JP4163540B2 - Ventilator and building using the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ventilation device and a building having a function of taking air outside a building into the room and discharging the indoor air to the outside of the building.
[0002]
[Prior art]
Conventionally, a ventilator shown in FIG. 7 is known as a ventilator having a function of taking air outside a building into the room and discharging the indoor air to the outside of the building.
[0003]
The ventilation device 100 is installed on an indoor ceiling plate S, and the indoor ceiling plate S is formed with an opening S1 for sucking indoor air. The main body case 101 of the ventilating apparatus 100 is formed with an opening 102 that opens from the opening S1 of the ceiling board S to the room. The opening 102 is covered by a front panel 103 provided near the indoor ceiling. The front panel 103 has an opening 104 through which air passes.
[0004]
A heat exchange element 105 is disposed inside the opening 102 of the main body case 100. The heat exchanging element 105 includes a passage A through which indoor air sucked from the opening 104 of the front panel 103 and taken in through the opening 102 is passed, and a passage B through which air outside the building passes. Heat exchange can be performed between the air passing through the passages A and B, respectively. The opening 102 communicates with the passage A of the heat exchange element 105, and the passage A of the heat exchange element 105 is connected to the exhaust introduction chamber 107 through the blower passage 106. Further, the exhaust introduction chamber 107 is connected to the exhaust passage 108. It is connected. An exhaust fan 109 is stored in the exhaust introduction chamber 107, and the exhaust fan 109 can suck air from the air passage 106 and blow it into the exhaust passage 108. The exhaust passage 108 communicates with the outside of the building through a duct (not shown). The exhaust fan 109 is rotated by a motor M <b> 1 attached to a partition plate 114 at the center of the main body case 101.
[0005]
An introduction passage 110 for introducing air outside the building is formed in the side wall portion of the main body case 101, and the introduction passage 110 is connected to a duct (not shown) that leads to the outside of the building. The passage B of the exchange element 105 is connected. The passage B is connected to the air supply chamber 112 via the blower passage 111, and an outside air introduction fan 113 is disposed in the air supply chamber 112. The outside air introduction fan 113 is rotated by a motor M2 attached to a partition plate 114 between the air supply chamber 112 and the exhaust introduction chamber 107. A supply passage 115 is connected to the air supply chamber 112, and the supply passage 115 is connected to a predetermined room via a duct (not shown) so that air outside the building is supplied to the predetermined room. Yes. The air outside the building is filtered by a filter F that removes dust / dust contained in the outside air.
[0006]
[Patent Document 1]
JP-A-10-281523 (paragraphs 0014-0021, FIGS. 1 and 3)
[0007]
[Problems to be solved by the invention]
By the way, even if the filter F is provided, the minute dust / dust contained in the outside air cannot be completely removed, but these minute dust / dust, microorganisms or water vapor enters the heat exchange element 105, It is assumed that it will be introduced indoors.
[0008]
In particular, when water vapor condenses inside the heat exchange element 105, it is assumed that mold grows and microorganisms propagate.
[0009]
This invention is made paying attention to such a subject, and it aims at providing the ventilation apparatus, ventilation system, and building which can prevent mold | fungi generation | occurrence | production inside or propagation of microorganisms. .
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is directed to an outside air introduction air passage for taking air outside a building into a room, an exhaust air passage for exhausting room air outside the building, and the exhaust air A first blower that sucks indoor air from an opening for exhausting the road and exhausts it to the outside of the building; a second blower that introduces outside air from the outside air introduction air passage and supplies the air into the room; and the outside air introduction air passage And a heat exchange element formed at an intersection where the exhaust air passage intersects each other, and the heat exchange element includes an outside air passage through which air outside the building passes and an exhaust passage through which room air passes. In the ventilator for exchanging heat between the air passing through the outside air passage and the exhaust passage,
An ion generator that generates positive ions and negative ions is provided upstream of the heat exchange element and downstream of the second blower in the outside air introduction air passage.
[0015]
According to the second aspect of the ventilator, clean air can be supplied indoors by suppressing the growth of bacteria and the generation of mold contained in dust attached to the filter.
