Abstract:
Disclosed is a heat removal apparatus to be used in conjunction with a case of a computer processing unit. The apparatus comprises an air permeable cover disposed over a top opening of the case, the air permeable cover for enabling the hot air in the case to egress therethrough and a cap secured over the air permeable cover for preventing dust and liquids from entering the case therethrough while allowing the passage of hot air therethrough by virtue of the stack effect.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit of priority of U.S. provisional Application No. 61/711,621, filed on Oct. 9,2012 ; entitled “A HEAT REMOVAL APPARATUS AND A METHOD OF REMOVING HEAT”, owned by the assignee of the present application and herein incorporated by references in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The disclosure herein generally relates to a heat removal apparatus and a method of removing heat, and specifically but not exclusively to a heat removal apparatus and a method of removing heat having consumer appeal. 
       BACKGROUND 
       [0003]    Processing units, for example a computing device&#39;s CPU, motherboard, graphics accelerators, and their peripherals, generate heat. This heat must be removed from the processing unit case for reliable long-term operation of the processing units. 
         [0004]    A personal computer may be modified to operate faster than specified by the manufacturer. Speed enhancing modifications may include increasing the clock frequency (“overclocking”), changing the CPU multiplier, changing memory timing, and changing an operating voltage. 
         [0005]    These changes may increase power consumption by the processing unit, generating more heat that must be removed. Without adequate heat removal, some digital circuits will slow down or even fail. 
         [0006]    Powerful fans, larger heat sinks, heat pipes and water cooling may remove the generated heat. There is a need to cool processing units using an arrangement and in a manner that is effective and attractive to consumers, especially to those that may wish to modify their personal computers. 
       SUMMARY 
       [0007]    Disclosed herein is a heat removal apparatus. The apparatus comprises at least one wall arranged to be disposed around the perimeter of an opening in a case for a processing unit. The apparatus comprises an air permeable cover arranged to be disposed over the opening and arranged to cooperate with the at least one wall to block at least one of radio wave and microwaves that egress the case through the opening. The apparatus comprises an adjustable cap supporting structure arranged to support a cap over the air permeable cover at an adjustable separation from the air permeable cover. 
         [0008]    Examples of processing units include but are not limited to a central processing unit, a motherboard, a graphics accelerator, and their peripherals. 
         [0009]    Generally, but not necessarily, the at least one wall constitutes a stack. Air made buoyant by heat from a processing unit that may be disposed in the case may be driven through the stack by the stack effect, providing an optional completely passive means for removing heated air from the case. The air permeable cover may provide egress of the heated air while blocking the at least one of radio waves and microwaves that may be generated by the processing unit. The air permeable cover may also block objects moving into the case that may damage the processing unit. The air permeable cover may, however, be permeable to a liquid and may not prevent the inadvertent flow of a liquid into the case. The cap when so supported may provide a barrier for a liquid such as a beverage being consumed by a person near the case. Consequently, an embodiment may provide a relatively quiet heat removal apparatus which may not require a fan, and which may prevent the ingress of objects and liquids into the case. The adjustable supporting structure provides great flexibility on choice of cap. A consumer may wish the cap to conform to their preference. For example, a consumer may wish to use a body of a model car as a cap. Different model cars have different shapes and so require to be held at a different separation from the air permeable cover. Another consumer may wish to use a sculpture as a cap, for example. Generally the heat removal apparatus may accommodate a wide range of consumer selected caps. 
         [0010]    In an embodiment the cap when so supported conceals the at least one wall and air permeable cover. A consumer may not wish to have the relatively unappealing at least one wall and air permeable mesh exposed and may wish to conceal them with the cap. 
         [0011]    In an embodiment, the air permeable cover comprises a mesh arranged to block the at least one of radio waves and microwaves. The at least one wall may be arranged to block the at least one of radio waves and microwaves. A mesh may have relatively very good airflow properties while still blocking the at least one of radio waves and microwaves. 
         [0012]    In an embodiment, the at least one wall and the air permeable cover define a heat exchanger receiving space for receiving a heat exchanger thermally coupled to the processing unit. A water cooled block may be in thermal contact with the processing unit. The heat exchanger may be in water communication with the water cooled block. Water moved through the water cooled block may move through the heat exchanger and so be cooled before being returned to the water cooled block. The air permeable cover may be arranged to attach to the heat exchanger. The air permeable cover may have a plurality of fastener receiving apertures having the same relative disposition as that of a plurality of fastener receiving apertures of the heat exchanger. A plurality of fasteners may be received by the fastener receiving apertures of the air permeable cover, and also may be received by fastener receiving apertures of the heat exchanger. An embodiment and the heat exchanger may be attached by any suitable means including but not limited to screws, adhesive, rivets, and clips. 
