JP2000314539A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent impairing comfort of the inside of a room upon reversed cycle defrosting operation. SOLUTION: A ceiling suction port 18 for introducing air in a ceiling space 12 and a ceiling outlet port 19 for sending out the air in the ceiling space 12 are formed in a casing 13 for a recessed indoor machine 1. A first damper 20 is provided in a corner between the ceiling suction port 18 and an indoor suction port 16. A second damper 21 is provided in a corner between the ceiling outlet port 19 and an indoor outlet port 17. Upon reversed cycle defrosting operation, the ceiling suction port 18 and the ceiling outlet port 19 are opened, while the indoor suction port 16 and the indoor outlet port 17 are closed by the first damper 20 and the second damper 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly, to an air conditioner that performs a reverse cycle defrost operation for defrosting an outdoor heat exchanger.

[0002]

2. Description of the Related Art Conventionally, a refrigeration cycle that includes an indoor heat exchanger and an outdoor heat exchanger and condenses refrigerant in an indoor heat exchanger and evaporates refrigerant in an outdoor heat exchanger is used.
BACKGROUND ART An air conditioner that heats a room is known. At this time, if the evaporation temperature of the refrigerant in the outdoor heat exchanger is 0 ° C. or lower, frost is formed on the outdoor heat exchanger.

[0003] When frost is generated in the outdoor heat exchanger, the heat exchange capacity is reduced due to a decrease in the heat transfer area and a decrease in the air supply amount. Therefore, in order to maintain the performance and operating efficiency of the air conditioner, usually, when the amount of frost on the outdoor heat exchanger increases,
A defrost operation (defrosting operation) is performed.

As the defrosting operation, there are known a normal cycle defrosting operation and a reverse cycle defrosting operation in which frost is melted by a refrigerant in a refrigerant circuit, in addition to a method using an external heating source such as an electric heater. The normal cycle defrost operation is an operation in which the high-temperature refrigerant is supplied to the indoor heat exchanger while the circulation direction of the refrigerant remains unchanged. On the other hand, the reverse cycle defrost operation is an operation in which the circulation direction of the refrigerant is reversed from that in the heating operation, and the refrigerant is condensed in the outdoor heat exchanger and the refrigerant is evaporated in the indoor heat exchanger.

A method using an external heating source such as an electric heater requires an extra electric input for the heating source,
This leads to a decrease in the efficiency of the device. Positive cycle defrost operation does not require extra electrical input for the heating source,
Only heat given to the refrigerant from the compressor is a heat source for melting the frost, and it takes a considerable time to melt the entire frost of the outdoor heat exchanger. Therefore, the heating of the room is stopped for a relatively long time until the defrost operation is completed, so that it is difficult to say that the heating capacity is sufficient.

On the other hand, the reverse cycle defrost operation does not require an extra electric input for a heating source and uses indoor air as a part of the heat source.
Defrosting can be completed in a relatively short time.

[0007]

However, since the conventional reverse cycle defrosting operation uses room air as a heat source for defrosting as described above, indoor air is deprived as a result. Was. Also, warm indoor air is cooled in the indoor heat exchanger, and the cooled air is returned directly to the room. Therefore, comfort for indoor occupants is impaired.

[0008] The present invention has been made in view of such a point, and an object of the present invention is to perform a reverse cycle defrost operation so as not to impair indoor comfort.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention does not return air cooled by the indoor heat exchanger directly to the room during the reverse cycle defrost operation,
We decided to release it into the space above the ceiling. Also, the air under the ceiling was used as a heat source for defrost.

Specifically, the air conditioner according to the present invention comprises at least an indoor heat exchanger (15) and an outdoor heat exchanger (35).
An air conditioner comprising: the outdoor heat exchanger (35)
During the reverse cycle defrost operation for defrosting, the air cooled by the indoor heat exchanger (15) is discharged to the space above the ceiling (12).

According to the above, the air cooled by the indoor heat exchanger and used as the defrost heat source is discharged into the space above the ceiling without being directly blown out toward the room. The air discharged into the space above the ceiling mixes with warm air in the space above the ceiling, and returns to the room after the temperature rises. Therefore, the low-temperature air cooled by the indoor heat exchanger does not directly flow into the room, so that the indoor comfort is maintained.

Another air conditioner according to the present invention is an air conditioner provided with at least an indoor heat exchanger (15) and an outdoor heat exchanger (35), excluding the outdoor heat exchanger (35). Space above the ceiling during reverse cycle defrost operation for frost (12)
Some or all of the warm air inside is used as a heat source.

