Abstract:
The present invention relates to an add on filter and air filtration system and method incorporating an add on filter for applying ultraviolet light to an environment to create oxidizing agents for killing microbes, such as bacteria, mold, and viruses, and for destroying odors. The add on filter may be coupled to existing air filtration systems to provide further filtration of the air. The add on filter includes an ultraviolet light source for emitting a broad spectrum of ultraviolet light and a catalytic target structure mechanically coupled to the ultraviolet light source. The system and method result in the production of Hydroxyl Radicals, Super Oxide ions and Hydro Peroxide for killing microbes.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates generally to the field of air filtration and, more particularly, to an add on filter and air filtration system and method incorporating an add on filter for applying ultraviolet light to an environment to create oxidizing agents for killing microbes, such as bacteria, mold, and viruses, and for destroying odors. 
       BACKGROUND 
       [0002]    Traditional air filtration systems include filters designed to trap particulates. Particulates are tiny particles suspended in the air. Common particulates include residential pollen, dust mites, dust, smoke and dander (skin flakes). However, there are other types of indoor pollutants, such as microbials and gases. Microbials are bacteria, germs, viruses, fungi, spores and mold. Although bacteria are small in size and usually microscopic, they have an amazing ability to do damage to all living organisms including humans. Many everyday illnesses are also caused by viruses like the common cold or the flu. Mold can be a dangerous allergen, cause infections, and destroy property requiring extensive repair and rebuilding. Traditional air filtration systems are not effective at treating many such microbials and gases. 
         [0003]    Indoor odors, caused by things like pets, cooking, garbage, etc., exist in every home and office. Gases, such as benzene, formaldehyde, chloroform, hydrogen sulfide, ammonia, etc., are released from furniture, cabinets, carpets, cleaning chemicals, insulation, insect sprays, hair sprays, etc. Manufactures use chemicals to make these products and they come off as gas into the air in homes and offices. Traditional air filtration systems are not effective at treating such gases. 
         [0004]    Microbials cannot be trapped by the filters in traditional air filtration systems. Microbials must be killed in order to cleanse the air supply. Hydroperoxides are very effective at destroying harmful microbials in the air and on surfaces through a process called cell lysing or by changing its molecular structure. Hydroperoxides are also effective at rendering gases harmless by changing its molecular structure. 
         [0005]    Therefore, a need exists to further treat air that has been treated by traditional air filtration systems to neutralize the various deleterious effects caused by such microbials and gases. The present invention addresses the shortcomings of traditional air filtration systems and methods. 
       SUMMARY 
       [0006]    Particular embodiments of the present invention are directed to an add on filter and an air filtration system and method incorporating such an add on filter for applying ultraviolet light to an environment to create oxidizing agents for killing microbes, such as bacteria, mold, and viruses, and for destroying odors. 
         [0007]    According to particular embodiments of the present invention, an add on filter comprises a first cartridge including an ultraviolet light source for emitting a broad spectrum of ultraviolet light and a catalytic target structure mechanically coupled to the ultraviolet light source. The add on filter may include a box frame configured to be coupled with an intake side of an air handler and may be further configured to house the first cartridge. 
         [0008]    In some embodiments, the add on filter also includes a second cartridge. The second cartridge can include a pleated filter, charcoal, sulfur coated carbon or potassium permanganate coated carbon. 
         [0009]    In some embodiments, the add on filter further includes a plurality of faces and at least one of the plurality of faces is adjustable between an open and closed position. In some embodiments, the first cartridge is capable of being removed from or placed into the box frame when the adjustable face is in an open position. In some embodiments, the add on filter includes a second cartridge, and the first cartridge and the second cartridge are capable of being removed from or placed into the box frame when the adjustable face is in an open position. 
         [0010]    In some embodiments, the catalytic target structure of the add on filter includes a plurality of fin elements. 
         [0011]    In some embodiments, the add on filter also includes a ballast configured to provide power to the ultraviolet light source. The ballast can include a power connector configured to receive power from an external source and at least one of the plurality of faces of the box frame includes an opening configured to expose the power connector. 
         [0012]    In some embodiments, the box frame is configured to mate with an evaporator unit. 
         [0013]    According to particular embodiments of the present invention, the box frame includes two rails positioned on opposite sides of the box. The first end of each of the rails is pivotably coupled to an interior side of a face of the box frame and each of the rails is configured to support the first cartridge. The box frame can include a latch adjustable between a locked position, in which the first cartridge and rails are held in place, and an open position in which the rails are pivotable. 
         [0014]    In some embodiments, the box frame is comprised of insulative material. 
