CABINET COOLING FAN

Abstract

An electric fan core having a generally rectilinear shape, a positive pressure side, and a vacuum side is disclosed. A fan bracket attached to the positive pressure side of the electric fan core and offset from the fan core thereby defining a gap between the fan core and the fan bracket, the gap having a width less than an amount required to sustain a Venturi effect air intake when the electric fan core is in an operating state is disclosed. A grille attached to the vacuum side of the fan core and having a grille face that is offset from the fan core, the offset being greater than an amount of offset required to reduce turbulence noise from the grille face when the electric fan core is in an operating state is also disclosed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patent application No. 60/720,121 filed on Sep. 23, 2005, which is hereby incorporated by reference.

TECHNICAL FIELD OF THE INVENTION

This invention relates to electronics cabinet cooling generally and, more specifically to bracket mounted, electronically controlled cooling fans.

BACKGROUND

Electronic devices typically generate waste heat during operation. If left unattended, the excess heat can cause devices to malfunction and, in some cases, be permanently damaged. The problem is exacerbated by the small form factors and increased performance of many electronic devices. Often, electronics will be stacked together or mounted or placed in cabinets (the personal computer is one example of a cabinet based device). This can lead to additional heating as the amount of ambient air reaching heated components is reduced.

Cooling fans may be added to an electronics cabinet or enclosure to force cooling air to the components. However, typical cooling fans may be inefficient and may not move enough air to produce the desired cooling effect. In addition, known fan designs may be unacceptably noisy and the noise may be amplified by the installation location of the fan or the location of the electronics cabinet in a room. Fans are typically mounted to the cabinet in such a way that noise and vibration are transmitted through the material of the cabinet itself.

Therefore what is needed is a device and method for addressing the above, and related, issues.

SUMMARY OF THE INVENTION

The present invention disclosed and claimed herein, in one aspect thereof, includes an electronic cooling fan assembly with an electric fan core having a generally rectilinear shape, a positive pressure side, and a vacuum side. A fan bracket attaches to the positive pressure side of the electric fan core and is offset from the fan core thereby defining a gap between the fan core and the fan bracket, the gap having a width less than an amount required to sustain a Venturi effect air intake when the electric fan core is in an operating state. A grille attaches to the vacuum side of the fan core and has a grille face that is offset from the fan core, the offset being greater than an amount of offset required to reduce turbulence noise from the grille face when the electric fan core is in an operating state.

The present invention disclosed and claimed herein, in another aspect thereof, includes a fan mounting bracket for reducing noise and vibration in an enclosure. The bracket has a generally cylindrical shroud having a circumference and first and second ends, the shroud providing first and second mounting tabs substantially on opposite sides of the circumference on the first end, the mounting tabs each defining a fastening hole, the shroud also providing first and second stabilization tabs on substantially opposites side of the circumference on the fist end and being offset approximately 90 degrees from the mounting tabs. The bracket has a mounting flange attached to the second end of the shroud and defining a plane substantially orthogonal to an axis of the shroud, the mounting flange defines a plurality of fan attachment holes. The bracket has a plurality of elastic grommets wherein one of the plurality of elastic grommets is inset into each one of the plurality of fan attachment holes..

The present invention disclosed and claimed herein, in another aspect thereof, includes a method of reducing noise and vibration from a fan core operating to cool a container through an air vent. The method includes attaching a flanged shroud to the fan core with noise and vibration isolating grommets, attaching a grille to the fan core such that a face of the grille is offset from the fan core, the offset being at least a distance necessary to reduce turbulence noise through the grille face, and affixing the shroud to the air vent.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and is not limited by the figures of the accompanying drawings, in which like reference numbers indicate similar parts. Moreover, the drawings are not to scale and some features may be enlarged or reduced for illustrative purposes:

FIG. 1 is an exploded perspective view of a one embodiment of a cabinet cooling fan according to aspects of the present disclosure;

FIG. 2 is a frontal view of one embodiment of a cabinet cooling fan according to aspects of the present disclosure;

FIG. 3 is a side view of one embodiment of a cabinet cooling fan according to aspects of the present disclosure;