[0017]
According to the ventilator of claim 1 , if the ion generator is provided upstream of the outside air passage of the heat exchange means, the floating bacteria floating in the air entering the heat exchange means can be sterilized. In addition, in the heat exchange means, it is possible to prevent the growth of bacteria and the generation of mold, and to sterilize the floating bacteria in the air sent indoors.
[0018]
Moreover, if it is provided on the downstream side of the outside air passage of the heat exchange means, it is possible to sterilize the floating bacteria floating in the air that has passed through the heat exchange means, so the bacteria in the air sent indoors are sterilized. It is possible to prevent the occurrence of mold such as ducts connected to the outside air introduction air passage.
[0019]
Furthermore, if it is provided before and after the heat exchanging means, the process of sterilizing the floating bacteria in the air sent to the room is performed twice, and the occurrence of mold in the heat exchanging means and the duct can be prevented.
[0020]
In addition, when the ion generator is provided in the vicinity of the inlet of the blower before reaching the heat exchange means in the outside air introduction air passage, sterilization treatment of floating bacteria floating in the air of the blower or the outside air introduction air passage Is done.
[0022]
According to a second aspect of the present invention, there is provided the ventilator according to the first aspect , wherein a filter for removing dust / dust is provided upstream of the outside air passage of the heat exchange element, and the ion generator is provided upstream of the filter. characterized in that was.
[0035]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a ventilator as an air conditioner according to an embodiment of the present invention will be described with reference to the drawings.
[0036]
FIG. 1 shows a schematic configuration of a ventilation device 1 according to an embodiment of the present invention. The ventilation apparatus main body 1a is attached to the upper part of the indoor ceiling board. This ventilator main body 1a includes an outside air introduction air path AR1 for taking in air outside the building (outside air) and supplying it to the inside of the main body case 2 disposed on the ceiling of the room, and the building by taking in indoor air. An exhaust air path AR2 for exhausting to the outside is formed. In addition, outside air introduction air path AR1 and exhaust air path AR2 shall include the duct connected to these other than each air path in ventilation apparatus main body 1a.
[0037]
The main body case 2 of the ventilation device 1 is attached to an upper part of a ceiling board in a building such as a room or a hallway, and is connected to a duct portion 7 via a duct 30 (see FIGS. 4A and 4B). It is a fully concealed type that takes in indoor air from a suction port (circulatory port) provided in the ceiling, but it can also be used for a semi-concealed type installed on the ceiling.
[0038]
In the case of the semi-concealment type ventilation device 1 (see FIGS. 1B and 2), the opening 17 at the bottom of the main body case 2 and the ceiling opening (not shown) formed directly below the opening 17 Air can be introduced and exhausted. In the case of the semi-concealment type, the air in the other room can be sucked and exhausted through a louver or the like provided on the partition wall in the room.
[0039]
In addition, a heat exchange element 3 (heat exchange means) is provided at the intersection of the outside air introduction air path AR1 and the exhaust air path AR2. The heat exchange element 3 performs heat exchange between an outside air passage through which air outside the building passes and an exhaust passage through which room air passes. Although the site | part which stores the heat exchange element 3 is divided | segmented into space A, B, C, D, the space A, B is connected via the channel | path which lets the external air OA of the heat exchange element 3 pass. The spaces C and D are connected via a passage for exhausting the indoor air RA of the heat exchange element 3.
[0040]
A fan case 4 is provided in the outside air introduction air path AR <b> 1 of the main body case 2, and a sirocco fan 5 is disposed inside the fan case 4. The sirocco fan 5 is attached to the rotating shaft of the motor 6. The motor 6 is attached to the partition wall 6A of the outside air introduction air path AR1 and the exhaust air path AR2, and the rotation shaft of the motor 6 protrudes on both sides of the partition wall 6A. An outlet of the introduced outside air OA is formed on the downstream side of the heat exchange element 3 in the outside air introduction air path AR1 of the main body case 2, and a duct joint 8 is provided at this outlet. A filter 9 and an ion generator 10C are provided on the upstream side of the passage through which the outside air of the heat exchange element 3 passes, and an ion generator 10D is also attached on the downstream side of the passage through which the outside air of the heat exchange element 3 passes. ing. A duct joint 18 is attached to a room air intake port of the exhaust air passage AR2 in the main body case 2.
