Abstract:
An apparatus for providing cool air to electronic equipment in closed cabinets wherein a plurality of electronic equipment (such as stereo equipment) are stacked within a cabinet such that front surfaces of the equipment face a front cabinet door or fill in the front cabinet opening, the apparatus including a whisper quiet energy efficient fan and automatic temperature controlling thermostat being mounted with supplied hardware in an upper rear area of the cabinet, causing the warmer air to be expelled and pulling fresh cooler air through lower front inlets, thereby forcing a rapid air exchange within the equipment cabinet.

Description:
BACKGROUND OF INVENTION  
       [0001]     The present invention is directed to cabinet air-cooling systems for electronic equipment placed in cabinets with inadequate ventilation.  
         [0002]     Over the past several decades, people have started using small computers and stereo equipment with many unsightly wires connected to them. In an attempt to make their homes attractive and still be high tech, many people have placed their expensive electronic equipment into cabinets, often times with front door assemblies constructed of clear or smoked Plexiglas or safety glass. This practice is very commonplace since people do not want their small office or home to appear lab like. Because of this widespread method of upgrading the aesthetics, the disadvantages have also become a very clear problem. Equipment failures are extremely high when the electronic equipment cannot adequately cool its internal components due to a lack of access to cooler air. In effect, these failures represent a massive loss to individuals and in some cases to honest companies attempting to honor warranties on products that failed through no fault of their own.  
         [0003]     To provide stimulating entertainment, many people purchase very expensive stereo equipment along with plasma TV&#39;s and build them into their homes in cabinetry. To provide the high tech computing and Internet access for needed education and purchasing, many people conceal the computer equipment and unsightly wires in desk cabinets. Hereinafter, Stereo Equipment, TV&#39;s (HD, Plasma, Projection), Computers and other heat generating electronic equipment, will collectively be referred to as electronic equipment in order to simplify this explanation.  
         [0004]     A cabinet is typically constructed to include a top, and bottom, opposing lateral walls, front doors and a back. The front doors are often hinged and readily opened to facilitate access to the electronic equipment inside the cabinet. In addition, the front door or doors are often transparent but darkly smoked so as to allow the operator to use infrared remote controls for the operation of their electronic equipment and to facilitate use from various visual displays that the electronic equipment may provide.  
         [0005]     Often times, the electronic equipment placed within a cabinet will be replaced by other newer electronic equipment to modify capabilities or change other important system operating parameters. This newer equipment may have differing operating temperature tolerances and consequently may not last when subjected to the same environment as its predecessor.  
         [0006]     One problem with virtually all electronic equipment is that, during operation, electronic equipment generates heat. If equipment generated heat is not dissipated quickly enough the heat can cause the equipment to malfunction, or when extreme, can destroy the equipment.  
         [0007]     The industry has developed several different ways in which to cool electronic equipment. For example, in the case of a plasma TV in a small shallow cabinet, some professional installation companies mount several small light duty fans positioned in the back wall of the cabinet. The noisy fans run whenever the operator does not forget to plug them in or turn them on.  
         [0008]     In the case of most closed cabinet electronic equipment installations, small light duty noisy fans alone cannot be relied upon to maintain low temperatures.  
         [0009]     Specifically, these types of fans alone cannot be relied upon because, in a typical critical environment, there are so many (heat generating) electronics pumping heat into the ambient, that the ambient temperature in the critical environment would reach dangerous levels relatively quickly. In effect, the ambient air would not be cool enough to effectively cool the electronic equipment.  
         [0010]     One common way to cool critical environments has been to install multiple small light duty noisy fans (similar to the fans inside a computer). A reasonable environment temperature can sometimes then be obtained possibly for a short period of time before one or more of the fans quietly die or slow down. The environment temperature is then compromised and the electronic equipment is now subjected to temperatures exceeding specifications causing the often times permanent failures to occur.  
         [0011]     While identical and constant temperatures throughout the critical environment are ideal, unfortunately there are several sources of temperature irregularity in typical critical environments. For instance, the ambient temperature in some critical environments can be different than in others. Cabinets (and electronic equipment therein) in warmer room areas tend to be warmer than cabinets in the cooler areas.  