According to the above, a part or all of the warm air in the space above the ceiling is used as a heat source for defrosting, so that the amount of indoor air used as a heat source is reduced or the indoor air is used as a heat source. It is no longer necessary to use it. Therefore, a decrease in the indoor temperature is suppressed, and the indoor comfort is maintained.

Another air conditioner according to the present invention is an air conditioner provided with at least an indoor heat exchanger (15) and an outdoor heat exchanger (35). While the air heated by the exchanger (15) is supplied to the room (11), during the reverse cycle defrost operation for defrosting the outdoor heat exchanger (35), the indoor heat exchanger (15) is supplied. ) Is provided with air path switching means (M) for switching the air path so as to release the air cooled by the above to the space above the ceiling (12).

According to the above, during the heating operation, the air heated by the indoor heat exchanger is supplied into the room, and the room is heated. During the reverse cycle defrost operation, the air is cooled by the indoor heat exchanger, but the cooling air is discharged to the space above the ceiling, so that the cooling air is not directly supplied to the room. Therefore, indoor comfort is maintained.

The above air conditioner comprises an indoor inlet (16) and an indoor outlet (17) facing the room (11), and a ceiling inlet (18) and an overhead outlet (17) facing the space above the ceiling (12). An indoor heat exchanger (15) comprising: an indoor casing (13) formed with an indoor casing (13); and an indoor blower (14) provided in the indoor casing (13).
Is provided in the indoor casing (13), and the air path switching means (M) opens the indoor suction port (16) and the indoor air outlet (17) and performs the ceiling operation during the heating operation. The back suction port (18) and the ceiling back outlet (19) are closed, and in the reverse cycle defrost operation, the ceiling back suction port (18) and the ceiling back outlet (19) are opened and the back suction port (19) is opened. It may be constituted by dampers (20, 21) that close the indoor suction port (16) and the indoor air outlet (17).

According to the above, in the heating operation, the indoor air is sucked into the indoor casing from the indoor suction port by the indoor blower, the air is heated when passing through the indoor heat exchanger, and the indoor air is discharged from the indoor air outlet to the indoor air outlet. Is blown out. On the other hand, during the reverse cycle defrost operation, warm air in the space above the ceiling is sucked into the indoor casing from the space above the ceiling by the indoor blower, the air is cooled when passing through the indoor heat exchanger, and the air above the ceiling is cooled. It is blown out from the outlet into the space above the ceiling. Therefore, during the reverse cycle defrost operation, the cooled air is not directly supplied to the room, so that the indoor comfort is maintained.

Further, the above air conditioner has an indoor air inlet (16) and an indoor air outlet (17, 17A, 17B) facing the room (11) and a ceiling air outlet (19, 17) facing the space above the ceiling (12). 19A, 19B), and an indoor blower (14) provided in the indoor casing (13b, 13c, 13d), and the indoor heat exchanger (15 , 15A, 15B)
(13b, 13c, 13d), the air path switching means (M) opens the indoor air outlets (17, 17A, 17B) and performs the above-the-ceiling air outlets (19 , 19A, 19B), and in the case of reverse cycle defrost operation, the air outlet above the ceiling (19, 19B).
19A, 19B) and the indoor outlets (17, 17A, 17B)
May be constituted by a damper (21, 23A, 23B, 24A, 24B) for closing the valve.

According to the above, in the heating operation, the indoor air is sucked into the indoor casing from the indoor suction port by the indoor blower, the air is heated when passing through the indoor heat exchanger, and the indoor air is blown from the indoor outlet to the indoor air outlet. Is blown out. On the other hand, during the reverse cycle defrost operation, indoor air is sucked into the indoor casing from the indoor suction port by the indoor blower, and the air is cooled when passing through the indoor heat exchanger. Be blown out into space. Therefore, during the reverse cycle defrost operation, the cooled air is not directly supplied to the room, so that the indoor comfort is maintained.

