Air conditioning system

Abstract

This air conditioning system comprises: a first air conditioning unit (20) in which a blowout port (32) is provided in a ceiling surface (11) of a target space (S1), and which blows out air containing outdoor air, which has been temperature-adjusted, from the blowout port (32) into the target space (S1); a heating unit (H) that heats the ceiling surface (11); and a control unit (CU) that controls the temperature of the air blown out from the first air conditioning unit (20) so that the temperature of the air blown out from the blowout port (32) is lower than the air temperature of the target space (S1).

Description

Air conditioning system

[0001] This disclosure relates to an air conditioning system.

[0002] Patent Document 1 discloses an air conditioner that performs a heating operation of blowing air of different temperatures to two different height positions in a target space. Thereby, layers of different air temperatures are formed in the target space, and a highly comfortable thermal environment can be formed such that the feet are warm and the head side is relatively low in temperature.

[0003] Japanese Unexamined Patent Application Publication No. 2017 - 138040

[0004] It is conceivable to perform displacement ventilation of the target space during the heating operation using the air conditioner described in Patent Document 1. However, when the heating load of the target space increases, the blowing temperature becomes high, and it may rise due to buoyancy before reaching a position near the feet or near the face. In such a case, there is a risk that displacement ventilation of the target space cannot be realized.

[0005] An object of the present disclosure is to provide an air conditioning system that can realize displacement ventilation of a target space and can perform heating.

[0006] A first aspect of the present disclosure is an air conditioning system including: a first air conditioning unit (20) provided with an outlet (32) on a ceiling surface (11) of a target space (S1), and blowing air including temperature - adjusted outdoor air from the outlet (32) into the target space (S1); a heating unit (H) for heating the ceiling surface (11); and a control unit (CU) for controlling the temperature of the blown - out air of the first air conditioning unit (20) so that the temperature of the blown - out air from the outlet (32) is lower than the air temperature of the target space (S1).

[0007] In the first aspect, since the air blown out from the outlet (32) on the ceiling surface (11) is at a temperature lower than the room temperature, it can reach the floor surface. Thereby, displacement air conditioning can be realized. The heat radiated from the ceiling heated by the heating unit (H) can heat the air while suppressing the turbulence of the air flow in the target space (S1). Thus, displacement air conditioning by the air blown out from the ceiling of the target space (S1) and heating of the target space (S1) can be realized.

[0008] A second aspect of the present disclosure further comprises a first temperature sensor (90) for measuring the air temperature of the target space (S1), wherein the control unit (CU) controls the heating unit (H) so that the value detected by the first temperature sensor (90) becomes a first target value.

[0009] In the second embodiment, the heating unit (H) is operated so that the value detected by the first temperature sensor (90) reaches the target temperature, so that the air temperature in the target space (S1) rises relatively quickly. This allows for control such as preventing the first air conditioning unit (20) from overcooling the target space (S1) or operating the first air conditioning unit (20) only after the air temperature in the target space (S1) has risen to a certain level. As a result, a decrease in the comfort level of the target space (S1) can be suppressed.

[0010] A third aspect of the present disclosure is, in the first or second aspect, the heating unit (H) is a second air conditioning unit (50) that blows heated air from the ceiling surface (11) into the target space (S1).

[0011] In the third embodiment, the ceiling surface (11) can be heated by the blown air from the second air conditioning unit (50).

[0012] A fourth aspect of the present disclosure, in the third aspect, further comprises a second temperature sensor (91) for detecting the temperature of the ceiling surface (11) or the air temperature near the ceiling surface (11), wherein the control unit (CU) controls the second air conditioning unit (50) so that the value detected by the second temperature sensor (91) becomes a second target value.

[0013] In the fourth embodiment, the second air conditioning unit (50) can be controlled based on the temperature of the ceiling surface (11) or the air temperature near the ceiling surface (11). This allows the ceiling surface (11) to be efficiently heated so that the air temperature in the indoor space (S1) reaches the target temperature.

[0014] A fifth aspect of the present disclosure is, in the third aspect, the second air conditioning unit (50) blows heated air along the ceiling surface (11).

[0015] In the fifth embodiment, the heated air flows along the ceiling surface, thereby heating the ceiling surface, and the blown air has difficulty reaching the lower part of the target space (S1), thus suppressing turbulence in the airflow at the lower part of the target space (S1).

[0016] A sixth aspect of the present disclosure is, in the third aspect, the second air conditioning unit (50) blows heated air downward, and the control unit (CU) controls the second air conditioning unit (50) so that the first air velocity of the air blown out from the ceiling surface (11) is 1.0 m / s or less.

[0017] In the sixth embodiment, even when heated air is blown downwards, by setting the discharge velocity at the outlet to 1.0 m / s or less, the discharged air is less likely to reach the lower part of the target space (S1). Therefore, turbulence in the airflow at the lower part of the target space (S1) can be suppressed.

[0018] A seventh aspect of the present disclosure is, in the first or second embodiment, the heating unit (H) is a third air conditioning unit (100) that blows heated air into the space behind the ceiling surface (11).

[0019] In the seventh embodiment, the ceiling surface can be heated by heating the air in the space above the ceiling.

[0020] An eighth aspect of the present disclosure is, in the first or second aspect, the heating element (H) is a radiant panel (200) provided on the ceiling surface (11).

[0021] In the eighth embodiment, the ceiling surface can be heated by the radiant panel (200).

[0022] A ninth aspect of the present disclosure is that in any one of the first to eighth aspects, the target space (S1) has a living area (R1) adjacent to the floor surface and a non-living area which is the space between the living area (R1) and the ceiling surface (11).

[0023] In the ninth embodiment, displacement air conditioning can be achieved for the living area (R1) in the target space (S1), and the living area (R1) can be heated.

[0024] A tenth aspect of this disclosure is, in the ninth aspect, the living area (R1) is the space below the target space (S1).

[0025] In the tenth embodiment, the space below the target space (S1) can be subjected to displacement air conditioning and heated.

[0026] Figure 1 is a schematic diagram showing the indoor space and ceiling space in which the air conditioning system of this embodiment is installed. Figure 2 is a piping diagram of the refrigerant circuit of the outdoor air handling air conditioner. Figure 3 is a cross-sectional view showing the internal configuration of the air handling unit. Figure 4 is a piping diagram of the refrigerant circuit of the air conditioning device. Figure 5 is a cross-sectional view showing the configuration of the indoor unit. Figure 6 is a block diagram showing the relationship between the control unit of the air conditioning system and various devices. Figure 7 is a flowchart showing the operation of the control unit when executing the displacement air conditioning mode. Figure 8 is a schematic diagram corresponding to Figure 1 showing the indoor space and ceiling space in which the air conditioning system according to Modification 2 is installed. Figure 9 is a schematic diagram corresponding to Figure 1 showing the indoor space and ceiling space in which the air conditioning system according to Modification 3 is installed.

[0027] The embodiments of this disclosure will be described in detail below with reference to the drawings. However, this disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of ​​this disclosure. Since the drawings are for conceptual explanation of this disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for ease of understanding.