         [0013]    In an embodiment, the plurality of fastener receiving apertures of the air permeable cover also have the same relative disposition as that of a plurality of fastener receiving apertures of a fan. The fan may be fixed to the air permeable cover by fasteners that are received by the plurality fastener receiving apertures of the air permeable cover and the plurality of fastener receiving apertures of the heat exchanger. 
         [0014]    In an embodiment, the adjustable cap supporting structure comprises a carriage. The carriage may be have slots through which fasteners that are fixed to the at least one wall pass. 
         [0015]    Alternatively or additionally, the carriage may be movable along a slot formed in the at least one wall. The carriage may be arranged to be fixed to the cap. There may be a plurality of carriages. 
         [0016]    An embodiment comprises a skirt. The skirt may have apertures formed therein for receiving fasteners. The fasteners may secure the embodiment to the case. The heat removal apparatus may be retrofitted to the case. Alternatively, the heat removal apparatus may be integral with the case. 
         [0017]    In an embodiment the at least one wall has at least one air flow intake formed therein. 
         [0018]    In an embodiment, the cap is a decorative cap. The at least one wall may have at least one aperture formed therein for attaching at least one decorative item to the at least one wall. 
         [0019]    Disclosed herein is a case for a processing unit having a heat removal apparatus attached thereto in accordance with the above disclosure. 
         [0020]    Disclosed herein is a method of removing heat. The method comprising the step of disposing at least one wall around a perimeter of an opening in a case housing a processing unit. The method comprises the step of disposing an air permeable cover over the opening. The method comprises the step of blocking at least one of radio waves and microwaves traveling through the opening with the at least one wall and the air permeable cover. The method comprises the step of adjusting the separation of a cap over the air permeable cover. 
         [0021]    An embodiment comprises the step of using a stack effect to move air through the opening and the air permeable cover. 
         [0022]    An embodiment comprises the step of disposing a heat exchanger thermally coupled to the processing unit in a heat exchanger receiving space defined by the at least one wall and the air permeable cover. A fan may be used to move air through the opening and the air permeable cover. 
         [0023]    In an embodiment, the cap is a decorative cap. The method may comprise the step of attaching at least one decorative item to the at least one wall. 
         [0024]    In an embodiment, the step of adjusting the separation conceals the at least one wall and air permeable cover with the cap. 
         [0025]    Any of the various features of each of the above disclosures, and of the various features of the embodiments described below, can be combined as suitable and desired. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0026]    Embodiments will now be described by way of example only with reference to the accompanying figures in which: 
           [0027]      FIG. 1  shows a perspective view of one embodiment of a heat removal apparatus. 
           [0028]      FIG. 2  shows a plan view of the embodiment of the heat removal apparatus of  FIG. 1 . 
           [0029]      FIG. 3  shows another perspective view of the embodiment of the heat removal apparatus of  FIG. 1 . 
           [0030]      FIG. 4  shows an exploded perspective view of the embodiment of the heat removal apparatus of  FIG. 1 . 
           [0031]      FIG. 5  shows a perspective view of another embodiment of a heat removal apparatus revealing a heat exchanger receiving space. 
           [0032]      FIG. 6  shows an exploded perspective view of a computing assembly including the embodiment of the heat removal apparatus of  FIG. 1 . 
           [0033]      FIG. 7  shows another perspective view of the embodiment of a heat removal apparatus of  FIG. 5 . 
           [0034]      FIGS. 8 and 9  show different perspective views of the embodiment of a heat removal apparatus of  FIG. 5  having fixed thereto an optional airflow molding. 
           [0035]      FIG. 10  shows a perspective view of another embodiment of a heat removal apparatus and a cap in the form of a model car body to be receiving thereby. 
           [0036]      FIGS. 11 and 12  show perspective views of a method of attaching an example cap to the eat removal apparatus of  FIG. 1 . 
