JPH09309330A - Driving method of air purifying device and air blowing device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving method of an air purifying device and an air blowing device for an automobile to prevent intrusion of air of a high pollution level outside of the automobile. SOLUTION: Whether a self-car enters an area of a high pollution level of atmospheric air or not is judged (S26, S28, S30, S32, S34) by receiving (S18) a current position computed by a navigation device. Hereby, at the time of entering the area of the high pollution level (S26, S28, S30, S32, S34 are Yes), outside air introduction is previously changed over to inside sir circulation, intrusion of outside air to the inside of the car is prevented, an air purifier is started, and rise of NOx and CO density in the air inside of the car is restrained (B). Thereafter, when it is judged as the self car is out of the relative area of the high pollution level, it is changed over to the outside air introduction or the air purifier is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile air purification apparatus for purifying air inside a vehicle, and a method for operating a blower apparatus for switching air between internal air circulation and external air introduction to send air under pressure.

[0002]

2. Description of the Related Art An air conditioning apparatus for a vehicle is provided with a switch for switching between the circulation of the inside air and the introduction of the outside air, and is constructed so as to switch between the air inside the vehicle and the air outside the vehicle to perform heating and cooling. . That is, the driver operates the changeover switch to switch from the introduction of the outside air to the circulation of the inside air when entering a region such as a tunnel where the degree of pollution of the air is high, so that the air with a high degree of pollution enters the vehicle. It is preventing.

[0003]

DISCLOSURE OF THE INVENTION The present inventor has made it possible, in an automobile air purification apparatus, to perform purification by switching the air to be introduced between the inside and outside of the vehicle, and has a high degree of pollution with a gas sensor. When air was detected, we devised a configuration that automatically switches from the introduction of outside air to the circulation of inside air.

However, even if the air is highly polluted by the sensor and then the air is switched from the introduction of the outside air to the circulation of the inside air, the air having a high degree of the pollution from the outside is actually released before the switching from the introduction of the outside air to the circulation of the inside air. It has already been invaded into the car, and it was revealed that a strange odor remained in the car.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to operate an air purifying device for a vehicle and an air blower for preventing invasion of highly polluted air outside the vehicle in advance. To provide a method.

[0006]

In order to achieve the above-mentioned object, a first aspect of the present invention is an air purifying apparatus for an automobile which purifies air by selecting the introduction of outside air and the circulation of inside air. Based on the current position detected by the position detecting means for detecting, the area storing means for storing an area having a high degree of air pollution, and the current position detected by the position detecting means, Contaminated area entry predicting means for predicting whether or not to enter a high area, adsorbing means for adsorbing pollutant components in the air, blowing means for blowing air to the adsorbing means, and intake air for switching the external air introduction to the internal air circulation Switching means and the contaminated area entrance prediction When it is predicted to enter a highly contaminated area by manual throw,
And a purifying device starting means for starting the adsorbing means, the blowing means, and the intake switching means.

According to a second aspect of the present invention, there is provided an automobile air purifying apparatus for purifying air by selecting the introduction of outside air and the circulation of inside air.
A vehicle is stored in the area storage means based on the position detection manual pitch for detecting the current position of the vehicle, an area storage means for storing an area with a high degree of air pollution, and a current position detected by the position detection means. A polluted area entry predicting means for predicting whether or not to enter an area having a high degree of air pollution, an adsorbing means for adsorbing a pollutant component in the air, a blowing means for blowing air to the adsorbing means, and the adsorbing means. The adsorbing capacity determining means for judging the adsorbing capacity of the means, the regenerating means for regenerating the adsorbing means, the intake switching means for switching the external air introduction to the internal air circulation, and the contaminated area entry predicting means for entering the highly contaminated area. When it is predicted, the adsorbing means, the air blowing means, and the intake switching means are activated, and the adsorbing capacity determining means operates to adsorb the adsorbing means. If the stage of regeneration is judged to be necessary, and technical; and a purifying device reproducing means for initiating said reproduction means to suppress the blowing by the blowing means.

