JPH1176718A - Dust removal filter, method of manufacturing the same, air conditioner and air purifier - Google Patents

Abstract

(57) [Problem] To carry out a high-temperature treatment in order to carry a photocatalyst on a substrate, there is a problem that a substrate having a low melting point made of a polymer such as a resin cannot be used. SOLUTION: Titanium oxide fine particles 1 having a photocatalytic function
However, it is dispersed and adhered to the surface of the substrate 2 of the dust filter 3 by the dust collecting property of the substrate 2. Further, as the substrate 2 having a dust collecting property, a composite nonwoven fabric in which a polypropylene nonwoven fabric and a polyethylene terephthalate nonwoven fabric were laminated was used. Then, the application amount of the photocatalyst is variously changed by spray coating, and the photocatalyst is applied to the composite nonwoven fabric.
Baking was performed at 2 ° C. for 2 hours to prepare a dust filter 3. By utilizing the dust-collecting property of the substrate 2, it becomes possible to apply only the titanium oxide fine particles 1 directly to the substrate 2, and even when the titanium oxide fine particles 1 are dispersed in a solution and applied, the firing temperature is 80 ° C.
This made it possible to use a flammable resin or the like as the base material 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust filter having a function of removing dust from indoor air, and an air conditioner or an air cleaner provided with the dust filter.

[0002]

2. Description of the Related Art Conventionally, Japanese Patent Application Laid-Open No. HEI 8-117606 discloses a document in which a photocatalyst is used to add a deodorizing function. In JP-A-8-117606, a layer having a photocatalytic function is formed on the surface of a base material, and a gap formed on the surface of the layer is filled with particles smaller than the gap to form a smooth surface. There is disclosed a multifunctional material having a photocatalytic function for suppressing adhesion of odor molecules and the like.

[0003] Japanese Patent Application Laid-Open No. 3-60720 discloses an air purifier having a dust removing function. JP-A-3-60
No. 720, in a ventilation path of an air purifier provided with a blower fan and a filter for removing dust on the suction side, a light-shielding plate serving also as a wind direction plate is provided between the filter and the blower fan, and a photocatalyst is added to the surface. Alternatively, an air cleaner is provided which includes an adsorbing means for adsorbing an odor component into which a photocatalyst has been kneaded, and an exciting means for irradiating the photocatalyst with ultraviolet rays to excite the photocatalyst.

[0004]

However, in the multifunctional material having the deodorant function described in JP-A-8-117606, the surface area of the photocatalyst exposed on the surface is small due to the smooth surface. And the photocatalytic performance is reduced. In addition, since high-temperature treatment must be performed at the time of manufacture, there is a problem that a base material having a low melting point made of a polymer such as a resin cannot be used.

On the other hand, in the air purifier disclosed in Japanese Patent Application Laid-Open No. Hei 3-60720, the odor is not deposited on the dust removing portion, and the odor adheres and accumulates. Although the odor is removed by the deodorizing section on the downstream side, if the odor accumulates in the dust removing section, there is a problem that the odor component cannot be completely removed by the deodorizing section and is released to the outside. I was

An object of the present invention is to solve the above-mentioned problems and to provide a dust filter having a deodorizing effect by coating a dust filter with a photocatalyst to prevent odor components from adhering and decomposing the attached odor components by the photocatalyst. The purpose is to provide an installed air conditioner or air purifier.

[0007]

In order to achieve the above object, the present invention provides a photocatalyst supported on a dust-removable substrate. According to a second aspect of the present invention, the photocatalyst and the silica sol or the alumina sol are applied to a dust-removable substrate.

According to a third aspect of the present invention, the photocatalyst and the silica sol or the alumina sol are applied to the surface of a base material so as to have a concentration of 80 μg / cm ² or more and 200 μg / cm ² or less.

In the invention according to claim 4, the mixing ratio of the photocatalyst and the silica sol or alumina sol is such that the weight of the photocatalyst is 50% or more. According to a fifth aspect of the present invention, the base material is an electrostatic filter, and in the sixth aspect of the present invention, the base material is a HEPA filter.

