Outside air supply system

Abstract

To increase the amount of outside air supply above the capacity of an air supply fan while suppressing complication of configuration and cost increase.SOLUTION: An outside air supply system includes: an air supply passage 4 which communicates between an outside air introduction section 3 and the indoors 2; an air supply fan 5 which supplies outside air A introduced into the outside introduction section 3 to the indoors through the air supply passage 4; an exhaust passage 7 which communicates between the indoors 2 and the outdoors 6; an exhaust fan 8 which exhausts indoor air B to the outdoors 6 through the exhaust passage 7; and an exhaust-fan-using outside air supply section 31 which supplies outside air A introduced into the outside air introduction section 3 to the exhaust passage 7 and supplies the outside air to the indoors 2 through the exhaust passage 7 by operation of the exhaust fan 8. As control modes which can be executed by a control section 9, the system has a first outside air supply mode in which the air supply fan 5 and the exhaust fan 8 are operated to supply outside air A to the indoors 2 through the air supply passage 4, and a second outside air supply mode in which the air supply fan 5, the exhaust fan 8 and the exhaust-fan-using outside air supply section 31 are operated to supply outside air A to the indoors 2 through the air supply passage 4 and the exhaust passage 7.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an outside air supply system for supplying outside air into a room.

Background Art

[0002] In this outside air supply system, an air supply passage communicating the outside air introduction part and the room, an air supply fan for supplying the outside air introduced from the outside air introduction part into the room through the air supply passage, an exhaust passage communicating the room and the outdoors, and an exhaust fan for exhausting the indoor air outdoors through the exhaust passage are known (for example, see Patent Document 1).

[0003] In the outside air supply system described in Patent Document 1, a heat exchange part for heat-exchanging the indoor air flowing through the exhaust passage and the outside air flowing through the air supply passage is provided, and ventilation in the room is performed in a form of simultaneously performing air supply and exhaust while performing heat exchange.

[0004] In the intermediate period such as spring and autumn, for example, when the outside air is lower in temperature than the indoor air, even if the outside air is directly supplied into the room without heat exchange, the room can be cooled. Therefore, in the outside air supply system described in Patent Document 1, not only ventilation in the room is performed in a form of simultaneously performing air supply and exhaust while performing heat exchange, but also an outside air cooling mode for cooling the room by directly supplying the outside air into the room without heat exchange is made executable.

[0005] In the outside air supply system described in Patent Document 1, in order to execute the outside air cooling mode, a bypass passage for bypassing the heat exchange part in the exhaust passage is provided. In the outside air cooling mode, while supplying the outside air into the room through the air supply passage, the indoor air is made to flow through the bypass passage and exhausted outdoors in a form of bypassing the heat exchange part.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the outside air supply system described in Patent Document 1, since the outside air supply amount for supplying outside air into the room is determined by the supply air fan, it is not possible to supply an outside air supply amount exceeding the capacity of the supply air fan into the room. Therefore, for example, when it is desired to increase the ventilation volume due to the presence of a large number of people or the like, or when it is desired to increase the outside air supply amount in outside air cooling, it becomes impossible to meet such demands. When performing outside air cooling, if a cooling load that cannot be completely processed by the outside air cooling remains, it becomes necessary to cover that cooling load with another air conditioner or the like. Therefore, when performing outside air cooling, the demand for increasing the outside air supply amount is remarkable.

[0008] Incidentally, by adding an outside air supply configuration for supplying outside air into the room separately from the supply air fan and the supply air duct, it becomes possible to increase the outside air supply amount when performing ventilation or outside air cooling. However, in this case, an outside air supply configuration must be provided separately, leading to a complication of the configuration and an increase in cost.

[0009] In view of this actual situation, the main problem of the present invention is to provide an outside air supply system that can increase the outside air supply amount beyond the capacity of the supply air fan while suppressing the complication of the configuration and the increase in cost.

Means for Solving the Problems

[0010] The first characteristic configuration of the present invention is a supply air duct that communicates the outside air introduction part and the room, a supply air fan that supplies the outside air introduced into the outside air introduction part into the room through the supply air duct, an exhaust duct that communicates the room and the outdoors, an exhaust fan that exhausts the indoor air outdoors through the exhaust duct, an outside air supply part using the exhaust fan that supplies the outside air introduced into the outside air introduction part to the exhaust duct and supplies it into the room through the exhaust duct by the operation of the exhaust fan, The air supply fan, the exhaust fan, and a control unit for controlling the operating states of the exhaust fan and the outside air supply unit using the exhaust fan are provided. As control modes executable by the control unit, a first outside air supply mode in which the air supply fan and the exhaust fan are operated to supply outside air into the room through the air supply passage; and a second outside air supply mode in which the air supply fan, the exhaust fan, and the outside air supply unit using the exhaust fan are operated to supply outside air into the room through the air supply passage and the exhaust passage.