According to a third aspect of the present invention, there is provided an air blower having an area storage device for storing an area having a high degree of air pollution and a position detection device for detecting a current position, and which blows air by selecting outside air introduction and inside air circulation. And a step of detecting a current position of the vehicle, and determining whether or not the vehicle enters an area with a high degree of air pollution stored in the area storage device based on the detected current position. It is a technical feature to have a step and a step of switching to the internal air circulation when it is judged that the vehicle enters a highly contaminated area in the above step.

[0009]

According to the invention of claim 1, the contaminated area entry predicting means is based on the present position detected by the position detecting means,
It is predicted whether or not the vehicle will enter an area where the degree of air pollution stored in the area storage means is high. Here, when it is predicted to enter an area with a high degree of pollution, the purifier activation means activates the adsorbing means and the air blowing means to start air purification, and activates the intake switching means to start the introduction of outside air. Switch to internal air circulation. Therefore, before entering a highly polluted area, it is possible to switch from outside air introduction to internal air circulation in advance to prevent the entry of highly polluted air into the vehicle and to activate the automobile air purification device. it can.

According to the second aspect of the present invention, when the adsorption capacity determination means determines that the adsorption means needs to be regenerated, the purifying device regenerating means suppresses the air blowing by the air blowing means and activates the regenerating means, thereby adsorbing the adsorbing means. Start playing. That is, when the capacity of the adsorbing means is reduced, the adsorbing means is regenerated by suppressing the air flow rate.

According to the third aspect of the present invention, the current position of the vehicle is detected, and based on the detected current position, it is determined whether or not the vehicle will enter an area with a high degree of air pollution stored in the area storage means. . Here, when it is determined that the vehicle enters a highly polluted area, the internal air circulation is switched to. That is, before entering the highly polluted area, the introduction of the outside air is switched to the internal air circulation in advance to prevent the highly polluted air from entering the vehicle in advance.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments embodying the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an automobile air purification device according to a first embodiment of the present invention. This vehicle air purification device is a navigation device 6 for a vehicle that detects the position of the vehicle and guides the route.
0, a communication device 80 that receives traffic congestion information, information about air polluted areas, etc., an air purifier 10, an air purifier control device 70 that controls the air purifier 10, and a memory that holds various data. And 74.

The navigation device 60 receives the radio wave from the artificial satellite via the antenna 60a by using GPS (Global Positioning System), calculates the current position, and reads the map data stored in the CDROM 60b to determine the destination. When is set, the route is searched, the current position on the map is identified, and route guidance is provided. The CDROM 60b also holds information on areas with a high degree of air pollution such as factory areas.

FIG. 2 shows the structure of the air purifier 10 according to the first embodiment of the present invention. As shown in FIG. 2, the air purifier 10 includes a turbo fan 42 for pumping air taken in from the outside air intake pipe 14 or the inside air intake pipe 12.
And the first switching between the outside air intake pipe 14 and the inside air intake pipe 12
The damper 20, the DC motor 40 that drives the turbo fan 42, the motor controller 44 that stops and operates the DC motor 40, the adsorption filter 30 that adsorbs NO _{X and the} like, and the CO oxidation that oxidizes CO into CO _2. Catalyst 3
2, an ultraviolet lamp 58 for irradiating the adsorption filter 30 with ultraviolet rays, a ballast 50 for turning on the ultraviolet lamp 58, a temperature sensor 56 for measuring the temperature of the adsorption filter 30, and a passage through the adsorption filter 30. N of the air
A NO _x sensor 46 for detecting the O _x concentration, a blow-out pipe 16 for blowing air into the vehicle, an exhaust pipe 18 for discharging exhaust gas to the outside of the vehicle, and a second damper 22 for switching the blow-out pipe 16 and the exhaust pipe 18. It consists of The air purifier 10 is controlled by an air purifier control device 70.

The structure of the adsorption filter 30 will be described with reference to FIG. The adsorption filter 30 is composed of a metal filter 31 shown in FIG. 3, which comprises activated carbon for adsorbing odorous components such as NO _X , and a photocatalyst for oxidizing and decomposing aldehydes, ammonia, etc. which are difficult to adsorb with activated carbon. The agent is carried. That is, the photocatalyst is supported on the activated carbon. The filter 31 is a thin stainless plate 31.
A member in which a is folded in a honeycomb shape is laminated and used. Although the filter 31 made of a thin stainless plate is used here, it is also possible to use a filter formed by folding a thin plate of copper, aluminum or the like into a honeycomb shape instead of stainless steel. Here, a filter formed by folding a thin plate in a honeycomb shape is used as the filter 31 that holds the adsorbent, thereby reducing the pressure loss, increasing the surface area of the adsorbent, and efficiently irradiating ultraviolet rays. I am trying.

