conditioning apparatus 3 including the indoor units 20-1 to 20-n, the temperature detectors 24 each of which detects a temperature of the associated one of the zones set in association with the positions of the indoor units 20-1 to 20-n, the human detection sensor 25, and the controller 30. The human detection sensor 25 detects whether each of the zones is a human presence zone where a person or persons are present or a human absence zone where no person is present. The controller 30 causes the indoor unit in a human presence zone detected by the human detection sensor 25 to perform the cooling operation or the heating operation such that a temperature in the human presence zone that is detected by the temperature detector 24 reaches a set temperature. The controller 30 causes the indoor unit in the human absence zone of the zones that is detected by the human detection sensor 25 to perform the air-sending operation, and determines the volume of air from the indoor unit in the human absence zone based on the volume of air from the indoor unit in the human presence zone.

In Embodiment 1, the cooling operation or the heating operation is performed in the human presence zone, the air-sending operation is performed in the human absence zone, and the volume of air for the air-sending operation in the human absence zone is determined based on the volume of air for the cooling operation or the heating operation in the human presence zone. The above description concerning the example of the control in Embodiment 1 is made with respect to the case where the volume of air from the indoor unit in the human absence zone is set larger than that of the indoor unit in the human presence zone. However, it is also conceivable that the volume of air from the indoor unit in the human absence zone can be equalized to that of the indoor unit in the human presence zone. By determining the volume of air from the indoor unit in the human absence zone, depending on the volume of air from the indoor unit in the human presence zone, it is possible to reduce occurrence of air convection between the human presence zone and the human absence zone, thus reducing the probability that the human absence zone will be indirectly air-conditioned. As a result, the human presence zone is more efficiently air-conditioned, and the energy consumption of the air-conditioning apparatus 3 can be reduced.

In Embodiment 1, the air-volume controller 33 may cause the volume of air from the indoor unit in the human absence zone to be larger than that of the indoor unit in the human presence zone. In this case, occurrence of the leakage of an air flow in the human presence zone therefrom into the human absence zone is reduced, thus reducing occurrence of the air convection between the human presence zone and the human absence zone that are adjacent to each other. The space in the human presence zone is more reliably isolated from the space in the human absence zone, whereby air conditioned by heating or cooling can be more effectively trapped in the human presence zone.

In Embodiment 1, in the case where a plurality of human presence zones are present, the air-volume controller 33 determines the volume of air from the indoor unit in the human absence zone based on the volume of air from the indoor unit in one of the human presence zones that is the closest to the human absence zone. This is because the volume of air from the indoor unit in the human absence zone that is the closest to the human presence zone greatly affects an air curtain produced at the boundary between the human presence zone and the human absence zone.

In Embodiment 1, the air-volume controller 33 may cause the volume of air from the indoor unit in the human absence zone to increase depending on the distance between the indoor unit in the human absence zone and the indoor unit in the human presence zone. For example, in the case where the zones each have a square shape as viewed in plan view and the level of the volume of air from the indoor unit in the human presence zone is the air volume level fL1, the air-volume controller 33 sets the level of the volume of air from the indoor unit in a human absence zone adjacent to the human presence zone to the air volume level fL2. The air-volume controller 33 sets the level of the volume of air from the indoor unit in a human absence zone located on an extension of a diagonal line of the human presence zone to the air volume level fL3. By reducing an excess of the volume of air from the indoor unit in the human absence zone adjacent to the human presence zone, it is possible to reduce the flow of the air in the human absence zone into the human presence zone. Thus, an air flow in the human absence zone can serve as an air curtain. By setting the volume of air in the air curtain such that the greater the distance by which part of the air curtain is located apart from the human presence zone, the larger the volume of air in the part of the air curtain, it is possible to provide a multi-layered air curtain around the human presence zone.

In Embodiment 1, the airflow direction controller 34 may determine the depression angle θ of the airflow direction louvers 28a to 28d at the air outlets of the indoor unit in the human absence zone on the basis of the depression angle θ of the airflow direction louvers 28a to 28d at the air outlets of the indoor unit in the human presence zone adjacent to the human absence zone. For example, the airflow direction controller 34 causes the airflow direction louvers 28a to 28d at the air outlets of the indoor unit in the human absence zone to have the same depression angle θ as that of the airflow direction louvers 28a to 28d at the air outlets of the indoor unit in the human presence zone. An air-conditioned air flow blown from an air outlet of the indoor unit in the human presence zone and an air flow blown from an air outlet of the indoor unit in the human absence zone collide with each other and flow parallel to each other. As a result, the air flow in the human absence zone forms an air curtain at the boundary between the human presence zone and the human absence zone, thereby reducing occurrence of leakage of the air flow in the human presence zone therefrom into the human absence zone.

