Patent Publication Number: US-2021187151-A1

Title: Air germicidal device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a continuation of U.S. application Ser. No. 15/813,506, filed Nov. 15, 2017, which claims priority to provisional U.S. Application Ser. No. 62/422,803 filed Nov. 16, 2016, to which Applicant claims the benefit of the earlier filing date. These applications are incorporated herein by reference and made a part hereof. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an air germicidal device and, more particularly, a germicidal device having a removable irradiation chamber adapted and shaped to define a generally trapezoidally shaped irradiation chamber area as well as an air pre-chamber area with positive pressure and an air post-chamber area having a negative pressure. 
     2. Description of the Related Art 
     Multiple methods have been proposed to inactivate or remove potentially pathogenic organisms from indoor air. Airborne bacteria, viruses and fungi are the cause of tremendous global disease, human suffering and economic loss. The issue of airborne pathogens is growing worse with increasing population density in urban areas, the emergence of drug-resistant pathogens, and an increasing elderly population with vulnerability to airborne infection. 
     Methods to disinfect air include mechanical filtration, irradiation, and chemical application. Each method has its benefits and drawbacks. Mechanical filtration is limited to organisms of a certain size, and the filtration of tiny viruses is impractical. Chemical application is effective, but airborne sprays of disinfecting chemicals present health and environmental challenges which often outweigh potential benefit. Air irradiation holds the greatest potential for efficient broad-spectrum disinfection of large air volumes, while maintaining environmental safety. 
     Air irradiation presents significant challenges. In order for an air disinfection device to be practical, it needs to disinfect large volumes of air travelling at high velocity. Biocidal rates are directly proportional to radiation output and exposure time. Radiation output is limited by practical power limitations for residential devices. In general, the required radiation power is squared as air velocity is doubled, quickly requiring impractical radiation outputs. Exposure time is related to the velocity and linearity of the treated airstream. U.S. Pat. No. 9,457,119, a device is shown for increasing biocidal efficiency of an air-irradiation device by transiently lowering air velocity and linearity. This was achieved by running the airstream though an irradiation chamber filled with a multitude of randomly-oriented radiation and air permeable cylinders. 
     What is needed, therefore, is a system, device and method that improves over the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention improves upon U.S. Pat. No. 9,457,119 in several important ways. In order for the irradiation chamber to be utilized in a practical commercial product, additional development was performed. In order to maintain even airflow through the irradiation chamber, two fans were utilized, one each on the air inlet and exhaust. A single inlet fan creates a relative high pressure zone on the inlet side, resulting in an undesirable concentration of microbes in this location. Additionally, due to concerns about radiation leakage, a shielded pre-chamber and post-chamber were incorporated. In order to ensure adequate air dispersal in the irradiation chamber, a central spar was placed in the chamber, forcing the air to travel in a U-shaped pattern through the chamber, maximizing exposure to the cylinders. Finally, due to the desire for odor control in such a system, a layer of photocatalytic material is placed on the internal surfaces of the chamber to allow for radiation-induced oxidation of long-chain carbon compounds. 
     The features of the embodiments described herein may be used alone or in combination with the features of the embodiments shown and described in U.S. Pat. Nos. 9,433,693; 9,457,119; 9,764,054 and U.S. Patent Publication Nos. 2016/0263267 and 2017/0296691, all of which are incorporated herein by reference and made a part hereof. 
     A primary object of the invention is to provide an air germicidal device that is adapted to improve over the devices in the prior art. 
     Another object of the invention is to provide an air germicidal system and device having substantially even airflow through the device. 
     Another object of the invention is to provide an air germicidal device having an air pre-chamber area that is pressurized and an air post-chamber area that is under negative pressure. 
     Still object of the invention is to provide a removable irradiation chamber that is generally trapezoidal in shape and is situated between the air pre-chamber area and the air post-chamber area. 
     Yet another object of the invention is to provide an air treatment device and system that comprises means for reducing velocity of the air flowing through the device or system and increases irradiation time and efficiency of the air passing through the system or device. 