In the adsorption filter 30 of the present embodiment, as described above, the activated carbon for adsorbing the odorous components such as NO _x and the photocatalyst of aldehydes, ammonia and the like which are the main components of the odor of tobacco which are difficult to be adsorbed by activated carbon are used as the photocatalyst. It uses a photocatalyst that is oxidized and decomposed by the reaction and finally converted into water, carbon dioxide, and nitric acid. This photocatalyst also has an action of oxidizing NO, which is difficult to be adsorbed by activated carbon, to NO _X which is easily adsorbed by activated carbon.

The photocatalyst for the oxidation and decomposition in substances more like HNO ₃ and NO _X adsorbed in the adsorbent, NO _X is suppressed the rate at which accumulated in the activated carbon by supporting a photocatalyst. In addition to this, various organic substances (odor components) other than NO _x that actually exist inside and outside the vehicle are oxidized and
Since the organic substance is decomposed, the rate of accumulation of the organic substance can be suppressed, and the organic substance once adsorbed by the adsorbent can be oxidized and decomposed.

[0018] In the photocatalyst even while degradation such as NO _X, continues to be adsorbed to NO _X such as activated carbon decreases the adsorption performance. Therefore, in the air purifier 10 of the first embodiment,
By stopping the blast or intermittently blasting,
The surface temperature of the adsorption filter 30 is increased by the ultraviolet rays of the ultraviolet lamp 58, the adsorbed substance is desorbed to regenerate the adsorbent, and the activity of the photocatalyst is enhanced to further accelerate the oxidation / decomposition by the photocatalyst. and it allowed removing odor components of the NO _X or the like which is adsorbed on activated carbon. At the time of this desorption operation, the second damper 22 is opened to release the NO _X , HNO _3, etc. separated from the activated carbon to the outside of the vehicle. Here, instead of releasing it to the outside of the vehicle, the exhaust gas is pumped to the air cleaner of the engine and burned in the combustion chamber of the engine, or reduced by the three-way catalyst to nitrogen to make it harmless and then released to the outside of the vehicle. It is also possible.

On the other hand, the CO oxidation catalyst 32 is Pd which oxidizes CO to CO ₂ on a carrier such as activated carbon fiber or alumina.
Noble metal oxidation catalysts such as

Next, the operation of the air purifier control device 70 according to the first embodiment of the present invention will be described with reference to the flowcharts of FIGS. 4 to 6. The control device 70 is
A switch process for operating the air purifier 10 is performed according to the operation by the driver (S12). This switch process will be described with reference to the flowchart of FIG. 5 showing the subroutine of the process.

First, when a start switch (not shown) is turned on by the driver (Yes in S42), the air purifier 10 is started (S44). Here, UV lamp 5
8 is turned on, ultraviolet rays are radiated to the adsorption filter 30, and the second damper 22 is operated on the side that opens the blow-off pipe 16 that sends out purified air into the vehicle. Then, the DC motor 40 is rotated to start pressure feeding of air to the adsorption filter 30 side. As a result, the air taken in from inside or outside the vehicle is pressure-fed and passed through the adsorption filter 30 to oxidize and decompose aldehyde, ammonia, etc. by the photocatalyst as described above, and at the same time, to adsorb NO _X on the activated carbon, and further to CO oxidation catalyst At 32, CO is oxidized into CO ₂ and then introduced into the vehicle. Subsequently, it is determined whether the inside air circulation is selected or the outside air introduction is selected by a changeover switch (not shown) (S46). Here, when the inside air circulation is selected (Yes in S46), the inside air intake pipe 12 is opened by the first damper 20 (S48) to purify the air inside the vehicle. On the other hand, when outside air introduction is selected (S
46 is No), the outside air intake pipe 14 is opened by the first damper 20 (S50), the air outside the vehicle is introduced, and this is purified and then discharged into the vehicle.

Subsequently, in step 52, it is judged whether the start switch is turned off by the driver (S52),
When the start switch is turned off (S52 returns Yes
s), the air purifier 10 is stopped (S56).