[0028] (1) Overall configuration of the air conditioning system As shown in Figure 1, the air conditioning system (1) of this embodiment is installed indoors, which has an indoor space (S1) and an attic space (S2) as the target space (S1). The air conditioning system (1) performs displacement air conditioning in the indoor space (S1) and also heats the indoor air. Displacement air conditioning introduces fresh conditioned air, including outside air, into the indoor space (S1) and discharges indoor air with a relatively high concentration of pollutants in the indoor space (S1). The pollutants include carbon dioxide. The arrows shown in Figure 1 indicate the flow of air. Also, OA indicates outside air, RA indicates indoor air, SA indicates supply air, and EA indicates exhaust air.

[0029] The interior space (S1) is the space enclosed by the ceiling surface (11), the floor surface (12), and the walls (13). Above the ceiling surface (11) is the space above the ceiling (S2). The space above the ceiling (S2) is not included in the interior space (S1). A ventilation opening (11a) is provided in the ceiling surface (11). The ventilation opening (11a) is an opening that connects the interior space (S1) and the space above the ceiling (S2). Air from the interior space (S1) flows through the ventilation opening (11a) to the space above the ceiling (S2). The ceiling surface (11) is in contact with the interior space (S1).

[0030] An interior space (S1) is a space in which people live or engage in activities. For example, an interior space (S1) includes offices, conference rooms, hotel rooms, rooms in buildings, hospital rooms, and rooms in apartments or houses. An interior space (S1) has adjacent residential areas (R1) and non-residential areas (R2) in the vertical direction.

[0031] The living area (R1) is the space below the non-living area (R2). In this embodiment, the living area (R1) is the space adjacent to the floor surface (12) of the interior space (S1). The living area (R1) is the area where people spend most of their time while in the interior space (S1). For example, the living area (R1) includes the area below the height of a person's head when standing on the floor surface (12). Alternatively, the living area (R1) may be the area below a height slightly higher than the height of a person's head when standing on the floor surface (12). Specifically, if a person's height is 1.7m, the living area (R1) may be the space below a height of 1.7m from the floor surface (12), or it may be the space below a height of 1.8m from the floor surface (12).

[0032] The non-residential area (R2) is the space above the residential area (R1). In this embodiment, the non-residential area (R2) is the space adjacent to the ceiling surface (11) of the interior space (S1). The non-residential area (R2) includes an area above a height that a person standing on the floor cannot reach. Alternatively, the non-residential area (R2) may be an area above a height slightly higher than a person standing on the floor, or an area above a height slightly lower than a person standing on the floor. Specifically, if a person's height is 1.7m, the non-residential area (R2) may be a space above a height of 1.7m from the floor, a space above a height of 1.8m from the floor, or a space above a height of 1.6m from the floor.

[0033] The displacement air conditioning in this embodiment is performed to ensure the cleanliness of the air in the occupied area (R1). In this embodiment, the occupied area (R1) is the space below a height of 1.8 m from the floor surface (12) of the indoor space (S1), and the non-occupied area (R2) is the space above a height of 1.8 m from the floor surface (12) of the indoor space (S1).

[0034] The air conditioning system (1) of this embodiment includes an outdoor air handling air conditioner (20), an air conditioning device (50), an exhaust device (80), and a control unit (CU). The outdoor air handling air conditioner (20) and the exhaust device (80) perform displacement air conditioning of the indoor space (S1).

[0035] (2) Outdoor air processing unit The outdoor air processing unit (20) takes in outdoor air or mixed air containing outdoor air and indoor air, purifies or temperature-regulates the taken-in air, and supplies it to the indoor space (S1) from the ceiling surface (11). In this way, the outdoor air processing unit (20) blows air containing temperature-regulated outdoor air from the ceiling surface (11) into the indoor space (S1). The outdoor air processing unit (20) is an example of the first air conditioning unit (20) of this disclosure. The outdoor air may be any air outside the indoor space (S1), and may be outside air.

[0036] As shown in FIGS. 1 to 3, the outdoor air handling air conditioner (20) mainly includes a chiller unit (20a) and an air handling unit (20b). The outdoor air handling air conditioner (20) has a first refrigerant circuit (21) and a water circuit (22). The first refrigerant circuit (21) is filled with a refrigerant. Water as a heat medium flows through the water circuit (22).

[0037] (2-1) Chiller Unit The chiller unit (20a) is arranged outdoors. The chiller unit (20a) heats or cools the water in the water circuit (22) and conveys warm water or cold water to the air handling unit (20b). The chiller unit (20a) has a first refrigerant circuit (21). The chiller unit (20a) heats or cools the water by exchanging heat between the refrigerant in the first refrigerant circuit (21) and the water in the water circuit (22).

[0038] Specifically, the chiller unit (20a) includes a first compressor (23), a first heat exchanger (24), a first expansion valve (25), a water heat exchanger (26), a first four-way switching valve (27), a first fan (28) and a water pump (29). The first compressor (23), the first heat exchanger (24), the first expansion valve (25), the water heat exchanger (26) and the first four-way switching valve (27) are sequentially connected to the first refrigerant circuit (21). The first refrigerant circuit (21) performs a vapor compression refrigeration cycle operation.

[0039] The first compressor (23) compresses the inhaled low-pressure gas refrigerant and discharges the compressed refrigerant. The first compressor (23) is a variable capacity type in which power is supplied from an inverter circuit to an electric motor.

[0040] The first heat exchanger (24) exchanges heat between the outdoor air conveyed by the first fan (28) and the refrigerant. The first fan (28) conveys the outdoor air passing through the first heat exchanger (24). The rotation speed of the first fan (28) is variable.

[0041] The water heat exchanger (26) exchanges heat between the refrigerant in the first refrigerant circuit (21) and the water in the water circuit (22). The water heat exchanger (26) is shared by the first refrigerant circuit (21) and the water circuit (22).

[0042] The first expansion valve (25) reduces the pressure of the refrigerant. The first expansion valve (25) is an electric expansion valve with an adjustable opening degree.

[0043] The first four-way switching valve (27) has four ports (P1 to P4). The first port (P1) is connected to the discharge part of the first compressor (23). The second port (P2) is connected to the suction part of the first compressor (23). The third port (P3) is connected to the gas end of the first heat exchanger (24). The fourth port (P4) is connected to the gas connection pipe.

[0044] The first four-way switching valve (27) switches between a first state (the state shown by the dashed line in FIG. 2) and a second state (the state shown by the solid line in FIG. 2). In the first state, the refrigerant in the first refrigerant circuit (21) flows in the direction of the dashed arrow in FIG. 2, and the first heat exchanger (24) functions as an evaporator. In the second state, the refrigerant in the first refrigerant circuit (21) flows in the direction of the solid arrow in FIG. 2, and the first heat exchanger (24) functions as a radiator.

[0045] The water pump (29) circulates the water in the water circuit (22). The water pump (29) conveys the heated or cooled water in the water heat exchanger (26) to the air handling unit (20b). FIG. 2 shows the circulation direction of the water in the water circuit (22) by a solid arrow.