     Another object of the invention is to provide an air treatment device and system that is adapted and configured to provide a substantially even or constant airflow through an irradiation chamber of the device or system. 
     Yet another object of the invention is to provide an air treatment device that is portable and easily situated in a room where it is desired to treat or disinfect the air in the room. 
     In one aspect, one embodiment of the invention comprises an irradiation chamber for use in a germicidal device comprising a chamber housing defining a primary chamber; at least one spar or deflector situated in said chamber housing for increasing a length of an air pathway through the irradiation chamber. 
     In another aspect, one embodiment of the invention comprises a germicidal device comprising a device housing; a removable irradiation chamber; means for reducing velocity and linearity of air flowing through said removable irradiation chamber; at least one airflow generator for creating an airstream through said germicidal device; and a germicidal irradiation source for inactivating airborne microbes and unwanted bacteria in said airstream. 
     In still another aspect, one embodiment of the invention comprises a germicidal treatment system comprising a housing; an irradiation source; an irradiation chamber that is sized and adapted to be removable mounted in said housing, said irradiation chamber cooperating with said housing to define an air pre-chamber and an air post-chamber, said irradiation chamber having an inlet opening, an outlet opening and an irradiation opening that becomes operatively associated with said irradiation source in order to receive radiation from said irradiation source; a first airflow generator mounted on said housing and adapted to generate a positive pressure in said air pre-chamber and for introducing airflow from said air pre-chamber to said inlet opening; and a second airflow generator mounted on said housing and adapted to generate a negative pressure in said air post-chamber and for permitting said airflow to exit said outlet opening and into said air post-chamber. 
     In yet another aspect, one embodiment of the invention comprises a germicidal device which utilizes a germicidal irradiation source for the inactivation of airborne microbes; a removable irradiation chamber with means for reducing velocity and linearity of irradiated air; an air pre-chamber adapted to prevent radiation leakage from said chamber; an air post-chamber adapted to prevent radiation leakage from said chamber; an intake fan creating a relative high air pressure in said air pre-chamber; and an exhaust fan creating a relative vacuum in said air post-chamber. 
     In still another aspect, one embodiment of the invention comprises an air irradiation chamber utilizing a shape to allow for air ingress and egress with minimal air resistance; a central spar for increasing the length air pathway through said air irradiation chamber; and a means for reducing air velocity and linearity. 
     This invention, including all embodiments shown and described herein, could be used alone or together and/or in combination with one or more of the features covered by one or more of the following list of features:
         The irradiation chamber wherein the chamber housing comprises a first wall and a generally opposing second wall, each of which are generally trapezoidal in shape and a first end wall and a second end wall coupling the ends of the first and second walls and being generally inclined relative to each other; the at least one spar or deflector being situated in the chamber housing to define a first chamber and a second chamber so that airflow is directed in a generally U-shaped path, the airflow passing into and through the first chamber in a first direction, around an edge of the at least one spar or deflector, and then into the second chamber where the airflow passes through the second chamber in a second direction that is generally opposite the first direction.   The irradiation chamber wherein the irradiation chamber comprises a reducer for reducing air velocity and linearity of the airflow as it passes through the irradiation chamber.   The irradiation chamber wherein the reducer comprises a plurality of multitude of discrete, randomly oriented and radiation-transmitting objects situated in at least one of the first chamber or the second chamber.   The germicidal device wherein the irradiation chamber is configured to define an air pre-chamber area adapted to facilitate preventing radiation leakage from the chamber and an air post-chamber area adapted to prevent radiation leakage from the chamber after the removable irradiation chamber is removable mounted in the device housing.   The germicidal device wherein the air pre-chamber and the air post-chamber are generally triangular.   The germicidal device wherein the air at least one airflow generator comprises a first airflow generator mounted in proximity to a first end of the device housing for creating a positive air pressure in the air pre-chamber and a second airflow generator mounted in proximity to a second end of the device housing for creating a negative pressure in the post-chamber area.   The germicidal device wherein the germicidal irradiation source is ultraviolet radiation.   The germicidal device wherein the means for reducing velocity and linearity comprises at least one spar or deflector being situated in a chamber housing to define a first chamber and a second chamber so that airflow is directed in a generally U-shaped path, the airflow passing into and through the first chamber in a first direction, around an edge of the at least one spar or deflector, and then into the second chamber where the airflow passes through the second chamber in a second direction that is generally opposite the first direction.   The germicidal device wherein the irradiation chamber comprises a reducer for reducing air velocity and linearity of the airflow as it passes through the irradiation chamber.   The germicidal device wherein the reducer comprises a plurality of multitude of discrete, randomly oriented and radiation-transmitting objects situated in at least one of the first chamber or the second chamber.   The germicidal device wherein the device housing comprises a first wall and a generally opposing second wall, each of which are generally trapezoidal in shape, a first end wall and a second end wall coupling the ends of the first and second walls to define an irradiation chamber, the generally opposing first and second walls being generally inclined relative to each other.   The germicidal device wherein the irradiation chamber comprises at least one spar or divider that divides the irradiation chamber to provide a first chamber area, a second chamber area and a joining area for joining the first and second chamber areas, the first and second chamber areas and the joining area cooperating to define a generally U-shaped or V-shaped airflow passageway.   The germicidal device wherein the irradiation chamber comprises at least one spar or divider that divides the irradiation chamber to provide a first chamber area for receiving airflow from the at least one airflow generator, a second chamber area and a joining area for joining the first and second chamber areas, the first and second chamber areas and the joining area cooperating to define a generally U-shaped or V-shaped airflow passageway.   The irradiation chamber wherein the joining area is operatively related and generally opposed to the germicidal irradiation source.   The irradiation chamber wherein the irradiation chamber is a one-piece construction and removable mounted in the germicidal device.   The germicidal treatment system wherein the air pre-chamber and the air post-chamber are generally triangular.   The germicidal treatment system wherein the first airflow generator is mounted in proximity to a first end of the housing for creating the positive air pressure in the air pre-chamber and the second airflow generator is mounted in proximity to a second end of the housing for creating the negative pressure in the air post-chamber.   The germicidal treatment system wherein the irradiation source is ultraviolet radiation.   The germicidal treatment system wherein the irradiation chamber comprises and irradiation chamber housing, the germicidal treatment system comprises at least one spar or divider situated in the chamber housing to define a first chamber and a second chamber so that airflow is directed in a generally U-shaped or V-shaped airflow passageway, the airflow passing into and through the first chamber in a first direction, around an edge of the at least one spar or deflector, and then into the second chamber where the airflow passes through the second chamber in a second direction that is not co-linear with the first direction.   The germicidal treatment system wherein the irradiation chamber comprises a reducer for reducing air velocity and linearity of the airflow as it passes through the irradiation chamber.   The germicidal treatment system wherein the reducer comprises a plurality of multitude of discrete, randomly oriented and radiation-transmitting objects situated in at least one of the first chamber or the second chamber.   The germicidal treatment system wherein the irradiation chamber housing comprises a first wall and a generally opposing second wall, each of which are generally trapezoidal in shape, a first end wall and a second end wall coupling the ends of the first and second walls to define an irradiation chamber, the generally opposing first and second walls being generally inclined relative to each other.   The germicidal treatment system wherein the at least one spar or divider divides the irradiation chamber to provide a first chamber area for receiving airflow from at least one airflow generator, a second chamber area and a joining area for joining the first and second chamber areas, the first and second chamber areas and the joining area cooperating to define the generally U-shaped or V-shaped airflow passageway.   The germicidal treatment system wherein the joining area is operatively related and generally opposed to the irradiation source.   The germicidal treatment system wherein the irradiation chamber is a one-piece construction and removable mounted in the germicidal treatment system.   The germicidal device wherein the air pre-chamber is substantially triangular.   The germicidal device wherein the air post-chamber is substantially triangular.   The germicidal device wherein the germicidal irradiation source is ultraviolet radiation.   The air irradiation chamber wherein the shape is substantially trapezoidal.   The air irradiation chamber wherein the means for reducing air velocity and linearity is a multitude of discrete, randomly oriented, radiation-transmitting objects.       

     These and other objects and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS 
         FIG. 1  is a perspective view of an assembled view of the air germicidal device and system in accordance with one embodiment; 
         FIG. 2  is an exploded view of the device shown in  FIG. 1  with a generally U-shaped cover removed; 
         FIG. 3  shows various details of the components in the device shown in  FIG. 1 ; 
         FIG. 4  is a bottom view, with cover removed, of the device shown in  FIG. 1 ; 
         FIG. 5  is a plan view, with cover removed, of the device shown in  FIG. 1 ; 
         FIG. 6  is a right side view of the embodiment shown in  FIG. 1 ; 
         FIGS. 7-9  are exploded views showing various features of the embodiment shown in  FIG. 1 ; 
         FIG. 10  is a view of the embodiment shown in  FIG. 1  with the removable irradiation chamber removed from the device; 
         FIG. 11  is another view of the device shown in  FIG. 1  with the cover housing removed and the irradiation chamber removed from the device showing a seal on a top surface of a frame of the device; 
         FIG. 12  is a view with the irradiation chamber situated in the device showing an airstream as it flows through the air pre-chamber area, into the irradiation chamber and through the air post-chamber area; 
         FIG. 13  is a view showing details of the removable irradiation chamber; and 
         FIG. 14  is a view of the removable irradiation chamber showing a multitude or a plurality of randomly-oriented radiation and air permeable cylinders or tubular members. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIG. 1 , a germicidal treatment device or system  10  is shown fully assembled. In the embodiments being described herein, the germicidal treatment device or system  10  is adapted to inactivate or remove potentially pathogenic organisms from indoor air. These organisms may include, but are not limited to, airborne bacteria, viruses and fungi. In general, the germicidal treatment device or system  10  is placed in an indoor area or room (not shown) in order to treat the air in the area or room. 
     The germicidal treatment device or system  10  has a housing or frame  12 , as illustrated in  FIGS. 2-9 , for supporting various components therein. A generally U-shaped housing cover  14  ( FIG. 2 ) is mounted on the housing or frame  12  with conventional fasteners, such as screws (not shown), in order to protect the components therein.  FIG. 3  and many of the other figures show various perspective and other views of the germicidal treatment device or system  10  with the housing or frame  12  removed. For example,  FIG. 4  is a bottom view,  FIG. 5  is a plan view and  FIG. 6  is a right side view of the germicidal treatment device or system  10 . The various components of the germicidal treatment device or system  10  will now be described relative to  FIGS. 1-14 . For ease of illustration and description, the description will proceed from the perspective view shown in  FIG. 7 . The housing or frame  12  comprises a first frame wall  16  having a first interior edge  16   a  and a second frame wall  18  that has an interior edge  18   a . The interior edges  16   a  and  18   a  define apertures  20  and  22 , respectively, each adapted and sized to receive at least one airflow generator  24 . 
     Thus, the germicidal treatment device or system  10  comprises at least one or a plurality of airflow generators  24  that are mounted in the apertures  20  and  22  on the housing or frame  12 . In the illustration being described, the at least one or plurality of airflow generators  24  comprises a first airflow generator  26  and a second airflow generator  28  that are adapted and sized to be received in the apertures  20  and  22 , respectively. In the illustration being described, the first airflow generator  26  is mounted to the housing or frame  12  and is adapted to generate a positive pressure in an air pre-chamber area  30  ( FIG. 12 ). Likewise, the second airflow generator  28  is mounted on the housing or frame  12  and is adapted to generate a negative pressure in an air post-chamber area  32 . The operation and flow of the airflow flowing through the germicidal treatment device or system  10  will be described later herein. 