The controller 70 then controls the NO _X sensor 46.
It is determined from the output from the controller whether the adsorption performance of the adsorption filter 30 has deteriorated, that is, whether the adsorption filter 30 needs to be regenerated (Yes in S58). Here, when the regeneration is necessary (S58 returns Yes), it is determined whether or not the pollution flag indicating that the air purifier 10 is purifying the air by traveling in a contaminated area is set ( If the contamination flag is not set (S60) (No in S60), the regenerating operation, that is, the desorbing operation of the adsorbed substance from the adsorption filter 30 is performed (S62). Here, the second damper 22 is opened on the side where the exhaust pipe 18 is opened so that the exhaust gas that has been desorbed is discharged to the outside of the vehicle. Next, the air blow by the DC motor 40 is stopped. As a result, the surface temperature of the adsorption filter 30 becomes 80
Up to ° C, the substances adsorbed on the adsorbent are desorbed,
In addition, the activity of the photocatalyst is increased. This photocatalyst oxidizes and decomposes NO _{x and the} like adsorbed on the activated carbon and desorbs it. Here, when the temperature of the adsorption filter 30 rises to 80 ° C., the temperature of the adsorption filter 30 is set to 80 ° C. or less by starting the DC motor 40. That is, the DC motor 40 is intermittently operated to keep the activated carbon at 80 ° C,
Continue desorption of the adsorbate. This reproduction process is continued until a preset time has elapsed.

By the above processing, step 12 shown in FIG.
The switch processing subroutine is completed, and step 14
Processing proceeds to In this step 14, it is judged whether or not the traffic jam information or the information about the area where the air is polluted is received through the communication device 80. Here, when the information is sent (Yes in S14), the information is received and stored in the memory 7
4 (S16). Subsequently, the current position data is received from the navigation device 60 (S18), and the route is predicted from the current position and the traveling direction of the vehicle (S2).
0), the vehicle speed is detected by a signal from a vehicle speed sensor (not shown) (S22). It should be noted that here, the case where no route is set in the navigation device 60 is described as an example, but when the route is set, the route is predicted based on the set route. After that, through the judgment in step 24, in steps 26 to 34,
It will be judged whether or not the air will enter the polluted area.

That is, the map data of the CDROM 60b is read out, and first, it is judged whether or not there is a tunnel on the predicted course (S26). Here, if there is no tunnel (No in S26), it is determined whether to enter the underground parking lot (S28). Further, as described above, the CDROM 60b holds information on areas with a high degree of air pollution such as factory areas, so it is determined whether or not to enter this held area (S30). Here, when entering the area (Yes in S30), the time set as a time zone having a high degree of air pollution in the area (for example, 9:00 am to 5:00 pm when the factory operates) It is determined whether it is inside (S32). Further, in step 34, it is determined whether or not the traffic is congested. Whether or not this traffic jam occurs is recognized from the map data of the CDROM 60b when it is recognized that the current position is before the signal and the vehicle is repeatedly started and stopped based on the detected vehicle speed.
Judge that it is in a traffic jam. Here, the above steps 26, 28,
If the determinations at 32 and 34 are both No, the process returns to step 12 and the above-described processing is repeated.

On the other hand, the above steps 26, 28, 32, 3
If any of the determinations in 4 is Yes, the procedure moves to the B section. The processing in this part B will be described with reference to the flowchart in FIG. First, a pollution flag indicating that the vehicle is currently traveling in a highly polluted area is set (S72), and then a start switch (not shown) for starting the air purifier 10 is set by the driver. It is determined whether it is turned on (S74). Here, when the start switch is not turned on (No in S74), the stop flag indicating that the start switch is turned off is set (S76), and then the air purifier 10 is started (S7).
8). That is, when traveling in a highly polluted area, the air purifier 10 is started regardless of the setting of the start switch.

Subsequently, the control device 70 determines whether the changeover switch for switching the inside air circulation and the outside air introduction is set to the inside air circulation (S80). Here, when the outside air introduction is selected (No in S80), the outside air flag indicating that the outside air introduction is selected is set (S82), and then the first damper 20 shown in FIG. 2 is operated, Switching from the introduction of outside air to the circulation of inside air (S84) prevents introduction of highly polluted air from the outside and purifies the air inside the vehicle.