(7) The photocatalyst has a particle size of 10 nm or more and less than 50 nm. The invention according to claim 8 is the first invention.
In the dust filter according to any one of to 6,
Only the photocatalyst, or, the photocatalyst and silica sol or alumina sol, in order to carry on the substrate,
Utilizing the dust collecting performance of the substrate, the heating temperature of the substrate is 80 ° C.
Performed below.

According to a ninth aspect of the present invention, there is provided an air conditioner including the dust filter according to any one of the first to seventh aspects. According to a tenth aspect of the present invention, in the air conditioner of the ninth aspect, a deodorizing section for deodorizing odor contained in air is disposed downstream of the dust filter.

[0012] The invention according to claim 11 is the ninth or tenth aspect of the present invention.
The air conditioner comprises an odor detecting means for detecting odor contained in the air transmitted through the dust filter, and a regeneration notifying means for notifying a regeneration timing of the dust filter, wherein the odor detecting means is equal to or more than a predetermined amount. When the odor is detected, the regeneration notifying unit notifies the regeneration timing of the dust filter.

[0013] The twelfth aspect of the present invention provides the first to seventh aspects.
An air purifier comprising the dust filter according to any one of the above. The invention according to claim 13 is
In the air purifier of the twelfth aspect, a deodorizing means for deodorizing odor contained in the air is disposed downstream of the dust filter.

The invention according to claim 14 is the invention according to claim 12 or 1.
3. The air purifier of claim 3, further comprising: an odor detection unit that detects an odor contained in the air that has passed through the dust filter; and a regeneration notifying unit that notifies a regeneration timing of the dust filter, wherein the odor detection unit has a predetermined amount. When the above odor is detected, the regeneration notifying unit notifies the regeneration timing of the dust filter.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a dust filter according to the present invention, an air conditioner provided with the dust filter and an air purifier will be described.

<First Embodiment> FIG. 1 shows a first embodiment of a dust filter of the present invention. FIG. 1 is an enlarged sectional view of a dust filter in which a photocatalyst is applied to both sides of an entrance and an exit.

Titanium oxide fine particles 1 having photocatalytic function
However, the particles are dispersed and attached to the surface of the substrate 2 of the dust removal filter 3 due to the dust collecting property of the substrate made of a material described later. By utilizing the dust collecting performance of the base material, only the titanium oxide fine particles 1 can be directly applied to the base material 2, and even when the titanium oxide fine particles 1 are dispersed and applied in a solution, the firing temperature can be lowered, and the flammable resin can be used. Etc. can be used as a base material. Further, the base material 2 is shaped so as to have a zigzag cross section as shown in FIG. 1 in order to increase the surface area. The arrows indicate the flow of air. By passing the air containing the dirt component through the dust filter 3, dust and dust are collected, and at that time, the odor component also adheres to the dust filter 3.

The adhered odor component is decomposed by irradiating the applied photocatalyst with ultraviolet rays, and the odor is not deposited, and the odor-preventing performance is exhibited. Further, since the attachment of the odor component is mainly at the entrance surface, the application of the photocatalyst can sufficiently obtain the deodorizing effect only with the entrance surface.

In Embodiment 1, a photocatalyst aqueous dispersion STS-21 (trade name) manufactured by Ishihara Sangyo Co., Ltd. was used as a photocatalyst, and a polypropylene nonwoven fabric and a polyethylene terephthalate nonwoven fabric were laminated as a substrate 2 of a dust filter 3. A composite nonwoven fabric was used. Then, the applied amount of the photocatalyst was variously changed by spray coating, and the photocatalyst was applied to the composite nonwoven fabric and baked at 80 ° C. for 2 hours to produce a dust filter 3.

These dust filters 3 are installed in a box of 1 m ³ , and after purifying the dried and burned clean air, five cigarettes are burned at the same time, and the air volume is 3 m ³ / min. 3
After circulating air for 0 minutes, the odor attached to the dust filter 3 was measured, and the dust filter was irradiated with light for 10 hours using a 15 W white fluorescent lamp manufactured by NEC Corporation or a 15 W black light manufactured by NEC Corporation. Was performed, and the decomposition of the attached odor component was measured. Table 1 shows the results.

[0021]

[Table 1]

In Table 1 and Tables 2 and 3 to be described later, the odor adhesion levels are level 1 (slight odor is attached), level 2 (odor is attached to a recognizable level), and level 3 (very odor is attached). Are attached). Similarly, the odor component decomposition levels are level 1 (decomposable with white light), level 2 (decomposable with ultraviolet light source), and level 3
(Not disassembled).

