Abstract:
A low profile, high volume window fan has a large air filter mounted horizontally therein. The fan is enclosed in a rectangular box-like frame having a sloped top cover. The front section includes a squirrel cage blower, a front louvered section for directing the flow of air into the room, and a horizontally opening door for controlling the flow of air through the fan from either the outside air or the inside air, and for the insertion of the filter therein. The bottom surface includes an external opening for outside air. A double plenum is provided within the frame with the filter dividing the two plenums. When the door is closed, outside air is forced to flow into the second plenum, being in the bottom of the frame and under the filter and through the filter. When the door is opened, interior air is then filtered and circulated.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
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     REFERENCE TO FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
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     REFERENCE TO JOINT RESEARCH AGREEMENTS 
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     REFERENCE TO SEQUENCE LISTING 
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     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to window fans, and, more particularly, to window fans with filters, and in greater particularly, to low profile and high volume window fans with filters. 
     2. Description of the Prior Art 
     Not having a good night sleep is probably one of the single most important factors leading to problems the next day. Many of the factors that affect our sleep are not within our control such as external events that still raise our level of anxiety, but even some things that we think that we have control over can still cause great anxiety such as family issues, money issues, work issues, health issues, etc. 
     Nothing is more stressful to a person trying to sleep than allergies to air borne agents such as pollen, animal dander, etc. These can cause sniffling, running eyes, coughing, etc. A person who suffers from pollen allergy greatly desires air purification in almost all locations in a home, but especially in the bedroom. Having a sleepless night caused by pollen allergy in the spring is very harmful and upsetting and thus having both purified air and fresh air would greatly aid sleep. 
     Obviously having a whole house air conditioning system with built in filters would offer the best solution, but this is expensive and many homes can not be retrofitted even if it was affordable. A prior solution to this issue is the use of window fans having some form of filters. 
     This problem is addressed by some of the products on the market. One attempted solution is the use of a filter mounted in the window where the house has a whole house exhaust fan. One such product is sold by Bionaire® as a window mounted air exchange system called EverFresh®. This unit is mounted in the lower open window area and has several unique and changeable filters therein. But this unit blocks the lower half of the window. This unit is thus not low profile, and it is not high volume since the size of the filters are limited to an open area smaller than the bottom half of an open window. 
     Several patents were found directed at window fans, but these are vertically mounted and substantially block the lower window in a double hung window. Even with the attachment of filters thereon, by hook or crook, a substantial frame would be required to prevent water entrance into the filter area and hold the filter separate from the window fan. See for example, U.S. Pat. No. 6,818,035 that has unique filters mounted within the plenums. 
     A low profile window fan is shown in U.S. Pat. No. 5,730,651, but it lacks any filters or even the ability to place such thereon. Its construction allows it to both input air and exhaust air at the same time by the use of two squirrel cage blowers operating in different directions. 
     U.S. Pat. No. 5,660,605 is similar to the above patent, but it does include a pair of filters mounted vertically in slots on the top inside of the fan frame. This patent employs a unique air deflector 36 that is not required in the present invention. Further the size of the filters are limited by the height of the fan and the width. They are vertically mounted as compared to the horizontal mounting of the large filter in the present invention. The above products and patents are incorporated by reference 
     Accordingly, there is a need for a low profile, high volume window fan having a large filter thereon. 
     SUMMARY OF THE INVENTION 
     The present invention is directed at a low profile, high volume window fan having a means for not only controlling the flow of air from the outside and inside, but also having filter means easily mounted therein without the need for opening the window or removing the unit from the window. 
     The present invention provides a low profile, high volume window fan having a large air filter therein. The fan is enclosed in a rectangular box-like frame having a sloped top cover with a height less than 9 inches. The frame being approximately sized as about 20 inches across the front and about 30 inches in depth. The frame is mounted in the bottom area of a double-hung window such as with an air conditioner. Side wings would be attached to block the area from the frame to the vertical sides of the window frame. The front section, being within the room, of the frame includes a squirrel cage blower with appropriate controls and wiring, and a front louvered section for directing the flow of air into the room although this embodiment may eliminate these louvers and replace with a screen to prevent accidental contact with the blower fan, and a horizontally opening door for controlling the flow of air through the fan from either the outside air or the inside air, and for the insertion of the filter therein. 