         [0015]    According to particular embodiments of the present invention, a filter system includes an evaporator including an input end and an output end and an add on filter including an input end and an output end. The add on filter includes a box frame and a first cartridge including an ultraviolet light source for emitting a broad spectrum of ultraviolet light and a catalytic target structure mechanically coupled to the ultraviolet light source. The output end of the add on filter is coupled to the input end of the evaporator. The filter system also includes an air supply including an output end. The output end of the air supply is coupled to the input end of the add on filter. 
         [0016]    In some embodiments, the air supply includes a structure carrying air returned from a building. 
         [0017]    In another aspect, certain embodiments of the present invention are directed to a method for installing an add on filter in a filter system comprising the steps of coupling an output end of the add on filter described above to an Input end of an evaporator. 
         [0018]    The method further includes the steps of coupling an input end of the add on filter to an output end of a return air supply structure and coupling an output end of the evaporator to an air supply structure. 
         [0019]    In some embodiments, the method further includes the step of removing a portion of the air supply structure equivalent to a height of the add on filter prior to coupling the output end of the evaporator to the air supply structure. 
         [0020]    In another aspect, certain embodiments of the present invention are directed to a method of filtering air comprising the steps of supplying air to an intake structure coupled to the add on filter and providing air to the add on filter. The method further includes the steps of producing an advanced oxidation product with an ultraviolet light and treating the air by killing microbes with the advanced oxidation product. The method also includes the steps of providing the treated air from the add on filter to an evaporator for further treatment and providing the treated air to an air supply. 
         [0021]    In some embodiments, the method further includes the step of providing air to a second filter disposed in the add on filter for further filtering. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The accompanying drawings, which are incorporated herein and form part of the specification, illustrate various embodiments of the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable a person skilled in the pertinent art to make and use the embodiments disclosed herein. 
           [0023]    In the drawings, like reference numbers indicate identical or functionally similar elements. 
           [0024]      FIG. 1  is a perspective view of an add on filter in accordance with exemplary embodiments of the present invention. 
           [0025]      FIG. 2  is a perspective view of an exploded add on filter in accordance with exemplary embodiments of the present invention. 
           [0026]      FIG. 3  is a perspective view of an exploded add on filter in accordance with exemplary embodiments of the present invention. 
           [0027]      FIGS. 4(   a )-( c ) illustrate an assembled add on filter in accordance with exemplary embodiments of the present invention. 
           [0028]      FIG. 5  illustrates a perspective view of an exploded add on filter in accordance with exemplary embodiments of the present invention. 
           [0029]      FIGS. 6(   a )-( c ) illustrate an add on filter in which the second cartridge has been removed in accordance with exemplary embodiments of the present invention. 
           [0030]      FIGS. 7(   a )-( d ) illustrate an add on filter configured to allow the first cartridge to be inserted or removed from the box frame in accordance with exemplary embodiments of the present invention. 
           [0031]      FIGS. 8(   a )-( b ) illustrate a detailed view of the removable wall of the add on filter box in accordance with exemplary embodiments of the present invention. 
           [0032]      FIGS. 9(   a )-( d ) illustrate a first cartridge of an add on filter in accordance with exemplary embodiments of the present invention. 
           [0033]      FIGS. 10(   a )-( d ) illustrate a first cartridge of an add on filter in accordance with exemplary embodiments of the present invention. 
           [0034]      FIG. 11  illustrates a perspective view an air filtration system including an add on filter in accordance with exemplary embodiments of the present invention. 
           [0035]      FIG. 12  illustrates a perspective view of an air filtration system including an add on filter in accordance with exemplary embodiments of the present invention. 
           [0036]      FIG. 13  illustrates a close-up view of an add on filter incorporated in an air filtration system in accordance with exemplary embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art. Further, the terms and phrases used herein are not intended to be limiting; but rather, to provide an understandable description of the invention. 
         [0038]    According to particular embodiments of the present invention, an add on filter for an air filtration system includes a box frame housing a first cartridge. The add on filter may be coupled to existing air filtration systems to provide further filtration of the air. The first cartridge of the add on filter includes an ultraviolet light source for emitting a broad spectrum of ultraviolet light and a catalytic target structure mechanically coupled to the ultraviolet light source. The target catalytic structure comprises a multi-metallic catalytic and hydrophilic material, and the hydrophilic surface attracts and absorbs moisture from the surrounding air. The broad spectrum ultraviolet light include two bands of ultraviolet light at about 254 nm wavelength and at about 185 nm wavelength. The ultraviolet energy at 254 nm strikes the target structure and activates production of Hydroxyl Radicals, Super Oxide ions and Hydro Peroxide on the surface. The ultraviolet energy at 185 nm is sufficient to split oxygen molecules to form ozone gas. These ozone molecules in the air are then reduced back to oxygen via decomposition process initiated by the 254 nm ultraviolet light energy, which results in the production of Hydroxyl Radicals, Super Oxide ions and Hydro Peroxide similar to the surface reaction. This process is described in further detail in co-owned U.S. Pat. No. 7,988,932, the entire disclosure of which is herein incorporated by reference. 
         [0039]      FIGS. 1-5  illustrate an add-on filter according to particular embodiments of the present invention. The add on filter  100  includes a box frame  102 , a first cartridge  104  and a second cartridge  106 . The box frame  102  includes a plurality of walls and is configured to house the first cartridge  104  and the second cartridge  106 . The box frame  102  is insulted and includes a plurality of faces or walls. The box frame  102  includes first opening in a first wall and a second opening in a second wall opposite the first opening. The openings are positioned to expose the at least one longitudinal face of the first cartridge  104  and the second cartridge  106  and allow for air to pass through the filter  100 . The box frame  102  can also include a third opening in a third wall configured to allow the first cartridge  104  and second cartridge  106  to be slidably removed from or positioned within the box frame  102 . The add on filter includes a removable wall  108  which can be coupled with the box frame  102  such that the third opening is covered by the wall  108 . In certain embodiments, the removable wall  108  includes protrusions  110 ( a ) and ( b ) configured to engage openings  112 ( a ) and ( b ) in the box frame  102 . The protrusions  110 ( a ) and ( b ) are configured to removably coupled with the openings  112 ( a ) and ( b ). The removable wall  108  and the process of coupling it with box frame  102  will be discussed below with reference to  FIGS. 8(   a ) and ( b ). 
         [0040]    The first cartridge  104  includes an ultraviolet light source for emitting a broad spectrum of ultraviolet light and a catalytic target structure mechanically coupled to the ultraviolet light source. The target catalytic structure comprises a multi-metallic catalytic and hydrophilic material, and the hydrophilic surface attracts and absorbs moisture from the surrounding air. The first cartridge will be discussed in further detail in the discussion of  FIGS. 9(   a )-( d ) and  10 ( a )-( d ). The second cartridge  106  can be a deep pleat replaceable filter configured to reduce odor and microbes. The second cartridge  106  can be a pleated filter with a MERV rating between 7-14. In an embodiment of the present invention, the second cartridge  106  can be a custom filter with material for specific air contaminant removal, e.g., charcoal, sulfur coated carbon for mercury removal, or potassium permanganate coated carbon for specific VOC removal. 
         [0041]    The add on filter  100  can also include a rack  114  configured to support the first cartridge  104  within the box frame  102 . The rack  114  includes two elongate members that are each pivotably coupled to the interior face of a wall of the box frame  102  at a first end. The rack  114  is configured to be approximately parallel to the faces of the walls including the first and second opening while supporting the first cartridge  104 , as illustrated in  FIGS. 6(   a )-( c ). 
         [0042]    Referring now to  FIGS. 6(   a )-( c ), the add on filter  100  can include a lock  600  for maintaining the first cartridge  104  and the rack  114  approximately parallel to the faces of the walls including the first and second opening even when the second cartridge  106  is not present to support the first cartridge  104 . The rack  114  can be pivoted to allow the first cartridge  104  to be positioned within or removed from the box frame  102 , as illustrated in  FIGS. 2 ,  3  and  7 ( a )-( d ). In this position, a second end of the rack  114  is angled downwardly such that the first cartridge  104  can be slidably removed from or placed on the rack  114 . 
         [0043]    The add on filter  100  can also include an opening  116 ( a )-( b ) configured to allow a power source to be provided to a ballast  118  of the first cartridge  104 . The opening  116 ( a )-( b ) includes a first opening  116 ( a ) in the box frame  102  and a second opening  116 ( b ) in the removable wall  108 . The first opening  116 ( a ) and the second opening  116 ( b ) are positioned such that when the removable wall  108  is coupled to the box frame  102 , the first opening  116 ( a ) and the second opening  116 ( b ) line up and allow a power source to provide power to the ballast  118 . 
         [0044]    Referring now to  FIGS. 4(   a )-( c ), an add on filter  100  in which an external power source  400  is providing power to the ballast  118  is shown. The external power source  400  includes a cord capable of passing through the openings  116 ( a ) and ( b ) and couple with the ballast  118 . 
         [0045]      FIG. 5  illustrates an add on filter  100  in which the removable wall  108  has been removed and the second cartridge  106  is being slidably moved in relation to the box frame  102 . When the removable wall  108  is not present, the second cartridge  106  can be slid in and out of the box frame  102  through the opening exposed by the removable wall  108 , the third opening. 
         [0046]      FIGS. 6(   a )-( c ) illustrate an add on filter  100  in which only the first cartridge  104  is present. In an embodiment of the present invention, the add on filter  100  may be used with only the first cartridge  104 , i.e., the add on filter  100  may be used without the second cartridge  106 . The first cartridge  104  can be held in position by a lock  600 . When the lock  600  is placed in an unlocked position, the first cartridge  104  may be slidably moved relative to the box frame  102  when the rack has been placed in a downwardly sloping position, as illustrated in  FIGS. 7(   a )-( d ). 
         [0047]      FIGS. 8(   a ) and ( b ) illustrate an add on filter  100  in which the removable wall  108  is partially coupled to the box frame  102 . The removable wall  108  includes top protrusions  110 , an insulative wall  800  and a bottom protrusion  802 . As already discussed, the top protrusions  110 ( a ) and ( b ) are configured to engage top openings  112 ( a ) and ( b ) of the box frame. The bottom protrusion  802  is configured to engage a bottom opening  804  in the box frame. The bottom opening  804  is configured such that it can receive the bottom protrusion  802  and the removable wall  108  can be pivoted into a coupled position, i.e., a position in which the top protrusions  110 ( a ) and ( b ) engage the top openings  112 ( a ) and ( b ). 
         [0048]    In certain embodiments of the present invention, the removable wall  108  includes a plurality of bottom protrusions  802  and the box frame  102  includes at least one bottom opening  804  for each bottom protrusion  802 . 
         [0049]      FIGS. 9(   a )-( d ) and  10 ( a )-( d ) illustrate a first cartridge  104  according to certain embodiments of the present invention. The first cartridge  104  includes an ultraviolet light source  900 , a target structure  902 , a ballast  118 , a cord  904  and a frame  906 . The ultraviolet light source  900  is an approximately U-shaped bulb. This design allows for the ultraviolet light emitted by the source  900  to contact a larger surface area in a rectangular cartridge filter. The target structure  902  is designed to maximize the surface area contacted by the ultraviolet light emitted by the source  900 . The target structure  902  is also designed to minimize the pressure drop of air passing through the filter caused by the structure. 
         [0050]    The ultraviolet light source  900  emits ultraviolet light at two bands: about 254 nm wavelength and at about 185 nm wavelength. The target catalytic structure  902  comprises a multi-metallic catalytic and hydrophilic material, and the hydrophilic surface attracts and absorbs moisture from the surrounding air. The ultraviolet energy at 254 nm strikes the target structure  902  and activates production of Hydroxyl Radicals, Super Oxide ions and Hydro Peroxide on the surface. The ultraviolet energy at 185 nm is sufficient to split oxygen molecules to form ozone gas. These ozone molecules in the air are then reduced back to oxygen via decomposition process initiated by the 254 nm ultraviolet light energy, which results in the production of Hydroxyl Radicals, Super Oxide ions and Hydro Peroxide similar to the surface reaction. The ultraviolet light source  900  is supplied energy by the ballast  118  via the cord  904 . 
         [0051]      FIGS. 11-13  illustrate the add on filter  100  in an air filtration system according to certain embodiments of the present invention. The air filtration system includes an evaporator or AC unit  1100 , the add on filter  100 , an air supply  1102  and an air return member  1104 . The air filter system can be vertical or horizontal. The add on filter  100  is coupled to the intake end of the evaporator or AC unit  1100  and the output of the air supply  1102 . In an embodiment of the present invention, the add on filter  100  can be coupled to the evaporator or AC unit  1100  by removing an access cover of the evaporator unit  1100  and screwing or otherwise coupling the evaporator unit  1100  to the add on filter  100 . The add on filter  100  can be coupled to the air supply  1104  by screwing or otherwise coupling the add on filter  100  while removable wall  108  is off and the cartridges are removed. Air to be filtered and treated is provided to the add on filter  100  from the air supply  1102 . As the air passes through the add on filter  100 , the air is treated with advanced oxidation products which reduce odors and microbes, as discussed above. The treated air is then provided to the evaporator unit  1100  where it is further treated and then supplied to its destination (e.g., home, office, building, etc.). In an embodiment of the present invention, the air is returned from the destination (e.g., home, office, building, etc.) via the air return member  1104  and provided to the air supply  1102 . 
         [0052]    The add on filter  100  is sized to match the evaporator or AC unit  1100 . The add on filter  100  can come in many different sizes to match the various evaporator or AC units  1100  on the market. 
         [0053]    The add on filter  100  may be coupled to air filtration systems upon initial installation or added as an aftermarket item. If the add on filter  100  is added to an existing air filtration system, the evaporator or AC unit  1100  must be raised enough to accommodate the height of the add on filter  100 . A portion of the ventilation, duct work or any other member the evaporator or AC unit  1100  is coupled to on its output end must be removed that is equivalent to the height of the add on filter  100 . The add on filter  100  may then be coupled to the evaporator or AC unit  1100  and placed into the air filtration system. 
         [0054]    While various embodiments have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context. 
         [0055]    Additionally, while the processes described above and illustrated in the drawings are shown as a sequence of steps, this was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, and some steps may be performed in parallel.