As shown in Table 1, when no photocatalyst is applied, odor is little attached, but since there is no photocatalytic function,
Odors accumulate on the dust filter 3.

On the other hand, when the coating amount of the photocatalyst is 300 μg / cm ²
In such a case, odor adherence becomes large, and it is difficult to sufficiently decompose odor components under a white fluorescent lamp. The photocatalyst coating amount is 80 μg / cm
^{When it is 2} or more and 200 μg / cm ² or less, the adhesion of the odor and the decomposition performance obtained by the photocatalyst due to the ultraviolet light contained in the white fluorescent lamp are balanced, and sufficient odor components can be decomposed under the white fluorescent lamp.

With such a configuration, when the air containing the dirt component is passed through the dust filter 3, the dust and dust in the air are collected by the dust filter 3, and the odor component contained in the air is also reduced. Adhere to.

Further, when the photocatalyst applied to the dust filter 3 is irradiated with ultraviolet rays, the odor component attached to the dust filter 3 is decomposed into carbon dioxide, water molecules and the like by the photocatalyst. Decomposed carbon dioxide, water molecules and the like are desorbed from the dust filter 3. As described above, the odor component attached to the dust filter 3 is decomposed, and generation of odor can be suppressed.

<Second Embodiment> A dust filter according to a second embodiment of the present invention will be described.

In the second embodiment, a photocatalyst aqueous dispersion STS-21 (trade name) manufactured by Ishihara Sangyo Co., Ltd. is used as a photocatalyst, and a colloidal silica sol snowtech 30 (trade name) manufactured by Nissan Chemical Co., Ltd. is used as a binder. The substrate 2 of the dust filter 3 was a composite nonwoven fabric obtained by laminating a polypropylene nonwoven fabric and a polyethylene terephthalate nonwoven fabric. Then, the mixing ratio of the photocatalyst and the silica sol was variously changed by spray coating, and the total coating amount was 20
0 μg / cm ² is applied to the composite non-woven fabric,
Baking was performed at 80 ° C. for 2 hours to prepare a dust filter 3. Note that alumina sol may be used instead of silica sol.

These dust filters 3 were set in a box of 1 m ³ , and after purifying the dried and burned clean air, 5 cigarettes were burned at the same time, and the air volume was 3 m ³ / min. 3
After circulating air for 0 minutes, the odor adhesion level of the dust filter 3 was measured, and the dust filter 3 was irradiated with light for 10 hours by a 15 W white fluorescent lamp manufactured by NEC Corporation or a 15 W flux light manufactured by NEC Corporation. Was performed, and the decomposition of the attached odor component was measured. Table 2 shows these results.
Shown in

[0030]

[Table 2]

As shown in Table 2, even if the mixing ratio of the photocatalyst and silica (adsorbent) is changed, the adhesion of the odor does not change much, but if the mixing weight% of the photocatalyst is not 50% or more,
Decomposition of odor components becomes difficult with a white fluorescent lamp.

With such a groove, the dust filter 3
When air containing a dirt component is allowed to pass through, dust and dirt in the air are collected by the dust removal filter 3, but adhesion of odor components contained in the air is reduced. This allows
Even if a small amount of ultraviolet light included in a white fluorescent lamp or the like is irradiated without providing an ultraviolet light source, the odor component attached to the dust filter 3 can be decomposed.

<Third Embodiment> A dust filter according to a third embodiment of the present invention will be described.

In the third embodiment, the photocatalyst ST-I manufactured by Ishihara Sangyo Co., Ltd.
01 (particle diameter 7 nm), ST-21 (particle diameter 20 nm) and ST-41 (particle diameter 50 nm) (trade name), and the base material 2 of the dust filter 3 is a composite in which a non-woven fabric of poly (propylene) and a non-woven fabric of polyethylene terephthalate are laminated. Non-woven fabric was used. Then, a solution obtained by mixing and dispersing the photocatalyst powder in ion-exchanged water is applied to the composite nonwoven fabric by spray coating so that the applied amount of the photocatalyst is 100 μg / cm ² , and baked at 80 ° C. for 2 hours to remove the dust. Was prepared.