FIG. 4 is a rear view of one embodiment of a cabinet cooling fan according to aspects of the present disclosure;

FIG. 5A is a side view of a disassembled fan shroud according to aspects of the present disclosure;

FIG. 5B is an end view of a fan bracket face according to aspects of the present disclosure;

FIG. 6 is an exploded perspective view of another embodiment of a cabinet cooling fan according to aspects of the present disclosure;

FIG. 7 is a side cutaway view of one embodiment of an electronics cabinet having cooling fans according to aspects of the present disclosure;

FIG. 8A is a schematic of one embodiment of a relay according to aspects of the present disclosure;

FIG. 8B is a schematic of one embodiment of a relay configured as a switch according to aspects of the present disclosure.

FIG. 9A is a schematic view of one embodiment of a method of connecting a cabinet cooling fan according to aspects of the present disclosure;

FIG. 9B is a schematic view of one embodiment of a method of connecting a cabinet cooling fan through a triggering device according to aspects of the present disclosure;

FIG. 9C is a schematic view of one embodiment of a method of connecting multiple cabinet cooling fans via a single triggering device according to aspects of the present disclosure; and

FIG. 10 is an exploded perspective view of another embodiment of a cabinet cooling fan assembly according to aspects of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described with reference to the drawings. Referring now to FIG. 1, an exploded perspective view of a one embodiment of a cabinet cooling fan according to aspects of the present disclosure is shown. The major component parts of the cabinet cooling fan assembly 100 are shown with respect to one another in the manner in which they would be assembled. A fan core 102, a grille 108, and a fan bracket 116 are assembled to complete the fan assembly 100. The fan assembly 100 may then be mounted into a desirable location such as an electronics cabinet. The fan bracket 116 provides a means for mounting the fan assembly 100 into a cabinet or other location as well as providing additional functionality as will be described below. Some embodiments of the fan assembly 100 will provide a relay 144 suitable for controlling the operation of the completed fan assembly 100.

The fan core 102 may be an off-the-shelf component or may be custom built. In some embodiments a personal computer (“PC”) cooling fan can be employed as a fan core. Generally speaking, the fan core 102 will be an axial, cross-flow type fan. The fan core 102 may also be a tube axial or ducted axial fan. Various physical sizes and air flow ratings may be used for the fan core 102 depending upon the needs of the user and the end application of the fan assembly 100. SilenX Corporation of Santa Fe Springs, Calif. produces a variety of fan cores that may be suitable, including the popular 3.5 inch (92 mm) and 4.5 inch (120 mm) sizes (e.g., part numbers IXP-64-11 and IXP-74-11, respectively). The brands and part numbers are given by way of example only and it is possible to utilize other suitably quiet fan cores with the disclosure provided herein. The fan core 102 will typically provide fan core mounts 104 to be used for attaching the fan to a mounting location (e.g, the fan bracket 116) and/or for attaching the grille 108 or other covering. In the embodiment shown, the fan core 102 provides a total of eight fan core mounts and is generally rectilinear in shape with a fan core mount 104 in each of the four corners on both sides of the fan core 102. Other embodiments may have other shapes or configurations. The fan core 102 will typically have leads 106 to power an electric motor driving the fan blades. As will be described in greater detail below, the fan leads 106 may be attached directly to a suitable power source or may be attached to a thermal switch or to a relay board 140 to provide additional functionality for the fan assembly 100.

The grille 108 may be attached to one side of the fan core 102. The fan core 102 will typically be configured to move air in the direction of the bracket 116. In such case, the grille 108 will be attached to the vacuum or intake side of the fan core 102. In the embodiment shown, the grille 108 mounts to the fan core 102 via a set of grille mounts 110. The grille 108 is shown with four mounts 110 corresponding to the four fan core mounts 104 on one side of the fan core 102. The grille 108 provides a grille face that covers the blades of the fan core 102 during operation. The grille 108 may be an off-the-shelf grille or may be custom made. The grille 108 may be a wire grille or made from another material. The grille face 112 may be offset from the plane of the grille mounts 110 by the distance shown as F in the drawings. The distance F will allow the fan core 102 to operate with reduced turbulence and noise generated by the airflow through the grille face 112 versus having the grille face 112 flush with the grille mounts 110. In some embodiments, the amount of offset distance F will be approximately one eighth of an inch and can cause a drop in noise of up to 6 to 9 dB versus a flush mount.