[0041]
The ion generator 10A is provided at the outside air introduction port into the building or in the vicinity (near). According to this, outside air can be sterilized (sterilization of floating bacteria) and introduced into the building (in the duct and the apparatus). The ion generator 10B is provided near the outside air inlet of the apparatus main body. According to this, the sterilized air can be taken into the apparatus, and the sterilization process in the apparatus such as a fan can be performed. The ion generator 10 </ b> C is provided in the vicinity of the filter 9 on the upstream side. According to this, bacteria, mold, etc. adhering to the filter 9 can be suppressed, and clean air can be supplied indoors by removing dust and dirt with the filter 9. The ion generator 10D is provided in the vicinity of the outlet of the ventilator main body 1a, and can sterilize airborne bacteria such as mold in the ventilator main body 1a and supply clean air to the room through the duct. The ion generator 10E is provided inside the duct at or near the bent portion, and can sterilize the inside of the duct. The ion generator 10F is provided in the air supply port. According to this, the sterilized air can be supplied into the room and the air already existing in the room can be sterilized.
[0042]
In addition, the air inlet 20 provided with the ion generator 10F is provided in the outer peripheral part on the plane of the building. When the air supplied from the outside air introduction path AR1 is supplied into the room from the air supply port by the sirocco fan 5 of the ventilator main body 1a, the air that has entered the room passes through the louver (undercut part), and the passage The air is sucked into an indoor air inlet (annular air outlet RA) provided on the ceiling surface of the air and exhausted to the outside of the building through the exhaust air passage AR2 of the ventilator main body 1a.
[0043]
As shown in FIG. 4 (c), the air supply port 20 is provided in the vicinity of the outer peripheral part on the plane of the building, and preferably on a diagonal line of the entrance B where the louver (undercut part) is provided. Therefore, clean air can be supplied to every corner of the room.
[0044]
A fan case 11 is provided in the exhaust air path AR <b> 2, and a sirocco fan 12 is disposed inside the fan case 11. The sirocco fan 12 is attached to the rotating shaft of the motor 6. An outlet for indoor air is formed on the downstream side of the heat exchange element 3 in the exhaust air path AR2, and a duct joint 13 is provided at the outlet. A filter 14 is provided on the upstream side of the passage through which the indoor air of the heat exchange element 3 passes.
[0045]
The ion generators 10A, 10B, 10C, 10D, 10E, and 10F (see FIG. 4B) and the motor 6 are connected to a commercial power supply 15 via relay switches SW2 and SW1. The relay switches SW1 and SW2 are turned on and off by the control device 16 to supply power to the ion generators 10A to 10F and the motor 6 or to cut off the power supply.
[0046]
The heat exchanging element 3 as a heat exchanging means is formed by laminating a large number of plastic sheets having a corrugated cross-sectional configuration similar to the cross-sectional shape of corrugated cardboard, and each sheet is arranged in parallel with a number of elongated passages for passing air Has been. The passage of the seat constituting a part of the exhaust air passage AR2 is directed along the exhaust air passage AR2, and the passage of the seat constituting a part of the outside air introduction air passage AR1 is along the outside air introduction air passage AR1. Is directed. A sheet constituting a part of the exhaust air path AR2 and a sheet constituting a part of the outside air introduction air path AR1 are made into a set, and are joined so that the directions of the passages through which the air passes cross each other. The heat exchange element 3 is configured by laminating a large number of sets. With the configuration of the heat exchange element 3, heat exchange is performed between exhaust air discharged from the room to the outside of the building and introduced air introduced from the outside of the building to the room.
[0047]
The ion generators 10A to 10F are connected to the control device 16, and the control device 16 discharges plasma to sterilize the floating bacteria. Here, “floating bacteria” to be sterilized include “general live bacteria” and “fungi”.
[0048]
The control device 16 includes a microcomputer and peripheral circuits, and controls the rotation of the motor 6 of the ventilation device 1 by controlling the switch Sw1. When the motor 6 is rotating, the control device 16 turns on the switch Sw <b> 2 to discharge the ion generator 10. The control device 16 turns on and off the switches Sw1 and Sw2 according to a control signal from the control device 16, and supplies power to the motor 6 and the high-voltage pulse drive circuit 106 or stops power supply. The plasma discharge by the ion generator 10 may be continued for a predetermined time after the rotation of the motor 6 is stopped.