     The housing or frame  12  comprises a wall  12   d  having an interior wall  41  ( FIG. 8 ) that defines an irradiating aperture  34 . As best illustrated in  FIGS. 3, 4, 7 and 10 , note that the germicidal treatment device or system  10  comprises an irradiation source  36  for inactivating airborne microbes and unwanted bacteria, viruses, fungi and the like from the airstream AS flowing past the aperture  34  and through the germicidal treatment device or system  10 . In the illustration being described, the irradiation source  36  comprises at least one or a plurality of ultraviolet light sources  38  and  40  ( FIG. 7 ) that have associated ballasts  38   a  and  40   a  that operate in a conventional manner. Any end caps or connectors between the first and second ultraviolet light sources  38  and  40  and a power supply  42  are not shown for ease of illustration. 
     The germicidal treatment device or system  10  comprises the power supply  42  and a controller  44  which are activated by a toggle switch  46 . The controller  44  controls the operation of the germicidal treatment device or system  10 . When the toggle switch  46  is actuated, the first and second airflow regulators  26  and  28  and the first and second ultraviolet light sources  38  and  40  are activated, thereby causing ultraviolet light to irradiate into and through the aperture  34  in order to disinfect the airstream AS flowing through the germicidal treatment device or system  10 . This operation will be described later herein. 
     In the illustration being described, the housing or frame  12  is a stamped housing having a second interior wall  48  that generally opposes the surface or wall  41  and that defines a first aperture  48   a  and a second aperture  50   a , each aperture  48   a  and  50   a  have an associated integral wall  48   b  and  50   b , respectively that are generally perpendicular to the surface or wall  41 . The housing or frame  12  further comprises a first plurality of apertures  52  and a second plurality of apertures  54 , both of which define grates. In the illustration being described and as will be described later herein, the first plurality of apertures  52  permit air to flow from the air pre-chamber area  30  ( FIG. 12 ) into a removable irradiation chamber  58 . 
     In the illustration being described, the removable irradiation chamber  58  is sized and adapted to be removably mounted in the housing or frame  12 . The removable irradiation chamber  58  comprises a wall  70  that cooperates with the housing or frame  12  and first airflow generator  26  to define the air pre-chamber area  30  and a wall  72  that cooperates with the frame  12  and second airflow generator  28  to define the air post-chamber area  32 . Note that the removable irradiation chamber  58  comprises a housing  60  having a plurality of grates or apertures  62  in a wall or surface  64 . The removable irradiation chamber  58  comprises a first side wall  66  and a generally opposing second side wall  68  as shown. The removable irradiation chamber  58  further comprises the first end wall  70  and the generally opposing second end wall  72 . Note that the end walls  70  and  72  are coupled to the ends of the side walls  66  and  68  and are generally inclined relative to each other and relative to a central plane CP (shown in phantom in  FIG. 8 ) of the removable irradiation chamber  58 . The end walls  70  and  72  couple the ends of the side walls  66  and  68  to define an irradiation chamber area  74 . 
     After the removable irradiation chamber  58  is removably received in the housing or frame  12 , the grate or aperture  62  becomes operatively positioned relative to the aperture  34  and the irradiation source  36 , namely the first and second ultraviolet light sources  38  and  40 , so that ultraviolet irradiating light can pass through the aperture  34  and into the irradiation chamber  58  as will be described in more detail later herein. 
     The irradiation chamber  58  comprises means for reducing velocity and increasing the time the airstream AS is exposed to radiation. In this regard, the irradiation chamber  58  comprises at least one spar, divider or deflector  75  that divides the chamber area  74  into a first chamber area  78  and a second chamber area  80  as best illustrated in  FIG. 13 . In the illustration being described, the irradiation chamber  58  is moved in the direction of arrow A in  FIG. 8 , whereupon the grates or apertures  52  and  54  of the housing or frame  12  become operatively associated with the irradiation chamber areas  78  and  80 , respectively. Note also that the grate or aperture  62  on surface  64  becomes operatively associated with the opening or aperture  34  in the housing or frame  12 . 
     After the first and second airflow generators  26  and  28  are conventionally mounted on the housing or frame  12  and secured thereto, the removable irradiation chamber  58  is removably mounted in the housing or frame  12 . Thereafter, the cover  14  is mounted on the housing or frame  12  using conventional fasteners, such as screws. 