         [0012]     One other source of temperature irregularity within the critical environment is the disparate amount of heat generated by the different electronic equipment and their uses within the separate cabinets. For instance, assuming identical plasma TV&#39;s, a first cabinet that operates near full brightness generates more heat than a second cabinet in a darker lower level room operating at half brightness. In this case, all other things being equal, the air temperature near the first cabinet (and inside the first cabinet for that matter) would be warmer than the air temperature near the second cabinet (and inside the second cabinet).  
         [0013]     Thus, despite efforts to maintain the same conditions throughout critical environments, often the temperatures within different critical environments will vary and this variance can result in electronic equipment failure or premature degradation in performance.  
         [0014]     One solution to the critical environment temperature disparity problem is to increase the volume of the cooling air forced into the critical environment so that even the warmest equipment is cooled enough to minimize or avoid equipment failure. Unfortunately, the consumer will not tolerate consistent loud noise or excessive white noise in their home or office and therefore this solution is often unworkable.  
         [0015]     Yet one other solution to the critical environment temperature disparity problem is to provide cabinet monitoring equipment including temperature sensors inside cabinet housings that are linked to a processor. The processor can then monitor temperature in the cabinets and generate an alarm when the temperature inside any given cabinet exceeds some threshold level.  
         [0016]     While some of the above solutions are advantageous they have some shortcomings. First, although cheap noisy fans provide a low cost solution, they provide completely inadequate insurance.  
         [0017]     Second, electronic equipment cooling with small low cost noisy fans is relatively inefficient. Clearly reliable low noise higher volume air exchange provides more efficient cooling.  
         [0018]     Third, fans producing obnoxious levels of noise are apt to be a relief when the noise subsides due to fans slowing down or quietly dying. In addition, if left up to the consumer to always remember to plug the fans in when operating the electronic equipment, this becomes an area for mistakes to manifest themselves in the form of damaged expensive electronic equipment.  
         [0019]     Fourth, multiple temperature sensors with linked processor control and monitoring, generating alarms upon exceeding temperature threshold levels is neither a consumer friendly installation or cost effective.  
         [0020]     One attempt to address the problems with cooling electronic equipment in cabinets is described in U.S. Pat. No. 6,188,189 (the &#39;189 patent) that was issued on Feb. 13, 2001 and that is entitled “fan Speed Control System” which teaches one system that automatically alters cooling air volume as a function of cabinet temperature. To this end, the &#39;189 patent teaches that dedicated temperature sensors can be positioned at various locations within a cabinet. The sensors are monitored and fan speeds are altered as a function of cabinet temperature.  
         [0021]     While the &#39;189 solution advantageously provides automated control of cooling air volume, this solution to the temperature control problem is relatively expensive requiring a plurality of dedicated temperature sensors.  
         [0022]     One other problem with a fan speed controlling system like that taught in the &#39;189 patent is that the fans continue to run at a lower speed through frequency current modulation (also known as pulse width modulation), or voltage clamping. Pulse width modulation is very noisy and tends to cause premature fan failure while voltage clamping is energy wasteful and can also cause premature fan failure. Also, the space from which the fans attempt to draw air could be blocked so that the fans, in fact, draw little air and the cooling effect is minimal. For small cabinets with stereo equipment, plasma TV&#39;s, and single computer systems, etc., (the &#39;189 patent) system is not practical from a cost standpoint and variable speed cooling is of no benefit without having fans and airflow completely oversized.  
         [0023]     One attempt to address the problems with ambient cooling systems is described in U.S. Pat. No. 5,216,579 (the &#39;579 patent) entitled “Rack Based Packaging System for Computers with Cable, Cooling and Power Management Module” issued on Jun. 1, 1993. The &#39;579 patent teaches a system including a power plenum, a cooling plenum and a cable plenum.  
         [0024]     In the configuration of the &#39;579 patent, it teaches that the cooling plenum may be positioned on the side of the cabinet adjacent the front cabinet wall. The &#39;579 patent also teaches that the cooling plenum, channels cooling air directly from a raised floor up along the side of the cabinet. This configuration is not practical or applicable to residential cabinets or small business computer desks.  
         [0025]     Other systems regulate cooling in other fashions (e.g., via damper control or cooling air temperature).  