The side of the fan core 102 not attached to the grille 108 is attached to the bracket 116. This will typically be the outgoing or positive pressure side of the fan core 102. The bracket 116 provides a face 118 for mounting to the fan core 102 and a shroud 122 for directing airflow. The face 118 is a flange attached to the shroud 122. The shroud 122 and face 118 may be separate components attached together or may be integrated as will be described. The face 118 has four mounts 120 corresponding to the four mounts 104 on the outward side of the fan core 102. The shroud 122 may be substantially circumferential or cylindrical or may have another shape corresponding to the fan core 102. The shroud 122 provides mounting tabs 124 that can be used to secure the fan assembly 100 into a desired location (only one tab 124 is shown in the view of FIG. 1) The mounting tabs 124 may be bendable and may be integrated with the shroud 122. Fasteners may be inserted through the mounting tabs 124 to secure the fan assembly 100 in place. In addition to mounting tabs 124, stabilization tabs 126 may be provided for preventing unwanted movement of the fan assembly 100. A strain relief cord 128 may also be provided on the bracket 116. The strain relief cord may be used to secure power or switching leads in place near the relay board 140 such that the connections themselves are not stressed. Additionally, the strain relief cord 128 may serve to secure power or switching leads to a vibration isolated portion of the fan assembly 100. This may prevent unwanted vibration and/or noise from propagating along power or switching lines.

The fan core 102, the grille 108 and the bracket 116 are connected by a series of fasteners, washers, and grommets. In one embodiment, the grille 108 attaches to the fan core 102 with rivets 114 through the grille mounts 110 and fan core mounts 104. In other embodiments bolts, screws, or other fasteners may be used. The fan core 102 and bracket 116 may attach together with bolts 130 and nuts 132. The bolts 130 may have a standard bolt head or a Philips head to aid in assembly. The nuts 132 may have Nylon inserts or other inserts to prevent untightening or noise from vibration. The bolts 130 pass through the bracket fan mounts 120 and the fan core mounts 104 to join with the nuts 132. In the embodiment shown, there are four bolts 130 and four nuts 132 corresponding to the four sets of bracket fan mounts 120 and fan core mounts 104 on one side of the fan core 102.

A set of grommets 134 may be inserted into the bracket fan mounts 104 prior to assembly. These grommets may be rubber or silicon or another suitable vibration and sound deadening material. One such suitable grommet is made by Gel-Mec UK of the United Kingdom (e.g., part no. 0905-90V). The grommets 134 and bracket fan mounts 120 will typically be sized such that the bracket fan mounts 120 are slightly larger than the grommets 134. The thickness of the face 116 will also typically be slightly thinner than necessary to use the grommets 134. This allows both ease of insertion and self centering of the grommets 134 with the fan assembly 100 mounted in any orientation. Washers 136 may be used where the bolts 130 meet the grommets 134 to allow the bolts 130 to be properly tightened without damaging or overstressing the grommets 134. The washers 136 may be Nylon or another material.

In some embodiments, the fan assembly may be attached to a power supply by the fan leads 106 in order to operate full time. In other embodiments, power may be supplied to the fan via a thermal switch such as the A2R model from Portage Electric Products of North Canton, Ohio. This allows the fan to activate upon a predetermined temperature instead of running all the time. In the embodiment shown in FIG. 1, a relay board 140 attaches to the fan core 102. The relay board 140 has a connection terminal 142 and a relay 144. The relay 144 allows the fan assembly 100 to be selectively powered from a remote location. In one embodiment, the relay 144 operates as a 12 volt triggered switch with a daisy chain output. That is, the relay board 140 can be used to activate a second fan assembly or another triggered device when the fan assembly 100 is activated. The operation and connection of the relay board 140 is described in greater detail below with respect to FIGS. 9A-9C.

Referring now to FIG. 2, a frontal view of one embodiment of a cabinet cooling fan according to aspects of the present disclosure is shown. FIG. 2 corresponds to a frontal view of the assembled fan assembly 100 of FIG. 1. The grille 108 can be seen in place over the intake side of the fan core 102 with the grille face 112 covering the interior moving parts of the fan core 102. From the view of FIG. 2, the relay board 140 with the relay 144 and connections 142 can be seen atop the fan core 102.

Referring now to FIG. 3, a side view of one embodiment of a cabinet cooling fan according to aspects of the present disclosure is shown. The fan assembly 100 shown in FIG. 3 is the same as those of FIGS. 1 and 2 except for the attachment of the grille 108. The fan assembly 100 of FIG. 3 has a series of standoffs 302 between the grille 108 and the fan core 102. Thus, the distance F required for quite operation of the fan core 102 can be achieved without offsetting the grille mounts 110 from the grille face 112 (see FIG. 1). The standoffs may be nylon, rubber, plastic or another material. A faster such as a bolt 304 may pass through the standoffs 302 and into a nut 306 to attach the grille 108 into position.

It can be seen from the view of FIG. 3 that due to the placement of the grommets 134 that the face 118 of the bracket 116 does not fit flush against the fan core 102. A gap 310 is thus created between the bracket face 118 and the fan core 102. When the fan core 102 is activated and running, a Venturi Effect is created at this gap 310. Thus, air will be drawn into the gap 310. The fan assembly 100 will typically be mounted in an enclosure such that the gap 310 is exposed to the heated air on the interior of the enclosure. In one embodiment, the Venturi Effect gap will be from around 1 to 3 mm. However, depending upon the grommet 134 and the configuration of the other components, this distance may vary so long as the gap does not become large enough that the Venturi Effect is destroyed and air begins to escape from the gap 310 rather than being drawn in. In some embodiments, the Venturi Effect gap can increase the volume of air expelled through the shroud 122 by up to 5%.

The view of FIG. 3 also shows the connection terminal 142 in greater detail. It can be seen that the terminal 142 provides a series connectors 312, which can be labeled for ease of use. The connectors 312 may be elevator style connectors or other connectors. A screw (location shown by arrow 314) may serve to adjust or tighten each connector 312. The electrical connection of the relay 144 and the connection terminal 142 will be explained in greater detail below.

Referring now to FIG. 4, a rear view of one embodiment of a cabinet cooling fan according to aspects of the present disclosure is shown. Here the fan assembly 100 is shown from the rear such that the placement of the mounting tabs 124 and the stabilization tabs relative to the shroud 126 can be seen. In the view of FIG. 4, the mounting tabs 124 have been folded out from the shroud 122 to show another position for the tabs that may be used for mounting the fan assembly 100 in place. Fastening holes 402 may be used for insertion of screws or other fasteners used to mount the fan assembly 100. In some embodiments, the holes 402 may provide a location for captive screws to speed installation of the fan assembly 100.

Referring now to FIG. 5A, a side view of a disassembled fan shroud according to aspects of the present disclosure is shown. FIG. 5 is illustrates the generally cylindrical fan shroud 122 “unrolled.” In some embodiments, the fan shroud 122 may be made from sheet metal and cut into the appropriate shape. The installation tabs 124 and stabilization tabs 126 can be seen in their appropriate locations on FIG. 5. Tabs 502 may be used to attach the shroud to the face 118 of the bracket 116 while the tab 504 may be used to secure the “flattened” shroud into the needed cylindrical shape. In one embodiment, the shroud as shown in FIG. 5 will be rolled up and spot welded together using the tab 504 and the tabs 502 will be bent outward and spot welded to the face 118.

Referring now to FIG. 5B, an end view of a fan bracket face according to aspects of the present disclosure is shown. The face 118 is shown here made from sheet metal, similar to the shroud 122 shown in FIG. 5. As described, the shroud 122 may be assembled and attached to the face 118 to complete the fan bracket 116.

Referring now to FIG. 6, an exploded perspective view of another embodiment of a cabinet cooling fan according to aspects of the present disclosure is shown. The fan assembly 600 of FIG. 6 functions in the same manner as those previously described. However, the fan assembly 600 provides for the placement and operation of the fan core 102 within an integrated grille and shroud assembly 602. The grille and shroud assembly 602 may be the same functionality as previously discussed. This includes, but is not limited to, the shroud 122, installation tabs 124, stabilization tabs 126, offset grille face 112, and Venturi Effect gap 310. The grille and shroud assembly may be a molded plastic product that may include additional machining to produce the desired features. Retaining clips 604 on the bracket face 118 interfit with the fan core mounts 104 to secure the fan core 102. The clips 604 may be snap fit or friction fit clips and may be molded along with the grille and shroud assembly 602 or may be added separately.

Referring now to FIG. 7, a side cutaway view of one embodiment of an electronics cabinet having cooling fans according to aspects of the present disclosure is shown. The cabinet assembly 700 may provide shelving and/or other storage options for one or more electronic components 704. Typically, the cabinet 702 will provide ventilation (e.g., through grating or spaces around the doors or other components) for allowing cool air to enter the cabinet 702. Fan assemblies 100 can be positioned in any location to provide forced air cooling of the cabinet 702. However, the fan assemblies 100 may be most efficient if located near the top portion of the cabinet 702 as shown. This is provided that adequate clearance is given inside the cabinet 702 to allow cooling air to reach the components 704. The arrows C show one possible entry location for cold air to be drawn into the cabinet 702 while the arrows H show hot air being exhausted by the fan assemblies 100.

Referring now to FIG. 8A, a schematic of one embodiment of a relay according to aspects of the present disclosure is shown. The relay assembly 800 shown in FIG. 8A, may be suitable for use in implementing switching of the fan assembly 100. The configuration shown in FIG. 8A is a standard relay assembly. The relay board 140 is shown in dotted line and mounted thereon are the relay 144 and the connection terminal 142. Normally open, common, and normally closed connections are provided by the relay 144 and attached to the connection terminal via leads 802, 804, and 806, respectively. Trigger inputs are also provide and attached to the connection terminal via leads 808 and 810. Thus, it can be seen that the relay 144 is a single throw double pole type relay. One such relay configured as shown in FIG. 8A is available from Elk Products, Inc. of Hildebran, N.C. (part no. ELK-912). In one embodiment, the relay assembly 800 as shown in FIG. 8A will be reconfigured for use as a switch for use with the fan assemblies shown herein.

Referring now to FIG. 8B, a schematic of one embodiment of relay configured as a switch according to aspects of the present disclosure is shown. The relay assembly 810 is similar the relay assembly 800 of FIG. 8A. However, the lead 804 has been disconnected and the common lead and the normally closed lead of the relay 144 have both been connected to lead 806. For convenience and reference, the connectors 312 on the connection terminal 142 have been relabeled as shown to reflect their updated purposes but this is not required. These changes shown may be achieved by altering the configuration of the relay assembly 800 of FIG. 8 (e.g., cutting lines or traces and soldering new ones). The assembly 810 could also be scratch built.

Referring now to FIG. 9A, a schematic view of one embodiment of a method of connecting a cabinet cooling fan according to aspects of the present disclosure is shown. In the schematic 900, a relay configured as shown in FIG. 8B is used. The fan core 102 is connected as shown by the load “L” between leads 804 and 806. Although a resistive load is shown, it is understood that the fan core 102 will also provide inductive loading. An A/C adapter 902 may be used to provide the appropriate voltage and current for the load L (fan core 102). Some embodiments will require 12 volts and 500 milliamps but other combination are possible. Connected to the terminals 312 labeled “P−” and “2+” by leads 904, it can be seen that the adapter 902 provides “always on” operation regardless of the state of the relay 144. In the embodiment shown, the relay 144 is not strictly necessary as the adapter 902 could be connected directly to the fan core 102. However, as shown below, other configurations will make use of the relay 144 in a more active capacity.

Referring now to FIG. 9B, a schematic view of one embodiment of a method of connecting a cabinet cooling fan and triggering device according to aspects of the present disclosure is shown. The schematic 910 illustrates one possibility for selective activation of the a fan assembly as described herein. The schematic 910 is similar to the schematic 900. However, in the schematic 910 shown in FIG. 9B, the adapter 902 has leads 904 attached to the connectors 312 labeled “P+” and “P−”. In can be seen that in this configuration, the fan core 102 (load “L”) remains unpowered until the relay 144 has been thrown or activated. A triggering device 912 attached to the connection terminal 142 by leads 914 and then to the relay trigger inputs by leads 808 and 810 activates the relay and powers the load L. The triggering device may be another switch, an electronic component, a thermostat, a signal output from a device, or any other triggering device suitable for driving the relay 144.

Referring now to FIG. 9C, a schematic view of one embodiment of a method of connecting multiple cabinet cooling fans via a triggering device according to aspects of the present disclosure is shown. The schematic 920 illustrates one way in which more than one cooling fan assembly may be activated using a single triggering device 912. The schematic 920 is similar to the schematic 910 previously described. However, a second connection terminal 925 is shown and represents a second cooling fan assembly wired in the same manner as shown in FIG. 9A. It can be seen that when the load L (fan core) is activated, power also flows from the connectors 312 of connection terminal 142 labeled “P−” and “2+” through leads 930 and 932, respectively and into the connectors 312 labeled “P−” and “2+” of the second connection terminal 925. Thus, a second fan core (not shown) may be powered in parallel with the original fan core (load L). Both fan cores are activated by the same triggering device 912.

Referring now to FIG. 10, an exploded perspective view of another embodiment of a cabinet cooling fan assembly according to aspects of the present disclosure. The assembly 1000 is functionally similar to the assembly 100 of FIG. 1 and the assembly 600 of FIG. 6, with differences in construction and design as will be described. It can be seen that the assembly 1000 employs the previously-described fan core 102. The fan core 102 will be placed fully or partially within a housing 1002. The housing may be made from Sanoprene or another plastic. In one embodiment, the Sanoprene will be tuned to about 300 Hz. In other embodiments, other composite materials or metals may be used to construct the housing 1002. The housing 1002 may be injection molded in some cases. The housing 1002 provides a shroud 122 as well as one or more mounting tabs 904. The shroud and mounting tabs may be molded into or onto the housing 1002, or could be attached separately. The mounting tabs 124 may have fastening holes 402 and may also provide captive fasteners (not shown). In one embodiment, the fastening holes are molded as crushable screw retainers that provide retention of a screw before installation of the assembly 900, but then crush down flush with the mounting tab 402 during installation. As in previous embodiments a, strain relief cord (not shown) may also be provided on one of the mounting tabs 402. Also as in previous embodiments, one or more Venturi effect slots 310 may be provided to improve airflow.

The housing 1002 provides one or more isolation pads 1006 located variously throughout the interior of the housing 1002. The pads 1006 may be placed as shown or in other configurations. Typically, the pads 1006 will be placed such that the fan core 102 rests only against the pads 1006 when the assembly 1000 is assembled. These pads 1006 may be silicon, rubber, or another vibration and/or sound dampening material.

In the embodiment shown in FIG. 10, the grille 108 may be Sanoprene or another material. As with the housing 902, the Sanoprene of the grille 108 could be tuned to about 300 Hz. The grille 108 may also be injection molded. As before, the grille face 112 may be offset from the plane of the grille 108 for additional noise reduction. Mounting tabs 1010 may be provided to interfit with a mating component such as slots or tabs (not shown) inside or outside the housing 1002 when the assembly 1000 is assembled. Grille pads 1008 may be provided on the grille 108 to rest against and/or retain the fan core 102 when the assembly 1000 is assembled. These may be similar to the pads 1006 and may be made from silicon, rubber, or another vibration and/or sound insulating material. It can be seen that when the assembly 1000 is assembled, the fan core 102 will be vibrationally isolated from the outside and from the final mounting location. The fan core 102 will also be acoustically isolated to the degree possible while still allowing air flow.

It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to limit the invention to the particular forms and examples disclosed. On the contrary, the invention includes any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope of this invention, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.

Claims

1. An electronic cooling fan assembly comprising:

an electric fan core having a generally rectilinear shape, a positive pressure side, and a vacuum side;

a fan bracket attached to the positive pressure side of the electric fan core and offset from the fan core thereby defining a gap between the fan core and the fan bracket, the gap having a width less than an amount required to sustain a Venturi effect air intake when the electric fan core is in an operating state; and

a grille attached to the vacuum side of the fan core and having a grille face that is offset from the fan core, the offset being greater than an amount of offset required to reduce turbulence noise from the grille face when the electric fan core is in an operating state.