       FIG. 12  illustrates an airflow pattern and further features which will now be described. Note that after the irradiation chamber  58  is removably mounted in the housing or frame  12 , the aperture  48   a  in a surface or wall  12   a  pf the housing or frame  12  becomes operatively associated with the wall  70  ( FIG. 12 ) and wall  48   b  and defines an inlet passageway  82 . Likewise, the wall  72  of the removable irradiation chamber  58  becomes operatively associated with the wall  50   b  and wall  72  and defines an exit passageway  84  into the air post-chamber area  32 . When the first and second airflow generators  26  and  28  are energized by controller  44  and power supply  42  by actuation of the switch  46 , the first airflow generator  26  generates a positive airflow pressure in the irradiation air pre-chamber area  30 . The second airflow generator  28  also generates an airflow and a negative airflow pressure in the air post-chamber area  32 . The first and second airflow generators  26  and  28  are axial fans in the illustration being described. 
     Note that an inner surface  14   a  ( FIG. 2 ) of the cover  14  engages a foam gasket or seal  86  ( FIGS. 2 and 9 ) which is mounted on the surface or wall  12   a  of the housing or frame  12 . 
     When the first and second airflow generators  26  and  28  are energized, the air is pressurized and in the air pre-chamber area  30  and flows into and through the inlet passageway  82  and through the first aperture  48   a  into an airflow channel area or passageway  88  that is in communication with the plurality of grates or apertures  52 . The air flows through the plurality of apertures  52  and into the first irradiation chamber area  78  and the air is forced past an end  75   a  ( FIG. 12 ) of the spar, divider or deflector  75  wherein it then passes into and through the second air chamber area  80 . The air flows through the plurality of grates or apertures  54  and into a second airflow channel or passageway  90  wherein it enters the second aperture  50   a  and into the air post-chamber area  32  whereupon it exits through the second airflow generator  28  to atmosphere. Note that the entire time that the air flows through the irradiation chamber  58 , it is exposed to the ultraviolet radiation provided by the irradiation source  36 , in this case the first and second fluorescent light sources  38  and  40 . In the illustration being described, the spar, divider or deflector  75  causes the airflow to flow in a generally U-shape or V-shape path as illustrated in  FIG. 12 . 
     Advantageously, the design and shape of the irradiation chamber  58  facilitates reducing the air velocity of the air flowing through the germicidal treatment device or system  10  as well as reducing or changing the linearity of the airflow as it passes through the irradiation chamber  58 . This in turn causes the airstream AS or airflow to be subjected to irradiation for a longer period of time compared to if the air flowed through the germicidal treatment device or system  10  linearly. This further has the benefit of increasing the effectiveness of the irradiation to kill unwanted pathogens or bacteria. 
     In order to further facilitate the effectiveness of the germicidal treatment device or system  10 , the germicidal treatment device or system  10  may comprise one or more reducers for further reducing or disturbing the air velocity and linearity of the airflow as it passes through the irradiation chamber  58 . In this regard, the at least one reducer may comprise a plurality or multitude of discrete, randomly oriented and radiation-transmitting objects or tubular members  92  ( FIG. 14 ), like those used in U.S. Pat. Nos. 9,433,693; 9,457,119; 9,764,054 and U.S. Patent Publication Nos. 2016/0263267 and 2017/0296691, situated in at least one or both of the first irradiation chamber area  78  or second irradiation chamber  80 . Note in  FIG. 14  that the portion of the objects or tubular members  92  is random in  FIG. 14 , but they could be ordered if desired, which is shown in  FIG. 12 . The 
     Additional Considerations 
     Advantageously, the first and second axial fans or airflow generators  26  and  28  maintain an even airflow through the irradiation chamber  58 . In contrast, the prior art oftentimes utilized a single inlet fan that created a relatively high pressure zone on an inlet side (not shown) of the device that resulted in an undesirable concentration of microbes in that location. 