           [0037]      FIG. 13  shows the heat removal apparatus with the suction fan 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0038]      FIG. 1  shows a perspective view of one embodiment of a heat removal apparatus, generally indicated by the numeral  10 . The apparatus  10  has a wall  12  that is arranged to be disposed around the perimeter of an opening in a case for a processing unit, for example a personal computer case. The wall  12  of the embodiment of  FIG. 1  has four wall sections arranged to form a rectangle, however the four sections may have generally any configuration. The wall may form a circle, or any suitable shape. Attached to the top of the wall  12  is an air permeable cover in the form of a mesh panel  14 . The mesh panel  14  has a plurality of apertures through which air may flow. The opening may be formed in a topmost surface of the case and the heat removal apparatus may be disposed above the opening. Buoyant air heated by the processing unit within the case may be drawn through the opening and through the air permeable cover  14 . Alternatively, air may be forced (by use of a fan, for example) through the opening and the mesh panel such that the heated air in the case is displaced. The mesh panel  14  is arranged to block to at least one of radio waves and microwaves that are generated by the processing unit. 
         [0039]    Consequently, the power of any interfering electromagnetic radiation released into the surroundings may be substantially reduced, in some embodiments to a negligible power. The mesh panel has a plurality of apertures each in the form of holes through the panel measuring between 1 and 10 mm In this embodiment, they are circular and holes have a diameter of between 5 and 6 mm, specifically 4 mm. Alternatively, the holes may be hexagonal or any other suitable shape. 
         [0040]    The movement of the air may be enhanced by a stack effect when the at least one wall forms a stack as shown in  FIG. 1 , for example. Not all embodiments comprise a stack, however. In this but not necessarily all embodiments have at least one fan lower in the case that may enhance the stack effect by drawing cool air into the lower portion of the case therefore assisting the movement of hot air out through the air permeable cover. 
         [0041]    The heat removal apparatus  10  has an adjustable cap supporting structure in the form of two carriages  16  attached to respective opposite wall sections of the wall  12 . As shown in  FIG. 4 , for example, the carriages  16  each comprise a bracket in the form of a right angled bracket that may be moved with respect to the at least one wall. Some embodiments, for example the embodiment  80  of  FIG. 10 , may have bracket  82  with an angle other than 90 degrees, for example less than 90 degrees, to accommodate a sloping surface of a cap  84  when so supported. Returning to  FIG. 4 , the carriage has guiding edges that define fastener receiving slots  22  through which fasteners in the form of screws, rivets or other suitable fasteners, may pass. The fasteners may be fixed to the at least one wall. Integrated into the at least one wall may be two threads provided by self-clinching nuts  20 . The self-clinching nuts  20  engage with threads formed on the fasteners. The position of the carriage  16  relative to the at least one wall may then be set by loosening the fasteners, moving the carriage to the desired position, and then re-tightening the screw. The guiding edges and the fasteners cooperate to guide the movement of the carriages to simplify cap placement. 
         [0042]    In an alternative embodiment that is not illustrated, each bracket has attachment lugs in the form of internally threaded projecting tubes. The internal threads are for engaging with fasteners in the form of screws. A screw may pass through the cap and be received by an internal thread for fastening the cap to a carriage. Any alternative fastening means, for example rivets or adhesive, may be used as suitable. The carriage may be movable along slots formed in the at least one wall  12 . A projecting tube may be attached to the carriage and may have an internal thread for a screw which is passed from the interior of the heat removal apparatus, through the slot and into the tube to engage the internal thread. The position of the carriage relative to the wall may then be set by loosening the screw, moving the carriage along the slot to the desired position, and then re-tightening the screw. In this embodiment, each carriage has two threaded tubes, each tube being for receiving a screw that passes through one of the slots. Other embodiments may have more or less tubes and slots as suitable. 
         [0043]      FIG. 5  shows a perspective view of another embodiment of a heat removal apparatus  50  that is similar to that of  FIG. 1 , where parts similar or identical in form or function are similarly numbered. The at least one wall  12  and the air permeable cover  14  define a heat exchanger receiving space  52  for receiving a heat exchanger  54  thermally coupled to the processing unit. In this embodiment, the heat exchanger is in the form of a radiator. The heat exchanger may be a shell and tube, plate heat, or any other suitable heat exchanger. A water cooled block may be in thermal contact with the processing unit. Water moved through the water cooled block may be communicated through fluid conduits in the form of pipes to the heat exchanger, moved through the heat exchanger  54  and so be cooled, and then returning to the water cooled block. The air moving within the at least one wall  12  may cool the heat exchanger. The air heated by the heat exchanger may be buoyant, driving a stack effect. 
         [0044]    The air permeable cover  14  may be arranged to attach to the heat exchanger. The air permeable cover may have a plurality of fastener receiving apertures  56  (labeled in  FIG. 2 ) having the same relative disposition as that of a plurality of fastener receiving apertures of the heat exchanger. The fastener receiving apertures  56  of the air permeable cover  14  may receive a plurality of fasteners. A plurality of fastener receiving apertures (which may be threaded) of the heat exchanger may also receive the plurality of fasteners. The air permeable cover  14  and the heat exchanger  54  may be attached by any suitable means including but not limited to screws, adhesive, rivets, and clips. 