The above air conditioner further comprises an indoor suction port (16) facing the room (11), an indoor air outlet (17, 17A, 17B), and a ceiling suction port (18, 17) facing the space above the ceiling (12). 30) and ceiling outlet
(19, 19A, 19B) and the formed indoor casing (13, 13f)
And an indoor blower (14) provided in the indoor casing (13, 13f), and the indoor heat exchanger (15, 15A, 15B) is provided in the indoor casing (13, 13f), Airway switching means
(M) indicates the indoor air outlet (17, 17A, 17
B) and the above-the-ceiling suction port (18, 30) and the above-the-ceiling air outlet (19, 19A, 19B) are closed, and in the case of reverse cycle defrost operation, the above-the-ceiling suction port (18, 30) is opened. 30) and a damper (20, 23A, 23B, 28) that opens the ceiling outlet (19, 19A, 19B) and closes the indoor outlet (17, 17A, 17B). .

According to the above, in the heating operation, the indoor air is sucked into the indoor casing from the indoor suction port by the indoor blower, and the air is heated when passing through the indoor heat exchanger, and is heated from the indoor air outlet. It is blown out into the room. On the other hand, during the reverse cycle defrost operation, air is sucked into the indoor casing from both the indoor suction port and the ceiling back suction port by the indoor blower, and the air is cooled when passing through the indoor heat exchanger, and the ceiling air is cooled. It is blown out from the back outlet to the space behind the ceiling. Therefore, during the reverse cycle defrost operation, the cooled air is not directly supplied to the room, so that the indoor comfort is maintained.

The above air conditioner further comprises an indoor air inlet (16) and an indoor air outlet (17) facing the room (11) and a space above the ceiling (12).
An indoor casing (13) formed with a ceiling inlet (18) and a ceiling outlet (19) facing the interior casing, and the indoor casing (13)
An indoor blower (14) provided in the inside and a temperature detecting means (36, 3
7), and the indoor heat exchanger (15) is
(13), the air path switching means (M) is configured to open the indoor suction port (16) and the indoor air outlet (17) and perform the above-the-ceiling suction port (18) during the heating operation. And closing the above-mentioned ceiling outlet (19), and opening the room inlet (16) and the above-ceiling outlet (19) when the room air temperature is equal to or higher than the ceiling air temperature during the reverse cycle defrost operation. At the same time, the above-the-ceiling suction port (18) and the indoor outlet (17) are closed, and when the room air temperature is lower than the above-the-ceiling air temperature, the above-the-ceiling suction port (18) and the above-the-ceiling outlet (19) are closed. ) And a damper for closing the indoor suction port (16) and the indoor air outlet (19).
(20, 21).

According to the above, in the heating operation, the indoor air is sucked into the indoor casing from the indoor suction port by the indoor blower, the air is heated when passing through the indoor heat exchanger, and the air is heated from the indoor outlet. It is blown out into the room. On the other hand, during the reverse cycle defrost operation, either the room air or the air above the ceiling, whichever has a higher temperature, is sucked in, the air is cooled when passing through the indoor heat exchanger, and the air above the ceiling is cooled. It is blown out from the outlet into the space above the ceiling. Therefore, in addition to maintaining indoor comfort, the higher temperature of the room air or the air behind the ceiling is used as a heat source, so that the operation time of the defrost operation is reduced.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1> The air conditioner according to the present embodiment is a room air conditioner in which an indoor unit (1) and an outdoor unit (2) are connected via a refrigerant pipe. As shown in FIG. 1, the indoor unit (1) is configured by a unit embedded in a ceiling, and is installed by being fitted into an opening formed in the ceiling (9). Above the ceiling (9), an under-ceiling space (12) separated from the indoor space (11) by the ceiling (9) is formed. The ceiling (9) is made of a material having a high air permeability as compared with a wall or the like, with a gap in a mounting portion (not shown) of the lighting fixture. Therefore, during the heating operation, warm air (warm air) in the room flows into the space above the ceiling (12), and the warm air stays in the space above the ceiling (12).

Inside the casing (13) of the indoor unit (1),
An indoor heat exchanger (15) and an indoor blower (14) are provided.

On one side of the casing (13), a ceiling suction port (18) for sucking the air in the space above the ceiling (air above the ceiling) is formed. On the side opposite to the side where the ceiling suction port (18) is formed, a ceiling outlet (19) for discharging air in the casing (13) to the space above the ceiling (12).
Are formed. On the lower surface of the casing (13), an indoor suction port (16) for inhaling room air, and a casing (13).
Indoor air outlet (1) to supply air inside the room to the indoor space (11).
7) is formed. The indoor suction port (16) is provided near the ceiling suction port (18). Meanwhile, indoor outlet (17)
Is provided near the ceiling outlet (19).