[0049]
The concentration of ions generated when an alternating high voltage was applied to the application electrode was measured. As an example, the applied AC voltage has a frequency of 20 kHz and an applied voltage of 6.6 kV (from 0 v to a positive or negative peak voltage). An air ion counter was used as the ion concentration measuring device, and small ions having a mobility of 1 cm / Vsec or more were detected at a position 25 cm from the discharge surface 10A of the ion generator 10. As a result, about 200,000 ions / cm positive ions and negative ions were measured simultaneously.
[0050]
FIGS. 3A and 3B are schematic perspective views of the ion generating element 101 in the ion generating apparatus 10. A rectangular opening is formed on the upper surface of the box-shaped main body 102, and a flat dielectric 103 is provided in the opening. The upper surface of the dielectric 103 coincides with the upper surface of the main body 102. A high voltage pulse drive circuit 106 is accommodated in the lower part of the main body 102. A plate-like internal electrode 104 and a net-like external electrode 105 are arranged opposite to each other on the upper and lower surfaces of the dielectric 103. The external electrode 105 is exposed to the outside from the upper surface of the main body 2. A high voltage pulse driving circuit 106 is connected to the internal electrode 104 and the external electrode 105 through a lead wire 107. When the high voltage pulse drive circuit 106 is driven, a high voltage pulse voltage composed of a positive voltage and a negative voltage is applied between the internal electrode 104 and the external electrode 105, and plasma discharge occurs. As a result, the air around the external electrode 105 is ionized, and approximately the same number of positive ions and negative ions are generated.
[0051]
By applying an alternating high voltage between the electrodes, oxygen or moisture in the air is ionized by receiving energy by ionization, and H ⁺ (H ₂ O) _m (m is an arbitrary natural number) and O ₂ ⁻ Ions mainly composed of (H ₂ O) _n (n is an arbitrary natural number) are generated, and these are released into the space by a fan or the like. These H ⁺ (H ₂ O) _m and O ₂ ⁻ (H ₂ O) _n adhere to the surface of floating bacteria and chemically react to generate H ₂ O ₂ or .OH as an active species. Since H ₂ O ₂ or .OH exhibits a very strong activity, they can surround and inactivate airborne bacteria in the air. Here, .OH is one kind of active species, and represents radical OH.
[0052]
Positive and negative ions react chemically on the cell surface of airborne bacteria as shown in formulas (1) to (3) to generate hydrogen peroxide (H ₂ O ₂ ) or hydroxyl radical (.OH) as active species. To do. Here, in Formula (1)-Formula (3), m, m ', n, and n' are arbitrary natural numbers. Thereby, floating bacteria are destroyed by the action of decomposing active species. Therefore, airborne bacteria in the air can be inactivated and removed efficiently.
[0053]
_{^{H + (H 2 O) m}} + O 2 - (H 2 O) n → · OH + 1 / 2O 2 + (m + n) H 2 O ··· (1)
H ⁺ (H ₂ O) _m + H ⁺ (H ₂ O) _{m ′} + O ₂ ⁻ (H ₂ O) _n + O ₂ ⁻ (H ₂ O) _{n ′}
→ 2 OH + O ₂ + (m + m ′ + n + n ′) H ₂ O (2)
H ⁺ (H ₂ O) _m + H ⁺ (H ₂ O) _{m ′} + O ₂ ⁻ (H ₂ O) _n + O ₂ ⁻ (H ₂ O) _{n ′}
→ H ₂ O ₂ + O ₂ + (m + m ′ + n + n ′) H ₂ O (3)
By the release of the positive and negative ions by the above mechanism, a bactericidal effect such as floating bacteria can be obtained. FIG. 8 and FIG. 9 schematically describe this.
[0054]
In addition, since the above formulas (1) to (3) can produce the same action even on the surface of harmful substances in the air, hydrogen peroxide (H ₂ O ₂ ) or hydroxyl radical (. OH) can oxidize or decompose harmful substances and convert chemical substances such as formaldehyde and ammonia into harmless substances such as carbon dioxide, water, and nitrogen, thereby making them virtually harmless. is there.
[0055]
Therefore, by driving the blower fan, positive ions and negative ions generated by the ion generating element 101 can be sent out of the main body. And by the action of these positive ions and negative ions, fungi and fungi in the air can be sterilized and their growth can be suppressed.
[0056]
Therefore, when the ventilator according to this embodiment is operated for a predetermined time while discharging the ion generators 10A to 10F, most of the airborne bacteria such as general live bacteria and fungi can be removed very well. In addition, since the ions released into the room fall and reach every corner of the indoor air distribution path, the floating bacteria can be sterilized efficiently.
[0057]
According to such a ventilator 1, since the ion generators 10 </ b> B and 10 </ b> C are provided on the upstream side of the outside air passage of the heat exchange element 3, the floating bacteria floating in the air entering the heat exchange element 3 are sterilized. Therefore, in the heat exchange element 3, it is possible to prevent bacteria from growing and mold even if condensation occurs due to heat exchange, and to sterilize floating bacteria in the air sent indoors.
[0058]
Since the ion generator 10D is also provided on the downstream side of the outside air passage AR1, the floating bacteria floating in the air that has passed through the heat exchange element 3 can be sterilized. Bacteria can be reduced and generation of molds such as ducts connected to the outside air introduction air passage AR1 can also be prevented.
[0059]
Further, as shown in FIG. 4, a duct 30 is connected to the duct joint 8 of the ventilator 1, and ion generators 10E and 10F are provided at bent portions of the duct 30 or indoor air supply ports so that sterilizable ventilation is possible. When the system is used, it is possible to prevent mold growth inside the duct 30 and sterilize a room for supplying outside air.
[0060]
In addition, before reaching the heat exchange element 3 in the outside air introduction air path AR1, an ion generator 10A is provided in the vicinity of the entrance of the sirocco fan 5 of the ventilator main body 1a or in the duct 7A on the upstream side of the duct joint 7. Is also assumed (see FIG. 4). In this case, the sirocco fan 5 of the ventilator main body 1a and the outside air introduction air path AR1 are sterilized, and generation of mold and the like can be prevented.
[0061]
Furthermore, since the ion generator 10C is provided further upstream of the filter 9 provided upstream of the heat exchange element 3, the filter 9 captures the dust / dust and attaches it to the filter 9 that captured the dust / dust. Since the growth of the floating bacteria in the part can be prevented, the generation of mold in the filter 9 can be prevented.
[0062]
The filter 9 is various such as a high-performance filter and a deodorizing filter that remove gaseous substances such as Nox (nitrogen oxide).
[0063]
The ion generators 10A to 10F have a function of generating ions when the sirocco fan 5 of the ventilator 1 is operating. Thereby, when the sirocco fan 5 of the ventilator 1 is operating, ions are generated, so that wasteful power consumption can be avoided.
[0064]
Further, the control device 14 has a function of generating ions from the ion generators 10A to 10F for a predetermined time after the sirocco fan 5 is stopped. In this way, by generating ions for a predetermined time after the sirocco fan 5 is stopped, the sterilization treatment of the air staying in the heat exchange element 3 and the filter 9 is performed.
[0065]
Moreover, since the ion generator 10F is provided in the indoor air supply port connected to the duct 30 and opened in the room, the sterilizing air can be supplied into the room and the air already existing in the room can be sterilized.
[0066]
In this embodiment, the ventilator 1 is described as an air conditioner. However, the present invention is not limited to this. The building of the present invention includes not only a detached house but also individual houses in an apartment house such as a condominium.
[0067]
【The invention's effect】
According to the first ventilator of the present application, since the air passing through the outside air introduction passage is sterilized, it is possible to prevent the growth of bacteria and the generation of mold in the outside air introduction passage and to be sent indoors. Airborne bacteria in the air can be sterilized.
[0068]
According to the 2nd ventilation apparatus, the external air (clean air) which sterilized mold, bacteria, etc. can be taken in the building and an apparatus, and clean air can be supplied indoors.
[0069]
According to the third ventilator, clean air can be supplied indoors by suppressing the growth of bacteria and the generation of mold contained in dust or the like attached to the filter.
[0070]
According to the fourth ventilator, if an ion generator is provided upstream of the outside air passage of the heat exchange means, the sterilization treatment of the air entering the heat exchange means is performed. Bacteria growth and mold growth can be prevented, and bacteria in the air sent indoors can be reduced.