The dust filter 3 is placed in a 27 L box, one cigarette is burned, and air is circulated through the dust filter 3 for 30 minutes.
The odor adhesion level was measured for 15
The dust filter 3 was irradiated with light using a W white fluorescent lamp or a 15 V flux light manufactured by NEC Corporation for 10 hours, and the decomposition level of the attached odor component was measured. Table 3 shows the results.

[0036]

[Table 3]

As shown in Table 3, the smaller the particle size of the photocatalyst powder, the larger the odor is attached and the higher the photocatalytic function tends to be. When the particle diameter is 7 nm, the odor adhesion level becomes large, and the decomposition of the odor component becomes difficult with a white fluorescent lamp. On the other hand, when the particle diameter is 50 nm, the photocatalytic function becomes small, and the decomposition of the odor component becomes difficult with a white fluorescent lamp. However, when the particle diameter is 20 nm, the adhesion of the odor and the photocatalytic function obtained by the white fluorescent lamp are balanced, and the odor component can be decomposed by the white fluorescent lamp.

<Fourth Embodiment> A dust filter according to a fourth embodiment of the present invention will be described.

In the fourth embodiment, a photocatalyst aqueous dispersion STS-21 (trade name) manufactured by Ishihara Sangyo Co., Ltd. is used as a photocatalyst, and a colloidal silica sol-based Snowtech 30 (trade name) manufactured by Nissan Chemical Co., Ltd. is used as a binder. , And the base material 2 of the dust filter 3 is a composite nonwoven fabric in which a polypropylene nonwoven fabric and a polyethylene terephthalate nonwoven fabric are laminated. Then, a mixed solution of a photocatalyst silica sol containing 70% by weight of the photocatalyst is applied to the composite nonwoven fabric by spray coating so that the applied amount of the photocatalyst is 80 μg / cm ² , and baked at 80 ° C. for 2 hours to remove dust. Filter 3 was produced.

The dust filter 3 and the dust filter not coated with a photocatalyst were installed in a box of 1 m ³ , and after purging dry clean room air, five cigarettes were simultaneously burned, and the air volume was 3 m ³ / min. . And the air was circulated for 30 minutes, and the removal rate of various odor components in each dust filter 3 was measured by a gas detector tube. Table 4 shows the results.

[0041]

[Table 4]

In the first to fourth embodiments, the base material of the dust filter is HEPA (High Efficiency).
A HEPA filter coated with a photocatalyst having the above-described configuration using a (Particulate Air) filter may be used.

The HEPA filter is a filter made of glass fiber.
Those having a collection rate of 99.7% or more with respect to the particles of m can be used. In addition, the collection rate of the HEPA filter is not limited to the above-described one, and may be any value that does not cause clogging in a state where the photocatalyst particles are supported. In addition, the HEPA filter is easily clogged,
A coarse filter may be arranged on the air suction side to form a composite, and this may be used as a substrate.

Further, in Embodiments 1 to 4, an electrostatic filter may be used as a base material of the dust filter. In addition, the electrostatic filter is dust in the passing air,
Equipped with an ionization line that charges particles such as dust, and to adsorb particles charged by the ionization line,
The electrostatic filter is charged to the opposite polarity to adsorb particles.

<Embodiment 5> Embodiment 5 of the present invention
Is an air conditioner provided with a dust filter as shown in FIG. In the fifth embodiment, the dust filter according to any one of the first to fourth embodiments is provided.

In FIG. 2, the air conditioner includes a suction port 9 formed on the front and top surfaces of the main body, a dust filter 3 through which room air sucked from the suction port 9 passes, and an air passing through the dust filter 3. The air conditioner includes a heat exchanger 5 for exchanging heat, a blower fan 6 for blowing air exchanged by the heat exchanger 5 into a room, and an outlet 7 for blowing air blown by the blower fan 6 into the room. .

The dust filter 3 is the one described in any one of the first to third embodiments and has a specification capable of decomposing odor components attached by ultraviolet rays contained in a white fluorescent lamp. An odor sensor 4 (odor detection means) is provided in a ventilation passage on the side of the outlet 7. Further, a deodorizing section may be provided downstream of the dust filter 3 in the ventilation passage.