[0028] A suction port (18) above the ceiling in the casing (13).
A first damper (20) rotatable around the corner portion is provided at a corner between the room and the indoor suction port (16). First
The damper (20) is formed to have a larger surface area than the suction ports (16) and (18) so that both the ceiling suction port (18) and the indoor suction port (16) can be selectively closed. ing. Similarly, a second damper (21) is provided at a corner of the casing (13) between the ceiling outlet (19) and the indoor outlet (17), the second damper (21) being rotatable around the corner. ing. 2nd damper
(21) also has a larger surface area than these outlets (17), (19) so that both the ceiling outlet (19) and the indoor outlet (17) can be selectively closed. I have. And
The first damper (20) and the second damper (21) form an air path switching means (M) for switching an air path according to an operation mode.

As shown in FIG. 2, the outdoor unit (2) includes a compressor (31), a four-way switching valve (32), an outdoor heat exchanger (35), an outdoor blower (34), and an expansion valve ( 33) is provided. Compressor (3
1), four-way switching valve (32), outdoor heat exchanger (35), expansion valve (33),
The indoor heat exchanger (15) forms a heat pump type refrigerant circuit (40) that can freely switch the refrigerant circulation direction.

As shown in FIG. 3, during the cooling operation, the first
The damper (20) is positioned vertically so as to close the ceiling inlet port (18), and the second damper (21) is positioned vertically so as to close the ceiling outlet port (19). As a result, the indoor inlet
(16) and the indoor outlet (17) are set in an open state, and the indoor air sucked from the indoor suction port (16) is supplied to the indoor heat exchanger.
After passing through (15), the air is blown out from the indoor outlet (17) into the indoor space (11). In the refrigerant circuit (40), the four-way switching valve (32) is set to the solid line side, and the refrigerant discharged from the compressor (31)
Condensed in the outdoor heat exchanger (35), decompressed by the expansion valve (33), evaporated in the indoor heat exchanger (15) by exchanging heat with indoor air, and returned to the compressor (31). .

During the heating operation, as shown in FIG. 3, the first damper (20) closes the suction port (18) above the ceiling, and the second damper (20) closes the second suction port (18).
The damper (21) closes the ceiling outlet (19). as a result,
The indoor suction port (16) and the indoor outlet (17) are open,
The indoor air sucked from the indoor suction port (16) passes through the indoor heat exchanger (15), and is blown out from the indoor air outlet (17) to the indoor space (11). In the refrigerant circuit (40), the four-way switching valve (32)
Is set to the broken line side, the refrigerant discharged from the compressor (31) exchanges heat with the indoor air in the indoor heat exchanger (15), condenses, is decompressed by the expansion valve (33), and A circulation operation of evaporating in the vessel (35) and returning to the compressor (31) is performed.

On the other hand, in the defrost operation for melting the frost generated in the outdoor heat exchanger (35), the refrigerant circuit (40)
, The four-way switching valve (32) is set on the solid line side and the compressor
The refrigerant discharged from (31) is condensed in the outdoor heat exchanger (35) and melts frost in the outdoor heat exchanger (35). Outdoor heat exchanger (3
The refrigerant flowing out of 5) is reduced in pressure by the expansion valve (33), and evaporates in the indoor heat exchanger (15). The refrigerant flowing out of the indoor heat exchanger (15) returns to the compressor (31) and repeats such a circulation operation again. That is, reverse cycle defrost operation is performed.

As shown in FIG. 4, in the indoor unit (1), the first
The damper (20) rotates to a horizontal position so as to open the suction port (18) behind the ceiling and close the indoor suction port (16). The second damper (21) rotates to a horizontal position so as to open the ceiling outlet (19) and close the indoor outlet (17). As a result, the air behind the ceiling is sucked into the casing (13) through the suction inlet (18), and the air behind the ceiling is cooled by the indoor heat exchanger (15) and used as a heat source for defrost. The cooled air is discharged to the space above the ceiling (12) through the air outlet (19) above the ceiling.
At this time, no indoor air is sucked into the casing (13), and no air in the casing (13) is blown out to the indoor space (11).

The air discharged into the space above the ceiling (12) mixes with the warm air staying in the space above the ceiling (12), and its temperature rises. Since the pressure in the space above the ceiling (12) is higher than that in the room (11), the air in the space above the ceiling (12) is slowly supplied to the room (11) through the ceiling (9). Therefore, the cooling air discharged from the casing (13) to the space above the ceiling (12) mixes with the warm air in the space above the ceiling (12), and then heats up.
It returns to the indoor space (11) through (9).