[0071]
Further, if the heat exchange means is provided on the downstream side of the outside air passage, the air passing through the heat exchange means is sterilized, so that bacteria in the air sent to the room can be sterilized and the outside air introduction air Generation of mold such as ducts connected to the road can be prevented.
[0072]
Furthermore, if it is provided before and after the heat exchanging means, double sterilization treatment of the heat exchanging means and the air sent to the room is carried out, and generation of mold in the heat exchanging means and the duct can be prevented.
[0073]
If an ion generator is installed near the entrance of the blower before reaching the heat exchange means in the outside air introduction air passage, sterilization processing of the blower and the outside air introduction air passage is performed and generation of mold and the like Can be prevented.
[0074]
According to the fifth ventilator, since the ion generating device is provided further upstream of the filter provided upstream of the heat exchanging means, the filter that has captured the dust and dust together with the dust is collected by the filter. It can be carried out.
[0075]
According to the sixth ventilator, since ions are generated when the blower of the ventilator is operating, wasteful power consumption can be avoided.
[0076]
According to the seventh ventilator, the sterilization treatment of the air staying in the heat exchange means and the filter is performed by generating ions for a predetermined time after the blower is stopped.
[0077]
According to the 8th ventilation system, since the ion generator is provided in the bending part of the duct, the inside of a duct can be sterilized and generation | occurrence | production of mold | fungi can be prevented.
[0078]
According to the ninth ventilator, not only the air supplied into the room can be sterilized but also the air existing in the room can be sterilized.
[0079]
According to the tenth ventilator, since such positive ions and negative ions are generated, sterilization of airborne bacteria can be performed.
[0080]
According to the eleventh building, the amount of air to be sterilized in the air sterilized in the ventilation device and the duct and the air sent to the room is increased, and the sterilizing effect is improved.
[Brief description of the drawings]
FIG. 1A is a cross-sectional view showing a configuration of a fully concealed ventilation device according to an embodiment of the present invention, and FIG. 1B is a partial cross-sectional view of a semi-concealed ventilation device.
FIG. 2 is a bottom view of a semi-hiding type ventilation device.
3A is a schematic perspective view of an ion generating element, and FIG. 3B is a schematic cross-sectional configuration diagram of the ion generating element.
4A is a diagram in which an ion generator is provided in an outside air supply duct connected to the ventilator in FIG. 1, and FIG. 4B is an explanation in which an ion generator is provided in an indoor air inlet of the air supply duct. FIG. 4C is an explanatory diagram in which the positions of the air supply port and the undercut portion are provided on a diagonal line in the planar arrangement of the room.
FIG. 5 is a composition diagram of positive ions and negative ions generated by plasma discharge.
FIG. 6 is a composition diagram of positive ions and negative ions generated by plasma discharge.
FIG. 7 is a schematic diagram showing a configuration of a conventional ventilation device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ventilator 1a Ventilator main body 2 Main body case 3 Heat exchange element 9, 14 Filter 10, 10B, 10C, 10D, 10E, 10F Ion generator 16 Control apparatus 101 Ion generator 102 Main body 103 Dielectric 104 Internal electrode 105 External electrode 106 High-pressure pulse drive circuit AR1 Outside air introduction air path AR2 Ventilation air path Sw1 Switch Sw2 Switch

Claims (2)

The outside air introduction air passage for taking air outside the building into the room, the exhaust air passage for exhausting the indoor air to the outside of the building, and the indoor air from the exhaust opening of the exhaust air passage A first blower that exhausts to the outside of the building, a second blower that introduces outside air from the outside air introduction air passage and supplies the air into the room, and an intersection where the outside air introduction air passage and the exhaust air passage intersect each other. A heat exchanging element, and the heat exchanging element includes an outside air passage through which air outside the building passes and an exhaust passage through which room air passes, the outside air passage and the exhaust passage. In a ventilator that exchanges heat between each passing air,
A ventilator comprising an ion generator for generating positive ions and negative ions upstream of the heat exchange element and downstream of the second blower in the outside air introduction air passage.   The ventilator according to claim 1, wherein a filter for removing dust / dust is provided upstream of the outside air passage of the heat exchange element, and the ion generator is provided upstream of the filter. Ventilation equipment to do.

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