[0011] According to this configuration, the control unit can effectively perform ventilation and outside air cooling in the room by executing the first outside air supply mode or the second outside air supply mode. In the second outside air supply mode, outside air can be supplied not only from the air supply passage according to the capacity of the air supply fan but also from the exhaust passage according to the capacity of the exhaust fan. Therefore, an outside air supply amount exceeding the capacity of the air supply fan can be supplied into the room. Thus, when there is a desire to increase the outside air supply amount during ventilation or outside air cooling, the control unit can meet the desire to increase the outside air supply amount by executing the second outside air supply mode. Moreover, the outside air supply unit using the exhaust fan to be operated in the second outside air supply mode uses the exhaust fan. Therefore, there is no need to newly provide a fan, and while suppressing complication of the configuration and cost increase, the blowing capacity of the exhaust fan can be utilized to effectively increase the outside air supply amount.

[0012] A second characteristic configuration of the present invention is that a casing for housing the air supply fan and the exhaust fan and receiving the supply of outside air introduced into the outside air introduction unit is provided. The outside air supply unit using the exhaust fan is provided with a first branch passage that is housed in the casing and branched from the air supply passage and connected to the exhaust passage.

[0013] The outside air supply section using the exhaust fan needs to have a flow path for supplying the outside air introduced into the outside air introduction section to the exhaust path by the operation of the exhaust fan. Therefore, according to this configuration, the outside air supply section using the exhaust fan includes a first branch path that branches from the air supply path and is connected to the exhaust path. By simply flowing a part of the outside air in the air supply path through the first branch path by the operation of the exhaust fan, the outside air introduced into the outside air introduction section can be supplied to the exhaust path, and the configuration can be simplified.

[0014] Moreover, since the first branch path is housed inside the casing, it is only necessary to connect the parts housed inside the casing in the air supply path and the exhaust path, and the flow path length of the first branch path can be shortened. If the casing is installed, there is no need to separately install the first branch path, simplifying the installation work of the first branch path and improving workability.

[0015] The third characteristic configuration of the present invention is that there is provided a casing in which the air supply fan and the exhaust fan are housed and which receives the supply of outside air introduced from the outside air introduction section. The outside air supply section using the exhaust fan is provided with a second branch path that is disposed outside the casing, branches from the outside air introduction section, and is connected to the exhaust path.

[0016] The outside air supply section using the exhaust fan needs to have a flow path for supplying the outside air introduced into the outside air introduction section to the exhaust path by the operation of the exhaust fan. Therefore, according to this configuration, the outside air supply section using the exhaust fan includes a second branch path that branches from the outside air introduction section and is connected to the exhaust path. By simply flowing a part of the outside air introduced into the outside air introduction section through the second branch path by the operation of the exhaust fan, the outside air introduced into the outside air introduction section can be supplied to the exhaust path, and the configuration can be simplified.

[0017] When increasing the outside air supply amount, if the supply amount of the outside air that the casing receives from the outside air introduction part is increased, measures such as increasing the flow path width of the air supply path in the casing are forced. Therefore, according to this configuration, the second branch path is disposed outside the casing and branched from the outside air introduction part. Thereby, outside the casing, the outside air introduced into the outside air introduction part can be directly passed through the second branch path without being supplied into the casing. Thus, measures such as increasing the flow path width of the air supply path in the casing become unnecessary, and simplification of the configuration and miniaturization of the casing can be achieved.

[0018] The fourth characteristic configuration of the present invention is that when the outside air temperature is equal to or lower than the set temperature in a state where the outside air cooling condition is satisfied, the control unit executes the first outside air supply mode, and when the outside air temperature is higher than the set temperature in a state where the outside air cooling condition is satisfied, the control unit executes the second outside air supply mode.

[0019] According to this configuration, when the outside air temperature is equal to or lower than the set temperature in a state where the outside air cooling condition is satisfied, since the control unit executes the first outside air supply mode, outside air cooling can be effectively performed by the outside air at or below the set temperature, and the cooling load can be appropriately covered.

[0020] On the other hand, when the outside air temperature is higher than the set temperature in a state where the outside air cooling condition is satisfied, since the control unit executes the second outside air supply mode, although the outside air is at a temperature higher than the set temperature, while the outside air can be supplied into the room to perform outside air cooling, the outside air supply amount can be increased to appropriately cover the cooling load.

[0021] In this way, since the control unit switches between the first outside air supply mode and the second outside air supply mode according to the relationship between the outside air temperature and the set temperature, the cooling load can be appropriately covered regardless of the relationship between the outside air temperature and the set temperature.

[0022] The fifth characteristic configuration of the present invention is that an outdoor exhaust part for exhausting indoor air to the outside is provided when the indoor pressure becomes equal to or higher than the set pressure.