     The center section of the frame, being both on the outside and inside of the window, has a large purification filter mounted therein. The bottom outer surface of the frame includes an external opening for outside air. A screen is mounted over the external opening to prevent bugs from entering therein. A double plenum is provided within the frame from bottom to top having the filter dividing the two plenums. The interior, or room side of the lower plenum has a hinged door which is connected to a louvered or sliding slat closing arrangement over the external opening for the outside air by means of a push rod or otherwise. When the interior door is closed, only outside/external air is allowed into the lower plenum, through the filter then into the upper plenum to the blower, then out into the room. When the interior door is open, the exterior louvers or slats are closed allowing only interior air to enter into the lower plenum, through the filter then into the upper plenum to the blower, then out into the room. A varying combination of both outside air and inside air could also be selected by intermediate movement of the door. 
     This low profile, high volume, air purification device also places positive air pressure in the room to maintain fresh purified interior air. Thus, any other openings such doors or other windows would have the air flowing out from this room. 
     As another embodiment, a low profile, high air flow, filtered window fan may just purify only outside air rather than both inside and outside air. In this regard, the lower plenum and the door and the linking means between the pivoting door and the louvers/slats on the outside air intake can be eliminated considerably lowering the cost of production. The front section may include a closable door where the filter may be inserted or the filter may be placed in the bottom section but this would require either the fan to be removed from the window or reaching up to remove the filter from the outside which may require the use of a ladder. 
     An object of the present invention is to provide a low profile, high volume air flow window fan with a large air purification filter therein. 
     It is another object of the present invention to provide the low profile, high volume air flow window fan with a large air purification filter therein which can be easily changed without removing the fan or opening the window. 
     It is a further object of the present invention to provide the low profile, high volume air flow window fan with a large air purification filter horizontally mounted therein which can be easily changed without removing the fan or opening the window. 
     It is still a further object of the present invention to provide the low profile, high volume air flow window fan with a large air purification filter therein which can output outside air or circulate interior air or a combination there between. 
     It is yet a further object of the present invention to provide the low profile, high volume air flow window fan with a large air purification filter therein that is able to place a positive air pressure in the room. 
     It is yet a further object of the present invention to provide the low profile, high volume air flow window fan with a large air purification filter therein that is able to only purify outside air. 
     It is yet a further object of the present invention to provide a device that could both filter fresh air going into a room or structure while providing a positive pressure inside that room, or in a reverse mode, filtering out old or contaminated air from a room or structure with a reverse flow and also creating a negative pressure by simply reversing the device and installing appropriate filters therein. 
     These and other objects, features, and advantages of the present invention will become more readily apparent from the attached drawings and the detailed description of the preferred embodiments, which follow. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The preferred embodiments of the invention will hereinafter be described in conjunction with the appended drawings provided to illustrate and not to limit the invention, where like designations denote like elements, and in which: 
         FIG. 1A  is a perspective view of a window fan of the present invention; 
         FIG. 1B  is a bottom view illustration of the window fan of the present invention as shown in  FIG. 1A  showing the exterior air intake and a means to control the air flow therethrough of the present invention; 
         FIG. 2  is a top view illustration of the window fan with a top cover removed showing some features therein of the present invention; 
         FIGS. 3A and 3B  illustrate the means of controlling air flow through the window fan as shown in  FIG. 1  of the present invention; 
         FIG. 4  is a cross sectional vertical view through the window fan of  FIG. 1  of the present invention; 
         FIGS. 5A to 5C  illustrate a different embodiment of a means to control the air flow through the window fan of the present invention; and 
         FIGS. 6A and 6B  illustrate by a top view and a side view a frame to provide for different sizes of filters in the window fan of the present invention. 
         FIGS. 7A and 7B  illustrate by a perspective view and a bottom view another embodiment of the invention for only purifying outside air. 
