US20060243423A1

US20060243423A1 - Compact heat exchanger and method

Info

Publication number: US20060243423A1
Application number: US11/120,141
Authority: US
Inventors: Lawrence Giacoma
Original assignee: Tellabs Operations Inc
Current assignee: Coriant Operations Inc
Priority date: 2005-05-02
Filing date: 2005-05-02
Publication date: 2006-11-02

Abstract

A compact heat exchanger increases the cooling capacity within existing sizes of electronics cabinets. The heat exchanger includes a core having multiple thermally conductive members defining internal and external pathways. The internal pathways define inlets for receiving fluid from and outlets for passing fluid to the inside of the enclosure. The external pathways define inlets for receiving fluid from and outlets for passing fluid to the outside of the enclosure. The heat exchanger further includes an external pathway fluid driving mechanism coupled to the core in fluid flow relationship with the external pathways that causes fluid to flow in a first direction through the external pathways and an internal pathway fluid driving mechanism coupled to the core in fluid flow relationship with the internal pathways that causes fluid to flow in a second direction through the internal pathways in a manner facilitating heat exchange by the multiple thermally conductive members.

Description

BACKGROUND OF THE INVENTION

Most electronics cabinets include cooling systems that cool electronics in the electronics cabinets by blowing external air in a manner cooling the electronics. As demand for high speed Internet services increases, electronics cabinets are equipped with additional electronics. As a result, the electronics dissipate heat within the electronics cabinets beyond the capacity of the cooling systems. Current techniques for increasing the cooling capacity to address the increased heat dissipation, however, are insufficient without increasing the size of the cooling systems. As a result, either the size or amount of electronics must be reduced, which may not be possible, leads to a second electronics cabinet, or the size of the electronics cabinet is increased to accommodate the electronics and increased size of the cooling system.

SUMMARY OF THE INVENTION

To increase the cooling capacity within existing sizes of electronics cabinets, a heat exchanger assembly with compact volume is placed within or externally attached to the electronics cabinet. The heat exchanger assembly includes a heat exchanger core with multiple thermally conductive members defining “internal” and “external” pathways. The internal pathways include inlets to draw fluid, such as air, from inside the electronics cabinet and outlets to exhaust fluid to inside the electronics cabinet. The external pathways include inlets to draw fluid from outside the electronics cabinet and outlets to exhaust fluid to outside the electronics cabinet. An external pathway fluid driving mechanism is coupled to the core in fluid flow relationship with the external pathways and causes air to flow in a first direction through the external pathways in the core. An internal pathway fluid driving mechanism is coupled to the core in fluid flow relationship with the internal pathways and causes air to flow in a second direction through the internal pathways in the core in a manner facilitating heat exchange by the multiple thermally conductive members.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
FIG. 1 is an external perspective view of an electronics cabinet having a heat exchanger assembly (partially shown) according to the principles of the present invention;
FIG. 2A is an internal perspective view of the electronics cabinet and heat exchanger assembly of FIG. 1;
FIG. 2B is a sectional view of the electronics cabinet and heat exchanger assembly of FIG. 1;
FIG. 2C is a sectional view of another embodiment of the electronics cabinet and heat exchanger assembly of FIG. 1;
FIG. 3A is an exploded view of the heat exchanger assembly of FIG. 2, with indications of fluid flow therein;
FIG. 3B is a perspective view of another embodiment of the heat exchanger assembly of FIG. 1;
FIG. 4 is a perspective view of thermally conductive members defining “internal” and “external” pathways through the heat exchanger core of FIG. 3A;
FIG. 5 is an exploded view illustrating in detail a grate and its relationship to the heat exchanger core of FIG. 3A;
FIG. 6 is an exploded view of an “internal” pathway fluid driving mechanism used with the heat exchanger core of FIG. 3A;
FIG. 7 is an exploded view of an “external” pathway fluid driving mechanism used with the heat exchanger core of FIG. 3A;
FIG. 8A is a front view of a thermally conductive member of FIG. 4 subject to a deforming process;
FIG. 8B is a top view of a thermally conductive member of FIG. 4 subject to the deforming process;
FIG. 8C is a left side view of a thermally conductive member of FIG. 4 subject to the deforming process;
FIG. 9A is a top view of a thermally conductive member of FIGS. 8A-C having an adhesive applied thereto;
FIG. 9B is a left side view of a thermally conductive member of FIGS. 8A-C having an adhesive applied thereto;
FIG. 10A is a top view of thermally conductive members of FIGS. 8A-C being positioned together to form “internal” and “external” pathways;
FIG. 10B is a left side view of thermally conductive members of FIGS. 8A-C being positioned together to form “internal” and “external” pathways;
FIG. 11A is a top view of thermally conductive members of FIGS. 10A and 10B self-assembled to define inlets and outlets of the internal and external pathways;
FIG. 11B is a left side view of thermally conductive members of FIGS. 10A and 10B self-assembled to define the inlets and outlets of the internal and external pathways; and
FIG. 11C is a right side view of thermally conductive members of FIGS. 10A and 10B self-assembled to define the inlets and outlets of the internal and external pathways.