[0023] When the control unit executes the second outside air supply mode, outside air is supplied to the interior not only from the air supply passage but also from the exhaust passage. Therefore, when the indoor pressure becomes an excessive positive pressure. Thus, according to this configuration, an outdoor exhaust unit that exhausts indoor air to the outside is provided when the indoor pressure becomes equal to or higher than the set pressure. Thereby, by exhausting the indoor air to the outside by the outdoor exhaust unit, the indoor pressure can be reduced, and it is possible to prevent the indoor pressure from being maintained at an excessive positive pressure. When the indoor pressure becomes an excessive positive pressure, it is conceivable that new problems such as difficulty in opening and closing the door and the entry of gap wind into the room occur. Therefore, by preventing the indoor pressure from becoming an excessive positive pressure, the occurrence of these new problems can be appropriately prevented.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0025] Embodiments of the outside air supply system according to the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, this outdoor air supply system 1 supplies outdoor air A to the interior 2 to perform ventilation, outdoor air cooling, and air conditioning in the interior 2. FIGS. 1 to 3 all show the schematic configuration of the same outdoor air supply system 1, but the flow states of parts such as the parts through which the outdoor air A and the indoor air B flow are different. In FIGS. 1 to 3, for a plurality of dampers D1 to D10, those in the open state are indicated by white "〇", and those in the closed state are indicated by black "●".

[0026] First, the schematic configuration of the outdoor air supply system 1 will be described with reference to FIG. 1. The outdoor air supply system 1 includes an air supply passage 4 that communicates the outdoor air introduction part 3 and the interior 2, an air supply fan 5 that supplies the outdoor air A introduced into the outdoor air introduction part 3 to the interior 2 through the air supply passage 4, an exhaust passage 7 that communicates the interior 2 and the outdoors 6, an exhaust fan 8 that exhausts the indoor air B to the outdoors 6 through the exhaust passage 7, and a control part 9 that controls the operating states of the air supply fan 5 and the exhaust fan 8 and the like.

[0027] The outdoor air supply system 1 is provided with a casing 10 in which the air supply fan 5 and the exhaust fan 8 are housed. In the casing 10, a part of the air supply passage 4 and a part of the exhaust passage 7 are housed in a partitioned state, and a first air supply passage 41 that is a part of the air supply passage 4 and a second exhaust passage 72 that is a part of the exhaust passage 7 are formed as partitioned spaces in the casing 10.

[0028] The air supply passage 4 is disposed inside the casing 10 and includes a first air supply passage 41 that is an upstream-side part in the flow direction of the outdoor air A, and a second air supply passage 42 that is disposed outside the casing 10 and is a downstream-side part in the flow direction of the outdoor air A. The upstream-side end of the first air supply passage 41 is connected to the outdoor air introduction part 3 and receives the supply of the outdoor air A introduced into the outdoor air introduction part 3. The downstream-side end of the first air supply passage 41 is connected to the upstream-side end of the second air supply passage 42, and the downstream-side end of the second air supply passage 42 communicates with the interior 2 to supply the outdoor air A to the interior 2.

[0029] In the first air supply passage 41 within the casing 10, a first filter 11, a temperature control section 12, and an air supply fan 5 are arranged in order from the upstream side in the flow direction of the outside air A (in order from the left side in FIG. 1). The first filter 11 removes foreign matters such as dust contained in the outside air A. The temperature control section 12 receives the supply of a heat medium (a cooling heat medium or a heating heat medium) from a heat source machine (not shown), and exchanges heat between the heat medium and the outside air A to cool or heat the outside air A and adjust the temperature of the outside air A.

[0030] In the first air supply passage 41 within the casing 10, the portion between the first filter 11 and the temperature control section 12 branches into a heat exchange side air supply passage 43 (the lower side branch passage in FIG. 1) where a total heat exchange section 13 is arranged and a non-heat exchange side air supply passage 44 (the upper side branch passage in FIG. 1) where the total heat exchange section 13 is not arranged. The heat exchange side air supply passage 43 and the non-heat exchange side air supply passage 44 merge in front of the temperature control section 12. A first damper D1 capable of interrupting the flow of the outside air A to the heat exchange side air supply passage 43 and a second damper D2 capable of interrupting the flow of the outside air A to the non-heat exchange side air supply passage 44 are provided.

[0031] The exhaust passage 7 is arranged outside the casing 10 and includes a first exhaust passage 71 that is the upstream side portion in the flow direction of the indoor air B and a second exhaust passage 72 that is arranged inside the casing 10 and is the downstream side portion in the flow direction of the indoor air B. The upstream end of the first exhaust passage 71 communicates with the interior 2 and receives the supply of the indoor air B. The downstream end of the first exhaust passage 71 is connected to the upstream end of the second exhaust passage 72, and the downstream end of the second exhaust passage 72 is connected to the indoor air discharge passage 21. The indoor air discharge passage 21 guides the indoor air B from the second exhaust passage 72 to the outdoors 6 and discharges it to the outdoors 6.

[0032] An exhaust fan 8 is disposed in a second exhaust passage 72 within the casing 10. A downstream portion of the second exhaust passage 72 from the exhaust fan 8 is branched into a heat exchange side exhaust passage 73 where a total heat exchanger 13 is disposed and a non-heat exchange side exhaust passage 74 where the total heat exchanger 13 is not disposed. The heat exchange side exhaust passage 73 and the non-heat exchange side exhaust passage 74 merge before reaching the end of the casing 10. A third damper D3 capable of interrupting the flow of a fluid such as indoor air B to the heat exchange side exhaust passage 73 and a fourth damper D4 capable of interrupting the flow of a fluid such as indoor air B to the non-heat exchange side exhaust passage 74 are provided.

