Abstract:
A method and apparatus for desktop air conditioning provides conditioned air to individuals sitting at a desk. A raised floor air delivery system provides a plenum having conditioned air under the raised floor upon which the individual and their desk sit. Small ducts extend vertically up from the floor to the underneath side of the desk where they are connected to a desktop diffuser. The desktop diffuser directs air from the plenum generally horizontally across a top of the desk toward the chest and face of the individual. The desktop diffuser is low profile so as not to interfere with the surface of the desktop and its aesthetics.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BRIEF SUMMARY OF THE INVENTION 
       [0003]    The present invention relates to a method and apparatus for providing desktop air conditioning. More particularly, this invention relates to a diffuser for use in combination with a raised floor air distribution system, wherein the diffuser is received in an opening in a desktop and provides a low profile air distribution component. 
         [0004]    Providing conditioned air to a room or rooms within a building having a raised floor air distribution system is known in the art.  FIGS. 1 and 2  illustrate a prior art raised floor air distribution system that was modified to provide personalized or individually controllable distribution of conditioned air to individual desks. While it is important that any air distribution system adequately control the temperature of the rooms as a whole, such may not be sufficient to accommodate the individual needs of persons in the rooms. Thus, while the room may be of a desired overall temperature, individuals in the room may have different desires as to the temperature in their specific locations. This is of particular concern in office buildings where individuals are asked to sit for long periods at a time at a specific location, such as at a desk and/or in a cubicle. 
         [0005]    The prior art system illustrated in  FIG. 1  or  2  attempted to accommodate the individual desires of a person sitting at a desk by providing a desk with a flow of conditioned air through a duct which would deliver the conditioned air out the front of the desk beneath the desktop. Presumably, the individual at the desk would have the ability to control the amount of air flowing through the duct underneath the desk and therefore the amount of air coming out of the desk. Unfortunately, this prior art system had several shortcomings that prevented widespread adoption. For example, the conditioned air was provided to an individual&#39;s lap or waist. Generally, however, when an individual is hot and desiring a cooler temperature, it is their upper body or torso that is in need of cooling, not their waist or legs. Additionally, because the air coming out of the duct underneath the desk is cooler, the air would have a tendency to drop down to the individual&#39;s feet, thereby making their feet cold and not cooling their core mass or upper body. Additionally, the provision of the large ductwork directly underneath the desktop where the user sits makes it impossible to provide a drawer in the opening where the user&#39;s legs reside while seated at the desk. 
         [0006]      FIG. 3  illustrates an alternate prior art embodiment that attempted to address the shortcomings of the system of  FIGS. 1 and 2 . The prior art system illustrated in  FIG. 3  discloses a desktop air conditioning system that makes use of a pair of air terminals or towers that extend or protrude upwardly from the desktop. A control box is also positioned on the desktop to permit the occupant to control the temperature and volume of air flowing through the system. 
         [0007]    In a cooling mode, conditioned air would be drawn up from a plenum underneath the floor upon which the user&#39;s chair sits. The conditioned air would pass through the ductwork and be forced out the front of the desktop units through manually adjustable louvers that are akin to the louvers found in automobile air distribution systems. The individual air terminals included knobs that control the volume of air through the face of the unit. 
         [0008]    If a warmer temperature is desired, the user may use the control panel to turn on a radiant heat panel adjacent the user&#39;s feet. This is because it has generally been found that when a user is cold, it is their feet that require heating. As such, the radiant panel by their feet emits warmer air. In this mode, the system can also intake the warmer air by the floor up into the ductwork and disperse it out the individual air distribution towers. 
         [0009]    While the system illustrated in  FIG. 3  represented an improvement over the prior art system illustrated in  FIGS. 1 and 2 , the prior art system in  FIG. 3  also has numerous shortcomings that have prevented widespread adoption of the system. Initially, the system is quite complex and is therefore expensive to manufacture and install. The control panel that sits on the desk must be connected to a number of items in order to control the various functions of the unit. In addition to having to have the control panel on the desktop, the occupant must also deal with having to have the two air distribution towers protruding up from the desktop. In a cubicle-type environment, desktop space is often at a premium and having to have three large components sitting on the desktop is often undesirable. 