As described above, according to the present embodiment, the indoor air outlet (17) is closed during the reverse cycle defrost operation, so that the air cooled by the indoor heat exchanger (15)
It is not blown directly into the indoor space (11). Further, the air supplied to the indoor heat exchanger (15) and used as a heat source for defrost is not room air but air above the ceiling, so that the indoor warm air is not lost. for that reason,
Despite the reverse cycle defrost operation, the indoor comfort can be maintained.

<Embodiment 2> As shown in FIG. 5, the air conditioner according to Embodiment 2 draws room air into the casing (13b) during the reverse cycle defrost operation and exchanges the air with room heat. After being cooled by the vessel (15), it is discharged into the space above the ceiling (12). In the following description, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

In this embodiment, the casing of the indoor unit (1)
(13b) has an indoor suction port (16), an indoor outlet (17), and a ceiling outlet (19). At the corner between the indoor outlet (17) and the ceiling outlet (19), a damper (21) for selectively closing the indoor outlet (17) or the ceiling outlet (19) is provided. ing.

During cooling operation or heating operation, the damper
By (21), the ceiling outlet (19) is closed and the indoor outlet (17) is opened. Then, indoor air is sucked into the casing (13b) from the indoor suction port (16), and the air is cooled or heated by the indoor heat exchanger (15). This air is blown into the indoor space (11) through the indoor outlet (17). Thereby, indoor cooling or heating is performed.

On the other hand, in the reverse cycle defrost operation, the air outlet (19) is opened by the damper (21) and the indoor air outlet (17) is closed. Then, indoor air is sucked into the casing (13b) from the indoor suction port (16),
The air is cooled by the indoor heat exchanger (15) and used as a heat source for defrost. The cooled air is discharged to the space above the ceiling (12) through the air outlet (19) above the ceiling.

As described above, also in the second embodiment, since the indoor air outlet (17) is closed during the reverse cycle defrost operation, the air cooled by the indoor heat exchanger (15) is used for the indoor space (11). ) Is not directly blown out. Therefore, indoor comfort can be maintained.

Third Embodiment As shown in FIG. 6, an air conditioner according to a third embodiment is obtained by applying the second embodiment to a two-way blown ceiling-mounted unit.

An indoor suction port (16) is formed at the center of the lower surface of the casing (13c), and a first suction port is provided on both sides of the indoor suction port (16).
And second indoor air outlets (17A) and (17B). A first ceiling outlet (19A) is formed on a side surface of the casing (13c) near the first indoor outlet (17A). A second ceiling back outlet (19B) is formed on a side surface of the casing (13c) near the second indoor outlet (17B). That is, in the present embodiment, on both sides of the casing (13c),
Two ceiling outlets (19A) and (19B) are provided.

The first indoor outlet (17A) and the first ceiling outlet
A first damper (23A) is provided at the corner with (19A). The first damper (23A) is a damper for selectively closing either the first indoor outlet (17A) or the first ceiling outlet (19A). A second damper (23B) is provided at a corner between the second indoor outlet (17B) and the second ceiling outlet (19B). The second damper (23B) is connected to the second indoor outlet (17
This is a damper for selectively closing either one of B) and the second ceiling outlet (19B).

An indoor blower (14) is provided in the center of the casing (13c), and first and second indoor heat exchangers (15A) and (15B) are provided on both sides of the indoor blower (14). Have been.

During the cooling operation or the heating operation, the first indoor air outlet (17A) is opened by the first damper (23A), the first ceiling air outlet (19A) is closed, and the second damper (23A) is closed. twenty three
B) opens the second indoor outlet (17B) and closes the second ceiling back outlet (19B). Then, the indoor air is drawn into the casing (13c) from the indoor suction port (16), and is cooled or heated by the first and second indoor heat exchangers (15A) and (15B), and the first and second indoor blowers are provided. Exit (17A), (17
B) is blown out into the indoor space (11). Thereby, indoor cooling or heating is performed.

On the other hand, during the reverse cycle defrost operation, the first damper (23A) opens the first ceiling back outlet (19A), closes the first indoor outlet (17A), and closes the second damper (17A). (23B) opens the second ceiling outlet (19B) and closes the second indoor outlet (17B). That is, both the first and second ceiling outlets (19A) and (19B) are opened, and the first and second indoor outlets (17A) and (17B) are opened.
Are both closed. Then, indoor air is sucked into the casing (13c) from the indoor suction port (16), and the air is cooled by the first and second indoor heat exchangers (15A) and (15B), and serves as a heat source for defrost. Used. The cooled air is discharged to the space above the ceiling (12) through the first and second air outlets (19A) and (19B).