[0033] Within the casing 10, a first air supply passage 41 and a second exhaust passage 72 are provided in a partitioned state, and a first communication portion 14 and a second communication portion 15 for communicating the first air supply passage 41 and the second exhaust passage 72 are provided.

[0034] The first communication portion 14 is configured to supply a part of the indoor air B in the second exhaust passage 72 to the first air supply passage 41, and the inflow of the indoor air B from the second exhaust passage 72 to the first air supply passage 41 is interrupted by a fifth damper D5. The first communication portion 14 is capable of supplying the indoor air B from a portion where the heat exchange side exhaust passage 73 and the non-heat exchange side exhaust passage 74 merge in the second exhaust passage 72 to before a portion where the heat exchange side air supply passage 43 and the non-heat exchange side air supply passage 44 branch downstream of the first filter 11 in the first air supply passage 41.

[0035] The second communication portion 15 is configured to supply a part of the outside air A in the first air supply passage 41 to the second exhaust passage 72, and the inflow of the outside air A from the first air supply passage 41 to the second exhaust passage 72 is interrupted by a sixth damper D6. The second communication passage 52 is capable of supplying the outside air A to upstream of the exhaust fan 8 in the second exhaust passage 72 from a portion between the temperature control portion 12 and the air supply fan 5 in the first air supply passage 41.

[0036] Outside the casing 10, a first connection path 22 that connects the indoor air discharge path 21 and the first exhaust path 71 is provided. In the first connection path 22, a seventh damper D7 that intermittently blocks the flow of fluid is disposed on the indoor air discharge path 21 side, and an eighth damper D8 that intermittently blocks the flow of fluid is disposed on the first exhaust path 71 side. In the indoor air discharge path 21, a ninth damper D9 that intermittently blocks the flow of fluid is disposed on the outdoor 6 side rather than at the connection location with the first connection path 22. In the first exhaust path 71, a tenth damper D10 that intermittently blocks the flow of fluid is disposed on the casing 10 side rather than at the connection location with the first connection path 22.

[0037] In the interior 2, an outdoor exhaust unit 23 that exhausts indoor air B to the outside 6 when the indoor pressure becomes equal to or higher than the set pressure is provided. The outdoor exhaust unit 23 includes an outdoor discharge path 24 that discharges indoor air B from the interior 2 to the outside 6, and a differential pressure damper 25 that is disposed at an intermediate portion of the outdoor discharge path 24 and is switched to an open state when the indoor pressure becomes equal to or higher than the set pressure.

[0038] In this outside air supply system 1, as shown in FIGS. 1 and 2, not only is outside air A supplied to the interior 2 through the air supply path 4, but also, as shown in FIG. 3, an outside air supply unit 31 that uses an exhaust fan is provided, which supplies the outside air A introduced into the outside air introduction unit 3 to the exhaust path 7 by the operation of the exhaust fan 8 and supplies it to the interior 2 through the exhaust path 7. The outside air supply unit 31 that uses an exhaust fan includes, in addition to the exhaust fan 8, a second communication portion 15, a sixth damper D6, a second exhaust path 72, an indoor air discharge path 21, a first connection path 22, seventh to tenth dampers D7 to D10, and the like.

[0039] As shown in FIG. 3, by switching the sixth damper D6 to the open state, a part of the outside air A in the first air supply passage 41 is supplied to the second exhaust passage 72 through the second communication part 15 (corresponding to the first branch passage). The outside air A supplied to the second exhaust passage 72 flows through the second exhaust passage 72 such as the non-heat exchange side exhaust passage 74 and is supplied to the indoor air discharge passage 21 connected to the casing 10. By switching the seventh damper D7 and the eighth damper D8 to the open state and switching the ninth damper D9 and the tenth damper D10 to the closed state, the outside air A supplied to the indoor air discharge passage 21 flows through the first connection passage 22 and is supplied to the first exhaust passage 71, and is supplied to the interior 2 through the first exhaust passage 71.

[0040] Thus, in the outside air supply system 1, not only the air supply fan 5 and the exhaust fan 8 but also the outside air supply part 31 using the exhaust fan and the first to tenth dampers D1 to D10 are provided. Therefore, the control unit 9 is configured to be able to execute various control modes by controlling the operating states of the air supply fan 5, the exhaust fan 8, and the outside air supply part 31 using the exhaust fan, and the opening and closing states of the first to tenth dampers D1 to D10.

[0041] As control modes that the control unit 9 can execute, there are provided a normal mode shown in FIG. 1, a first outside air supply mode shown in FIG. 2, and a second outside air supply mode shown in FIG. 3. Hereinafter, each control mode will be described.

[0042] (Normal Mode) As shown in FIG. 1, the normal mode is a control mode in which the air supply fan 5 and the exhaust fan 8 are operated, and the outside air A is supplied to the interior 2 through the air supply passage 4 while the outside air A and the indoor air B are heat-exchanged in the total heat exchange part 13.