         [0045]    The plurality of fastener receiving apertures  56  of the air permeable cover  14  also have the same relative disposition as that of a plurality of fastener receiving apertures of two fans  58  placed side by side. The fans may be fixed to the air permeable cover  14  by fasteners that are received by the fastener receiving apertures of the air permeable cover  14  and the fastener receiving apertures of the heat exchanger  54 . 
         [0046]    The embodiment shown in  FIG. 1  is integral with the case, specifically a removable cover  60  of the case  62 . The embodiment shown in  FIGS. 5 ,  7  and  8 , for example, are not integral with the case.  FIG. 7  shows this embodiment  74  having a skirt  64  in the form of a perimeter bracket or flange having apertures  66  formed at each corner therein for receiving case attaching fasteners. The skirt may additionally or alternatively be attached by adhesive or any other suitable means. 
         [0047]      FIG. 6  shows an exploded perspective view of a computing assembly including the heat removal apparatus  10  of  FIG. 1 , fans  58 , heat exchanger  54 , and a cap  68 . The cap  68  is a decorative cap in the form of a body of a model car. The body may have apertures formed therein for the passing of a shank of a fastener that is engaged by a thread of the carriage  18  which is part of a self-clinching fastener integrated with the carriage. The head of the fastener may bear against an upward facing surface of the model car body. The model car body has an internal cavity in which the at least one wall and air permeable panel may be concealed to improve consumer acceptance. The model car body also provides a physical barrier to liquids protecting the processing unit from accidental spills, for example, and is a protective barrier for the heat exchanger and/or fluid conduits. Decorative items in the form of model car wheels are attached to the at least one wall  12 . Fasteners in the form of screws pass through apertures  70  (labeled in  FIG. 3 ) formed in the at least one wall  12  to fix the wheels to the at least one wall. The wheels may alternatively or additionally be attached with adhesive or any suitable means. 
         [0048]      FIGS. 11 and 12  show an alternative method of attaching the cap  68  to the heat removal apparatus  10 . A piece of adhesive backed hook and loop (Velcro) strip  86  is adhered to the top surface of the carriage  16 . This piece  86  will be either hook or loop. The counterpart  88  of the hook or loop strip  86  is attached to the underside of the cap  68 . When the cap  68  is lowered the hook and loop contact and form a bond. If the gap is too wide to enable the bond the carriage is adjusted vertically up. This solution may not require any holes to be made in the cap  68  and may improve aesthetics and ease of removal of the cap while still securing it. 
         [0049]    The at least one wall  12  of the embodiments of  FIGS. 5 ,  7  and  8  also have at least one air flow aperture  72  formed therein for extra ventilation. This may be especially useful to introduce cool air between the at least one wall to cool the heat exchanger cooler used. 
         [0050]      FIGS. 8 and 9  show different perspective views of the heat removal apparatus  74  of  FIG. 7  having fixed thereto an optional airflow molding  76 . The molding has tabs  78  having distal hooks that fix the molding to the apparatus  74 . A user may pull the tabs  78  back to release the molding from the apparatus  74 . Cool air may be drawn through the air intake  72 , past the heat exchanger drawing away heat, and the heated exhaust air directed out on a side of the apparatus  74  not having an air intake  73 , away from the intake ventilation slots  72 . Consequently, there is relatively little exhaust air that enters the intake  73 . Exhaust air that enters the intake  73  may reduce cooling efficiency. 
         [0051]    Referring to  FIG. 13 , in one embodiment, a wall of the heat removal apparatus  74  is fitted with a suction fan  90  for evacuating the hot air emanated from within the case. 
         [0052]    Now that embodiments have been described, it will be appreciated that some embodiments may have some of the following advantages:
       Effective cooling may be achieved with low noise generation, especially when a stack effect is used to draw air through the case. The noise generated by fans may be distracting to computing users, examples of which include but are not limited to computer garners and persons using a home theater personal computer (HTPC).   A barrier against objects and liquids entering a case may be provided.   A decorative cap of the consumer&#39;s choice may be used to adorn a case and conceal the at least one wall and air permeable cap, increasing consumer appeal.       
 
         [0056]    Variations and/or modifications may be made to the embodiments described without departing from the spirit or ambit of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 
         [0057]    Prior art, if any, described herein is not to be taken as an admission that the prior art forms part of the common general knowledge in any jurisdiction. 
         [0058]    In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, that is to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.