As described above, also in the third embodiment, since the indoor outlets (17A) and (17B) are closed during the reverse cycle defrost operation, the indoor air outlets (15A) and (15B) are cooled by the indoor heat exchangers (15A) and (15B). The air does not blow out directly into the indoor space (11). Therefore, indoor comfort can be maintained.

Note that, as shown in FIG.
Of course, it is also possible to apply to a direction-blown ceiling embedded type unit. The in-ceiling suction port and the in-ceiling air outlet may be provided by four each so as to correspond to the indoor air outlets (17A), (17B), ..., or may be provided by two or three each. .

Fourth Embodiment As shown in FIG. 8, the air conditioner according to the fourth embodiment sucks both room air and air above the ceiling into the casing (13) during the reverse cycle defrost operation. After the air is cooled by the indoor heat exchanger (15), the air is discharged to the space above the ceiling (12). The configuration of the indoor unit (1) of the present embodiment is the same as that of the first embodiment.

During the cooling operation or the heating operation, as in the first embodiment, the first damper (20) controls the suction port (18) above the ceiling.
Is closed, and the second air damper (21) closes the ceiling outlet (19).
Is closed. Then, similarly to the first embodiment, indoor cooling or heating is performed.

In the reverse cycle defrost operation, FIG.
As shown in (1), the first damper (20) rotates to the inclined position, and both the indoor suction port (16) and the ceiling back suction port (18) are opened. The second damper (21) rotates to the horizontal position, and the ceiling outlet (19) is opened and the indoor outlet (17) is closed. Then, both the room air and the air behind the ceiling are sucked into the casing (13). The indoor air and the air behind the ceiling are cooled by the indoor heat exchanger (15), used as a heat source for defrost, and then discharged to the space above the ceiling (12) through the ceiling outlet (19).

As described above, also in the fourth embodiment, since the indoor air outlet (17) is closed during the reverse cycle defrosting operation, the air cooled by the indoor heat exchanger (15) is supplied to the indoor space (11). ) Is not directly blown out. In addition, since the warm air in the space above the ceiling (12) is used as a heat source for defrost, the amount of indoor air required as a heat source for defrost is reduced accordingly. Therefore, the indoor comfort can be improved.

<Fifth Embodiment> As shown in FIG. 9, an air conditioner according to a fifth embodiment of the present invention is a two-way blown ceiling-mounted unit, in which both indoor air and ceiling air are used during reverse cycle defrost operation. Is to inhale.

The configuration of the indoor unit (1) according to the present embodiment is almost the same as that of the indoor unit of the third embodiment. A mouth (30) is formed. In addition, the indoor unit (1) of the present embodiment is provided with a third damper (28) for opening and closing the ceiling inlet (30) in addition to the first and second dampers (23A) and (23B). I have.

In the cooling operation or the heating operation, first to
The first through third ceiling outlets (19A), (19B) and (30) are closed by the third dampers (23A), (23B) and (28). Then, indoor air is sucked into the casing (13f), and the indoor air is cooled or heated by the first and second indoor heat exchangers (15A) and (15B), and the first and second indoor outlets ( 17A), (17
B) is blown into the room.

On the other hand, during the reverse cycle defrost operation, the first and second chamber outlets (17A) and (17B) are closed by the first and second dampers (23A) and (23B), and 1
And the second ceiling back outlets (19A) and (19B) are opened. Further, the third damper (28) is opened, and the suction port (30) behind the ceiling is opened. And, in the casing (13f), the indoor suction port
The indoor air is sucked in from (16), and the air behind the ceiling is sucked in from the ceiling inlet (30). The indoor air and the air behind the ceiling are cooled by the first and second indoor heat exchangers (15A) and (15B), and then the first and second ceiling air outlets (19A) and (19).
It is released into the space above the ceiling (12) through B).

As described above, also in the fifth embodiment, when the reverse cycle defrost operation is performed, the indoor outlets (17A), (17B)
Is closed, the air cooled by the indoor heat exchangers (15A) and (15B) is not directly blown into the indoor space (11). In addition, since the warm air in the space above the ceiling (12) is used as a heat source for defrost, the amount of indoor air required as a heat source for defrost is reduced accordingly. Therefore, the indoor comfort can be improved.