[0043] In this normal mode, in addition to operating the air supply fan 5 and the exhaust fan 8, the control unit 9 switches the first damper D1, the third damper D3, the ninth damper D9, and the tenth damper D10 to the open state, and switches the other dampers to the closed state.

[0044] The outside air A introduced into the outside air introduction section 3 is supplied to the first air supply passage 41 inside the casing 10, and foreign matters and the like are removed by the first filter 11. The outside air A from which foreign matters and the like have been removed is supplied to the heat exchange side air supply passage 43, and heat is exchanged with the indoor air B in the heat exchange side exhaust passage 73 in the total heat exchanger 13. The outside air A after heat exchange passes through the temperature control section 12 and reaches the air supply fan 5, and is supplied to the room 2 through the second air supply passage 42 outside the casing 10.

[0045] The indoor air B is supplied to the second exhaust passage 72 inside the casing 10 through the first exhaust passage 71 outside the casing 10. The indoor air B supplied to the second exhaust passage 72 reaches the exhaust fan 8, is supplied to the heat exchange side exhaust passage 73, and heat is exchanged with the outside air A in the heat exchange side air supply passage 43 in the total heat exchanger 13. The indoor air B after heat exchange is supplied to the indoor air discharge passage 21 outside the casing 10 and is discharged to the outdoors 6 through the indoor air discharge passage 21.

[0046] In the normal mode, while heat is exchanged between the outside air A and the indoor air B in the total heat exchanger 13, the outside air A after heat exchange is supplied to the room 2. Therefore, the heat possessed by the indoor air B is utilized to pre-cool or pre-heat the outside air A and supply it to the room 2, and ventilation of the room 2 is performed while suppressing changes in the indoor temperature.

[0047] In this normal mode, the control unit 9 controls the operating state of the temperature control section 12, so that the temperature of the outside air A can be adjusted to the indoor required temperature or the like in the temperature control section 12, and the outside air A after the temperature control can be supplied to the room 2. Further, by the control unit 9 switching the fifth damper D5 to the open state, a part of the indoor air B can be mixed with the outside air A. Therefore, the mixture of the outside air A and the indoor air B can be adjusted to the indoor required temperature or the like in the temperature control section 12, and the outside air A after the temperature control can be supplied to the room 2. Thereby, the outside air supply system 1 not only has the function as an external conditioner for supplying the outside air A to the room 2, but also has the function as an air conditioner for air-conditioning the indoor air B, becoming a useful system.

[0048] (First outside air supply mode) As shown in Fig. 2, the first outside air supply mode is a control mode for cooling the interior 2 with outside air by operating the supply fan 5 and the exhaust fan 8 to supply the outside air A directly to the interior 2 through the supply air passage 4 without performing heat exchange between the outside air A and the indoor air B in the total heat exchanger 13.

[0049] In this first outside air mode, in addition to operating the supply fan 5 and the exhaust fan 8, the control unit 9 switches the second damper D2, the fourth damper D4, the ninth damper D9, and the tenth damper D10 to the open state and switches the other dampers to the closed state.

[0050] The outside air A introduced into the outside air introduction section 3 is supplied to the first supply air passage 41 inside the casing 10, and foreign matters and the like are removed by the first filter 11. The outside air A from which foreign matters and the like have been removed is supplied to the non-heat exchange side supply air passage 44, bypasses the total heat exchanger 13, passes through the temperature control section 12, reaches the supply fan 5, and is supplied to the interior 2 through the second supply air passage 42 outside the casing 10.

[0051] The indoor air B is supplied to the second exhaust passage 72 inside the casing 10 through the first exhaust passage 71 outside the casing 10. The indoor air B supplied to the second exhaust passage 72 reaches the exhaust fan 8, is supplied to the non-heat exchange side exhaust passage 74, bypasses the total heat exchanger 13, is supplied to the indoor air discharge passage 21 outside the casing 10, and is discharged to the outdoors 6 through the indoor air discharge passage 21.

[0052] In the first outside air supply mode, heat exchange between the outside air A and the indoor air B is not performed in the total heat exchanger 13, and the outside air A is directly supplied to the interior 2. Therefore, outside air cooling is performed to cool the interior 2 by utilizing the cold heat of the outside air A.

[0053] (Second outside air supply mode) As shown in Fig. 3, the second outside air supply mode is a control mode for cooling the interior 2 with outside air by operating the supply fan 5 and the exhaust fan 8, similar to the first outside air supply mode. However, it is a control mode for increasing the supply amount of the outside air A to the interior 2 compared to the first outside air supply mode.

[0054] In this second outside air mode, in addition to operating the supply fan 5 and the exhaust fan 8, the control unit 9 activates the outside air supply unit 31 that does not use the exhaust fan, switches the second damper D2, the fourth damper D4, the sixth damper D6, the seventh damper D7, and the eighth damper D8 to the open state, and switches the other dampers to the closed state.

[0055] The outside air A introduced into the outside air introduction unit 3 is supplied to the first air supply passage 41 inside the casing 10, and foreign matters and the like are removed by the first filter 11. The outside air A from which foreign matters and the like have been removed is supplied to the non-heat exchange side air supply passage 44, bypasses the total heat exchange unit 13, and passes through the temperature control unit 12. A part of the outside air A after passing through the temperature control unit 12 reaches the supply fan 5 and is supplied to the interior 2 through the second air supply passage 42 outside the casing 10.

[0056] The remaining part of the outside air A after passing through the temperature control unit 12 is supplied to the second exhaust passage 72 through the second communication unit 15 by the operation of the exhaust fan 8 and reaches the exhaust fan 8. The outside air A is supplied from the exhaust fan 8 to the non-heat exchange side exhaust passage 74, bypasses the total heat exchange unit 13, and is supplied to the indoor air discharge passage 21. The outside air A supplied to the indoor air discharge passage 21 flows through the first connection passage 22 and is supplied to the first exhaust passage 71, and is supplied to the interior 2 through the first exhaust passage 71.

[0057] In this way, the outside air A introduced into the outside air introduction unit 3 can be supplied to the interior 2 not only from the second air supply passage 42 of the air supply passage 4 but also from the first exhaust passage 71 of the exhaust passage 7. Therefore, the supply amount of the outside air A to the interior 2 can be increased, and the outside air cooling using the cooling and heating of the outside air A can be effectively performed. Thus, just by performing the outside air cooling, a sufficient cooling load can be covered. Therefore, even if the cooling load is somewhat large, the cooling load can be covered, and the remaining of the cooling load can be prevented. If the cooling load remains, for example, it is necessary to cover the remaining cooling load with another air conditioner or the like, which leads to an increase in energy consumption and is disadvantageous in terms of energy saving. However, such a problem can be prevented.

[0058] When it is desired to increase the supply amount of the outside air A to the interior 2, for example, it is conceivable to open the window of the room. In this case, an inflow of the outside air A from the window into the interior 2 is expected, but it is affected by various conditions such as the pressure relationship between the interior 2 and the outdoors 6 and the wind direction. Therefore, the inflow amount of the outside air A is not stable, and depending on the conditions, it is also conceivable that the interior air B is discharged from the window to the outdoors 6 and the outside air A does not flow into the interior 2. Further, when the outside air A flows in from the window, the outside air A containing foreign matters such as dust is directly supplied to the interior 2.

[0059] On the other hand, in this embodiment, the supply of the outside air A to the interior 2 through the first exhaust passage 71 of the exhaust passage 7 is pushed into the interior 2 by using the blowing ability of the exhaust fan 8 by the operation of the exhaust fan 8. Thereby, by using the exhaust fan 8, an increase in the supply amount of the outside air A can be stably and surely performed. Moreover, the outside air A supplied to the interior 2 in the second air supply passage 42 of the air supply passage 4 and the outside air A supplied to the interior 2 in the first exhaust passage 71 of the exhaust passage 7 both pass through the first filter 11, and foreign matters such as dust contained in the outside air A are removed, preventing foreign matters such as dust from flowing into the interior 2.

[0060] In this second outside air supply mode, since the outside air A is supplied to the interior 2 not only from the second air supply passage 42 of the air supply passage 4 but also from the first exhaust passage 71 of the exhaust passage 7, the interior pressure may become an excessive positive pressure. Therefore, as shown in FIG. 3, an outdoor exhaust section 233 for exhausting the interior air B to the outdoors 6 is provided when the interior pressure becomes equal to or higher than the set pressure. When the interior pressure becomes equal to or higher than the set pressure, the differential pressure damper 25 is opened, and the interior air B is discharged to the outdoors 6 through the outdoor discharge passage 24. Thereby, the interior pressure can be decreased, and when the interior pressure becomes lower than the set pressure, the differential pressure damper 25 is closed, and the interior pressure can be maintained at an appropriate positive pressure lower than the set pressure.

[0061] Thus, in the operating state of the outside air supply system 1, the control unit 9 can execute various control modes including the normal mode shown in FIG. 1, the first outside air supply mode shown in FIG. 2, and the second outside air supply mode shown in FIG. 3. Hereinafter, based on FIG. 4, the switching of the control mode by the control unit 9 will be described.

[0062] Although not shown in the figure, the temperature and humidity of the outside air A are detected by an outside air temperature and humidity sensor or the like, and the temperature and humidity of the indoor air B are detected by an indoor air temperature and humidity sensor or the like. The control unit 9 grasps the temperature and humidity of the outside air A and the temperature and humidity of the indoor air B from the detection information of the outside air temperature and humidity sensor and the indoor air temperature and humidity sensor. The control unit 9 switches the control mode based on the temperature and humidity of the outside air A and the temperature and humidity of the indoor air B.

[0063] In the air diagram of FIG. 4, the shaded area satisfies all of the following first to third conditions. The control unit 9 determines whether the conditions of the outside air A and the indoor air B belong to the shaded area by determining whether each of the first to third conditions is satisfied. Incidentally, if either the outside air temperature and humidity sensor or the indoor air temperature and humidity sensor is in an abnormal state, the temperature and humidity of the outside air A and the temperature and humidity of the indoor air B cannot be grasped. Therefore, it is a prerequisite that both sensors, the outside air temperature and humidity sensor and the indoor air temperature and humidity sensor, are in a normal state before determining the first to third conditions.

[0064] First condition: Outside air enthalpy < Indoor air enthalpy Second condition: Outside air temperature lower limit value < Outside air temperature < Indoor temperature Third condition: Outside air dew point temperature < Outside air dew point temperature upper limit value

[0065] In FIG. 4, C1 indicates the outside air temperature lower limit value, C2 indicates the set temperature, and C3 indicates the indoor temperature. E1 indicates the outside air dew point temperature upper limit value, F1 indicates the indoor air enthalpy, and G1 indicates the relative humidity. Accordingly, the shaded area in the conditions of the outside air A and the indoor air B is the area where outside air cooling is effective.

[0066] Therefore, based on the temperature and humidity of the outside air A and the temperature and humidity of the indoor air B, if the conditions between the outside air A and the indoor air B are outside the region indicated by the diagonal lines, the control unit 9 executes the normal mode, assuming that the outside air cooling conditions are not satisfied. On the other hand, based on the temperature and humidity of the outside air A and the temperature and humidity of the indoor air B, if the conditions between the outside air A and the indoor air B are within the region indicated by the diagonal lines, the control unit 9 executes the first outside air supply mode or the second outside air supply mode, assuming that the outside air cooling conditions are satisfied.

[0067] Regarding the switching between the first outside air supply mode and the second outside air supply mode, in FIG. 4, when the outside air temperature is equal to or lower than the set temperature C2, the control unit 9 executes the first outside air supply mode, and when the outside air temperature is higher than the set temperature C2, the control unit 9 executes the second outside air supply mode. Thereby, when the first outside air supply mode is executed, as shown in FIG. 2, the outside air A at or below the set temperature C2 can be supplied to the interior 2, effectively outside air-cooling the interior 2 and appropriately covering the cooling load. When the second outside air supply mode is executed, although the outside air A is at a temperature higher than the set temperature C2, while the outside air A can be supplied to the interior 2 to perform outside air cooling, the outside air supply amount can be increased to appropriately cover the cooling load.

[0068] Regarding the set temperature C2, for example, a constant temperature such as 17°C can be set, but the set temperature C2 can also be variably set according to various environments such as the environment of the interior 2 and the environment of the outdoors 6.

[0069] 〔Second Embodiment〕 This second embodiment is another embodiment of the flow path through which the outside air A flows in the exhaust fan-utilizing outside air supply unit 31 of the first embodiment. Regarding other configurations, since they are the same as those of the first embodiment, based on FIG. 5, the flow path through which the outside air A flows in the exhaust fan-utilizing outside air supply unit 31 will be mainly described, and the same reference numerals etc. will be used for other configurations, and the description thereof will be omitted.

[0070] In the first embodiment, as shown in FIG. 3, a second communication part 15 (corresponding to a first branch path) that communicates the first air supply path 41 and the second exhaust path 72 is provided in the casing 10, and a part of the outside air A in the air supply path 4 is supplied to the exhaust path 7 through the second communication part 15.

[0071] On the other hand, in the second embodiment, as shown in FIG. 5, a second connection path 26 (corresponding to a second branch path) branched from the outside air introduction part 3 and connected to the first exhaust path 71 is provided outside the casing 10, and a part of the outside air A introduced into the outside air introduction part 3 is supplied to the exhaust path 7 through the second connection path 26. The second connection path 26 is connected to the casing 10 side of the first exhaust path 71 rather than the tenth damper D10. An eleventh damper D11 that intermittently allows the flow of fluid is disposed in the second connection path 26.

[0072] FIG. 5 shows the flow state of the outside air A and the indoor air B in the second outside air supply mode. In the second outside air mode, in addition to operating the air supply fan 5 and the exhaust fan 8, the control unit 9 operates the outside air supply part 31 that does not use the exhaust fan, switches the second damper D2, the fourth damper D4, the seventh damper D7, the eighth damper D8, and the eleventh damper D11 to the open state, and switches the other dampers to the closed state.

[0073] A part of the outside air A introduced into the outside air introduction part 3 is supplied to the first air supply path 41 in the casing 10, and foreign matters and the like are removed by the first filter 11. The outside air A from which foreign matters and the like have been removed is supplied to the non-heat exchange side air supply path 44, bypasses the total heat exchange part 13, and passes through the temperature control part 12. The outside air A after passing through the temperature control part 12 reaches the air supply fan 5 and is supplied to the room 2 through the second air supply path 42 outside the casing 10.

[0074] A part of the remaining outside air A introduced into the outside air introduction section 3 flows through the second connection path 26 and is supplied to the first exhaust path 71. The outside air A supplied to the first exhaust path 71 is supplied to the second exhaust path 72 in the casing 10, passes through the second filter 16, and then reaches the exhaust fan 8. The outside air A is supplied from the exhaust fan 8 to the non-heat exchange side exhaust path 74, bypasses the total heat exchange section 13, and is supplied to the indoor air discharge path 21. The outside air A supplied to the indoor air discharge path 21 flows through the first connection path 22 and is supplied to the first exhaust path 71, and is supplied to the room 2 through the first exhaust path 71.