[0046] (2-2) Air handling unit The air handling unit (20b) shown in FIGS. 1 and 3 is provided in the ceiling space (S2). Specifically, the air handling unit (20b) is arranged on the lower surface in the ceiling space (S2). The air handling unit (20b) mainly has a first suction port (31), a first blowout port (32), a first casing (33), a second heat exchanger (34), a first filter (35) and an air supply fan (36).

[0047] (2-2-1) First intake port and first outlet port The first intake port (31) draws air into the first casing (33). The first intake port (31) has an outdoor intake port (31a) for taking in outdoor air and an indoor intake port (31b) for taking in indoor air. The outdoor intake port (31a) communicates with the outside. The indoor intake port (31b) communicates with the indoor space (S1). In this embodiment, the outdoor intake port (31a) and the indoor intake port (31b) are provided in the first casing (33). The outdoor intake port (31a) and the indoor intake port (31b) may communicate with the inside of the first casing (33) via a predetermined duct.

[0048] The first air outlet (32) blows the air processed in the first casing (33) into the room space (S1). The first air outlet (32) is provided on the ceiling surface (11). Specifically, the first air outlet (32) is provided so as to be exposed to the room space (S1) through an opening formed in the ceiling surface (11). The first air outlet (32) is configured so that the blown air flows straight down toward the floor. The first air outlet (32) may be formed on a predetermined blowing member attached to the ceiling surface (11).

[0049] (2-2-2) First Casing The first casing (33) is formed in a generally box shape. The first casing (33) houses the second heat exchanger (34), the first filter (35), and the supply air fan (36). Inside the first casing (33), a first airflow path (P1) is formed through which air flows from the first intake port (31) toward the first outlet port (32). The first airflow path (P1) has a main flow path (Pm) and a secondary flow path (Ps). The main flow path (Pm) is the flow path through which air flows from the outdoor intake port (31a) toward the first outlet port (32). The secondary flow path (Ps) is the flow path through which air flows from the indoor intake port (31b) toward the main flow path (Pm).

[0050] Specifically, the first air passage (P1) is provided with a partition member (37) that separates the main passage (Pm) and the sub-passage (Ps), and the partition member is provided with a damper (38) whose opening degree can be adjusted. The damper (38) is provided at the downstream end of the sub-passage (Ps). When the damper (38) is open, the air in the sub-passage (Ps) merges with the air in the main passage (Pm) and is blown out from the first outlet (32). In other words, when the damper (38) is open, indoor air and outdoor air are mixed, and the treated mixed air is blown out from the first outlet (32) into the indoor space (S1). When the damper (38) is closed, indoor air does not flow into the indoor intake (31b), and treated outdoor air is blown out from the first outlet (32) into the indoor space (S1). Thus, the ratio of the amount (volume or weight) of outdoor air to indoor air in the mixed air is determined by the opening degree of the damper (38). Furthermore, if the amount of outdoor air taken into the main flow path (Pm) is constant, the larger the opening degree of the damper (38), the greater the amount of air in the mixed air.

[0051] (2-2-3) Second heat exchanger The second heat exchanger (34) is connected to the water heat exchanger (26). The second heat exchanger (34) is located in the main flow path (Pm) of the first air flow path (P1). The second heat exchanger (34) exchanges heat between the hot or cold water transported from the water heat exchanger (26) and the air flowing through the main flow path (Pm). The second heat exchanger (34) has, for example, heat transfer tubes through which water from the water circuit (22) flows and heat transfer fins.

[0052] (2-2-4) First filter The first filter (35) purifies the air flowing through the first air passage (P1). Specifically, the first filter (35) captures dust in the outdoor air taken into the main passage (Pm). The first filter (35) is positioned in the main passage (Pm) closer to the outdoor intake port (31a). The first filter (35) may be made of nonwoven fabric as long as it is replaceable.

[0053] (2-2-5) Air supply fan The air supply fan (36) transports air from the first air passage (P1) to the first outlet (32). The air supply fan (36) is positioned in the main passage (Pm) downstream of the airflow of the second heat exchanger (34) and downstream of the position where the damper (38) is installed. The air supply fan (36) is, for example, a sirocco fan. The airflow velocity of the air supply fan (36) is variable. Specifically, the air supply fan (36) has a fan motor (not shown), and the rotation speed of the fan is controlled by inverter control of the fan motor. In this way, the airflow velocity of the air blown out from the first outlet (32) can be adjusted.

[0054] (2-2-6) Sensor Unit The air handling unit (20b) shown in Figure 1 has a predetermined sensor unit. The sensor unit includes a first outlet temperature sensor (39) and a first intake temperature sensor (40) (see Figure 5). The first outlet temperature sensor (39) detects the temperature of the air blown out from the first outlet (32). The first outlet temperature sensor (39) is located near the first outlet (32). The first intake temperature sensor (40) detects the temperature of the outdoor air. The first intake temperature sensor (40) is located near the outdoor intake port (31a) in the first airflow path (P1).

[0055] (3) Air Conditioning System The air conditioning system (50) shown in Figures 4 and 5 is equipped with a second refrigerant circuit (51) and air-conditions the indoor space (S1) by executing a refrigeration cycle. More precisely, the air conditioning system (50) air-conditions the occupied area (R1). The air conditioning system (50) is equipped with an indoor fan (64) that transports air and blows the air transported by the indoor fan (64) into the indoor space (S1). Specifically, the air conditioning system (50) is equipped with an outdoor unit (50a), an indoor unit (50b), a liquid communication pipe (52), and a gas communication pipe (53). The outdoor unit (50a) and the indoor unit (50b) are connected to each other via the liquid communication pipe (52) and the gas communication pipe (53). The connection of these constitutes the second refrigerant circuit (51).

[0056] The second refrigerant circuit (51) is filled with refrigerant. The second refrigerant circuit (51) performs a vapor compression type refrigeration cycle. The second refrigerant circuit (51) mainly comprises a second compressor (54), an outdoor heat exchanger (55), an outdoor expansion valve (56), an indoor heat exchanger (57), and a second four-way switching valve (58).

[0057] (3-1) Outdoor Unit The outdoor unit (50a) is installed outdoors. The outdoor unit (50a) has a second compressor (54), an outdoor heat exchanger (55), an outdoor fan (65), an outdoor expansion valve (56), and a second four-way switching valve (58).

[0058] The second compressor (54) compresses the inhaled low-pressure gaseous refrigerant and discharges the compressed refrigerant. The second compressor (54) is a variable-capacity type, and power is supplied to the motor from the inverter circuit.

[0059] The outdoor heat exchanger (55) exchanges heat between the outdoor air transported by the outdoor fan (65) and the refrigerant. The outdoor fan (65) transports the outdoor air that passes through the outdoor heat exchanger (55).

[0060] The outdoor expansion valve (56) reduces the pressure of the refrigerant. The outdoor expansion valve (56) is an electrically operated expansion valve with an adjustable opening.

[0061] The second four-way switching valve (58) has four ports (P1 to P4). The first port (P1) is connected to the discharge section of the second compressor (54). The second port (P2) is connected to the suction section of the second compressor (54). The third port (P3) is connected to the gas end of the outdoor heat exchanger (55). The fourth port (P4) is connected to the gas connecting pipe (53).

[0062] The second four-way switching valve (58) switches between a first state (shown by the solid line in Figure 4) and a second state (shown by the dashed line in Figure 4). In the first state, a refrigeration cycle is executed using the indoor heat exchanger (57) as the evaporator. In the first state, the cooling mode described later is executed. In the second state, a refrigeration cycle is executed using the indoor heat exchanger (57) as the radiator. In the second state, the heating mode described later is executed.

[0063] (3-2) Indoor Unit The indoor unit (50b) shown in Figure 6 is a ceiling-mounted type installed on the ceiling surface (11) of the indoor space (S1). The indoor unit (50b) has a second casing (61), an airflow adjustment unit (62), a bell mouth (63), an indoor fan (64), an indoor heat exchanger (57), a drain pan (66), and an indoor expansion valve (67). The indoor unit (50b) has a second intake port (68) for drawing in indoor air and a second outlet port (69) for blowing air into the room. The second intake port (68) and the second outlet port (69) open downwards.

[0064] (3-2-1) Second casing The second casing (61) is positioned in an opening formed in the ceiling of the interior space (S1). A second air passage (P2) is formed inside the second casing (61) that connects the second intake port (68) and the second outlet port (69). The second casing (61) has a main body (61a), a panel (61b), and an intake grille (61c).

[0065] The main body (61a) is formed in a generally box shape. The main body (61a) has an opening that is open downwards. The opening is formed over almost the entire area of ​​the lower surface of the main body (61a). The main body (61a) is placed in the space above the ceiling (S2).

[0066] The panel (61b) is provided to cover the opening of the main body (61a). The panel (61b) has a second intake port (68) and a second outlet port (69). The second outlet port (69) is positioned around the second intake port (68). Specifically, the panel (61b) has a rectangular frame member and an intake grille that fits inside the frame member. The second outlet port (69) is provided to extend along each side of the frame member. The intake grille is provided to cover the second intake port (68). The intake grille is provided with a second filter (70). The second filter (70) collects dust in the intake air, which is the air drawn in from the second intake port (68).

[0067] (3-2-2) Wind Direction Adjustment Section The wind direction adjustment section (62) adjusts the wind direction of the air blown out from the second outlet (69). The wind direction adjustment section (62) has a flap (62a), a drive shaft (62b), and a motor (not shown). The flap (62a) is formed in the shape of an elongated plate. The flap (62a) is positioned at the second outlet (69). The flap (62a) is provided to close the second outlet (69). The drive shaft (62b) rotates the flap (62a). As the drive shaft (62b) rotates, the position of the flap (62a) changes between a closed position that closes the second outlet (69) and an open position that opens the second outlet (69). The motor controls the rotation of the drive shaft (62b). Specifically, the motor controls the drive shaft (62b) so that the flap (62a) maintains several specific attitudes. In other words, the motor changes the attitude of the flap (62a) to several open positions. These open positions include, for example, a first position where the wind is blowing roughly straight down, a second position where the wind is directed diagonally downward, and a third position where the wind is directed roughly horizontal.

[0068] (3-2-3) Bell mouth The bell mouth (63) is positioned in the second air passage (P2). The bell mouth (63) is positioned above the second filter (70). The bell mouth (63) straightens the intake air.

[0069] (3-2-4) Indoor fan The indoor fan (64) is positioned above the bell mouth (63). The indoor fan (64) is centrifugal. The indoor fan (64) is positioned upstream of the indoor heat exchanger (57) in the second air passage (P2). The indoor fan (64) transports the air passing through the indoor heat exchanger (57). The rotational speed of the indoor fan (64) is variable. The indoor fan (64) is controlled to multiple rotational speeds. By controlling the rotational speed of the indoor fan (64), the wind speed of the air blown out from the second outlet (69) (hereinafter sometimes referred to as blown air) is adjusted. Hereafter, the wind speed of the blown air may be shown with the same meaning as the airflow rate of the blown air.

[0070] (3-2-5) Indoor heat exchanger The indoor heat exchanger (57) is positioned around the indoor fan (64). In the indoor heat exchanger (57), heat exchange occurs between the air transported by the indoor fan (64) and the refrigerant.

[0071] (3-2-6) Drain Pan The drain pan (66) is located below the indoor heat exchanger (57). The drain pan (66) receives condensation water generated inside the second casing (61) of the indoor unit (50b). The water accumulated in the drain pan (66) is discharged to the outside via a drain pipe (not shown).

[0072] (3-2-7) Indoor expansion valve The indoor expansion valve (67) reduces the pressure of the refrigerant. The indoor expansion valve (67) is an electrically operated expansion valve with an adjustable opening.

[0073] (3-2-8) Sensor Unit The air conditioning system (50) has a predetermined sensor unit. The sensor unit includes a second outlet temperature sensor (71) and a second intake temperature sensor (72) (see Figure 6). The second outlet temperature sensor (71) detects the temperature of the discharged air. The second outlet temperature sensor (71) is located near the second outlet (69) in the second air passage (P2). The second intake temperature sensor (72) detects the temperature of the intake air. The second intake temperature sensor (72) is located near the second intake port (68) in the second air passage (P2).

[0074] (4) Exhaust System The exhaust system (80) shown in Figure 1 is located in the ceiling space (S2). The exhaust system (80) discharges the air from the indoor space (S1) to the outside. Specifically, the exhaust system (80) discharges the air from the indoor space (S1) that has flowed into the ceiling space (S2) through the ventilation opening (11a) to the outside.

[0075] The exhaust system (80) has an exhaust fan (81). The exhaust fan (81) is, for example, a sirocco fan. The airflow velocity of the exhaust fan (81) is variable. Specifically, the exhaust fan (81) has a fan motor (not shown), and the rotational speed of the fan is controlled by inverter control of the fan motor. The exhaust system (80) in this embodiment is controlled in conjunction with the outdoor air processing air conditioner (20).

[0076] (5) Temperature sensor The air conditioning system (1) shown in Figure 1 has a temperature sensor. The temperature sensor has a first temperature sensor (90) and a second temperature sensor (91).

[0077] The first temperature sensor (90) detects the air temperature in the living area (R1). The first temperature sensor (90) is placed in the living area (R1). The first temperature sensor (90) may also be placed in the indoor space (S1). In this case, the sensor portion of the first temperature sensor (90) is placed in the living area (R1).

[0078] The second temperature sensor (91) detects the temperature of the ceiling surface (11). The second temperature sensor (91) is installed on the ceiling surface (11). The second temperature sensor (91) may be placed in the center of the ceiling surface (11) or at the position furthest from the air conditioning unit (50).

[0079] (6) Remote Controller As shown in Figure 1, the air conditioning system (1) has a remote controller (95). The remote controller (95) is a device for operating the air conditioning system (1). The remote controller (95) has an operating unit (96) and a display unit (97) (see Figure 6).