         [0010]    The method and apparatus of the present desktop air distribution system overcomes these and other drawbacks by providing a system which is low profile, simple to operate, and significantly less expensive to install. The system includes preferably, a pair of flexible tubular ducts that extend upwardly from openings in a floor tile of a raised floor air distribution system. The ducts engage with an underneath side of a low profile desktop diffuser. The diffuser includes a plurality of fins therein which direct the flow of air through an upper surface of the diffuser and out of the diffuser in a direction that is generally along the upper surface of the desk. In this manner, the air is directed to the occupant&#39;s torso and chest to provide cooling where desired. In one embodiment, the diffuser is a variable volume diffuser that includes a pair of plates that cooperate to control the volume of air flowing through the diffuser. The diffuser presents a low profile on the desktop and takes up a minimal amount of desk surface area. 
         [0011]    Further objects, features and advantages of the present invention over the prior art will become apparent from the detailed description of the drawings which follows, when considered with the attached figures. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0012]    The features of the invention noted above are explained in more detail with reference to the embodiments illustrated in the attached drawing figures, in which like reference numerals denote like elements, in which  FIGS. 1-16  illustrate several possible embodiments of the present invention, and in which: 
           [0013]      FIG. 1  is a side elevation view of a prior art system for providing conditioned air to individual desks using an under floor air distribution system with a plenum; 
           [0014]      FIG. 2  is a perspective view of an individual desk outfitted with the prior art system of  FIG. 1 ; 
           [0015]      FIG. 3  is a side elevation view of an alternate prior art system for providing conditioned air to individual desks using an under floor air distribution system with a plenum; 
           [0016]      FIG. 4  is a side elevation view of a system for providing conditioned air to individual desks using an under floor air distribution system with a plenum in accordance with an embodiment of the present invention; 
           [0017]      FIG. 5  is a perspective view of a desk of  FIG. 4  outfitted with an embodiment of the present invention; 
           [0018]      FIG. 6  is an enlarged side elevation view of one of the desks of  FIG. 4  with a user seated at the desk; 
           [0019]      FIG. 7  is a perspective view of an alternate embodiment of a desktop air conditioning system of the present invention; 
           [0020]      FIG. 8  is an enlarged perspective view of an embodiment of an adjustable desktop diffuser of the present invention with a portion of a desktop cut away for clarity; 
           [0021]      FIG. 9  is a fragmentary exploded perspective view of the diffuser of  FIG. 8  with a portion thereof cut away for clarity; 
           [0022]      FIG. 10  is a bottom perspective view of the diffuser of  FIG. 8  with a portion of a stationary plate cut away for clarity; 
           [0023]      FIG. 11  is a bottom plan view of the diffuser of  FIG. 8  with a movable plate in an open position; 
           [0024]      FIG. 12  is a bottom plan view of the diffuser of  FIG. 8  with the movable plate in a partially closed position; 
           [0025]      FIG. 13  is a bottom plan view of the diffuser of  FIG. 8  with the movable plate in a closed position; 
           [0026]      FIG. 14  is a top plan view of the diffuser of  FIG. 8  with the movable plate omitted; 
           [0027]      FIG. 15  is an enlarged fragmentary side elevation view of the diffuser of  FIG. 14  with a portion cut away for clarity; and 
           [0028]      FIG. 16  is a fragmentary perspective view of an embodiment of a constant volume diffuser of the present invention with a portion of the diffuser cut away for clarity. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    Referring now to the drawings in more detail and initially to  FIG. 4 , numeral  10  generally designates a desktop air conditioning system arranged in accordance with an embodiment of the present invention. The system  10  is implemented in a building  12  having walls  14  and structural floors  16 . The structural floors  16  can be concrete slabs and one structural floor  16  may be a ceiling to help define a room  18 . Often the lower surface of a structural floor  16  that is used as a ceiling is hidden from view by a false or a dropped ceiling (not shown). 