Then, when air containing a dirt component is passed through the dust filter 3, dust and dust are collected, and ultraviolet rays entering the inside of the main body from the suction port 9 are further removed.
As a result, the attached odor component is decomposed by the photocatalytic function, so that the accumulation of the odor component on the dust filter 3 and the desorption of the odor do not occur.

When sufficient ultraviolet light does not enter the dust filter 3 or when the degree of contamination is high, the photocatalyst provided in the dust filter 3 does not function sufficiently, and odor components are deposited on the dust filter 3 to generate odor. May cause

Therefore, in the present embodiment, an odor sensor 4 (odor detection means) and a filter refresh indicator (reproduction notifying means) are provided to indicate the refresh time of the dust filter 3.

With such a configuration, when the air conditioner is operated in a dark room or in a highly polluted air condition, the function of the photocatalyst is not sufficiently exhibited, and the odor component accumulates on the dust filter 3, Air containing odor is blown from the outlet 7. Then, the odor is detected by the odor sensor 3, and when the odor exceeds a predetermined value, it is determined that odor is generated at the time of blowing, and the filter refresh indicator lamp is turned on to notify the user. Thus, when the user removes the dust filter 3 and exposes it to ultraviolet light by drying in the sun, the odor component attached to the dust filter 3 is decomposed by the photocatalytic function.

<Embodiment 6> Embodiment 6 of the present invention
Is an air purifier provided with a dust filter as shown in FIG. In the sixth embodiment, the first to fourth embodiments are described.
The dust filter 3 described in any one of the above.

Referring to FIG. 3, the air purifier includes a suction port 9 formed in the front of the main body, a dust filter 3 through which room air passes through the suction port 9, and a blower for blowing air deodorized and deodorized by the dust filter 3. Fan 6 and deodorizing unit 1 for further deodorizing the air blown by blowing fan 6
0 and an outlet 7 for blowing the air deodorized by the deodorizing section 10 into the room.

The dust filter 3 is the same as that of the first embodiment.
As shown in Nos. 4 to 4, the attached odor component is decomposed by the ultraviolet light contained in the white fluorescent lamp. Further, an odor sensor 4 that detects odor in the air that has passed through the deodorizing section 10 is disposed between the outlet 7 and the deodorizing section 10.

By passing air containing a dirt component through the dust filter 3, dust and dirt are collected, and
When ultraviolet rays entering the main body from the filter strike the dust filter 3, the attached odor component is decomposed by the photocatalytic function, so that accumulation of the odor component and desorption of the odor do not occur.

In the case where ultraviolet rays do not enter, or when the degree of contamination is high, the photocatalyst of the dust filter 3 does not function sufficiently, and odor components may be deposited and odor may be generated.

When the air purifier is operated in a dark room or in a highly contaminated air environment with such a configuration, the function of the photocatalyst is not sufficiently exerted, and the odor component is reduced.
And air containing odor is blown from the outlet 7. Then, the odor is detected by the odor sensor 3, and when the odor exceeds a predetermined value, it is determined that odor is generated at the time of blowing, and the filter refresh indicator lamp is turned on to notify the user. Thus, when the user removes the dust filter 3 and exposes it to ultraviolet light by drying in the sun, the odor component attached to the dust filter 3 is decomposed by the photocatalyst.

[0058]

According to the first aspect, the photocatalyst is supported by utilizing the dust collecting property of the dust filter, so that the firing temperature for fixing the photocatalyst to the base material can be lowered. There is no restriction on the material and the resin can be used for the base material. Then, by irradiating the photocatalyst applied to the dust filter with ultraviolet rays, the odor component attached to the dust filter is decomposed. Thereby, the generation of odor from the dust filter can be suppressed as compared with the case where the photocatalyst is not applied.

According to the second aspect, by using silica sol or alumina sol as a binder, the adhesion between the substrate of the dust filter and the photocatalyst is increased, and the photocatalyst is irradiated with a small amount of ultraviolet light such as a white fluorescent lamp. ,
Odor components attached to the dust filter are decomposed. Thereby, the generation of odor from the dust filter can be suppressed as compared with the case where the photocatalyst is not applied.

According to the third aspect, the amount of odor adhering to the dust filter and the decomposition performance of the photocatalyst by the ultraviolet light contained in the white fluorescent lamp are balanced, and the odor component is sufficiently decomposed under the white fluorescent lamp. be able to.