Embodiment 2

An air-conditioning system according to Embodiment 2 efficiently increases the volume of air that is blown from an indoor unit installed in a human absence zone toward a human presence zone. Regarding Embodiment 2, components that are the same as those described regarding Embodiment 1 will be denoted by the same reference signs, and their detailed descriptions will be omitted. Regarding Embodiment 2, detailed descriptions of operations similar to operations described regarding Embodiment 1 will be omitted, and operations different from those in Embodiment 1 will be described in detail.

The configuration of the air-conditioning system 1 according to Embodiment 2 will be described with reference to FIGS. 1 to 3, 5, and 15. FIG. 15 is a schematic plan view illustrating an example of the arrangement of the indoor units as illustrated in FIG. 1 in Embodiment 2. In the example illustrated in FIG. 15, the number n of indoor units is four. FIG. 15 illustrates the arrangement of the indoor units 20-1 to 20-4 in a room RM3, which is an air-conditioning target space, as viewed from a region located above a ceiling of the room RM3. It is assumed that the zones as illustrated in FIG. 15 each have a square shape as viewed in plan view. Of the zones Z11 to Z22, the zone Z12 is a human presence zone. The other three zones are human absence zones.

The air-volume controller 33 causes the indoor unit in each of the human absence zones to perform the air-sending operation as in Embodiment 1. In

Embodiment 2, the airflow direction controller 34 receives the management table, which is updated by the zone determination module 32, from the refrigeration cycle controller 31. The airflow direction controller 34 refers to the management table, and closes one or more of the air outlets 27a to 27d of the indoor unit in the human absence zone that are relatively remote from the indoor unit in the human presence zone. For example, for the zone Z11 as illustrated in FIG. 15, the airflow direction controller 34 performs a control to set the depression angle ∂ of each of the airflow direction louvers 28a, 28b, and 27d as illustrated in FIG. 2 in the indoor unit 20-1 to zero to close the air outlets 27a, 27b, and 27d. As a result, the volume of air that is blown from the air outlet 27c, which is closer to the human presence zone than the other air outlets, is increased without changing the operating frequency of the indoor fan 23 of the indoor unit 20-1.

Next, operation of the air-conditioning system 1 according to Embodiment 2 will be described. A control in Embodiment 2 is the same as the control indicated in FIG. 8 described regarding Embodiment 1, except for the details of the process of step S110. Detailed descriptions of the processes other than step S110 will be omitted. FIG. 16 is a flowchart indicating an example of a specific operation procedure of the process of step S110 as indicated in FIG. 8 in Embodiment 2.

The zone determination module 32 refers to the management table, and calculates, with respect to the indoor unit in each of the human absence zones Zhk, the distance L between the indoor unit in the human absence zone and the indoor unit in the human presence zone (step S301). In the case where a plurality of human presence zones are present, the zone determination module 32 calculates, with respect to each of the indoor units in the human absence zones Zhk, the distance L between the indoor unit in the human absence zone and each of the indoor units in the plurality of human presence zones. The zone determination module 32 stores in the management table, the calculated distance L regarding each of the indoor units in the human absence zones Zhk.

The airflow direction controller 34 refers to the management table, and determines whether a plurality of human presence zones are present or not (step S302). In the case where only one human presence zone is present, the process by the airflow direction controller 34 proceeds to step S304. When determining in step S302 that a plurality of human presence zones are present, the airflow direction controller 34 determines, with respect to each of the human absence zones Zhk, one of the indoor units in the human presence zones that is separated from the indoor unit in the human absence zone Zhk by the shortest distance Lmin, which is the shortest one of the distances L between the indoor units in the human presence zones and the indoor unit in the human absence zone Zhk (step S303). The airflow direction controller 34 also determines the above determined indoor unit as the indoor unit in the human presence zone. In step S304, the airflow direction controller 34 closes one or more of the air outlets of the indoor unit in each human absence zone Zhk that are relatively remote from the indoor unit in the human presence zone (step S304).

In the case where the human absence zone Zhk is the zone Z11 in the room RM3 provided as illustrated in FIG. 15, the airflow direction controller 34 closes the air outlets 27a, 27b, and 27d of the indoor unit 20-1 in step S304 indicated in FIG. 16. As a result, the volume of air that is blown from the air outlet 27c close to the human presence zone is increased without the need for the air-volume controller 33 to change the operating frequency of the indoor fan 23 of the indoor unit 20-1.

In the case where the human absence zone Zhk is the zone Z21 provided as illustrated in FIG. 15, the airflow direction controller 34 closes the air outlets 27a and 27d of the indoor unit 20-2 in step S304 indicated in FIG. 16. As a result, the volume of air which is blown from the air outlets 27b and 27c which are close to the human presence zone is increased without the need for the air-volume controller 33 to change the operating frequency of the indoor fan 23 of the indoor unit 20-2.