[0080] The control unit (96) is a functional unit for the user to input various operating instructions to the outdoor air handling unit (20) and the air conditioning system (50). The control unit (96) includes switches, buttons, or a touch panel. The display unit (97) displays the operating mode menu for the outdoor air handling unit (20) and the air conditioning system (50), the settings of the operating mode, the current air temperature in the occupied area (R1), the target air temperature in the occupied area (R1), and so on.

[0081] (7) Control Unit The control unit (CU) shown in Figure 6 controls the air conditioning system (1). The control unit (CU) has a first control unit (C1), a second control unit (C2), a third control unit (C3), and a fourth control unit (C4). Each of the first to fourth control units (C1 to C4) includes an MCU (Micro Control Unit), an electrical circuit, and an electronic circuit. The MCU includes a CPU (Central Processing Unit), memory, and a communication interface. Various programs for the CPU to execute are stored in the memory. The control unit (CU) is an example of a control unit (CU).

[0082] The first control unit (C1) communicates with various components of the outdoor air handling air conditioner (20). Specifically, the first control unit (C1) controls the supply air fan (36), the first compressor (23), the first expansion valve (25), the first four-way switching valve (27), the water pump (29), the first fan (28), and the damper (38). The first control unit (C1) receives signals indicating the air temperature from the first intake temperature sensor (40) and the first discharge temperature sensor (39), respectively. The first control unit (C1) may also have a first control board (not shown) for controlling the chiller unit (20a) and a second control board (not shown) for controlling the air handling unit (20b). The first control board is provided in the chiller unit (20a) and controls the first compressor (23), the first expansion valve (25), and the first four-way switching valve (27). The second control board is installed in the air handling unit (20b) and controls the air supply fan (36) and damper (38).

[0083] The second control unit (C2) controls various components of the air conditioning system (50). Specifically, the second control unit (C2) controls the second compressor (54), the outdoor expansion valve (56), the outdoor fan (65), the second four-way switching valve (58), the indoor fan (64), the indoor expansion valve (67), and the airflow control unit (62). The second control unit (C2) receives signals from the first temperature sensor (90) indicating the air temperature in the living area (R1) and signals from the second temperature sensor (91) indicating the temperature of the ceiling surface (11). The second control unit (C2) also receives signals from the second intake temperature sensor (72) and the second discharge temperature sensor (71) indicating their respective air temperatures. The second control unit (C2) may also have an outdoor control board (not shown) for controlling the outdoor unit (50a) and an indoor control board (not shown) for controlling the indoor unit (50b). The outdoor control board is installed in the outdoor unit (50a) and controls the second compressor (54), the outdoor expansion valve (56), the outdoor fan (65), and the second four-way switching valve (58). The indoor control board is installed in the indoor unit (50b) and controls the indoor expansion valve (67), the indoor fan (64), and the airflow adjustment unit (62).

[0084] The third control unit (C3) controls the exhaust fan (81) of the exhaust system (80). The third control unit (C3) is configured to communicate with the second control unit (C2).

[0085] The fourth control unit (C4) is located in the remote controller (95). The fourth control unit (C4) transmits various commands input to the remote controller (95) based on user operations to the first control unit (C1) or the second control unit (C2).

[0086] (8) Various Operation Modes of the Air Conditioning System The air conditioning system (1) of this embodiment has a ventilation operation mode, a heating operation mode, a cooling operation mode, and a displacement air conditioning mode. The various operation modes are selected by the user by operating the remote controller (95). The various modes will be described below.

[0087] (8-1) Ventilation Operation Mode The ventilation operation mode is a mode for ventilating the indoor space (S1). In ventilation operation mode, treated outside air is introduced into the indoor space (S1) and the air in the indoor space (S1) is discharged to the outside. In ventilation operation mode, the outside air processing unit (20) and the exhaust device (80) are operated, but the air conditioning unit (50) is not operated.

[0088] The control unit (CU) controls the outside air handling air conditioner (20) and the exhaust system (80). Specifically, the control unit (CU) starts the operation of the first compressor (23), the first fan (28), and the water pump (29), and adjusts the first expansion valve (25) to a predetermined opening. As a result, the first refrigerant circuit (21) performs a refrigeration cycle operation, and the water in the water circuit (22) flows out in a predetermined direction.

[0089] The control unit (CU) switches between heating the air in the first air passage (P1) and cooling the first air passage (P1) based on the current air temperature in the living area (R1) and the target temperature.

[0090] Specifically, the control unit (CU) switches the first four-way diverter valve (27) of the first refrigerant circuit (21) to either the first or second state. If the current air temperature in the living area (R1) is below the target temperature, the control unit (CU) sets the first four-way diverter valve (27) to the first state. As a result, the refrigerant discharged from the first compressor (23) dissipates heat into the water in the water circuit (22) in the water heat exchanger (26). The refrigerant is then depressurized by the first expansion valve (25), whose opening is adjusted by the control unit (CU), and after exchanging heat with air in the first heat exchanger (24), it is drawn back into the first compressor (23). The water heated in the water heat exchanger (26) dissipates heat into the air in the first air passage (P1) in the second heat exchanger (34). The air in the first air passage (P1) that has been heated in this way is then blown out from the first outlet (32).

[0091] On the other hand, if the current air temperature in the living area (R1) exceeds the target temperature, the control unit (CU) sets the first four-way switching valve (27) to the second state. As a result, the refrigerant discharged from the first compressor (23) dissipates heat into the air in the first heat exchanger (24). Subsequently, the refrigerant is depressurized by the first expansion valve (25), whose opening is adjusted by the control unit (CU), and then cools the water in the water circuit (22) by heat exchange in the water heat exchanger (26). The refrigerant is then drawn back into the first compressor. The water cooled in the water heat exchanger (26) cools the air in the first air passage (P1) in the second heat exchanger (34). The air in the first air passage (P1) that has been cooled in this way is then blown out from the first outlet (32).

[0092] The control unit (CU) controls the supply fan (36) and the exhaust fan (81) to a predetermined rotational speed. To maintain a constant room pressure, the supply fan (36) and the exhaust fan (81) may be controlled to have the same airflow or airflow velocity. The control unit (CU) closes the damper (38). This prevents indoor air from flowing back into the indoor space (S1) via the air handling unit (20b).

[0093] When the supply air fan (36) is operated, outside air is drawn into the main flow path (Pm) via the outdoor intake port (31a) and purified by passing through the first filter (35). The purified outdoor air is heated or cooled by the second heat exchanger (34) and then blown out into the indoor space (S1) from the first outlet (32). When the exhaust fan (81) is operated, the indoor air moves to the space above the ceiling (S2) via the ventilation opening (11a) on the ceiling surface (11) and is discharged to the outside via the exhaust device (80).

[0094] (8-2) Cooling operation mode In cooling operation mode, the air conditioning unit (50) operates, but the outdoor air handling unit (20) and exhaust unit (80) do not operate.

[0095] The control unit (CU) operates the second compressor (54) and the outdoor fan (65), sets the second four-way switching valve (58) to the first state, and fully opens the outdoor expansion valve (56).

[0096] The control unit (CU) operates the indoor fan (64) and adjusts the indoor expansion valve (67) to a predetermined opening. As a result, the outdoor heat exchanger (55) functions as a radiator (more precisely, a condenser), and the indoor heat exchanger (57) functions as an evaporator.