         [0030]    The building  12  preferably also has a raised floor air distribution system  20 . The raised floor air distribution system  20  includes a plurality of floor tiles  22  that are supported above the structural floor  16  to create an operating floor  24 . The floor tiles  22  are supported by a plurality of adjustable pedestals or stands  26 . The operating floor  24  and the structural floor  16 , along with a portion of the walls  14 , cooperate to define a plenum  28  between the operating floor  24  and the structural floor  16 . An air handling unit (not shown) provides conditioned air to the plenum  28  underneath the operating floor  24 . The plenum  28  is kept at a positive pressure when compared to the pressure of the ambient air in the room  18 . As such, the conditioned air will attempt to move from the plenum  28  into the room  18  when permitted to do so. A floor terminal  30  may be provided in a floor tile  22  to accommodate the passage of air from the plenum  28  into the room  18 , as illustrated by the arrows  32 . 
         [0031]    In the illustrated embodiment, the system  10  is preferably coupled with the plenum  28  by way of a floor unit  34 . The floor unit  34  may be of a similar size as the floor terminal  30  such that the floor unit  34  may be placed in a standard opening of a floor tile  22  for a floor terminal  30 . Alternatively, and as illustrated, the floor unit  34  may be of a smaller size to decrease the size of the opening through the floor tile  22  into which the floor unit  34  is received. The floor unit  34  permits conditioned air from the plenum  28  to pass therethrough into the desktop air conditioning system  10 , as discussed in more detail below. 
         [0032]    The desktop air conditioning system  10  includes at least one supply duct  36  and a desktop diffuser  38 . As illustrated in  FIGS. 5 and 7 , the desktop air conditioning system  10  may be implemented with a pair of supply ducts  36  coupled with a pair of desktop diffusers  38 . As illustrated in  FIG. 5 , the floor unit  34  may take the shape of a rectangular metal plate or lid for covering an opening in a floor tile  22  and having a pair of openings therethrough to permit the ducts  36  to be in fluid communication with the plenum  28 . In the embodiment illustrated in  FIG. 5 , the floor unit  34  is provided with a pair of cylindrical collars (not shown) that extend upwardly from an upper surface of the plate like portion of the floor unit  34 . These collars provide a structural portion of the floor unit  34  onto which ends of the supply duct  36  may be received and to which they may be coupled. As illustrated in  FIG. 7 , a floor unit  34  may be omitted and the supply ducts  36  may be directly coupled with floor tiles  22  around openings therein. Additionally, the supply ducts  36  may be rigid, as illustrated in  FIG. 7 , or flexible tubing, as illustrated in  FIG. 5 . Similarly, the supply duct  36  may have any type of configuration, beyond just the cylindrical configuration illustrated. 
         [0033]    The desktop air conditioning system  10  is preferably implemented in a desk  40  having a work surface or desktop  42  with a generally horizontal upper surface  44 . An opening  46  is provided in the desktop  42  to receive a portion of the desktop diffuser  38 , as illustrated in  FIG. 8 .  FIG. 8  also illustrates that the diffuser  38  is coupled with an upper end  48  of the supply duct  36 . A lower end  50  of the supply duct  36  is coupled with a floor unit  34  or directly with a floor tile  22 . 
         [0034]    Turning now to  FIGS. 8-10 , the desktop diffuser  38  will now be described in more detail. Preferably, the diffuser includes a grille portion  52  and a body portion  54 . In the illustrated embodiment where the desktop diffuser  38  is round in appearance, the grille portion takes the shape of a circular disc-like member and the body portion takes the shape of a cylindrical member, such as a section of a pipe or tube. The grille portion  52  has an upper surface  56  that is also the upper surface of the desktop diffuser  38 . The upper surface  56  is preferably flat or planar, for reasons that will be discussed below, and oriented in a generally horizontal position. The body portion  54  is preferably coupled with a lower surface  58  of the grille portion  52  adjacent an upper or proximal edge  60  of the body portion  54  such that the body portion  54  depends downwardly from the grille portion  52 , as illustrated in  FIGS. 8 and 9 . 