In the case where the human absence zone Zhk is the zone Z22 provided as illustrated in FIG. 15, the airflow direction controller 34 closes the air outlets 27a, 27c, and 27d of the indoor unit 20-4 in step S304 indicated in FIG. 16. As a result, the volume of air which is blown from the air outlet 27b close to the human presence zone is increased without the need for the air-volume controller 33 to change the operating frequency of the indoor fan 23 of the indoor unit 20-4.

FIG. 17 is a schematic plan view illustrating another example of the arrangement of the indoor units as illustrated in FIG. 1 in Embodiment 2. In the example illustrated in FIG. 17, the number n of indoor units is nine. FIG. 17 illustrates the arrangement of the indoor units 20-1 to 20-9 in a room RM 4 which is an air-conditioning target space, as viewed from a region located above a ceiling of the room RM4. It is assumed that the zones as illustrated in FIG. 17 each have a square shape as viewed in plan view. Of the zones Z11 to Z33, the zone Z22 is a human presence zone, and the other eight zones are human absence zones.

It will be described how the airflow direction controller 34 controls the indoor units in the human absence zones, which are included in the indoor units 20-1 to 20-9 as illustrated in FIG. 17. With respect to each of the indoor units 20-1, 20-3, 20-7, and 20-9 in four human absence zones located on extensions of diagonal lines of the human presence zone, the airflow direction controller 34 closes two of the four air outlets 27a to 27d that are relatively remote from the human presence zone. With respect to each of the indoor units 20-2, 20-4, 20-6, and 20-8 in four human absence zones which are adjacent to the human presence zone, the airflow direction controller 34 closes one of the four air outlets 27a to 27d that is relatively remote from the human presence zone.

In Embodiment 2, as described above with reference to FIGS. 15 and 17, occurrence of the leakage of a conditioned air flow in the human presence zone therefrom into the human absence zones is reduced, and occurrence of air convection between the zones is reduced, thereby improving the efficiency of air conditioning in the human presence zone.

In Embodiment 2, the control as described above regarding Embodiment 1 may also be applied. For example, the air-volume controller 33 may increase the volume of air from the indoor unit in the human absence zone, depending on the distance between the indoor unit in the human absence zone and the indoor unit in the human presence zone. With respect to the plurality of zones as illustrated in FIGS. 15 and 17, the number of human presence zones is not limited to one. In addition, the number n of indoor units is not limited to four which is that in the example illustrated in FIG. 15 or nine which is that in the example illustrated in FIG. 17.

In the air-conditioning system 1 according to Embodiment 2, the indoor unit in each of the human absence zones has a plurality of air outlets, and the controller 30 closes one or more of the plurality of air outlets that are relatively remote from the indoor unit in the human presence zone.

In Embodiment 2, the volume of air that is blown from the indoor unit in the human absence zone toward the human presence zone can be increased without the need to change the operating frequency of the indoor fan of the indoor unit in the human absence zone. It is therefore possible to reduce an increase in the energy consumption that would be caused by an increase in the operating frequency of the indoor fan, and improve the efficiency of air conditioning in the human presence zone. Thus, the energy consumption of the air-conditioning apparatus 3 is further reduced than in Embodiment 1.

The above descriptions concerning Embodiments 1 and 2 are made with respect to the case where each of the zones has a square shape as viewed in plan view. The shape of each zone as viewed in plan view is not limited to the square shape; that is, the zones may each have a rectangular shape as viewed in plan view. The shapes of the zones as viewed in plan view may be different from each other. Each of the indoor units is not limited to a four-way ceiling cassette type indoor unit. For example, each indoor unit may be a two-way ceiling cassette type indoor unit. An indoor unit which is close to a wall of a room which is an air-conditioning target space may be a wall-mounted indoor unit. The air-conditioning apparatus 3 may include a plurality of outdoor units 10.

REFERENCE SIGNS LIST

1: air-conditioning system, 3: air-conditioning apparatus, 10: outdoor unit, 11: compressor, 12: four-way valve, 13: heat-source-side heat exchanger, 14: outdoor fan, 15: refrigerant pipe, 20-1 to 20-n: indoor unit, 21: load-side heat exchanger, 22:

expansion valve, 23: indoor fan, 24: temperature detector, 25: human detection sensor, 26: air inlet, 27a to 27d: air outlet, 28a to 28d: airflow direction louver, 29: lower surface, controller, 31: refrigeration cycle controller, 32: zone determination module, 33: air-volume controller, 34: airflow direction controller, 40: refrigerant circuit, 45: rotary shaft, 80: processing circuit, 81: processor, 82: memory, 83: bus, RM1 to RM4: room, Z11 to Z34: zone

Claims

1. An air-conditioning system comprising:

an air-conditioning apparatus including a plurality of indoor units each configured to condition air in an air-conditioning target space;

a plurality of temperature sensors each configured to detect a temperature of an associated one of a plurality of zones into which the air-conditioning target space is divided in association with positions of the plurality of indoor units;

a human detection sensor configured to detect whether each of the plurality of zones is a human presence zone where a person or persons are present or a human absence zone where no person is present; and

a controller configured to cause, in the human presence zone detected by the human detection sensor, the indoor unit in the detected human presence zone to perform cooling operation or heating operation, thereby causing a temperature detected by an associated one of the temperature sensors to reach a set temperature,

wherein the controller is configured to:

cause the indoor unit in the human absence zone detected by the human detection sensor to perform air-sending operation, and determine a volume of air from the indoor unit in the detected human absence zone based on a volume of air from the indoor unit in the human presence zone; and

cause the volume of air from the indoor unit in the human absence zone to be larger than the volume of air from the indoor unit in the human presence zone.

2. The air-conditioning system of claim 1, wherein the controller is configured to determine, when a plurality of the human presence zones are present, the volume of air from the indoor unit in the human absence zone based on the volume of air from the indoor unit in one of the human presence zones that is the closest to the human absence zone.

3. (canceled)

4. The air-conditioning system of claim 1, wherein the human detection sensor includes an infrared sensor.

5. A controller for an air-conditioning apparatus, which is connected to the air-conditioning apparatus, a plurality of temperature sensors, and a human detection sensor, the air-conditioning apparatus including a plurality of indoor units each configured to condition air in an air-conditioning target space, the plurality of temperature sensors each being configured to detect a temperature of an associated one of a plurality of zones into which the air-conditioning target space is divided in association with positions of the plurality of indoor units, the human detection sensor being configured to detect whether a person or persons are present or no person is present in each of the plurality of zones or not,

wherein the controller is configured to:

cause the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human presence zone where a person or persons are present to perform cooling operation or heating operation, thereby causing a temperature detected by the temperature sensor in the human presence zone to reach a set temperature;

cause the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human absence zone where no person is present to perform air-sending operation, and determine a volume of air from the indoor unit in the human absence zone based on a volume of air from the indoor unit in the human presence zone; and

cause the volume of air from the indoor unit in the human absence zone to be larger than the volume of air from the indoor unit in the human presence zone.

6. The controller of claim 5, wherein the controller is configured to determine, when a plurality of the human presence zones are present, determine the volume of air from the indoor unit in the human absence zone based on the volume of air from the indoor unit in one of the human presence zones that is the closest to the human absence zone.

7. (canceled)

8. The controller of claim 5, wherein the controller is configured to increase the volume of air from the indoor unit in the human absence zone, depending on a distance between the indoor unit in the human absence zone and the indoor unit in the human presence zone.

9. The controller of claim 5, wherein

the indoor unit in the human absence zone has a plurality of air outlets, and

the controller is configured to close at least one of the plurality of air outlets that is relatively remote from the indoor unit in the human presence zone.

10. The controller of claim 5, wherein the controller is configured to determine a depression angle of an airflow direction louver at an air outlet of the indoor unit in the human absence zone, based on a depression angle of an airflow direction louver at an air outlet of the indoor unit in the human presence zone adjacent to the human absence zone.

11. The controller of claim 5, wherein the controller is configured to control an operating frequency of each of a compressor and an outdoor fan that are included in the air-conditioning apparatus to cause a temperature detected by the temperature sensor in the human presence zone to fall within a predetermined range with reference to the set temperature.

12. A method of controlling, using a controller, an air-conditioning apparatus including a plurality of indoor units each configured to condition air in an air-conditioning target space, the controller being connected to the air-conditioning apparatus, a plurality of temperature sensors, and a human detection sensor, the plurality of temperature sensors each being configured to detect a temperature of an associated one of a plurality of zones into which the air-conditioning target space is divided in association with positions of the plurality of indoor units, the human detection sensor being configured to detect whether a person or persons are present or no person is present in each of the plurality of zones, the method comprising:

causing the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human presence zone where a person or persons are present to perform cooling operation or heating operation, thereby causing a temperature detected by the temperature sensor in the detected human presence zone to reach a set temperature; and

causing the indoor unit in one of the plurality of zones that is detected by the human detection sensor as a human absence zone where no person is present to perform air-sending operation, and determining a volume of air from the indoor unit in the detected human absence zone based on a volume of air from the indoor unit in the human presence zone,

wherein in the determining the volume of air from the indoor unit in the human absence zone based on the volume of air from the indoor unit in the human presence zone, the volume of air from the indoor unit in the human absence zone is caused to be larger than the volume of air from the indoor unit in the human presence zone.