In the present embodiment, the purification of air is started by circulating the inside air before entering a highly polluted area. That is, if the outside air is being introduced when entering an area with a high degree of air pollution (for example, a tunnel), the outside air is taken in as it is, and the air inside the vehicle is contaminated, and the adsorption filter 30 Since adsorption of NO _{x and the} like progresses, it is switched to the internal air circulation in advance. Furthermore, even if internal air circulation is performed,
Since NO _X in the outside air from the gap or the like of the window glass, CO or the like invade, by purifying the air in the vehicle to start the air purifier 10, keeping car NO _X, the CO concentration below a certain value .

Subsequently, the control device 70 causes the step 8
At 6, 88, 90, 92, 94 it is determined whether the contaminated area has been passed. That is, it is determined whether the tunnel has passed (S
86) Also, it is judged whether or not the passenger has escaped from the underground parking lot (S
88), it is judged whether it passed through a highly polluted area such as a factory area (S90), and whether the time set as the time zone of high pollution has passed (S92), and then exit from the traffic jam. It is determined whether or not (S94). Here, when all of these steps 86, 88, 90, 92, 94 are No, the process returns to step 14 shown in FIG.
The current position of the vehicle is obtained by the processing up to. Then, the determination in step 24 as to whether the pollution flag is set is Yes.
Then, the determinations in step 86 to step 94 are made again.

The above process is repeated to escape from the contaminated area, and when the determinations in steps 86 to 94 are Yes, the process proceeds to step 96. In step 96, first, the pollution flag is cleared. Then, it is determined whether or not the stop flag indicating that the air purifier 10 has been activated is set even though the activation switch has been turned off (S98). Here, when the stop flag is set (Yes in S98), the air purifier 10 is stopped (S10) after clearing the stop flag (S100).
4). Further, it is determined whether or not the outside air flag indicating that the inside air circulation has been switched is set even though the outside air introduction has been selected by the changeover switch (S10).
4). Here, when the outside air flag is set (Yes in S104), after the outside air flag is cleared (S104).
106), operate the first damper 20 to switch to the introduction of outside air, and take in air from outside the vehicle. Then, the process returns to step 12 shown in FIG. 4 and the above-mentioned processing is repeated.

Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment described above with reference to FIG. 2, the configuration of the present invention is applied to the air purifier 10. However, in the second embodiment, not only the air purifier 10 but also the air control device 110 is used. Also applies the configuration of the present invention. In the description of the second embodiment, the same members as those in the first embodiment will be designated by the same reference numerals, and detailed description thereof will be omitted.

In this air control device 110,
The heater unit 92 for heating the air and the cooling unit 96 for cooling the air are provided with a third damper 9 for controlling the amount of ventilation to the heater unit 92 and the cooling unit 96.
The third and fourth dampers 94 are arranged, and the fifth damper 95 is provided.
Thus, the outside air intake pipe 14 for introducing the outside air and the inside air intake pipe 12 for introducing the air inside the vehicle can be switched. The air control device 110 is controlled by the control device 170. That is, the control device 170
Is the fifth damper 95 based on a signal (a signal associated with the pollution flag) issued from the controller 70 of the air purifier 10 shown in FIG. 2 while traveling in a highly polluted area.
When the air purifier 10 is circulating the inside air in order to run in a highly polluted area, the air control device 110 also switches to the inside air circulation to prevent outside air from entering the vehicle. .

In the second embodiment described above, the example in which the air purifier 10 and the air control device 110 are provided is given. However, when only the air control device 110 is provided, the air control device is Four
By performing the same processing as described above with reference to FIG. 6, it is possible to automatically change from the introduction of outside air to the circulation of inside air to perform heating and cooling when traveling in a highly polluted area. Furthermore, in an air venturation device (air blower) that does not perform cooling, when traveling in an area with a high degree of air pollution, it is also possible to automatically switch from outside air introduction to internal air circulation in the same manner as described above. it can.

Further, in the description of the first embodiment, the control device 70 of the air purifier 10 was made to perform the processing of FIGS. 4 to 6, but the navigation apparatus 60 may be made to perform this processing, or Of course, the control device 70 and the navigation device 60 can share the processing.