         [0035]    The grille portion  52  has an outer periphery  62  of a first circumference and the body portion  54  has an outer surface  64  that defines a second circumference. As illustrated in  FIG. 10 , the first circumference of the grille portion  52  is larger than the second circumference of the body portion  54  such that an outwardly depending lip  66  is created about the proximal edge  60  of the body portion  54 . The lip  66  includes an annular ring of the lower surface  58  of the grille portion  52 . When the desktop diffuser  38  is received in the opening  46  in the desktop  42 , the lower surface  58  of the grille portion  52  that is part of the lip  66  rests on the upper surface  44  of the desktop  42  about the opening  46  to support the diffuser  38  in the opening  46 , as illustrated in  FIG. 8 . The grille portion  52  includes a plurality of fins  68  which cooperate to define air channels  70  through which air may exit the diffuser  38  through the upper surface  56 . 
         [0036]    The raised floor air distribution system  20  with its floor terminals  30  provide general control of the temperature in the room  18 . The desktop air conditioning system  10  of the present invention supplements those efforts by providing individualized, personalized, and customizable conditioned air to individual users  72  to help accommodate the different temperature desires of occupants of the building  12 . In that regard, the desktop air conditioning system  10  can be used by the user  72  in  FIG. 6  to provide cooler air from the plenum  28  when the user  72  feels hot. To best cool the user  72 , the conditioned air that passes through the diffuser  38  should be primarily directed at the user&#39;s upper body or torso  74 . To accomplish this, the fins  68  are angled with respect to the upper surface  56  to direct the flow of air, as represented by the arrows  76  in  FIG. 6 , primarily along the upper surface  44  of the desktop  42 . To accomplish the desired generally horizontal throw of the desktop diffuser  38 , the fins  68  were designed accordingly. 
         [0037]    As illustrated in  FIG. 15 , the fins include an angled upper surface  78  and an angled lower surface  80 . The angled upper surface  78  preferably slopes downwardly from the upper surface  56  an angle α and the angled lower surface  80  slopes downwardly with respect to the upper surface  56  and angle β. The angle α is preferably between 15°-55° and, in one embodiment, is approximately 35°. The angled β is in the range of 25°-65° with respect to the upper surface  56 , and, in one embodiment, is approximately 48°. The angled lower surface  80  joins a downwardly facing surface  82  that provides a ledge  84  that is generally parallel to the upper surface  56 . The ledge  84  helps direct air coming up the lower angled surface  80  of the fin into a generally horizontal throw. 
         [0038]    The fins  68  also preferably include an upper vertical wall  86  and a lower vertical wall  88 . The fins also include a lower surface  90  at the bottom of the angled lower surface  80  and a ridge  92  at a bottom of the angled upper surface  78 . 
         [0039]    As illustrated in  FIG. 14 , the fins may also be arranged in an arcuate shape to spread the air flow out in a wide direction radially from the diffuser  38 . As will be appreciated from the plan view in  FIG. 14 , the air would be disbursed across an angle of less than 180°, with the majority of the throw being directed along a centerline of the diffuser  38  which would fall along a rib  94  that separates the two groups of air channels  70 . The arcuate fins  68  create arcuate air channels  70 . As illustrated in  FIG. 14 , the fins can be arranged in a concentric orientation about a point  96  adjacent and edge of the grille portion  52 . 
         [0040]    To provide the user  72  with some control of the volume of air flowing through the diffuser  38 , the diffuser  38  in  FIGS. 8-13  is a variable air volume diffuser. As such, the diffuser  38  includes a volume control mechanism  98 . In the illustrated embodiment, the mechanism includes a movable plate  100  and a stationary plate  102 . The plates  100 ,  102  take the shape of disc-like objects and have a plurality of radially aligned pie shaped openings therethrough, thereby providing a wagon wheel appearance. The plates  100 ,  102  are received in the body portion  54  and coupled with a hub  106  in the center of the lower surface  58  of the grille portion  52  along the rib  94  by a screw  108  that passes through the center of the plates  100 ,  102 . As illustrated in  FIG. 9 , the movable plate  100  is placed closest to the grille portion  52  and includes a user engageable tab  110  that is generally perpendicular to an upper surface  112  of the movable plate  100 . The tab  110  extends upwardly through an arcuate slot  114  in the grille portion  52  of the diffuser  38 . The user  72  may then move the tab  110  side to side to rotate the movable plate  100 . 