According to the fourth aspect, a sufficient mixing ratio of the photocatalyst required under a white fluorescent lamp can be secured, and the odor component can be decomposed.

According to the fifth aspect, the odor can be extremely efficiently adsorbed by the electrostatic filter, and the adsorbed odor can be decomposed at the same time.

According to the sixth aspect, the HEPA filter can also remove fine particles contained in the air, and can also decompose the adsorbed odor.

According to the seventh aspect, the amount of odor adhering to the photocatalyst is balanced with the performance of decomposing the photocatalyst by the ultraviolet light contained in the white fluorescent lamp, and the odor component is sufficiently decomposed under the white fluorescent lamp. Can be.

According to the eighth aspect, since the photocatalyst is carried by utilizing the dust collecting property of the dust filter, the firing temperature for fixing the photocatalyst to the substrate can be set to 80 ° C. There is no restriction on the material, and the resin can be used for the base material.

According to the ninth and twelfth aspects, it is possible to remove the odor from the air and to operate while decomposing the odor.

According to the tenth and thirteenth aspects, the odor can be reliably removed from the blown air. It also has a deodorizing function when the dust filter is removed for cleaning or regeneration.

According to the eleventh and fourteenth aspects, when the air conditioner or the air purifier is operated in a dark room or a highly polluted air condition, the function of the photocatalyst is not sufficiently exhibited, and the odor component is reduced. The air containing the odor that accumulates on the dust removal filter is blown, but is detected by the odor detection means. If the odor exceeds a predetermined value, it is determined that odor is generated at the time of the blowing, and the user is notified of the regeneration time by the regeneration notification means. . Thus, the user can remove the dust filter and expose the dust filter to ultraviolet rays by sun drying or the like, so that the dust filter can be regenerated.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view showing a dust filter of the present invention.

FIG. 2 is a side sectional view of an air conditioner including the dust filter of FIG.

FIG. 3 is a side sectional view of an air purifier provided with the dust filter of FIG. 1;

Claims (14)

[Claims] 1. A dust filter comprising a photocatalyst carried on a dust-removing base material. 2. A dust filter comprising a photocatalyst and silica sol or alumina sol applied to a dust-removable substrate. 3. The dust filter according to claim 2, wherein the photocatalyst and the silica sol or the alumina sol are applied to a surface of a base material so as to have a concentration of 80 μg / cm ² or more and 200 μg / cm ² or less. 4. The dust filter according to claim 2, wherein the weight ratio of the photocatalyst to the silica sol or the alumina sol is 50% or more. 5. The dust filter according to claim 1, wherein the substrate is an electrostatic filter. 6. The dust filter according to claim 1, wherein the substrate is a HEPA filter. 7. The photocatalyst having a particle size of 10 nm or more and 50 n or more.
The dust filter according to any one of claims 1 to 6, wherein the diameter is less than m. 8. The dust filter according to claim 1, wherein only the photocatalyst is used, or
Production of a dust filter, wherein the photocatalyst and the silica sol or the alumina sol are carried on the base material, using the dust collecting performance of the base material, and heating the base material at a heating temperature of 80 ° C. or lower. Method. 9. An air conditioner comprising the dust filter according to claim 1. Description: 10. The air conditioner according to claim 9, further comprising a deodorizing section disposed on a downstream side of the dust filter to deodorize odor contained in air. 11. An odor detecting means for detecting an odor contained in the air transmitted through the dust filter, and a regeneration notifying means for notifying a regeneration timing of the dust filter, wherein the odor detecting means has a predetermined amount or more. The air conditioner according to claim 9 or 10, wherein when the odor is detected, the regeneration notifying unit notifies the regeneration timing of the dust filter. 12. An air purifier comprising the dust filter according to claim 1. Description: 13. The air purifier according to claim 12, wherein a deodorizing means for deodorizing odor contained in the air is provided downstream of the dust filter. 14. An odor detecting means for detecting an odor contained in the air transmitted through the dust filter, and a regeneration notifying means for notifying a regeneration timing of the dust filter, wherein the odor detecting means has a predetermined amount or more. 14. The air conditioner according to claim 12, wherein, when an odor is detected, the regeneration notifying unit notifies the regeneration timing of the dust filter.