         [0026]     Thus, there is a need for a more efficient cool air delivery system for use in electronic equipment cabinet environments. In addition, there is a need for an air delivery system that can automatically provide increased ventilation to cabinets based on cabinet and or equipment temperature. Moreover, there is a need for a very low noise system that automatically becomes perfectly quiet when equipment environment temperatures drop to acceptable levels after equipment is turned off, thereby providing residents with a noise free environment. Furthermore, there is a need for a cabinet cooling system that is energy efficient with energy requirements averaging as low as a night-light and will not produce unwanted RFI during running or switch times. Finally, there is a need for a cabinet cooling system that is aesthetically pleasing and is designed in most cases to outlast the equipment it is protecting.  
       SUMMARY OF INVENTION  
       [0027]     It has been recognized that a plenum or other form of air delivery member can be constructed on the inside of an electronic equipment cabinet door that can deliver cool air extremely efficiently to electronics inside the cabinet to increase cooling efficiency. In some embodiments the plenum includes the cabinet door while in others the plenum is a retrofit assembly that can be added to an existing door to provide the cooling air. In several instances, cool air is pumped directly into the plenum via a conduit member that extends from a cooling air source below the cabinet.  
         [0028]     In general terms, the present invention includes an apparatus for use with a cabinet, housing electronic equipment and generally having a front door that closes creating a confined non-circulating air space. The apparatus is for purging the confined heated air and drawing in fresh cooler air thereby allowing the design of the electronic equipment (be it convection or forced air cooling) to perform its job properly.  
         [0029]     In some applications the air inlet is comprised of a dispersed specified relative area due to constraints in the cabinet locations or configuration.  
         [0030]     In some embodiments the apparatus further includes multiple energy efficient whisper quiet fans to facilitate effective cooling for larger or more tightly confined electronic equipment, which might otherwise create a static dead air space inside the cabinet.  
         [0031]     In these special embodiments the apparatus instructions require the total air intake area to be a multiple of the original required air intake area times the number of additional energy efficient whisper quiet fans.  
         [0032]     These and other objects, advantages and aspects of the invention will become apparent from the following description. In the description, reference is made to the accompanying drawings, which form a part hereof, and in which there is shown a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention and reference is made therefore, to the claims herein for interpreting the scope of the invention.  
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0033]      FIG. 1  is a schematic view of a critical environment in which the present invention should be employed;  
         [0034]      FIG. 2  is a schematic diagram illustrating positioning and implementation of the present invention with additional detail;  
         [0035]      FIG. 3  is an actual view of a common embodiment of the present invention;  
         [0036]      FIG. 4  is a schematic view of a critical environment with some additional detail;  
         [0037]      FIG. 5  is a picture view of a typical critical environment depicting inadequate ventilation for the electronic equipment while displaying the front view of the entertainment center;  
         [0038]      FIG. 6  is similar to  FIG. 5  albeit with a glass door closed in front of the additional electronic equipment;  
         [0039]      FIG. 7  is a picture of a typical roll top computer workstation desk with a critical computer environment even without the door in front;  
         [0040]      FIG. 8  is similar to  FIG. 7 , albeit without a roll top and depicting actual computer equipment;  
         [0041]      FIG. 9  is a perspective view of a wall critical environment entertainment center;  
         [0042]      FIG. 10  is a view similar to  FIG. 9 , albeit illustrating a single high definition TV installation; 
     
    
     DETAILED DESCRIPTION  
       [0043]     Referring now to the figures where like reference numerals correspond to similar elements throughout the several views and, specifically, referring to  FIG. 1 , the present invention will be described in the context of an exemplary critical environment cabinet including front glass doors, back, top, bottom and sides that define an environment space. Within this critical environment, a plurality of electronic equipment would be arranged so as to create critical ambient temperatures. For reference, a similar cabinet in  FIG. 6  is shown populated with examples of such electronic equipment. The invention CABINET COOL is depicted in  FIG. 2 ,  FIG. 3 , and  FIG. 4  in a manner, which will be described in more detail below.  
         [0044]     Referring now to  FIG. 2 , as illustrated, this critical environment embodiment typically requires a second whisper quiet energy efficient fan, whereas the whisper quiet energy efficient fans are installed in locations (E &amp; F). Whereas the grille in  FIG. 2  as shown, is reversed and faces the outside back of the cabinet leaving the whisper quiet energy efficient fans mounted on the inside of the back of the cabinet. These whisper quiet energy efficient fans accomplish the expulsion of heated air at a rate of 100 cubic feet per minute out the top back of the cabinet. The cooling air source originates through the lower back of the critical environment through a slot cut in location (A). The cooling air source is routed through a series of equal area slots in the removable shelves sequencing from (B) to (C) and then through a final equal area slot in the upper side panel (D).  