         [0041]    The stationary plate  102  can be held in place by a number of different ways. In one embodiment, an inner surface  116  of the body portion  54  includes a plurality of longitudinally extending ridges  118  thereon. The stationary plate  102  has a corresponding set of notches  120  in its outer periphery  122  that align with and cooperate with the ridges  118  on the inner surface  116  of the body portion  54 , as illustrated in  FIG. 10 . The movable plate  100  has a smaller diameter than the stationary plate  102  so that the outer edge of the movable plate  100  fits within and does not engage with the ridges  118 . 
         [0042]    In  FIG. 11 , the movable plate  100  is in an open or first position, where the openings  104  in the movable plate  100  are aligned with the openings  104  in the stationary plate  102 . In this position, the maximum amount of air is allowed to pass through the desktop diffuser  38 . In  FIG. 12 , the user  72  has rotated the movable plate  100  by way of the tab  110  such that a portion of the openings  104  in the stationary plate  102  are covered by portions of the movable plate  100 . In this position, the air flow has been reduced by an amount somewhat less than half.  FIG. 13  illustrates the movable plate  100  in a second or closed position where none of the openings  104  in the movable plate  100  are aligned with the openings  104  in the stationary plate  102 . As such, the volume control mechanism  98  operates to prevent the flow of air through the diffuser  38 . 
         [0043]      FIG. 16  illustrates an alternate embodiment of the desktop diffuser  38 . In this embodiment, the desktop diffuser  38  is a constant volume diffuser and does not include a volume control mechanism  98 . The user  72  could still control the amount of air blown in their direction by rotating the diffuser  38  in the opening  46  in the desktop  42  such that the centerline of the throw pattern, represented by the rib  94 , points away from them. The farther the user rotates the diffuser away from pointing at them, the lower the volume of air being directed to the user, and therefore the user will notice a decrease in cooling. 
         [0044]    In one embodiment of the invention, the supply ducts  36  are 4″ flexible ducts and the outer surface  64  of the body portion  54  has a circumference that is sized for receipt in the ducts. In this embodiment, the floor unit  34  is 5″×10″ and is received in an opening in a 24″×24″ floor tile  22 . The plenum  28  is kept at a pressure of 0.02-0.1″ water gauge compared to the standard pressure in the room  18 . This results in a volume of air of approximately 15 cubic feet per minute being directed to the user  72  at a velocity of less than 50 feet per minute. A velocity of zero to 50 feet per minute has been found beneficial and a volume of 5-50 cubic feet per minute has also been found beneficial. The majority of the air exiting the diffuser should fall between 0°-45° angle from the desktop  42 . 
         [0045]    Accordingly, the desktop diffuser  38  is well designed to provide a low profile desktop air conditioning delivery mechanism. Preferably, the upper surface  56  of the diffuser  38  projects up from the desktop  42  less than one-half of one inch. More preferably, the upper surface  56  of the desktop diffuser  38  protrudes from the desktop approximately less than two-tenths of one inch. 
         [0046]    Many variations can be made to the illustrated embodiment of the present invention without departing from the scope of the present invention. Such modifications are within the scope of the present invention. For example, the diffusers can be square in shape and the air channels be straight across as opposed to arcuate. This would provide for a more uni-directional throw of the air across the desktop. Another modification would be to permit volume control of the constant volume diffuser of  FIG. 16  by placing an object on top of the upper surface  56  of the diffuser  38 . The user  32  could move the object back and forth across the upper surface of the diffuser to control the amount of air passing therethrough. It should be noted that while the diffuser was described as having a grille portion coupled with a body portion, the diffuser  36  may be cast as a single unitary member. Other modifications would be within the scope of the present invention. 
         [0047]    From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the method and apparatus. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the invention. 
         [0048]    Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative of applications of the principles of this invention, and not in a limiting sense.