[0097] Specifically, the refrigerant compressed in the second compressor (54) flows through the outdoor heat exchanger (55). In the outdoor heat exchanger (55), the refrigerant condenses as it releases heat into the outdoor air. The refrigerant condensed in the outdoor heat exchanger (55) flows into the indoor unit (50b). In the indoor unit (50b), the refrigerant is depressurized by the indoor expansion valve (67) and then flows through the indoor heat exchanger (57). In the indoor heat exchanger (57), the refrigerant absorbs heat from the indoor air and evaporates. The refrigerant evaporated in each indoor heat exchanger (57) is then drawn back into the second compressor (54).

[0098] (8-3) Heating operation mode In heating operation mode, the air conditioning unit (50) operates, but the outdoor air handling unit (20) and exhaust unit (80) do not operate.

[0099] The control unit (CU) operates the second compressor (54) and the outdoor fan (65), sets the second four-way switching valve (58) to the second state, and adjusts the outdoor expansion valve (56) to a predetermined opening.

[0100] The control unit (CU) operates the indoor fan (64) and adjusts the indoor expansion valve (67) to a predetermined opening. As a result, the indoor heat exchanger (57) functions as a radiator (more precisely, a condenser), and the outdoor heat exchanger (55) functions as an evaporator.

[0101] Specifically, the refrigerant compressed in the second compressor (54) flows into the indoor unit (50b). In the indoor unit (50b), the refrigerant flows through the indoor heat exchanger (57). In the indoor heat exchanger (57), the refrigerant condenses as it releases heat into the indoor air. The refrigerant condensed in the indoor heat exchanger (57) is depressurized by the indoor expansion valve (67), then further depressurized by the outdoor expansion valve (56), and then flows through the outdoor heat exchanger (55). In the outdoor heat exchanger (55), the refrigerant absorbs heat from the outdoor air and evaporates. The refrigerant evaporated in the outdoor heat exchanger (55) is drawn into the second compressor (54).

[0102] (8-4) Displacement Air Conditioning Mode The displacement air conditioning mode described below is performed during periods when the outside air temperature is relatively low, such as in winter. The displacement air conditioning mode of this embodiment is an operation in which the indoor space (S1) is conditioned by displacement air conditioning using an outside air processing air conditioner (20) and an exhaust device (80), and the air in the indoor space (S1) (especially the living area (R1)) is heated by radiant heat or radiation heat from the heated ceiling surface (11). The flow of the displacement air conditioning mode will be explained using Figure 7. Although each step of the flow is explained mainly with respect to the control unit (CU), not all of the first to fourth control units (C1 to C4) execute each step, and different control units (CU) may execute different steps. In other words, at least one of the first to fourth control units (C1 to C4) controls each step.

[0103] Prior to step ST01 of the flow, it is assumed that there are no users in the indoor space (S1), and that the outdoor air handling air conditioner (20) and the air conditioning system (50) are stopped. In other words, step ST01 is executed after the user enters the indoor space (S1). Since the outside temperature is relatively low, the air temperature in the indoor space (S1) at the start of step ST01 is also relatively low.

[0104] In step ST01, the control unit (CU) determines whether or not the execution of the displacement air conditioning mode has been input. Specifically, based on the user's operation, the control unit (CU) determines from the menu screen displayed on the display unit (97) of the remote controller (95) whether or not the displacement air conditioning mode has been selected from among the displacement air conditioning mode, ventilation operation mode, heating operation mode, and cooling operation mode. If the displacement air conditioning mode is selected (YES in step ST01), step ST02 is executed. If the displacement air conditioning mode is not selected (NO in step ST01), the other selected mode is executed. The other modes are as described above.

[0105] In step ST02, the control unit (CU) sets the target temperature of the air in the indoor space (S1). Specifically, the control unit (CU) receives the target temperature output from the remote controller (95) by user operation. Since the first temperature sensor (90) is installed in the living area, the control unit (CU) sets the first target value, which is the target value of the air temperature in the living area (R1).

[0106] In step ST03, the control unit (CU) sets a target temperature for the ceiling surface (11). The target temperature for the ceiling surface (11) is the second target value of this disclosure. Specifically, the control unit (CU) determines the target temperature for the ceiling surface (11) based on the first target value. More specifically, the control unit (CU) determines the target temperature for the ceiling surface (11) based on the amount of heat radiated from the ceiling surface (11) and the target temperature of the air temperature in the living area (R1). In this case, assuming that the wall surface temperature other than the ceiling surface (11) is at the first target value, the second target value can be obtained by a predetermined calculation formula.

[0107] In step ST04, the control unit (CU) starts the operation of the outdoor air handling air conditioner (20), the air conditioning system (50), and the exhaust system (80). Specifically, the control unit (CU) starts the refrigeration cycle operation of the first refrigerant circuit (21) and the water pump (29) so that the outdoor air handling air conditioner (20) performs heating operation. The control unit (CU) starts the refrigeration cycle operation of the second refrigerant circuit (51) so that the air conditioning system (50) performs heating operation. The control unit (CU) also starts the operation of the exhaust fan (81).

[0108] In step ST05, the control unit (CU) controls the temperature of the air discharged from the outdoor air processing unit (20). Specifically, the control unit (CU) controls the first temperature, which is the temperature of the air discharged from the first outlet (32). The first temperature is detected by the first discharge temperature sensor (39).

[0109] The control unit (CU) controls the first temperature to be lower than the second temperature, which is the air temperature in the indoor space (S1). Since the second temperature is detected by the first temperature sensor (90), the second temperature may be considered to be the air temperature in the occupied area (R1). Specifically, the control unit (CU) sets the first temperature to be lower than the second temperature. Based on the first temperature, the control unit (CU) appropriately adjusts the rotational speed of the first compressor (23) and the opening degree of the first expansion valve (25). For example, if the second temperature is 22°C, the control unit (CU) controls the operation of the outdoor air handling air conditioner (20) so that the first temperature becomes 20°C.

[0110] In step ST06, the control unit (CU) adjusts the opening of the damper (38) based on the first temperature. The larger the opening of the damper (38), the greater the proportion of indoor air in the mixture of outdoor and indoor air. Since the temperature of indoor air is higher than that of the outdoor air, a larger proportion of indoor air reduces the operating load on the outdoor air handling air conditioner (20).

[0111] In step ST07, the control unit (CU) controls the supply air fan (36) so that the air velocity of the air discharged from the outside air processing unit (20) reaches a predetermined value. The air velocity from the first outlet (32) is relatively low. Specifically, the air velocity is such that it suppresses the air discharged from the first outlet (32) from entraining the air in the indoor space (S1) and also suppresses turbulence in the airflow of the indoor space (S1).

[0112] In step ST08, the control unit (CU) controls the exhaust device (80) based on the airflow velocity of the blown air controlled in step ST05. Specifically, the control unit (CU) adjusts the rotational speed of the exhaust fan (81) based on the rotational speed of the supply fan (36).