     The removable irradiation chamber  58  becomes sealed in the housing or frame  12  which reduces or eliminates concerns about radiation leakage. removable irradiation chamber  58  comprises a first edge  58   a  which is generally rectangular and which engages the aperture  48   a  and engages or becomes sealed against the surface  12   b  ( FIGS. 2 and 8 ) after the removable irradiation chamber  58  is mounted in the housing or frame  12 . Likewise, the surface  58   b  engages and becomes sealed against the surface  12   c  ( FIG. 8 ) of the housing or frame  12 . It is important to note that the air pre-chamber area  30  and air post-chamber area  32  are shielded and sealed from the irradiation chamber  58 . Note in the illustration being described and shown in  FIG. 12 , the air pre-chamber area  30  and air post-chamber area  32  are generally triangular as viewed from the side in  FIG. 12  and, again, shielded from the radiation generated by the irradiation source  38 . 
     Note as illustrated in  FIG. 12 , that the spar, divider or deflector  75  has a length L 1  that is shorter than an overall length L 2  of the irradiation chamber  58 . This forces the air flowing into and through the irradiation chamber  58  to travel in a serpentine or the generally U-shaped or V-shaped pattern. This maximizes the exposure of the airstream AS to the irradiation source  38 . 
     There may be a desire for odor control in the germicidal treatment device or system  10 , in which case a layer of photocatalytic material  85  ( FIG. 13 ) may be placed on one or more of the interior surfaces of the irradiation chamber  58 . The photocatalytic material  85  allows for radiation-induced oxidation of long-chain carbon compounds in a manner conventionally known. 
     It should be appreciated and as illustrated in the airflow diagram of  FIG. 12 , that the airflow path caused by the irradiation chamber  58  and the spar, divider or deflector  75  maximizes radiation exposure time and prevents leakage of ultraviolet energy through the intake and exhaust of the germicidal treatment device or system  10 . 
       FIG. 5  illustrates a plan view of the germicidal treatment device or system  10  with the cover  14  removed showing the vents and various apertures  48   a ,  50   a ,  52  and  54  that allow air to enter and exit the irradiation chamber  58 .  FIG. 3  illustrates the irradiation chamber  58  positioned in the housing or frame  12  and showing the first and second irradiation light sources  38  and  40 . Once the irradiation chamber  58  is positioned in the housing or frame  12  as shown, the cover  14  ( FIG. 2 ) may be mounted on the housing or frame  12 .  FIG. 4  is a bottom view demonstrating the plurality of second irradiation light sources in operative relationship with the aperture  34  and the grate or aperture  62  of the removable irradiation chamber  58 . 
     In order for an air disinfection device to be practical, it needs to disinfect large volumes of air travelling at high velocity. Biocidal rates are directly proportional to radiation output and exposure time. Radiation output is limited by practical power limitations for residential devices. In general, the required radiation power is squared as air velocity is doubled, quickly requiring impractical radiation outputs. Exposure time is related to the velocity and linearity of the treated airstream. U.S. Pat. No. 9,457,119, which is assigned to the same Assignee as the present application, describes a device for increasing biocidal efficiency of an air-irradiation device by transiently lowering air velocity and linearity. This was achieved by running the airstream though an irradiation chamber filled with a multitude of randomly-oriented radiation and air permeable cylinders. These may be used in the embodiments described herein. The circular and rotatably-oriented tubular members  92  in  FIGS. 12 and 14  illustrate this feature. Moreover, other features of the system or devices shown in U.S. Pat. Nos. 9,433,693; 9,457,119; 9,764,054 and U.S. Patent Publication Nos. 2016/0263267 and 2017/0296691, may be used in combination with features of the embodiments described herein, and those references are incorporated herein by reference and made a part hereof. 
     This invention, including all embodiments shown and described herein, could be used alone or together and/or in combination with one or more of the features covered by one or more of the claims set forth herein, including but not limited to one or more of the features or steps mentioned in the Summary of the Invention and the claims. 
     While the system, apparatus and method herein described constitute preferred embodiments of this invention, it is to be understood that the invention is not limited to this precise system, apparatus and method, and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.