DETAILED DESCRIPTION OF THE INVENTION

A description of preferred embodiments of the invention follows.
Electronics cabinets are being equipped with additional electronics to meet the increased demand for high speed Internet services, such as Internet Protocol Television (IPTV). As a result, the electronics dissipate heat within the electronics cabinets beyond the capacity of existing cooling systems. Embodiments of the heat exchanger design, some of which are described herein below, maximize the total surface area of thermally conductive members to increase a heat transfer surface area by two to five times over existing heat exchanger designs for the same volume. The efficiency of a heat exchanger is generally directly proportional to the total surface area of the thermally conductive members. Therefore, the heat exchanger design in some embodiments is two times more efficient than existing cooling systems having the same volume without increasing the size of the electronics cabinet.
FIG. 1 shows an external perspective view of an electronics cabinet 5 having a heat exchanger assembly 1 (partially shown) according to the principles of the present invention. The heat exchanger assembly 1 includes a heat exchanger core (not shown) in which heat exchange occurs with “internal” pathways (not shown) through which air or other fluid internal to the electronics cabinet 5 flows and “external” pathways (not shown) through which air or other fluid external to the electronics cabinet 5 flows.
The electronics cabinet 5 includes an external pathway inlet plenum 15 a through which fluid, such as air, from outside of the electronics cabinet 5 enters external pathways of a heat exchanger core (not shown) disposed within the electronics cabinet 5, as indicated by airflow arrows 22 directly below the external pathway inlet plenum 15 a. The electronics cabinet 5 further includes an external pathway, fluid driving mechanism 10 a. Examples of fluid driving mechanisms include motorized impellers and axial fans. The external pathway, fluid driving mechanism 10 a draws the fluid entering the external pathway inlet plenum 15 a through the external pathways of the heat exchanger core (not shown) and exhausts the fluid outside of the electronics cabinet 5. An electronics cabinet roof 12 is disposed on top of the electronics cabinet 5, which itself includes a top cover 17 that contains “internal” air contained inside the electronics cabinet 5. The electronics cabinet roof 12 prevents dust, rain, and other contaminants from entering the electronics cabinet 5 while allowing air to exit via vent holes or other pathways (not shown) to the air outside of the electronics cabinet 5, as indicated by arrows shown along the edges of the electronics cabinet roof 12.
FIG. 2A shows a heat exchanger assembly 1 arranged within the electronics cabinet 5 of FIG. 1. The heat exchanger assembly 1 includes a heat exchanger core 20. The external pathway inlet plenum 15 a connects to an opening in the bottom of the electronics cabinet 5 through which cool air from the external air 29 passes into the heat exchanger core 20 (as shown by way of airflow arrows 22). The external pathway, fluid driving mechanism 10 a is connected to the heat exchanger core 20 through an external pathway, fluid driving mechanism outlet plenum 15 b (“external pathway outlet plenum”). The external pathway, fluid driving mechanism 10 a draws the cool air through the heat exchanger core 20, which warms the cool air 22 by a heat exchange process described further herein and exhausts the warmed air 26 to outside of the electronics cabinet 5.
Electronics (not shown) within the electronics cabinet 5 generate heat which warms the air within the electronics cabinet 5. The warm air rises and collects at the top of the electronics cabinet 5, including in a volume between the top cover 17 of the electronics cabinet 5 and internal pathway inlets 45 a, . . . , 45 n of the heat exchanger core 20. An internal pathway, fluid driving mechanism 10 b connected to the heat exchanger core 20 through an internal pathway, fluid driving mechanism outlet plenum 15 c (“internal pathway outlet plenum”) draws the warm air into the internal pathway inlets 45 a, . . . , 45 n, as shown by way of airflow arrows 24. The warm air passes through the heat exchanger core 20 where it is cooled and exhausts as cool air to the inside of the electronics cabinet 5, as shown by way of airflow arrows 28. In this way, internal air 27 is circulated through the electronics cabinet 5 to cool the electronics therein.
FIG. 2B illustrates another embodiment of the electronics cabinet 5 and heat exchanger assembly 1 of FIG. 1. In this embodiment, a battery 18, providing power to the electronics in the electronics cabinet 5, is placed in a bottom compartment 19 of the electronics cabinet 5. Air drawn into the sides of the bottom compartment 19 by the external pathway, fluid driving mechanism 10 a (as shown by way of an airflow arrow 22 directed into the external pathway inlet plenum 15 a) may cool the battery 18 on its route into the heat exchanger core 20.
FIG. 2C illustrates yet another embodiment of the electronics cabinet 5 and heat exchanger assembly 1 of FIG. 1. As shown in FIG. 2C, the heat exchanger assembly 1 may mount to the side of the electronics cabinet 5. In this way, an electronics cabinet may be retrofitted with the heat exchanger assembly 1 by simply making two holes 38 in the side of the electronics cabinet 5 and connecting the internal pathway inlets 45 a, . . ., 45 n and outlets 55 a, . . . , 55 n of the heat exchanger assembly 1 to the respective holes 38. Grommets, O-rings 41 or other devices may be used to provide an air-tight fitting between the electronics cabinet 5 and the heat exchanger assembly 1. In a similar way, the heat exchanger core 20 may be placed anywhere on or in the electronics cabinet 5.
FIG. 3A shows how air circulates through the heat exchanger core 20. The heat exchanger core 20 has two airflows, an external airflow 44 and an internal airflow 48. Airflow through the internal and external pathways are indicated by dashed- line arrows 44 and 48. The external airflow 44 (indicated by dashed-line arrows pointing upward) is effected when the external pathway, fluid driving mechanism 10 a pulls outside ambient air (airflow arrows 22) at external pathway inlets 50 a, . . . , 50 n through the external pathways of the heat exchanger core 20 and exhausts warmed air at external outlet 40 a, . . . , 40 n to the external air 29 at the top of the electronics cabinet 5 (FIGS. 1, 2A, and 2B). The internal airflow 48 (indicated by dashed-line arrows pointing downward) is created when the internal pathway, fluid driving mechanism 10 b circulates the internal electronics cabinet air 27 into (airflow arrows 24 (FIG. 2A)), through (airflow arrows 48), and out of (airflow arrows 28 (FIG. 2A)) the internal pathways of the heat exchanger core 20. In a preferred embodiment, the two airflows 44, 48 do not mix air. As understood in the art, the more the two airflows 44, 48 pass air across common areas of thermally conductive members, the more capacity the heat exchanger core 20 has for cooling the internal air 27 of the electronics cabinet 5.
FIG. 3B shows an alternative embodiment in which there are multiple airflows 44, 48 through the core 20. Two external airflows 44 (indicated by dashed-line arrows pointing upward) are created when external pathway, fluid driving mechanisms 10 a, 10 c pull outside ambient air through the external pathways of the heat exchanger core 20 and exhaust it to the external air 27 at the top of the electronics cabinet 5. Two internal airflows 48, indicated by dashed-line arrows pointing downward, are created when the internal pathway, fluid driving mechanisms 10 b, 10 d circulate the internal electronics cabinet air 27 through the internal pathways of the heat exchanger core 20. Other embodiments may include fluid driving mechanisms at different positions including in the middle of the heat exchanger core 20 rather than at the top and bottom of the heat exchanger core 20. Also, in other embodiments, different numbers of internal airflows 48 and external airflows 44 may be configured in a static or dynamic manner through fixed or electronically controlled arrangement(s) of fluid driving mechanisms 10.
FIG. 4 shows the external pathways 30 a, . . . , 30 n (collectively 30) and internal pathways 35 a, . . . , 35 n (collectively 35) in detail. In one embodiment, the pathways 30, 35 may be separated by vertically mounted thermally conductive members 32 a, . . . , 32 n (collectively 32) (e.g., thin pieces of sheet metal or any other thermally conductive material) in the heat exchanger core 20. In other embodiments, the thermally conductive members 32 may be mounted in other orientations, such as horizontally with airflow passing through the core 20, accordingly. The heat transfer from the warmer internal electronics cabinet air in the internal pathways 35 a, . . . , 35 n to the cooler external air in the external pathways 30 a, . . . , 30 n occurs through the thermally conductive members 32 a, . . . , 32 n.
FIG. 4 further shows the direction of the airflow 44, 48 in the internal and external pathways 30, 35, respectively. In this embodiment, the air in the internal pathways flows in the opposite direction from the air in the external pathways. A heat exchanger configured in this way is generally known as a “counter-flow” heat exchanger. Other embodiments of the heat exchanger may be configured to facilitate “diagonal-flows,” “cross-flows,” or any other combination(s) thereof.
FIGS. 5 and 6 illustrate the relationship of a first grate 25 a and a second grate 25 b to the heat exchanger core 20 of FIG. 3A. The grates 25 a, 25 b are used to route the air into appropriate pathways. Each half of the grates 25 a, 25 b causes air to flow through either the internal pathways 35 or the external pathways 30 by covering either the external pathways 30 or the internal pathways 35, respectively. As shown in FIG. 5, the left half of the first grate 25 a covers the external pathways 30 a, . . . , 30 n and provides internal pathway inlets 45 a, . . . , 45 n to receive internal electronics cabinet air 27. The right half of the first grate 25 a covers the internal pathways 35 a, . . . , 35 n and provides external pathway outlets 40 a, . . . , 40 n through which external air 29 is drawn into the external pathway outlet plenum 15 b and is exhausted outside of the electronics cabinet 5.
As shown in FIG. 6, the right half of the second grate 25 b covers the external pathways 30 a, . . . , 30 n and provides internal pathway outlets 55 a, . . . , 55 n through which internal air 27 is drawn into the internal pathway outlet plenum 15 c and is exhausted radially into the electronics cabinet 5 compartment. The left half of the second grate 25 b covers the internal pathways 35 a, . . . , 35 n and provides external pathway inlets 50 a, . . . , 50 n to receive air from outside of the electronics cabinet 5.
It should be understood that the first grate 25 a and second grate 25 b may be one, two, or more pieces of material (e.g., metal, aluminum, rubber).
FIG. 7 shows in further detail how, in one embodiment, the external pathway fluid driving mechanism 10 a, the external pathway outlet plenum 15 b, the first grate 25 a, and the heat exchanger core 20 fit together. The external pathway fluid driving mechanism 10 a pulls external air 29 upwards through the external pathway outlets 40 a, . . . , 40 n of the first grate 25 a into the external pathway outlet plenum 15 b and exhausts it to the external air 29 outside of the electronics cabinet 5. The external pathway outlet plenum 15 b is used in part to extend the external pathway, fluid driving mechanism 10 a above the top cover 17 of the electronics cabinet 5 and below the electronics cabinet roof 12 (FIG. 1).
Existing heat exchangers use a special core. These cores can only be manufactured in places having specialized manufacturing equipment, and assembly of the cores requires hand caulking or other labor intensive techniques. Another aspect of the present invention addresses these limitations of existing cores by providing a simple core design that may be manufactured by any sheet metal or assembly house not having specialized manufacturing equipment with a further benefit of reducing much of the labor required to assemble existing cores. This simple core design is a “snap together” or “self-assembling” design that does not require hand caulking and that eliminates the need for grates 25 a, 25 b (FIGS. 5-7).
FIGS. 8A-11C illustrate the process of manufacturing the heat exchanger core 20 according to the principles of that aspect of the present invention.
FIGS. 8A-8C show a front view, a top view, and a left side view, respectively, of a left thermally conductive member 32 a undergoing a deforming process. In the front view (FIG. 8A), top edge areas 80 a, 80 b (forming a top region 81) and bottom edge areas 82 a, 82 b (forming a bottom region 83) are shown. As indicated, the top left edge area 80 a and the bottom right edge area 82 b are deformed “Forward” out of the page, and the bottom left edge area 82 a and the top right edge area 80 b are deformed “Backward” into the page. In other words, opposing edge areas or edge areas perpendicularly across from each other (e.g., 80 a and 82 a) and adjacent edge areas (e.g., 80 a and 80 b) are deformed in opposite directions. In the case of the right thermally conductive member 32 b described herein below with reference to FIGS. 10A and 10B, the top left edge area 80 a and the bottom right edge area 82 b are deformed “Backward” into the page, and the bottom left edge area 82 a and the top right edge area 80 b are instead deformed “Forward” out of the page.
FIGS. 8B and 8C show the top view and the left side view, respectively, of a left thermally conductive member 32 a undergoing the deforming process. The dashed line 33 in each of the views represents the nominal position of the left thermally conductive member 32 a surface before the deforming process. As indicated by the arrows in the views, opposite and adjacent edge areas of the left thermally conductive member 32 aare deformed in opposite directions, where the dotted lines 37 and 39 indicate the bottom edge areas 82 a, 82 b and the right edge areas 80 a, 82 a, respectively, of the left thermally conductive member 32 a and the solid lines 36 and 42 indicate the top edge areas 80 a, 80 b and the left edge areas 80 b, 82 b, respectively, of the thermally conductive member 32 a. In this embodiment, a major portion of the left thermally conductive member's 32 a surface maintains its nominal position.
As shown in FIGS. 9A and 9B, an adhesive (not shown) is applied to the top and bottom edge areas of the left thermally conductive member 32 a by an adhesive application mechanism 60. The adhesive is also applied to the top and bottom edge areas of the right thermally conductive member 32 b (FIGS. 10A and 10B ). The adhesive provides a seal between two thermally conductive members that are positioned together. In one embodiment, the adhesive application mechanism 60 is part of a machine. In another embodiment, a person 62 uses the adhesive application mechanism 60 to apply the adhesive quickly. In some embodiments, the adhesive may be a structural “heat sink” tape.
FIGS. 10A and 10B illustrate the assembly of right and left thermally conductive members 32 a, 32 b with adhesive on their top and bottom edge areas. As indicated by the arrows, the two thermally conductive members 32 a, 32 bare brought together such that the top and bottom edge areas 80, 82 of the two thermally conductive members 32 a, 32 b connect. Any number of additional thermally conductive members 32 a, . . . , 32 n subjected to the processes shown in FIGS. 8A-9B may be connected in a similar manner to form the assembled heat exchanger core 20 illustrated in FIGS. 11A-11C.
FIG. 11A shows the top view of the internal pathways 35 a, . . . , 35 n and external pathways 30 a, . . . , 30 n formed by assembling the thermally conductive members 32 a, . . . , 32 n according to the processes shown in FIGS. 8A-10B and by positioning the assembled thermally conductive members 32 a, . . . , 32 n in an enclosure 85 having walls and openings at the top and at the bottom (See FIGS. 11B and 11C). Thus, the internal pathways 35 a, . . . , 35 n and external pathways 30 a, . . . , 30 n are closed except at the inlets 45 a, . . . , 45 n, 55 a, . . . , 55 n and outlets 40 a, . . . , 40 n, 50 a, . . . , 50 n. In other embodiments, side panels may be positioned around the assembled thermally conductive members 32 a, . . . , 32 n, or edges of the thermally conductive members 32 a, . . . , 32 n may be bent, or any other method may be used to close the internal pathways 35 a, . . . , 35 n and external pathways 30 a, . . . , 30 n except at the inlets 45 a, . . . , 45 n, 55 a, . . . , 55 n and outlets 40 a, . . . , 40 n, 50 a, . . . , 50 n. As shown by the left side view and the right side view in FIGS. 11B and 11C, internal electronic cabinet air 27 enters the heat exchanger core 20 through the internal pathway inlets 45 a, . . . , 45 n and exits the heat exchanger core 20 through the internal pathway outlets 55 a, . . . , 55 n. Air outside the electronics cabinet 5 enters the external pathway inlets 50 a, . . . , 50 n and exits through the external pathway outlets 40 a, . . . , 40 n. As further shown in FIGS. 11B and 11C, the inlets 45 a, . . . , 45 n, 55 a, . . . , 55 n have greater volume than their respective internal pathways 35 a, . . . , 35 n and external pathways 30 a, . . . , 30 n. Thus, air passing from the inlets 45 a, . . . , 45 n, 55 a, . . . , 55 n to respective internal pathways 35 a, . . . , 35 n and external pathways 30 a, . . . , 30 n increases in velocity, thereby facilitating increased heat exchange by the thermally conductive members 32 a, . . . , 32 n.
While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
For example, the air may be any other fluid, such as a liquid (e.g., water) or any other gas, in applications in which heat exchangers can be used with liquids or gases.
The internal and external pathway fluid driving mechanisms 10 a, 10 b may be positioned anywhere along the external and internal pathways 30, 35, respectively. For example, the internal pathway fluid driving mechanism 10 b may be positioned at one end of the internal pathways 35 to exhaust air out of the internal pathways 35 or at the other end of the internal pathways 35 to force air into the internal pathways 35.
The heat exchanger core 20 may be configured to draw air into and exhaust air out of the right and left sides of the heat exchanger core 20.
The thermally conductive members 32 may include holes through which air heat exchange occurs. The thermally conductive members 32 may also have a curvilinear shape or any other shape or include fins or other conductive extensions.
In some embodiments, the bending of edge areas of the thermally conductive members is done at multiple places along the same region (e.g., top and bottom) to accommodate multiple inlets and outlets in the same region. For example, the embodiment of FIG. 3B has multiple edge areas along the top and bottom regions 81, 83 of the thermally conductive members bent in opposite directions as described in reference to FIGS. 8A-11C to define the multiple external and internal pathway inlets and outlets.
Deformation of edge areas 80, 82 in the top and bottom regions 81, 83, respectively, may be performed in various ways. For example, in some embodiments, the thermally conductive members may be cut along a line dividing edge areas. Then, opposing and adjacent edge areas may be folded in opposite directions. Materials may be added to seal or fill the gaps caused by the discontinuity between the edge areas. For example, triangular-shaped materials may be added to fill in the gaps. Bending or otherwise deforming the edge areas 80, 82 may be done by hand, machine, casting, or other preform technique.
It should be understood that the heat exchanger assembly 1 described herein may be used with other forms of heat exchangers, such as refrigeration units or air conditioning units, to supplement its cooling capacity to maintain cooling of the electronics cabinet 5 or other cabinet with which it is tasked with cooling.

Claims

1. A heat exchanger comprising:

a core configured to cool an enclosure;

multiple thermally conductive members disposed inside the core that define internal pathways and external pathways, the internal pathways defining inlets adapted to receive fluid from inside the enclosure and outlets adapted to pass fluid to inside the enclosure, the external pathways defining inlets adapted to receive fluid from outside the enclosure and outlets adapted to pass fluid to outside the enclosure;

an external pathway fluid driving mechanism coupled to the core in fluid flow relationship with the external pathways and causing fluid to flow in a first direction through the external pathways; and

an internal pathway fluid driving mechanism coupled to the core in fluid flow relationship with the internal pathways and causing fluid to flow in a second direction through the internal pathways in a manner to facilitate heat exchange by the multiple thermally conductive members.

2. The heat exchanger according to claim 1 wherein the fluid is air.

3. The heat exchanger according to claim 1 wherein the multiple thermally conductive members have a continuous surface.

4. The heat exchanger according to claim 1 wherein at least one of the multiple thermally conductive members has a surface defining fluid flow pathways between the internal pathways and the external pathways.

5. The heat exchanger according to claim 1 wherein the core is disposed in the enclosure in an arrangement defining a volume from which the internal pathway inlets receive fluid from inside the enclosure.

6. The heat exchanger according to claim 1 wherein the core is coupled to the enclosure outside of the enclosure.

7. The heat exchanger according to claim 1 wherein the core is disposed in the enclosure in an arrangement defining a first volume between the core and a first side internal to the enclosure and a second volume between the core and a second side internal to the enclosure.

8. The heat exchanger according to claim 1 wherein at least one of the fluid driving mechanisms comprises multiple fluid driving mechanisms.

9. The heat exchanger according to claim 8 wherein the fluid driving mechanisms comprise multiple internal fluid driving mechanisms and multiple external fluid driving mechanisms offset from each other.

10. The heat exchanger according to claim 1 further comprising plenums extending the internal pathways and external pathways to respective fluids inside and outside the enclosure.

11. The heat exchanger according to claim 1 further comprising grates in operational relationship with at least one of the internal or external pathways of the core, the grates causing fluid to flow through the internal pathways or the external pathways.

12. The heat exchanger according to claim 1 wherein the multiple thermally conductive members are adapted to self-assemble in a manner defining the inlets, outlets, internal pathways, and external pathways.

13. The heat exchanger according to claim 1 wherein the positions of the fluid driving mechanisms relative to respective pathways cause fluid flow in at least one of counter, cross, or diagonal directions.

14. The heat exchanger according to claim 1 wherein the fluid driving mechanism is a motorized impeller.

15. The heat exchanger according to claim 1 wherein the fluid driving mechanism is an axial fan.

16. The heat exchanger according to claim 1 wherein the fluid driving mechanism is positioned at the inlets, outlets, or combination thereof.

17. The heat exchanger according to claim 1 wherein the heat exchanger is used in an electronics cabinet.

18. A method for cooling an enclosure, the method comprising:

causing fluid to flow in a first direction through external pathways of a core configured to cool an enclosure having multiple thermally conductive members disposed inside the core to define internal pathways and the external pathways, the internal pathways defining inlets adapted to receive fluid from inside the enclosure and outlets adapted to pass fluid to inside of the enclosure, the external pathways defining inlets adapted to receive fluid from outside the enclosure and outlets adapted to pass fluid to outside of the enclosure; and

causing fluid to flow in a second direction through the internal pathways of the core in a manner facilitating heat exchange by the multiple thermally conductive members.

19. The method according to claim 18 wherein the fluid is air.

20. The method according to claim 18 wherein causing fluids to flow includes causing the fluids to flow continuously from the inlets to the outlets.

21. The method according to claim 18 wherein causing fluids to flow includes causing fluid to flow between at least one of the internal pathways and at least one of the external pathways.

22. The method according to claim 18 wherein causing fluid to flow through the internal pathways of the core includes drawing the fluid from a first volume between the core and a first side of the cabinet and a second volume between the core and an opposing second side of the cabinet.

23. The method according to claim 18 wherein causing fluids to flow includes causing fluid in respective internal pathways and external pathways to flow in at least one of counter, cross, or diagonal directions.

24. The method according to claim 18 wherein the method is performed within an electronics cabinet.