[0075] Since the outside air A flowing through the second connection path 26 is a part of the outside air A introduced into the outside air introduction section 3, it has not passed through the first filter 11 or the like and may contain foreign matters such as dust. Therefore, the second filter 16 is disposed in the second exhaust path 72 in the casing 10, and the outside air A flowing through the second connection path 26 is supplied into the casing 10 using the first exhaust path 71, so that foreign matters contained in the outside air A when flowing through the second connection path 26 are removed by the second filter 16.

[0076] Also in this second embodiment, similar to the first embodiment, the supply of the outside air A to the room 2 through the first exhaust path 71 of the exhaust path 7 is pushed into the room 2 using the blowing ability of the exhaust fan 8 by the operation of the exhaust fan 8. Thereby, by using the exhaust fan 8, the increase in the supply amount of the outside air A can be stably and surely performed. Moreover, the outside air A supplied to the room 2 in the first exhaust path 71 of the exhaust path 7 also passes through the second filter 16, and foreign matters such as dust contained in the outside air A are removed, preventing foreign matters such as dust from flowing into the room 2.

[0077] 〔Alternative Embodiment〕 Other embodiments of the present invention will be described. Note that the configurations of the respective embodiments described below are not limited to being applied alone, and can also be applied in combination with the configurations of other embodiments.

[0078] (1) In the above-described embodiment, as a condition for the control unit 9 to execute the second outside air supply mode, the case where the outside air temperature is higher than the set temperature C2 in a state where the outside air cooling condition is satisfied is exemplified. However, for example, even if the outside air cooling condition is not satisfied, when it is desired to increase the ventilation volume, such as when the number of people in Room 2 increases, the control unit 9 can execute the second outside air supply mode. Thus, as conditions for executing the second outside air supply mode, various conditions can be set regardless of whether the outside air cooling condition is satisfied. Also, for example, when a person or the like present in Room 2 operates the operation unit, the control unit 9 can also execute the second outside air supply mode, and it is not limited to being automatically executed by the control unit 9, and it can also be executed based on a manual operation.

[0079] (2) In the above-described embodiment, the first communication part 14 that connects the first air supply path 41 and the second exhaust path 72 in the casing 10 is provided, and a part of the indoor air B in the second exhaust path 72 can be supplied to the first air supply path 41 through the first communication part 14. However, it can also be implemented by omitting the first communication part 14.

Explanation of Signs

[0080] 1 Outside air supply system 2 Room 3 Outside air introduction part 4 Air supply path 5 Air supply fan 6 Outdoor 7 Exhaust path 8 Exhaust fan 9 Control unit 10 Casing 15 Second communication part (first branch path) 26 Second connection path (second branch path) 31 Exhaust fan utilization outside air supply part A Outside air B Indoor air

Claims

1. An air supply passage that communicates the outside air introduction part with the interior, An air supply fan that supplies outside air introduced into the outside air introduction part into the interior through the air supply passage, An exhaust passage that communicates the interior with the outdoors, An exhaust fan that exhausts indoor air outdoors through the exhaust passage, An outside air supply part using the exhaust fan that supplies outside air introduced into the outside air introduction part to the exhaust passage and supplies it into the interior through the exhaust passage by the operation of the exhaust fan, A control unit that controls the operating states of the air supply fan, the exhaust fan, and the outside air supply part using the exhaust fan, As a control mode executable by the control unit, A first outside air supply mode in which the air supply fan and the exhaust fan are operated to supply outside air into the interior through the air supply passage, An outside air supply system provided with a second outside air supply mode in which the air supply fan, the exhaust fan, and the outside air supply part using the exhaust fan are operated to supply outside air into the interior through the air supply passage and the exhaust passage.

2. A casing that houses the air supply fan and the exhaust fan and receives the supply of outside air introduced into the outside air introduction part is provided, The outside air supply system according to claim 1, wherein the outside air supply part using the exhaust fan is provided with a first branch passage that is housed in the casing and branches from the air supply passage and is connected to the exhaust passage.

3. A casing that houses the air supply fan and the exhaust fan and receives the supply of outside air introduced from the outside air introduction part is provided, The outside air supply system according to claim 1, wherein the outside air supply part using the exhaust fan is provided with a second branch passage that is disposed outside the casing and branches from the outside air introduction part and is connected to the exhaust passage.

4. When the outside air temperature is equal to or lower than the set temperature in a state where the outside air cooling condition is satisfied, the control unit executes the first outside air supply mode, The outside air supply system according to any one of claims 1 to 3, wherein when the outside air temperature is higher than the set temperature in a state where the outside air cooling condition is satisfied, the control unit executes the second outside air supply mode.

5. The outside air supply system according to any one of claims 1 to 3, further comprising an outdoor exhaust part that exhausts indoor air outdoors when the indoor pressure becomes equal to or higher than the set pressure.

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