         [0045]     Specifically, according to the present invention, since warm air rises, the expelled heated air does not descend to the level of the cooling air intake (e.g., A), hence delivery of cool air through slot (A) to locations there above in the critical environment.  
         [0046]     Referring still to  FIG. 2 , the automatic adjustable temperature control unit is secured to position (G) as depicted. Cooling controller in position (G) samples ambient air temperature out of the air pathway and therefore will not disengage prematurely. In the event that this critical environment contains electronic equipment, (other than satellite receiver, VCR&#39;s, TV surround sound amp), which could be used independent of the TV, the automatic adjustable temperature control unit should be relocated into the slot (D) opening between the adjacent cabinets to enable air temperature sampling from either equipment cabinet. An alternative to the common area location is to locate a second temperature control unit in the rear top of the cabinet defined by slot (C &amp; D).  
         [0047]     Referring to  FIGS. 3 &amp; 4 , for the purposes of the present invention it is assumed that the  FIG. 4  cabinet houses stereo equipment in the left side behind a glass door. This embodiment would require a cool air intake slot to be opened up in the lower rear of the cabinet below shelf  1 . The cool air path would then proceed up through slots in the rear of (Shelf  1  &amp;  2 ). Expulsion of the heated air by the electronic equipment is accomplished through the installation of one whisper quiet energy efficient fan as represented in  FIG. 3 , mounted as depicted in  FIG. 4  location (E) or in the back of same cabinet above (Shelf  2 ).  
         [0048]     Controlled cool air is accomplished through the installation of the automatic adjustable temperature control unit as represented in  FIG. 3 , mounted in  FIG. 4  within the rear top cabinet area above (Shelf  2 ).  
         [0049]     In addition to the components described above, the present invention also includes a plurality of bolts which facilitate mounting adaptation to a respectable range of cabinet wall thicknesses along with nylon locking nuts to prevent vibration loosening over time.  
         [0050]     Referring still to  FIG. 3  and now to  FIGS. 5, 6 ,  9  &amp;  10 , for the purposes of the present invention, these cabinets represent examples of critical environments such that tremendous benefit is obtained through the installation of the whisper quiet energy, efficient fan and thermostat as depicted in  FIG. 3 .  
         [0051]     Referring still to  FIG. 3  and now to  FIGS. 7 &amp; 8  illustrating critical environments for personal computer systems. Computer desks having the same critical over temperature problems and even to a greater degree than home entertainment systems, require a method of air exchange to prevent the computers from sustaining damage.  
         [0052]     Referring still to  FIGS. 5, 6 ,  7 ,  8 ,  9 , and  10  a plurality of desk and cabinet configurations enclose electronic equipment in cabinets and lack sufficient ability to reduce ambient temperature without the attainable help afforded through the installation of automatic temperature controlled air cooling systems as depicted in  FIG. 3 .  
         [0053]     It should be appreciated from the above-described configuration of components that the present invention delivers cool air from a cool air source directly to the position relative to heat generating electronic equipment that is most efficient for use. When the Whisper quiet, energy efficient fans operate, cool air is pulled past each stacked piece of electronic equipment causing a torrent of air turbulence over heat generating components therein, prior to being expelled into open room space. Controlling the startup of the whisper quiet, energy efficient fans is an adjustable threshold temperature at the high end of an acceptable electronic equipment temperature range, whereas controlling the shutoff of the whisper quiet energy efficient fans is accomplished by an approximate 7 degrees Fahrenheit drop below the adjustable high threshold temperature setting. This same adjustable threshold temperature thermostat is equipped with RFI canceling snubber circuitry to eliminate entertainment equipment interference and stabilize temperature threshold settings. In conventional systems that cool all of the space within a critical environment, differences in equilibrium, although important, are relatively less important as the air pulled into the environment generally mixes prior to being expelled out of the cabinet.  
         [0054]     While certain methods and apparatus are described above, the present invention is not meant to be so limited and other embodiments are contemplated.  
         [0055]     For example, individual plenums could be easily added in a multi cabinet entertainment center with common passageways opened up between the cabinets and ambient air temperature being sampled as a result of convection with stacked cabinets.  
         [0056]     To apprise the public of the scope of this invention, the following claims are made: