Patent Publication Number: US-2011069449-A1

Title: Electronic device enclosures having improved ventilation to dissipate heat

Description:
FIELD OF THE DISCLOSURE 
     This disclosure relates generally to enclosures and, more particularly, to electronic device enclosures having improved ventilation to dissipate heat. 
     BACKGROUND 
     Process control systems are widely used, for example, in factories and/or plants in which products are manufactured or processes are controlled (e.g., chemical manufacturing, power plant control, etc.). Most modern process control systems include smart field devices and other process control components that are communicatively coupled to each other and/or to one or more controllers, Ethernet switches, and/or other electronic devices. 
     Electronic devices include electronic components or circuitry (e.g., an electronic circuit board) disposed within a housing or enclosure. During operation, the electronic components can generate significant amounts of heat, which may cause the electronic components to overheat and become damaged or otherwise impaired. To prevent overheating of the electronic devices, the heat generated by electronic components should be properly dissipated via the enclosure. Proper heat dissipation can improve reliability and prevent premature damage and failure of the electronic devices and/or components. 
     SUMMARY 
     In one example, an enclosure for holding an electronic circuit board includes a body having a first face, a second face opposite the first face, and an exterior peripheral surface separating the first and second faces. The electronic circuit board is to be disposed between the first and second faces so that a first side of the electronic circuit board faces the first face and the second side of the electronic circuit board faces the second face. A first portion of the exterior peripheral surface includes at least one opening for at least one electrical connector to electrically couple the electronic circuit board to another electronic device. A second portion of the exterior peripheral surface includes a first air vent to be oriented in a downwardly facing direction and a third portion of the exterior peripheral surface includes a second air vent opposite the first air vent and which is to be oriented in an upwardly facing direction. A baffle is coupled to the body adjacent at least the second and third portions of the exterior peripheral surface such that the baffle is configured to direct airflow into the first air vent and out the second air vent. Also, the baffle is to be coupled adjacent the second and third portions of the exterior peripheral surface to at least partially visually cover the air vents. 
     In another example, an enclosure for holding an electronic circuit board includes a housing having a first portion coupled to a second portion to form a cavity to hold the electronic circuit board. Each of the first and second portions comprises openings to direct convection airflow across opposing faces of the electronic circuit board at the same time. A baffle is coupled to the housing to substantially visually obscure the openings and to define a gap between the housing and the baffle to direct the convection airflow across the opposing faces of the electronic circuit board. 
     In yet another example, an enclosure for holding an electronic circuit board includes a housing having a cavity to hold the electronic circuit board. The housing having first openings on a first side of the housing to be oriented in a downwardly facing direction and second openings on a second side of the housing to be oriented in an upwardly facing direction. A baffle is coupled to the housing and spaced from the openings to visually obscure the openings and to direct airflow into the first openings, adjacent opposing faces of the electronic circuit board at the same time, and out the second openings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  illustrate an electronic module implemented with an example enclosure described herein. 
         FIGS. 2A-2D  illustrate different views of the example enclosure illustrated in  FIGS. 1A and 1B . 
         FIG. 3  illustrates an exploded view of the example enclosure shown in  FIGS. 1A ,  1 B and  2 A- 2 D. 
         FIGS. 4A and 4B  illustrate respective first and second portions of an example housing of the example enclosure of  FIGS. 1A ,  1 B and  2 A- 2 D. 
         FIGS. 5A and 5B  illustrate the example housing of  FIGS. 1A ,  1 B and  2 A- 2 D. 
         FIG. 6  illustrates an example baffle described herein of the example enclosure of  FIGS. 1A ,  1 B and  2 A- 2 D. 
         FIG. 7  is another illustration showing the example baffle of  FIG. 2A-2D ,  3  and  6  coupled to the example housing of  FIGS. 2A-2D ,  3 ,  5 A and  5 B. 
         FIG. 8  is a schematic cross-sectional illustration showing the example baffle of  FIG. 2A-2D ,  3  and  6  coupled to the example housing of  FIGS. 2A-2D ,  3 ,  5 A and  5 B. 
     
    
    
     DETAILED DESCRIPTION 
     The example enclosures described herein may hold an electronic circuit board of an electronic device (e.g., an Ethernet switch). In particular, the example enclosures described herein provide improved ventilation to dissipate heat generated by an electronic device more efficiently. Ventilation is provided by the example enclosures via a natural convection and passive cooling configuration that does not require the use of fans, liquid cooling systems, heat sinks, etc. In this manner, the example enclosures described herein can be used to properly dissipate heat to improve the overall reliability and prevent premature damage and failure of electronic device components (e.g., an electronic circuit board) mounted within or held by the enclosures. 
     In one example, an enclosure described herein includes a housing having a cavity to hold one or more electronic circuit boards. The housing includes air vents or openings to direct convection or passive airflow across opposing faces of the electronic circuit board(s) at the same time. The enclosure also includes a baffle coupled to the housing to visually obscure the openings and to define a gap between the housing and the baffle to direct or channel the convection airflow across the opposing faces of the electronic circuit board. Also, the air vents are recessed relative to outer surfaces of the housing and the baffle at least partially covers the air vents to help prevent or substantially reduce the ingress of debris, dirt, air-borne particles, and/or other contaminates or objects to an interior surface of the enclosure via the air vents or openings. 
     Additionally, the example enclosure is shaped and/or sized to provide improved passive airflow (e.g., increased airflow velocity) as air flows between the air vents or openings (e.g., to provide a chimney effect or a stack effect). For example, the housing may be configured such that a height of the housing is larger than a width of the housing. The air vents are located adjacent the substantially vertical ends of the enclosure (e.g., adjacent top and bottom ends of an enclosure) to provide cross-ventilation across all surfaces of the electronic components disposed within the housing at the same time. In some examples, the housing may include a curved surface or profile to facilitate the channeling of air flow between the air vents. 
     In contrast, some known electronic devices may include heat sinks, fans, and/or liquid cooling systems to dissipate heat from one or more electronic devices. However, heat sinks, liquid cooling systems, fans, etc., significantly increase manufacturing costs. Additionally, such heat dissipation systems typically increase the overall physical or dimensional envelope or footprint of the enclosure. Further, in some instances, space may be limited. Thus, natural convection ventilation may be the only means available to dissipate heat from an electronic circuit board. 
       FIGS. 1A and 1B  illustrate an example electronic module  100  described herein. Referring to  FIGS. 1A and 1B , the example electronic module  100  described herein can be used, for example, with a process control system. For example, the electronic module  100  can be used to implement a network device such as, for example, an Ethernet switch. The example electronic module  100  may be communicatively coupled to a second electronic module  101 , a controller, and/or or any other device. In this example, the electronic module  100  includes an enclosure  102  that removably couples to a base  104  via a latching mechanism  106 . The base  104  includes ports  108   a - d  such as, for example, a power port, a data transmission port, an uplink port, and/or any other suitable ports to receive power lines and/or transmission lines to communicate data to a desired location and/or device. The base  104  may be mounted within and/or to, for example, a cabinet, a rack, a field device, and/or any other suitable mounting surface(s). 
     The enclosure  102  provides an improved passive cooling or natural convection ventilation to provide more efficient dissipation of heat. In particular, as shown in  FIG. 1B , the enclosure  102  may include air passages or vents  110  along a peripheral external surface  112  of the enclosure  102  to provide ventilation between the air passages or vents  110 . The enclosure  102  also includes a baffle or spine  114  to at least partially visually cover the air passages or vents  110 . Alternatively, the enclosure  102  may include an air passage or vent  116  along a body portion  118  of the enclosure  102 . A second baffle  120  may be coupled to the enclosure  102  to at least partially visually cover the air passage or vent  116 . The second baffle  120  may provide indicia  122  associated with a characteristic of the electronic module  100 . Although not shown, the air passage or vent  116  may be projected inwardly (e.g.,) recessed relative to the body portion  118  via a beveled edge  124  to provide a gap between the air passage or vent  116  and the second baffle  120  to enable air flow through the air passage or vent  116 . The enclosure  102  may be configured to include the air passages or vents  110 , the air passage or vent  116  and/or other air passages disposed along other portions of the external peripheral edge  112  and/or the body  102 . 
       FIGS. 2A-2D  illustrate another example enclosure  200  described herein that may be used to implement the example electronic module  100  of  FIGS. 1A and 1B . Referring to  FIGS. 2A-2D , the example enclosure  200  includes a housing or body  202  having a cavity  204  to hold, for example, one or more electronic circuit boards  206 . The housing  202  includes a first or right face  208  and a second or left face  210  opposite the first face  208 . The housing  202  also includes an exterior peripheral surface  212  separating the first and second faces  208  and  210 . 
     In this example, a first electronic circuit board  214   a  is electrically coupled to (e.g., via a connector) and disposed adjacent a second electronic circuit board  214   b  to provide a smaller dimensional footprint. In other examples, the first electronic circuit board  214   a  may not be electrically coupled to the electronic second circuit board  214   b  and may function independently from the second electronic circuit board  214   b . In yet other examples, more than two electronic circuit boards may be disposed within the housing  202 . 
     The first and second electronic circuit boards  214   a  and  214   b  are disposed within the housing  202  such that respective first sides  216   a  and  216   b  of the first and second electronic circuit boards  214   a  and  214   b  face the first face  208  of the housing  202  and respective second sides  218   a  and  218   b  of the first and second circuit boards  214   a  and  214   b  face the second face  210  of the housing  202 . The first and second electronic circuit boards  214   a  and  214   b  are disposed within the housing  202  such that a space  220  is defined between the first side  216   b  of the second electronic circuit board  214   b  and the second side  218   a  of the first electronic circuit board  214   a . Additionally, in this example, the first and second electronic circuit boards  214   a  and  214   b  are substantially vertically orientated when the electronic module  100  is in use. 
     In this example, the enclosure  200  includes racks, brackets or holders  222  and  224   a - b  to retain the electronic circuit boards  214   a - b  within the housing  202 . In other examples, the housing  202  may include pins to help retain the electronic circuit board(s)  206  within the housing  202 . A light bar  226  may be coupled to the electronic circuit board(s)  206  to provide indicator or status lights  228  (e.g., LED lights) to display the operational status of the electronic module  100  ( FIGS. 1A and 1B ). For example, one or more of the status lights  228  may be illuminated to indicate, for example, a power status, a speed status, a connection status, and/or any other operational status of the electronic module  100  and/or a network system to which the electronic module  100  is operatively coupled. 
     As shown in  FIG. 2B , the enclosure  200  includes a rear portion  230 . The rear portion  230  includes at least one opening  232  and/or other connectors  234  to electrically couple the electronic circuit boards  214   a - b  to, for example, the base  104  ( FIGS. 1A and 1B ) and/or other electronic devices. In yet other examples, the rear portion  230  may include communication ports, power supply ports, or any other suitable ports to receive, for example, data transmission lines or cables so that the base  104  is not required. 
     As noted above, the enclosure  200  provides an improved passive cooling or natural convection ventilation to provide more efficient dissipation of heat generated by the electronic circuit boards  214   a - b  disposed within the housing  202 . In particular, the housing  202  includes a first air vent  238  along a first portion  240  of the exterior peripheral surface  212  of the housing  202  and a second air vent  242  along a second portion  244  of the exterior peripheral surface  212  of the housing  202  to direct convection airflow across opposing faces (e.g., the first sides  216   a - b  and second sides  218   a - b ) of the electronic circuit boards  214   a - b . Thus, the airflow is directed between the space  220  formed between the electronic circuit boards  214   a - b  and along respective interior portions or surfaces (e.g., of the opposing faces  208  and  210 ) of the housing  202  at the same time. 
     In this example, the first air vent  238  is to be oriented in a downwardly facing direction and the second vent  242  is to be oriented in an upwardly facing direction and opposite the first vent  238 . As shown, the air vents  238  and  242  are adjacent the first and second faces  208  and  210  of the housing  202 . Additionally, the housing  202  is shaped and/or sized (e.g., has a greater height relative to its width) to provide improved air flow (e.g., increased airflow velocity) as the air flows between the first and second air vents  238  and  242 . 
     The enclosure  200  also includes a baffle or spine  246  coupled (e.g., mechanically coupled) to the housing  202  to be a structural member of the enclosure  200 . In general, the baffle  246  is coupled to the housing  202  adjacent at least the first portion  240  of the exterior peripheral surface  212  and the second portion  244  of the exterior peripheral surface  212  adjacent the respective first and second air vents  238  and  242 . When coupled to the housing  202 , the baffle  246  at least partially visually obscures or covers the first and second air vents  238  and  242 . The baffle  246  is coupled to the housing  202  such that the baffle  246  directs the convection airflow across the opposing faces of the electronic circuit board  206 . In other words, the baffle  246  is configured to direct airflow into the first air vent  238 , across the surfaces  216   a - b ,  218   a - b  of the electronic circuit boards  214   a - b , and out of the second air vent  242 . 
     In other examples, a third vent may be provided along a third portion (e.g., a front portion) of the exterior peripheral surface  212  of the housing  202 . The baffle may included openings (e.g., downwardly angled openings) to at least partially cover the third vent. In other examples, at least one of the first or second faces  208  and  210  may include another air vent to direct airflow adjacent a respective one of the sides (e.g.,  216   a - b  and  218   a - b ) of the electronic circuit boards  214   a - b . Additionally, a second baffle (not shown) may be coupled to the first or second faces  208  and  210  to at least partially cover the other air vent (e.g., similar to the air vent  116  and the baffle  120  of  FIG. 1B ). 
       FIG. 3  illustrates an exploded view of the example enclosure  200  of  FIGS. 2A-2D . The housing  202  includes a first portion or panel  302  and a second portion or panel  304 . In this example, a latch release mechanism  306  is coupled to the baffle  246  to enable the enclosure  200  to be coupled to and/or released from, for example, the base  104 . The latch release mechanism  306  includes a rocking arm  308 , a button portion  310 , and a retaining clip  312 . The baffle  246  includes a slot or opening  314  to receive the rocking arm  308 , and the rocking arm  308  pivotally couples to the baffle  246  via a pivot  316 . The button portion  310  couples (e.g., via snap fit) to the rocking arm  308  and is retained adjacent a first end  318  of the rocking arm  308  via the retaining pin  312 . When the button portion  310  is depressed toward a surface  320  of the baffle  246 , the first end  318  of the rocking arm  308  rotates about the pivot  316  to actuate or release, for example, the latching mechanism  106  of the base  104  ( FIGS. 1A and 1B ). Also, in this example, the rear portion  230  ( FIG. 2B ) of the enclosure  200  ( FIG. 2B ) is a third portion or panel  322 . The third panel  322  couples to the first and second panels  302  and  304  and includes at least one opening  324  for at least one electrical connector to electrically couple the electronic circuit boards  214   a - b  ( FIGS. 2C-D ) to at least one other electronic device. 
       FIGS. 4A and 4B  depict the first and second panels  302  and  304  of  FIG. 3 , respectively. Referring to  FIGS. 4A and 4B , in this example, the first panel  302  includes grill or air vent portions  402   a - b  about a peripheral edge  404  of the first panel  302 . The second panel  304  includes grill or air vent portions  406   a - b  about a peripheral edge  408  of the second panel  304 . The grill portions  402   a - b  and  406   a - b  project inwardly relative to the respective first and second sides  410  and  412  via beveled edges  414  and  416 . Additionally, the grill portions  402   a - b  and  406   a - b  protrude or extend from the respective peripheral edges  404  and  408  of the first and second panels  302  and  304 . As shown, each of the grill portions  402   a - b  and  406   a - b  includes apertures  418  or slots  420 . 
     Although not shown, in other examples, the first panel  302  may be configured to only include the grill portion  402   a  having at least one aperture  418  and the second panel  304  may be configured to only include the grill portion  406   b  having at least one aperture  418 . In yet other examples, only the first panel  302  may include the grill portions  402   a - b  having apertures  418 . In yet other examples, the first panel  302  and/or the second panel  304  may include additional grill portions having apertures  418  and/or slots  420  disposed along other portions of the respective peripheral edges  404  and  408 . For example, additional grill portions may be provided along a front portion  436  of the edges  404  and  408 . 
     In this example, the first and second panels  302  and  304  couple together via snap fit to define the housing  202 . As shown, the second panel  304  includes flexible members  424  having edges  426  and tapered portions  428 , and the first panel  302  includes receiving members  430  having apertures  432 . When coupled together, the receiving members  430  receive respective ones of the flexible members  424  such that the edges  426  of the flexible members  424  engage respective surfaces  434  adjacent the apertures  432  to couple the first and second panels  302  and  304 . In other examples, the first and second panels  302  and  304  may be coupled together via mechanical fasteners, chemical fasteners, and/or any other fastening mechanism(s). Each of the first and second panels  302  and  304  is made of a plastic material via, for example, injection molding or any other suitable manufacturing process(es). However, in other examples, the first and second panels  302  and  304  may be made of any other suitable material. 
       FIGS. 5A and 5B  illustrate the example first and second panels  302  and  304  coupled together to define the housing  202 . When coupled together, the first panel  302  defines the first face  208  of the housing  202  and the second panel  304  defines the second face  210  of the housing  202 . Also, when the first and second panels  302  and  304  are coupled together, the grill portions  402   a - b  and  406   a - b  matably engage to define at least a part of the exterior peripheral surface  212  of the housing  202  separating the first and second faces  208  and  210 . In this example, the exterior peripheral surface  212  includes a first or top face or side  502 , a second or bottom face or side  504 , and a third or front face or side  506 . 
     When coupled together, the apertures  418  and/or the slots  420  ( FIGS. 4A and 4B ) of the first and second panels  302  and  304  provide openings  508  to define the first and second air vents  238  and  242 . More specifically, the housing  202  includes a first plurality of openings  510   a  to be oriented in a first or downwardly facing direction and a second plurality of openings  510   b  to be oriented in a second or upwardly facing direction opposite the first plurality of openings  510   a . The first plurality of openings  510   a  is distributed in first and second parallel rows and the second plurality of openings  510   b  is also distributed in third and fourth parallel rows. However, in other examples, the first plurality of openings  510   a  may be oriented in a different direction and/or configuration than the second plurality of openings  510   b.    
     As shown, the first plurality of openings  510   a  is adjacent the bottom face  504  of the exterior peripheral surface  212  of the housing  202  and the second plurality of openings  510   b  is adjacent the top face  502  of the exterior peripheral surface  212 . Further, the rows of openings making up each of the plurality of openings  510   a  and  510   b  are adjacent respective ones of the faces  208  and  210  of the housing  202 . The first and second plurality of openings  510   a  and  510   b  provide the first and second air vents  238  and  242  to enable airflow to pass through the housing  202  to provide a passive cooling or natural convection ventilation to cool the electronic circuit board(s)  206  ( FIGS. 2C and 2D ) disposed within the housing  202 . In other examples, the first plurality of openings  510   a  may include a greater number of openings  508  than the second plurality of openings  510   b . In yet other examples, the openings  508  of the first plurality of openings  510   a  may be sized larger than the openings  508  of the second plurality of openings  510   b , or the second plurality of openings  510   b  may be sized larger than the openings  508  of the first plurality of openings  510   a.    
     The front face  506  of the exterior peripheral surface  212  also includes openings  512  to receive, for example, the light bar  226  ( FIG. 2D ). A rear face  514  of the housing  202  includes at least one opening  516  to receive at least one electrical connector to electrically couple the electronic circuit board(s)  206  ( FIGS. 2C and 2D ) to at least one other electronic device. As described above, in this example, the rear face  514  of the housing  202  receives the third panel  322  ( FIG. 3 ), which includes the opening or port  324  to electrically couple the electronic circuit board(s)  206  to at least one other electronic device. 
       FIG. 6  illustrates the baffle  246 . In this example, the baffle  246  is depicted as a unitary band or spine structure. However, in other examples, the baffle  246  may be separate pieces or structures that couple to the housing  202 . In this example, the baffle  246  includes a top face  602 , a front face  604  and a bottom face  606 . As noted above, the top face  602  includes the slot  314  to receive the latch release mechanism  306  ( FIG. 3 ). The baffle  246  also provides indicia associated with a characteristic of the electronic circuit board  206 . For example, the front face  604  includes a plurality of openings  608  to display the status lights  228  of the light bar  226 . Additionally, the front face  604  may include an opening  610  (e.g., a V-shaped opening) to receive an indicator light to indicate, for example, that electrical power is being supplied to the electronic module  100  ( FIGS. 1A and 1B ). The baffle  246  may also include a curved surface or profile  612  that may help channel the airflow through the housing  202  when the baffle  246  is coupled to the housing  202 . 
     Additionally, the baffle  246  includes protruding members or clips  614  (e.g., hook-like members) that engage (e.g., interlock) with portions of the housing  202  to mechanically couple the baffle  246  to the housing  202  via snap-fit. In other examples, the baffle  246  may be coupled to the housing  202  via mechanical fasteners, chemical fasteners, and/or any other suitable fastener(s). In this example, the baffle  246  is made of a metallic material. However, in other examples, the baffle  246  may be made of a plastic material, a plastic-metal laminate, and/or any other suitable material. 
       FIG. 7  illustrates a side view of the enclosure  200  showing the baffle  246  coupled to the housing  202 . As shown, the housing  202  may include a curved portion or profile  702  between the first and second plurality of openings  510   a  and  510   b . The curved portion  702  may facilitate or help channel the airflow between the first and second plurality of openings  510   a  and  510   b . Also, when coupled to the housing  202 , the baffle  246  substantially surrounds or wraps around a substantial portion of the exterior peripheral surface  212  of the housing  202 . More specifically, the baffle  246  substantially surrounds the top face  502 , the front face  506 , and the bottom face  504  of the exterior peripheral surface  212  of the housing  202 . Thus, in this example, the baffle  246  does not cover the opening or rear face  514  of the housing  202  when the baffle  246  is coupled to the housing  202 . Additionally, the baffle  246  covers or at least partially visually obscures the plurality of openings  510   a  and  510   b  to provide a guard or shield, but does not inhibit airflow between the baffle  246  and the plurality of openings  510   a  and  510   b.    
       FIG. 8  is a schematic cross-sectional illustration of the example baffle  246  coupled to the housing  202 . As shown, the baffle  246  is mechanically coupled or captured between the first and second panels  302  and  304  when the first and second panels  302  and  304  are coupled together. When coupled to the housing  202 , the baffle  246  is spaced away from the first plurality of openings  510   a  of the first air vent  238  and the second plurality of openings  510   b  of the second air vent  242  to define a gap  802  between the baffle  246  and the housing  202 . The gap  802  enables airflow between the baffle  246  and the plurality of openings  510   a  and  510   b  as indicated by respective arrows  804  and  806 . 
     The gap  802  between the baffle  246  and the openings  508  enables the baffle  246  to direct convection airflow into the first air vent  238  across all internal surfaces of the housing  202 . More specifically, the baffle  246  directs airflow through the first air vent  238  adjacent the sides  216   a - b  and  218   a - b  (e.g., opposing faces) of the electronic circuit board(s)  206  as indicated by arrows  808  at the same time and out of the second air vent  242 . Specifically, the first and second air vents  238  and  242  are spaced at opposite ends of the housing  202  to provide cross ventilation across the electronic circuit boards  214   a - b.    
     As noted above, the gap  802  is dimensioned to enable the baffle  246  to direct or facilitate the direction of airflow across the first and second sides  216   a - b  and  218   a - b  of the electronic circuit boards  214   a - b . Additionally, a first edge  810  of the baffle extends beyond the grill portions  402   a - b  of the first panel  302  adjacent the first face  208  of the housing  202  and a second edge  812  of the baffle  246  extends beyond the grill portions  406   a - b  of the second panel  304  adjacent the second face  210  of the housing  202 . By recessing the grill portions  402   a - b  and  406   a - b , the edges  810  and  812  extend beyond the recessed portions  402   a - b  and  406   a - b  so that the baffle  246  at least partially covers or shields and visually obscures the openings  508  of the housing  202  to prevent the ingress of debris, dirt, air-borne particles, and/or other contaminates or objects within the cavity  204  (e.g., the electronic circuit board  206 ) of the housing  202  via the openings  508 . Also, when coupled to the housing  202 , the baffle  246  helps channel the air flow through the housing  202  between the first air vent  238  and the second air vent  242 . 
     In operation, electrical power is applied to the electronic circuit boards  214   a - b  disposed within the housing  202 . The status lights  228  indicate whether electrical power is provided to the electronic circuit boards  214   a - b . Also, the status lights  228  of the light bar  226  are visually displayed via the openings  608  of the baffle  246  when the baffle  246  is coupled to the housing  202 . During operation, the electronic circuit boards  214   a - b  generate heat. The heat generated by the electronic circuit boards  214   a - b  increases the temperature of the air adjacent the electronic circuit boards  214   a - b  within the housing  202 . In turn, the density of the warmer air is less when the temperature of the air increases relative to the surrounding air mass, causing the air to rise within the housing  202 . As the air temperature within the housing  202  increases, air flows between the openings  508  of the first air vent  238  and the openings  508  of the second air vent  242 . 
     More specifically, the baffle  246  directs the airflow through the first air vent  238  adjacent opposing faces of the electronic circuit boards  214   a - b  at the same time as indicated by arrows  808 . In this manner, airflow is provided to substantially all sides (e.g., the first sides  216   a - b  and the second sides  218   a - b ) of the electronic circuit boards  214   a - b  to substantially prevent a hot spot condition that may otherwise occur if the airflow is not distributed (e.g., evenly) across all surfaces of the electronic circuit boards  214   a - b . Also, the baffle  246  channels the air flow such that the warmer air exiting the second air vent  242  draws or pulls the cooler air from the first air vent  238  providing a chimney or stack effect. For example, a height  814  of the housing  202  may be sized significantly larger than a width  816  of the housing  202 . In other words, the housing is configured (e.g., shaped and sized) and/or the baffle  246  is positioned to duct the warmer air rising toward the second air vent  242  more rapidly and efficiently (e.g., a passive cooling configuration). 
     Although not shown, in other examples, forced convection airflow may be provided toward or adjacent the first air vent  238  and/or the second air vent  242 . Such forced convection may be provided via, for example, a cooling fan. In yet other examples, heat sinks may be disposed within the housing  202  to further improve dissipation of the heat from within the housing  202 . In other words, the airflow provided through the housing  202  between the first and second air vents  238  and  242  may flow across heat sinks disposed within the housing  202  and/or the electronic circuit board  206  to further dissipate heat from within the housing  202 . 
     Although certain example apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all apparatus and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.