Further, in the above-mentioned embodiment, the air purifier 10 purifies harmful substances such as NO _x and CO. However, the present invention is of a type that purifies a bad odor in a vehicle by using an ozone generator or the like. It goes without saying that it can also be used in an air purifier.

In this embodiment, since the activated carbon is used while desorbing the adsorbed substance, the air can be continuously purified for a long time without exchanging the activated carbon. Furthermore,
Since high heat is not applied during the desorption operation of the adsorbed material, the activated carbon is not deteriorated.

In the first embodiment, various lamps can be used as the ultraviolet lamp as long as they can excite the photocatalyst. Furthermore, although TiO ₂ was used as the photocatalyst, various materials can be used as long as the odor component can be oxidized and decomposed. For example, Ti, Cu, Zn, La, Mo,
V, Sr, Ba, Ce, Sn, Fe, W, Mg, or A
It can be composed of at least one selected from the group consisting of each oxide of 1 and a noble metal. Further, the photocatalyst can be supported not by activated carbon but by an adsorbent such as silica gel. Also, in the embodiment described above,
Although the filter 31 in which the thin plate supporting the activated carbon is folded in a pleated shape is used, the activated carbon can be supported on the filters of various shapes.

[0038]

As described above, according to the method for operating the air purifying device for a vehicle and the air blower of the present invention, it is possible to prevent the invasion of air having a high degree of pollution outside the vehicle.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a vehicle air purification device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an air purifier in the first embodiment.

FIG. 3 is a perspective view of an adsorption filter.

FIG. 4 is the first half of a flowchart showing the main routine of the control device.

5 is a flowchart showing a switch processing subroutine shown in FIG. 4. FIG.

FIG. 6 is the latter half of the flowchart showing the main routine of the control device.

FIG. 7 is a configuration diagram of an air control device according to a second embodiment of the present invention.

[Explanation of symbols]

 10 Air Purifier 30 Adsorption Filter 42 Turbofan 58 Ultraviolet Lamp 70 Control Device 60 Navigation Device 60b CDROM 110 Air Control Device 170 Control Device

Claims (3)

[Claims] 1. An air purification apparatus for an automobile that purifies air by selecting between introduction of outside air and circulation of inside air, and position detection means for detecting a current position of the vehicle, and an area having a high degree of atmospheric pollution is stored. Area storage means to perform, based on the current position detected by the position detection means,
A polluted area entry predicting means for predicting whether or not a vehicle will enter an area with a high degree of air pollution stored in the area storage means, an adsorbing means for adsorbing pollutant components in the air, and an air for the adsorbing means. Blowing means for blowing air, intake air switching means for switching the introduction of outside air to the inside air circulation, and the adsorbing means, the blowing means, and the An air purification device for a vehicle, comprising: 2. An air purifying device for an automobile that purifies air by selecting either the introduction of outside air or the circulation of inside air, which comprises a position detection manual detection for detecting the current position of the vehicle and an area with a high degree of atmospheric pollution. Area storage means to store, based on the current position detected by the position detection means,
A polluted area entry predicting means for predicting whether or not a vehicle will enter an area with a high degree of air pollution stored in the area storage means, an adsorbing means for adsorbing pollutant components in the air, and an air for the adsorbing means. Blowing means for blowing air, adsorbing capacity judging means for judging adsorbing capacity of the adsorbing means, regenerating means for regenerating the adsorbing means, intake switching means for switching the introduction of outside air to inside air circulation, and the contaminated area entry predicting means It is necessary to regenerate the adsorption means by the purification device activation means for activating the adsorption means, the air blowing means, and the intake switching means when it is predicted that the adsorption means will enter an area with a high degree of pollution. And a purifying device regenerating unit for suppressing the air blowing by the air blowing unit and starting the regenerating unit when judged. Air purification device. 3. An operating method of an air blower, which has an area storage device for storing an area with a high degree of air pollution and a position detection device for detecting a current position, and which blows air by selecting outside air introduction and inside air circulation. And a step of detecting a current position of the vehicle, and a step of determining whether the vehicle enters an area with a high degree of air pollution stored in the area storage device based on the detected current position, In the above step, when it is determined to enter an area with a high degree of pollution, a step of switching to internal air circulation is included.