[0113] In step ST09, the control unit (CU) controls the air conditioner (50) so that the temperature of the ceiling surface (11) reaches the target temperature (second target value). The air conditioner (50) executes the heating operation mode and adjusts the flap (62a) to the third position. As a result, heated air is blown out horizontally from the second outlet (69) of the indoor unit (50b). In other words, the air conditioner (50) blows out heated air along the ceiling surface (11). As a result of the air blown out from the second outlet (69) flowing in contact with the ceiling surface (11), the ceiling surface (11) is heated. The air conditioner (50) is also an example of the second air conditioning unit (50). The air in the indoor space (S1) is heated by the radiant heat emitted from the heated ceiling surface (11) toward the indoor space (S1).

[0114] In step ST10, the control unit (CU) determines whether the air temperature in the living area (R1) is higher than the first target value. If it is determined that the air temperature in the living area (R1) is higher than the first target value (YES in step ST10), step ST11 is executed. If it is determined that the air temperature in the living area (R1) is lower than the first target value (NO in step ST10), step ST10 is executed again.

[0115] In step ST11, the control unit (CU) turns off the thermostat of the air conditioner (50). Thermo-off is a state in which heat exchange between the indoor heat exchanger (57) and the indoor air is restricted. When thermo-off, for example, the air conditioner (50) stops the operation of the second compressor (54) or stops the operation of the indoor fan (64) or operates it at the minimum speed. After step ST11, step ST10 is executed again.

[0116] If the displacement air conditioning mode is running and the user inputs a command to terminate the displacement air conditioning mode, the above flow is stopped. A command to terminate the displacement air conditioning mode is given, for example, when the user changes from the displacement air conditioning mode to a different operating mode, or when the user inputs a command to stop the air conditioning system (1).

[0117] (9) Features (9-1) The air conditioning system (1) of this embodiment includes an outdoor air processing air conditioner (20) that blows air containing temperature-controlled outdoor air from the first outlet (32) into the indoor space (S1), an air conditioning device (50) that heats the ceiling surface (11), and a control unit (CU) that controls the temperature of the air blown out from the first outlet (32) of the outdoor air processing air conditioner (20) so that the temperature of the air blown out from the first outlet (32) is lower than the temperature of the air in the indoor space (S1).

[0118] According to this, the air blown out from the outlet (32) on the ceiling surface (11) is at a temperature lower than the room temperature, so it can reach the floor. This makes displacement air conditioning possible.

[0119] In addition, the air blown out from the air conditioning unit (50) heats the ceiling surface (11), and the heat radiated from the ceiling surface (11) warms the air in the indoor space (S1). By utilizing this radiant heat, heating and displacement air conditioning can be achieved in the indoor space (S1) without disturbing the air in the living area (R1). Thus, in periods when the outside temperature is relatively high, such as in summer, the cool air blown towards the floor easily reaches the floor, making it relatively easy to perform both displacement air conditioning and cooling. However, in periods when the outside temperature is relatively low, such as in winter, the warm air blown towards the floor may not reach the floor due to buoyancy, making it difficult to achieve both displacement air conditioning and heating. In contrast, in the displacement air conditioning mode of this embodiment, not only can displacement air conditioning be achieved even in winter, but the air in the indoor space (S1) can also be heated to the target temperature.

[0120] In addition, by using an outside air handling air conditioner (20) installed on the ceiling for displacement air conditioning, the burden of installation work and installation costs can be reduced compared to, for example, installing a device that supplies air from the wall.

[0121] (9-2) The air conditioning system (1) of this embodiment further includes a first temperature sensor (90) for measuring the air temperature of the indoor space (S1). The control unit (CU) controls the air conditioning device (50) so that the value detected by the first temperature sensor (90) becomes a first target value.

[0122] According to this, the air conditioning system (50) operates so that the air temperature in the living area (R1) reaches the target temperature, and the air temperature in the living area (R1) rises relatively quickly. This allows for control such as preventing the outdoor air handling unit (20) from overcooling the living area (R1) or operating the outdoor air handling unit (20) only after the air temperature in the living area (R1) has risen to a certain level. As a result, the decrease in comfort in the living area (R1) of the indoor space (S1) can be suppressed.

[0123] (9-3) In the air conditioning system (1) of this embodiment, the control unit (CU) controls the air conditioner (50) so that the value detected by the second temperature sensor (91) becomes the second target value. As a result, the air conditioner (50) is controlled based on the temperature of the ceiling surface (11), and the ceiling surface (11) can be efficiently heated so that the air temperature in the indoor space (S1) reaches the target temperature.

[0124] (9-4) In the air conditioning system (1) of this embodiment, the air conditioner (50) blows heated air along the ceiling surface (11). This allows the ceiling surface (11) to be heated by the heated air from the second outlet (69) of the indoor unit (50b). The heated ceiling surface (11) in this way allows the air temperature in the living area (R1) to be raised to the target temperature. In addition, since the air blown out from the second outlet (69) is prevented from reaching the living area (R1), turbulence in the airflow of the living area (R1) can be suppressed, and displacement air conditioning by the outside air handling air conditioner (20) can be realized.

[0125] (10) Modified Examples Modified examples of the air conditioning system (1) of the above embodiment will be described.

[0126] (10-1) Modification 1 In the air conditioning system (1) of Modification 1, in step ST09 of the displacement air conditioning mode of the above embodiment, the control unit (CU) adjusts the flap (62a) to a position other than the third position. As a result, air is blown downward from the second outlet (69) into the indoor space (S1). Here, "downward" includes not only the direction directly below but also the direction diagonally downward. At this time, the control unit (CU) controls the rotation speed of the indoor fan (64) so ​​that the wind speed of the air blown out from the second outlet (69) on the ceiling surface (11) is less than or equal to the first wind speed. The first wind speed is a wind speed such that the air blown out from the second outlet (69) on the ceiling surface (11) does not reach the living area (R1), or even if it does reach the living area (R1), it does not affect the airflow within the living area (R1). The first wind speed is, for example, 1.0 m / s. Thus, in the displacement air conditioning mode of the modified example 1, the air conditioning unit (50) blows heated air downward from the second outlet (69), and the control unit (CU) controls the air conditioning unit (50) so that the air velocity of the air blown out from the second outlet (69) on the ceiling surface (11) is less than or equal to the first air velocity.

[0127] Here, we will explain one example of how to determine the first wind speed. First wind speed v ０ Hereinafter, the wind velocity v is at a distance x from the second outlet (69) toward the floor, and the air density ρ is that of the discharged air. １ Air density ρ in the residential area (R1) ２ It can be expressed in terms of gravitational acceleration g and time t. Furthermore, time t is expressed in terms of distance x and the first wind speed v. ０ It can be expressed as follows: Distance x is the vertical length from the second outlet (69) to the top of the living area (R1). That is, wind speed v indicates the wind speed at the top of the living area (R1). Also, if the wind direction of the air blown out from the second outlet (69) is not directly downward, i.e., if the wind direction is diagonally downward, the vertical downward component is v ０ Let v be the first wind speed v such that v ≤ 0. ０ By setting the outlet temperature accordingly, the air blown out from the second outlet (69) is prevented from reaching the living area (R1). When the outlet temperature of the second outlet (69) is set to its maximum value T, the outlet air velocity v ０When examining the relationship between the wind speed v and the primary wind speed, it was found that v ≤ 0 in the range where the primary wind speed is 1.0 m / s or less.

[0128] (10-2) Modified Example 2 As shown in Figure 8, the heating unit (H) in Modified Example 2 is a third air conditioning unit (100) that blows heated air into the ceiling space (S2). The third air conditioning unit (100) can be any air conditioning device that heats the air in the ceiling space (S2). For example, the third air conditioning unit (100) may have a refrigerant circuit, such as the air conditioning device (50) in the above embodiment, and may consist of an outdoor unit and a floor-standing or wall-mounted indoor unit. In this case, the indoor unit is placed in the ceiling space (S2).

[0129] The control unit (CU) controls the third air conditioning unit (100) so that the air temperature in the living area (R1) reaches the target temperature. When the air in the space above the ceiling (S2) is heated, the ceiling surface (11) that makes up the lower surface (floor) of the space above the ceiling (S2) is heated. As the temperature of the ceiling surface (11) rises, heat is radiated from the ceiling surface (11) toward the interior space (S1). The control unit (CU) may also control the direction of the blown air from the third air conditioning unit (100) so that it heats the lower surface (floor) of the space above the ceiling (S2).

[0130] (10-3) Modification 3 As shown in Figure 9, the heating unit (H) of Modification 3 is a radiant panel (200) provided on the ceiling surface (11). The radiant panel (200) can be any heat-generating element that heats the ceiling surface (11). For example, the radiant panel (200) may have a water pipe provided inside the ceiling surface (11). By flowing hot water through the water pipe, the radiant panel (200) generates heat and heats the ceiling. The hot water may be generated by heating it in a water heat exchanger (26), similar to the water circuit (22) in the above embodiment. The radiant panel (200) may also have an electric heater. In this case, the radiant panel (200) generates heat by energizing the electric heater.

[0131] The control unit (CU) controls the radiant panels (200) so that the air temperature in the living area (R1) reaches the target temperature.

[0132] (11) Other embodiments The air conditioning system (1) of the above embodiments and each modified example may be configured as follows.

[0133] In displacement air conditioning mode, the first temperature to be set does not have to be based on the value of the first temperature sensor (90) in the indoor space (S1), but may be set based on the air temperature in the indoor space (S1). For example, the first temperature may be a preset temperature. Specifically, the first temperature may be determined to be lower than the lowest air temperature in the indoor space (S1) from the present to the past few years.

[0134] The heating element (H) can be any device that heats the ceiling surface (11), and is not limited to an air conditioning system (50) or a radiant panel.

[0135] In the above embodiment, the second temperature sensor (91) may detect the air temperature near the ceiling surface (11). In this case, the second target value is set based on the air temperature near the ceiling surface (11). The vicinity of the ceiling surface (11) is a position above a position 1.0 m below the ceiling surface (11), preferably a position above a position 0.3 m below the ceiling surface (11), more preferably a position above a position 0.1 m below the ceiling surface (11), even more preferably a position above a position 5 cm below the ceiling surface (11), and most preferably a position above a position 1 cm below the ceiling surface (11).

[0136] In the above embodiment, in step ST05, the control unit (CU) may appropriately adjust the rotational speed of the first compressor (23) and the opening degree of the first expansion valve (25) based on the first temperature and the water temperature of the water circuit (22). In this case, a water temperature sensor for detecting the water temperature of the water circuit (22) is provided at a predetermined position.

[0137] In the above embodiment, in step ST10, the control unit (CU) may determine whether the temperature of the ceiling surface (11) or the air temperature near the ceiling surface (11) is higher than the second target value.

[0138] The air conditioning system (1) of the above embodiment may not have a second temperature sensor (91). Specifically, the step ST03 may be omitted. In this case, in step ST09, the air conditioning device (50) adjusts the position of the flap (62a) to the third position and executes the heating operation mode.

[0139] The air conditioning systems (1) of the above modified examples 2 and 3 may also have a second temperature sensor (91).

[0140] The living area (R1) can be any space below the interior space (S1). The lower area is the region between 1 / 3 and 1 / 2 of the height from the floor (12) to the ceiling (11).

[0141] While embodiments and variations have been described above, it will be understood that a variety of modifications to the form and details are possible without departing from the spirit and scope of the claims. Furthermore, these embodiments and variations may be combined or substituted as appropriate, as long as they do not impair the functions covered by this disclosure.

[0142] As explained above, this disclosure is useful for air conditioning systems.

[0143] 1 Air conditioning system 11 Ceiling surface 12 Floor surface 20 Outdoor air handling unit (first air conditioning unit) 32 First air outlet (air outlet) 50 Air conditioning device (second air conditioning unit) 90 First temperature sensor 100 Third air conditioning unit CU Control unit (control unit) H Heating unit R1 Living area R2 Non-living area S1 Target space (indoor space)

Claims

1. An air conditioning system comprising: a first air conditioning unit (20) having an outlet (32) on the ceiling surface (11) of a target space (S1) and blowing air including temperature-controlled outdoor air from the outlet (32) into the target space (S1); a heating unit (H) for heating the ceiling surface (11); and a control unit (CU) for controlling the temperature of the air blown out from the first air conditioning unit (20) so that the temperature of the air blown out from the outlet (32) is lower than the air temperature of the target space (S1).

2. The air conditioning system according to claim 1, further comprising a first temperature sensor (90) for measuring the air temperature of the target space (S1), wherein the control unit (CU) controls the heating unit (H) so that the value detected by the first temperature sensor (90) becomes a first target value.

3. The air conditioning system according to claim 1 or 2, wherein the heating unit (H) is a second air conditioning unit (50) that blows heated air from the ceiling surface (11) into the target space (S1).

4. The air conditioning system according to claim 3, further comprising a second temperature sensor (91) for detecting the temperature of the ceiling surface (11) or the air temperature near the ceiling surface (11), wherein the control unit (CU) controls the second air conditioning unit (50) so that the value detected by the second temperature sensor (91) becomes a second target value.

5. The air conditioning system according to claim 3, wherein the second air conditioning unit (50) blows heated air along the ceiling surface (11).

6. The air conditioning system according to claim 3, wherein the second air conditioning unit (50) blows heated air downward, and the control unit (CU) controls the second air conditioning unit (50) so that the first air velocity of the air blown out from the ceiling surface (11) is 1.0 m / s or less.

7. The air conditioning system according to claim 1 or 2, wherein the heating unit (H) is a third air conditioning unit (100) that blows heated air into the space behind the ceiling surface (11).

8. The air conditioning system according to claim 1 or 2, wherein the heating unit (H) is a radiant panel (200) provided on the ceiling surface (11).

9. The air conditioning system according to any one of claims 1 to 8, wherein the target space (S1) comprises a living area (R1) adjacent to the floor surface and a non-living area which is the space between the living area (R1) and the ceiling surface (11).

10. The air conditioning system according to claim 9, wherein the living area (R1) is the space below the target space (S1).

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