2. The electronic cooling fan assembly of claim 1, further comprising a set of elastic grommets interposing the fan bracket and the electric fan core.

3. The electronic cooling fan assembly of claim 1, further comprising at least one stress relief cord attached to the fan bracket, the at least one stress relief cord being adapted to retain at least one lead wire in proximity to the electric fan core.

4. The electronic cooling fan assembly of claim 1, wherein the fan bracket has a fan shroud that is substantially cylindrical and defines at least one bendable mounting tab, the at least one mounting tab defining a mounting hole that receives a fastener.

5. The electronic cooling fan assembly of claim 4, wherein the fastener is a captive screw.

6. The electronic cooling fan assembly of claim 5, wherein the shroud further defines at least one bendable stabilization tab, the at least one stabilization tab being offset by approximately 90 degrees on the circumference of the shroud from the at least one stabilization tab.

7. The electronic cooling fan assembly of claim 1, further comprising:

a switch having a trigger input, an electrical input, and an electrical output;

wherein the electrical output is connected to the electric fan core and the switch activates the electrical output in response to a predetermine triggering current and voltage on the trigger input.

8. The electronic cooling fan assembly of claim 7, further comprising, a second electrical output that provides power in parallel with the first electrical output.

9. The electronic cooling fan assembly of claim 8, further comprising a second electric fan core connected to the second electrical output.

10. The electronic cooling fan assembly of claim 1, wherein the fan bracket has a two piece construction including a generally cylindrical fan shroud and a flange attached to the fan shroud, the flange being attached to the electric fan core.

11. The electronic cooling fan assembly of claim 1, further comprising a thermal switch configured to selectively activate the electric fan core when an ambient temperate reaches a predetermined threshold.

12. The electronic cooling fan assembly of claim 11, wherein the thermal switch deactivates the electric fan core when the ambient temperature stays below a predetermined minimum threshold for a predetermined amount of time.

13. A fan mounting bracket for reducing noise and vibration in an enclosure, the bracket comprising:

a generally cylindrical shroud having a circumference and first and second ends, the shroud providing first and second mounting tabs substantially on opposite sides of the circumference on the first end, the mounting tabs each defining a fastening hole, the shroud also providing first and second stabilization tabs on substantially opposites side of the circumference on the fist end and being offset approximately 90 degrees from the mounting tabs;

a mounting flange attached to the second end of the shroud and defining a plane substantially orthogonal to an axis of the shroud, the mounting flange defines a plurality of fan attachment holes; and

a plurality of elastic grommets;

wherein one of the plurality of elastic grommets is inset into each one of the plurality of fan attachment holes.

14. The fan mounting bracket of claim 13, wherein the grommets are sized such that a Venturi effect gap is created when the mounting bracket is attached to a fan core via the fan attachment holes.

15. The fan mounting bracket of claim 13, wherein the shroud and the mounting flange are made substantially from sheet metal.

16. The fan mounting bracket of claim 13, wherein the elastic grommets are substantially made from silicon.

17. A method of reducing noise and vibration from a fan core operating to cool a container through an air vent, the method comprising:

attaching a flanged shroud to the fan core with noise and vibration isolating grommets;

attaching a grille to the fan core such that a face of the grille is offset from the fan core, the offset being at least a distance necessary to reduce turbulence noise through the grille face; and

affixing the shroud to the air vent.

18. The method of claim 17, further comprising securing a power lead to the shroud in proximity to the fan core such that a length of the power lead spanning a distance from the shroud to the fan core is relaxed.

19. The method of claim 17, further comprising selectively engaging the fan core with a thermal switch.

20. The method of claim 17, wherein the step of affixing the shroud further comprises attaching the shroud to the air hole such that the shroud protrudes into the air vent with at least one mounting tab on the shroud being attached to an area surrounding the air vent and at least one stabilizing tab on the shroud being substantially flush against the area surrounding the air vent.