     
    
    
     Like reference numerals refer to like parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention is directed at a low profile, high air volume window fan having a means for not only controlling the flow of air from the outside and inside, but also having filter means easily mounted therein without the need for opening the window or removing the unit from the window. A further embodiment only allows outside air to be filtered. 
     Turning to the drawings, wherein like components are designated by like reference numerals throughout the various figures, attention is initially directed to  FIG. 1A  which illustrates one embodiment by perspective view of a low profile, high air volume, filtered window fan  100  constructed according to the present invention. 
     The low profile, high volume, filtered window fan  100  has a box-like frame  102  that is adapted to mount in a lower section of a double hung window being of conventional design in a low profile configuration. The fan  100  is secured in the window frame by an upper window stop  104  resting against a horizontal sash of the window, and a lower window stop  106  shown in outline resting against a sill of the window. The mounting is similar to that of an air conditioner. 
     The low profile, high volume, filtered window fan with the box-like frame  102  has a top cover  124  that slopes downwardly from the window to allow water to drain away from the window. The box-like frame  102  is approximately 20 inches wide, approximately 30 inches deep and 8 inches high in the front section  118 , a back section  146  being about 5 inches high, and a flat upper section  166  being about 6 inches deep. The box-like frame can be made of plastic, metal or a combination of these as is well known to one skilled in the art. 
     As seen in  FIG. 1B , a bottom section  108 , or bottom outside surface, has an outside air intake  110  that is positioned on an outside of the window when the fan  100  is mounted therein. A means for controlling the air flow  112  through the outside air intake  110  is shown as a plurality of louvers  114  as to be further explained herein. An inside air intake  116  is shown in  FIG. 1A  as being mounted in a front section  118  of the box-like frame  102  and is located inside of the house when the fan  100  is mounted therein. The inside air intake  116  has a hinged door  120 , but other designs are clearly possible such as one or more sliding doors or rotatable louvers. A blower fan  122  is shown mounted near a front section  108  of the box-like frame  102  in  FIG. 2  where a top cover  124  has been removed for purposes of discussion. An air exhaust section  126  is shown between the blower fan  122  and the room. The air exhaust section  126  may have a plurality of hinged louvers  128 , but this may not be necessary since the air is not air-conditioned. The louvers  128  can be independently hinged or ganged together. Although louvers  128  are shown, a protective safe guard screen may also be placed therein to prevent accidental contact with the blower fan. 
     The blower fan  122  has an electric motor  130  being operated from a control section  132  mounted in the upper front section  134 . The control section  132  has a speed control  136  and an on-off switch  138  therein for supplying power to the blower fan motor  130  from an external power source input by an AC cord  140 . The motor  120  turns a squirrel cage blower fan  182  and mounted in a horizontal position. The speed control  136  and on-off switch  138  may be combined into a single unit that has an off position and when turned or rotated therefrom operates as a speed control. 
     A means for mounting a filter  142  is shown in outline in  FIGS. 3A and 3B  in said box-like frame  102 .  FIG. 4  shows one of two L shaped rails  144  mounted between a back wall section  146  and the front section  118 . To access this area for insertion of the filter  142 , the door  120  is opened to sufficiently allow the filter  142  to be inserted on to the rails  144 . The insertion of this large filter  142  is accomplished without removing the fan  100  or going outside. The main type of filter being those that are used in central air conditioning systems. Manufacturers are American Air Filter, Energy Aire, Flander E-Z Green being of a size of 20 inches by 25 inches by 1 inch; and 3M 1550 Allergen and 3M Filtrete 1250 microparticule performance rating and Filtrete Ultra Allergen Air Filter, 1250 Purple, claims to remove pollen, dust mites, smoke, dander, dust, smog, and particles carrying bacteria. In the preferred embodiment, a 20 by 25 by 1 inch filter is used. 
     When the filter  142  is insert therein as shown in  FIG. 3 , an upper plenum  148  and a lower plenum  150  are created within the box-like frame  102 . The upper plenum  148  provides outside air to the blower fan  122  and the lower plenum  150  provides inside air to the blower fan  122  but which must further travel through the upper plenum  148  through the filter  142  as will be further described. There are many types of filters available. 