<Embodiment 6> The air conditioner according to Embodiment 6 applies the higher temperature of the room air or the air above the ceiling to the casing (1) during the reverse cycle defrost operation.
3). As shown in FIG. 10, the indoor unit of the present embodiment is different from the indoor unit of Embodiment 1 in that an indoor temperature sensor (37) for detecting the indoor air temperature and an indoor temperature sensor ( 36).

In the reverse cycle defrost operation, the second cycle
The damper (21) opens the ceiling outlet (19) and closes the indoor outlet (17). Meanwhile, the first damper (20)
Is appropriately set as follows according to the temperatures of the room air and the air behind the ceiling. That is, when the room air temperature is equal to or higher than the ceiling air temperature, the first damper (20) is set at the vertical position, the indoor suction port (16) is opened, and the ceiling suction port (18) is closed. Is done. Thereby, room air is sucked into the casing (13). On the other hand, if the room air temperature is lower than the ceiling air temperature, the first damper
(20) is set in a horizontal position, and the ceiling suction port (18) is opened and the indoor suction port (16) is closed. This allows
The air behind the ceiling is sucked into the casing (13).

Therefore, according to the present embodiment, the air having the higher temperature of the room air or the air behind the ceiling is used as the heat source for the defrost, so that the defrost time can be shortened. Therefore, the heating operation can be restarted at an early stage, and the indoor comfort is improved.

[0061]

As described above, according to the present invention, during the reverse cycle defrost operation, the air used as the heat source of the defrost and cooled is not directly supplied into the room. Therefore, it is possible to execute the reverse cycle defrost operation so as not to impair indoor comfort.

By using the warm air staying in the space above the ceiling as a heat source for defrost, the amount of room air required as a heat source can be reduced or reduced to zero. Therefore, a decrease in the indoor temperature can be suppressed, and the indoor comfort can be maintained.

In the heating operation, the air heated by the indoor heat exchanger is supplied to the room, while in the reverse cycle defrost operation, the air cooled by the indoor heat exchanger is discharged to the space above the ceiling. By providing the air path switching means for switching the air path in such a manner, the indoor comfort can be improved based on a simple configuration.

In the reverse cycle defrosting operation, the operating time of the defrosting operation can be reduced by using the air having the higher temperature of the room air or the air behind the ceiling as the heat source of the defrosting.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an indoor unit according to a first embodiment.

FIG. 2 is a refrigerant circuit diagram of the air conditioner.

FIG. 3 is a diagram corresponding to FIG. 1 showing a flow of air during a cooling operation or a heating operation.

FIG. 4 is a diagram corresponding to FIG. 1, showing the flow of air during reverse cycle defrost operation.

FIG. 5 is a configuration diagram of an indoor unit according to a second embodiment.

FIG. 6 is a configuration diagram of an indoor unit according to a third embodiment.

FIG. 7 is a configuration diagram of a modification of the third embodiment.

FIG. 8 is a configuration diagram of an indoor unit according to a fourth embodiment.

FIG. 9 is a configuration diagram of an indoor unit according to a fifth embodiment.

FIG. 10 is a configuration diagram of an indoor unit according to a sixth embodiment.

[Explanation of symbols]

 (1) Indoor unit (9) Ceiling (11) Indoor space (12) Ceiling space (13) Casing (14) Indoor blower (15) Indoor heat exchanger (16) Indoor inlet (17) Indoor outlet (18) ) Ceiling inlet (19) Ceiling outlet (20), (21) Damper

Continuation of the front page (72) Inventor Yasushi Yasushi Yasushi, Okamotocho, Kusatsu-shi, Shiga 1000-2, Daikin Industries, Ltd. Shiga Works (72) Inventor Yoshikazu Sato 1304, Kanaokacho, Sakai-shi, Osaka Daikin Industries, Ltd. Sakai F term in the Kanaoka factory of the factory (reference) 3L049 BB01 BB10 BB11 BC01 3L051 BG06 BH01 BJ10

Claims (7)

[Claims] An air conditioner comprising at least an indoor heat exchanger (15) and an outdoor heat exchanger (35), wherein the air conditioner is operated in a reverse cycle defrost operation for defrosting the outdoor heat exchanger (35). An air conditioner that discharges the air cooled by the indoor heat exchanger (15) into the space above the ceiling (12). 2. An air conditioner comprising at least an indoor heat exchanger (15) and an outdoor heat exchanger (35), wherein the air conditioner is operated in a reverse cycle defrost operation for defrosting the outdoor heat exchanger (35). At this time, an air conditioner that uses part or all of the warm air in the space above the ceiling (12) as a heat source. 3. An air conditioner comprising at least an indoor heat exchanger (15) and an outdoor heat exchanger (35), wherein the air conditioner is heated by the indoor heat exchanger (15) during a heating operation. While supplying air to the room (11), during the reverse cycle defrost operation for defrosting the outdoor heat exchanger (35), the air cooled by the indoor heat exchanger (15) An air conditioner including an air passage switching means (M) for switching an air passage so as to discharge air to a space (12). 4. An indoor air inlet (16) and an indoor air outlet (17) facing the room (11), and a ceiling air inlet (18) facing the space above the ceiling (12).
And an indoor casing (1) formed with a ceiling outlet (19).
3), and an indoor blower (14) provided in the indoor casing (13).
The indoor heat exchanger (15) is provided in the indoor casing (13), and the air path switching means (M) is configured to be connected to the indoor suction port (16) and the indoor Open the air outlet (17) and close the above-the-ceiling suction port (18) and the above-the-ceiling air outlet (19),
At the time of reverse cycle defrost operation, the above-
8) and a damper (20, 2) that opens the ceiling back outlet (19) and closes the indoor suction port (16) and the indoor outlet (17).
The air conditioner according to claim 3, wherein the air conditioner is configured as described in (1). 5. An indoor air inlet (16) and an indoor air outlet (17, 17A, 17B) facing the room (11), and a ceiling air outlet (19, 19A, 19B) facing the space above the ceiling (12). (13b, 1)
3c, 13d) and an indoor blower (14) provided in the indoor casing (13b, 13c, 13d), and the indoor heat exchanger (15, 15A, 15B) includes the indoor casing (13
b, 13c, 13d), the air passage switching means (M) opens the indoor air outlets (17, 17A, 17B) and the ceiling air outlet (1
(9, 19A, 19B) and a damper for opening the above-the-ceiling outlets (19, 19A, 19B) and closing the indoor outlets (17, 17A, 17B) in the reverse cycle defrost operation. (21,23A, 23B,
24. The air conditioner according to claim 3, wherein the air conditioner is constituted by 24A, 24B). 6. An indoor air inlet (16) and an indoor air outlet (17, 17A, 17B) facing the room (11), and a ceiling air inlet (18, 30) and a space above the ceiling facing the space above the ceiling (12). An indoor casing (13, 13f) having an outlet (19, 19A, 19B) formed therein, and an indoor blower provided in the indoor casing (13, 13f).
(14), the indoor heat exchanger (15, 15A, 15B), the indoor casing (13,
13f), the air path switching means (M) opens the indoor air outlets (17, 17A, 17B) and performs the above-
8, 30) and the above-mentioned ceiling outlets (19, 19A, 19B) are closed, and in the case of reverse cycle defrost operation, the above-
30) and the dampers (20, 23A, 19A, 19B) that open the ceiling outlets (19, 19A, 19B) and close the indoor outlets (17, 17A, 17B).
The air conditioner according to claim 3, which is constituted by 23B, 28). 7. An indoor air inlet (16) and an indoor air outlet (17) facing the room (11), and a ceiling air inlet (18) facing the space above the ceiling (12).
And an indoor casing (1) formed with a ceiling outlet (19).
3), and an indoor blower (14) provided in the indoor casing (13).
And a temperature detecting means (36, 37) for detecting a magnitude relationship between the indoor air temperature and the ceiling air temperature, wherein the indoor heat exchanger (15) is provided in the indoor casing (13); The road switching means (M) is connected to the indoor suction port during the heating operation.
(16) and the indoor air outlet (17) are opened, and the above-the-ceiling suction port (18) and the above-the-ceiling air outlet (19) are closed.In the reverse cycle defrost operation, the indoor air temperature rises above the ceiling. When the temperature is equal to or higher than the air temperature, the indoor suction port (16) and the ceiling back outlet (19) are opened and the ceiling back intake port (18) and the room outlet (17) are closed, and the indoor air temperature becomes When the temperature is lower than the back air temperature, the damper (20, 20) that opens the above-the-ceiling suction port (18) and the above-the-ceiling air outlet (19) and closes the indoor suction port (16) and the indoor air outlet (17). The air conditioner according to claim 3, wherein the air conditioner is constituted by (21).