     A means for controlling  152  an amount of outside air and inside air to the blower fan  122  is shown in  FIG. 3A , only outside air  154 , and  FIG. 3B , only inside air  156 . As seen therein, the means for controlling  152  the air flow in the outside air intake  110  shows a set of three louvers  158  each having a lever rod  160  that are ganged together by a first control rod  162 . The first control rod is then operatively connected to a second control rod  164  that is pivotally connected to the door  120 . Clearly other means for connecting louvers  158  and the door  120  are possible. As seen in  FIG. 3A , the air intake is open and the outside air  154  flows into the lower plenum  150  to the filter  142  and into the second plenum  148  to the blower fan  122 . To purify interior air, the door  120  is opened as shown in  FIG. 3B  to cause the second rod  164  to pull the first rod  162  that then rotates the louvers to the closed position as shown in  FIG. 3B . The inside air  156  flows into the lower plenum  150  and then through the filter  142  into the upper plenum  148  to the blower fan  122 .  FIG. 4 . 
     Another embodiment of the means  152  is shown in  FIGS. 5A ,  5 B, and  5 C. As seen in  FIG. 5A , a bottom air flow window  170 , being made of sheet plastic, for example, is fixedly mounted in the bottom of the air intake  110 . Two portal windows  172  are cut out. On top of that a movable air flow window  174  is attached with brackets  176 . Also two congruent portal windows  178  are cut out.  FIG. 5C  shows the movable air flow window  174  mounted on top of the bottom air flow window  170  and having the windows adjacent and not in communication. When the movable air flow window  174  is moved to the right by opening the door  120 , the adjacent windows will move to coincide to allow air to pass. As shown in  FIG. 3 , a screen  180  can be placed over the air intake  110  to prevent bugs from entering into the box-like frame  102 . 
     It is understood that a smaller filter  186 ,  FIGS. 6A and 6B , may be used in the present invention and thus a the smaller filter  186  is shown mounted in the reduced size filter frame  188  and this can then be inserted into the opening for the maximum sized filter having the rails thereon. The frame  188  may be made of either plastic or sheet metal and has two sides  190  and two ends  192 . These can be tack welded at points “x”. In order to hold the filter, each side or end has a wall  194  forming a box like opening with a lip  196  that would support the filter. 
     The fan  100  further includes a pair of side wings  198 , only one shown in  FIG. 1A , for mounting to the sides  200  of the box-like frame  102  to block an opening between the box-like frame  102  and the window frame when mounted therein. The side wing  198  may be made of a sheet of heavy plastic  202  attached to a mounting bracket  204  that can be screwed on to the sides  200 . The outer end  206  of the plastic wing  198  may be cut to fit behind a stop of the window frame with the top edge  208  resting against the bottom window stile. 
     An another embodiment of the low profile, high volume, filtered fan  210  is shown in  FIGS. 7A and 7B . This fan  210  provides only purification of outside air and has many similar features as the fan  100  above, but the differences go to providing only purified outside air. An outside air intake  212  is mounted in a bottom section  214  of said box-like frame  216  and positioned on an outside of the window when mounted therein. A filter  218  is mounted in the air intake  212  by means of a surrounding frame  220  being “T” shaped with the filter  218  resting upon one lip  222  of the “T”. The other lip  224  is attached to the bottom section  214  by screws, for example. When mounted therein, air flows through the outside air intake  212  and through the filter  218  and into a single plenum  226 . A blower fan  122  is mounted near a front section  228  of the box-like frame  216  and is operatively connected to the single plenum  226  therein. A similar control section  132  may be used. 
     The box-like frame  216  may include a filter door  230  in the front section  228  so that when the door  230  is opened the filter can be inserted over said outside air intake. This would prevent the need of removing the fan  210  or climbing or reaching up to the filter-surrounding frame  220  to remove it. The box-like frame  216  may be approximately 20 inches wide, approximately 30 inches deep and 6 to 8 inches high in the front section, a back section being about 6 inches high. 
     Since many modifications, variations, and changes in detail can be made to the described embodiments of the invention, it is intended that all matters in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents.