Hybrid cooling design for modular systems

A system and method for chassis cooling is provided. A preferred embodiment comprises an orthogonal backplane along with a hybrid cooling air flow. One air flow is routed horizontally through aligned and suitable openings on the backplane, vertically over components to be cooled, and horizontally out of the chassis. A second air flow is routed horizontally over components and through aligned and suitable openings on the backplane before it is routed horizontally out of the chassis.

TECHNICAL FIELD

The present invention relates generally to a system and method for providing cooling to electronic modules and, more particularly, to a system and method for providing cooling to a modular system such as a computer chassis that houses servers, data center network switch, or other similar data center equipment.

BACKGROUND

Generally, modular systems may utilize a backplane or midplane (hereafter the term of backplane is used for both a backplane or a midplane) in order to interconnect and organize a variety of modules (e.g., printed circuit boards or fans or power supply modules or other) within the modular system. For example, a backplane may be utilized in order to interconnect various functional modules such as blades to each other, to other chassis, and to external networks. Some backplanes may connect and organize the modules in a horizontal fashion, with each module connected to the backplane horizontally, while other backplanes may connect the modules in a vertical fashion. Additionally, other types of backplanes, such as an orthogonal backplane, may have a combination of connections, with some modules connected to the backplane horizontally and other modules connected to the backplane vertically.

However, while the orthogonal backplane configurations may have certain benefits, they also have certain drawbacks. For example, by having an orthogonal backplane configuration in which some modules are positioned vertically on one side of the backplane and other modules are positioned horizontally on another side of the backplane, cooling can become a major issue. In particular, the backplane and modules arranged in the orthogonal configuration create a complicated structure where a simple air flow over the modules is broken up by the various components and the backplane. This may become an even larger problem as processing and data transfer speeds continue their increases in speeds and heat generation.

FIG. 6Aillustrates one attempt to cool an orthogonal backplane and its associated modules, as described in U.S. Pat. No. 7,826,222 (the “'222 Patent”) to Aybay, et. al. As shown inFIG. 6A(which is a reprint of the '222 Patent's FIG. 10), this patent describes horizontal modules connected to a backplane and located in a front of a chassis along with vertical modules connected to the backplane and located in a back of the chassis. As shown inFIG. 6A, cooling air is pulled from a front of the chassis and over the horizontal modules, through radial blowers, and out the rear of the chassis. Similarly shown inFIG. 6B(which is a reprint of the '222 Patent's FIG. 11), to cool the horizontal modules, cooling air is pulled in at the top of the front of the chassis, pulled across the top of the chassis to bypass the horizontal modules, induced by horizontal fans trays to pass over the vertical modules to provide cooling to the vertical modules before the cooling air is expelled out of the chassis at the back bottom of the chassis.

SUMMARY OF THE INVENTION

These and other problems are generally solved or circumvented, and technical advantages are generally achieved, by preferred embodiments of the present invention which provide for the cooling of a chassis housing electronic modules.

In accordance with a preferred embodiment of the present invention, an electronic system comprising a first region adjacent to a first side, the first region comprising first sections for accepting first modules positioned in a first direction is provided. A second region is adjacent to a second side, the second side being opposite the first side, the second region comprising second sections for accepting second modules positioned in a second direction orthogonal to the first direction. A hybrid air flow path comprises a first air flow path having a first entrance in the first side, a first portion beneath the first region, a second portion between the second sections, and a first exit either through openings on top parts of faceplates of the second modules or through fans in the second side, and a second air flow path having a second entrance at the first side through openings on faceplates of the first modules in the first region, a third portion between the first sections, aligned and suitable openings on a backplane, and a second exit in the second side.

In accordance with another preferred embodiment of the present invention, a chassis comprising a first region located in a front of the chassis, the first region having horizontal sections, and a second region located in a back of the chassis, the second region having vertical sections, is provided. First fans are located to induce air to flow beneath the first region, flow through the second region, and exit the back of the chassis, and second fans are located to induce air to flow through the first region and exit the back of the chassis.

In accordance with yet another preferred embodiment of the present invention, a cooling system for a chassis comprising first modules located in a front region of the chassis and second modules located in a rear region of the chassis, the second modules arranged orthogonally to the first modules, is provided. A first entrance is at a front of the chassis, a first exit is at a back of the chassis, and a first path is between the first entrance and the first exit, wherein the first path is a reverse Z and passes between the second modules. A second entrance, a second exit, and a second path between the second entrance and the second exit, wherein the second path passes between the first modules is also provided.

In accordance with yet another preferred embodiment of the present invention, a chassis comprising a first set of rails aligned in a first direction located in a front region of the chassis and a second set of rails aligned in a second direction orthogonal to the first direction, the second set of rails located in a back region of the chassis is provided. A first air flow path having a first horizontal portion beneath the front region, having a first vertical portion through the back region, and having a first exit out of a back of the chassis is provided and a second air flow path having a second portion through the front region and having a second exit out of the back of the chassis is provided.

In accordance with yet another preferred embodiment of the present invention, a method of cooling modules in a chassis, the method comprising providing a first plurality of modules in a front region of the chassis and a second plurality of modules in a rear region of the chassis, the first plurality of modules being orthogonal to the second plurality of modules, the front region being adjacent to a front of the chassis and the rear region being adjacent to a rear of the chassis is provided. Air is induced to flow between the first plurality of modules and out of a first opening in the rear of the chassis and air is induced to flow beneath the front region of the chassis, vertically between the second plurality of modules, and out of a second opening in the rear of the chassis.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention will be described with respect to preferred embodiments in a specific context, namely a cooling system to provide cooling to an orthogonal backplane interconnected modular system. The invention may also be applied, however, to other cooling systems.

The specific embodiments of the present invention relate to a cooling airflow design methodology with a combination of a straight-forward front-to-rear airflow for front-side modules and a “Z”-shaped airflow for rear-side modules in a chassis-based modular system. As an example, the chassis-based modular system may include an orthogonal backplane with a combined air flow to cool modules within a modular system with a first region located in the front of the chassis and a second region located in the back of the chassis. First fans may be used to induce air to flow beneath the first region, flow through the second region, and exit the back of the chassis. Second fans may be used to induce air flow through the first region and exit the back of the chassis.

With reference now toFIG. 1A, there is shown a front view of a system100with a chassis101. However, as one of ordinary skill in the art will recognize, the embodiment illustrated inFIG. 1Aand the rest of the figures are merely illustrated embodiments of the present invention, and while specific details may be presented about the embodiments illustrated, the details are fully intended to be illustrative only, and are not intended to limit the present invention to the precise details described herein.

In the embodiment illustrated inFIG. 1A, the chassis101houses a backplane103(hidden from view inFIG. 1Aby the other components but represented by a dashed line) and also provides horizontal sections102into which a plurality of horizontal first modules105are connected to the backplane103. The chassis101is used to position and protect the various components of the system100(including, e.g., the backplane103and the horizontal first modules105). The chassis101may comprise a single housing that encloses all or portions of the various components, or else may simply be a tray or frame which provides support for the components without an external housing, such as providing support rails for each of the horizontal first modules105. For example, the chassis101may fit into the 19-inch wide rack with a height of 24.5 inches (otherwise known as 14U), although any other suitable size may alternatively be utilized.

Attached to the chassis101is the backplane103, which may be a printed circuit board having a plurality of interfaces or slots for the horizontal first modules105(discussed further below) and vertical second modules107(not shown inFIG. 1Abut illustrated inFIG. 1B). The backplane103may be arranged in an orthogonal fashion, with the horizontal first modules105located in the front of the chassis101connected to the backplane103in a horizontal position (relative to the chassis101) while the vertical second modules107are connected to the back of the chassis101(as shown inFIG. 1Bbelow) in a vertical position (again relative to the chassis101). In this manner the components of the system100connected to the front of the backplane103(e.g., the horizontal first modules105) are positioned to be orthogonal to the components of the system100connected to the back of the backplane103(e.g., the vertical second modules107).

The backplane103may be a FR4 backplane using orthogonal connectors such as, for example, the XCeded or Crossbow Orthogonal Backplane connectors from Amphenol-TCS, and supports data rate of 10 Gbps to 25 Gbps over a differential pair.

Further, it should be noted that, while the backplane103is referred to herein as a “backplane,” and is described with very specific specifications, this terminology and described embodiments are not intended to limit the embodiments of the present invention. In particular, the term “backplane” is not intended to limit the backplane103to an embodiment in which only one side of the backplane103comprises connections for the horizontal first modules105and the vertical second modules107. Rather, the backplane103is fully intended to include any arrangement of connections on the front side or rear side of the backplane103to allow for connections. As such, while the embodiments described herein use the term “backplane,” the backplane103may also be termed a “midplane” and still remain within the scope of the present embodiments. Additionally, the precise description, including the number of slots, data transfer rates, etc., are meant to be merely illustrative and are not intended to limit the present embodiments in any fashion.

The horizontal first modules105are connected to the front of the backplane103(as can be seen in the front view of the chassis101inFIG. 1A), and may be, as illustrative examples only, Server or Input/Output (SIO) blades such as server blades, linecard blades, combinations of these, or the like. In an embodiment in which the horizontal first modules105are SIO blades and the SIO blades are server blades, the horizontal first modules105provide modular and scalable computer services such as data processing, storage, routing, or other functions for the system100. Accordingly, the horizontal first modules105may each comprise a processor, memory modules, PCI cards, etc, and other functional components, in order to provide for the desired functionality, such as data processing, storage, routing, connectivity, translation, encoding/decoding, and the like. Other components which may be shared between horizontal first modules105, such as power supplies and cooling, may be shared between all of the horizontal first modules105through the backplane103and the chassis101. As such, each of the horizontal first modules105may comprise each of the components for the functionality while optimizing space by sharing non-functional components between the horizontal first modules105.

Alternatively, in an embodiment in which the horizontal first modules105are linecard blades, the horizontal first modules105may provide an interface to an external network (not shown). As such, the horizontal first modules105may provide connectivity, translation, encoding/decoding, and other communication functionality between the external network and the remainder of the horizontal first modules105. Similar to the server blades discussed above, the linecard blades may physically comprise all of the functional circuitry that may be needed to provide the interface, while optimizing space by sharing other functions such as power supplies and cooling with the other horizontal first modules105.

In an embodiment, the chassis100may comprise ten horizontal regions102to support a plurality of ten horizontal first modules105connected to the backplane103in a horizontal position and supported by horizontal rails114, as illustrated inFIG. 1A. In addition, the horizontal first modules105may be spaced apart from each other with a pitch such as 1.75 inches generally referred to herein as 1U or 1RU. However, the precise number and spacing of the horizontal first modules105described herein are intended to be illustrative only, and the described embodiments are not intended to be limiting. More or less than the number and spacing of the horizontal first modules105described herein may be used as desired for the overall design of the system.

FIG. 1Aalso illustrates a number of peripheral components that may also be connected on the backplane103to the front of the chassis101. For example, load sharing power supplies111may be connected to the backplane103in order to provide power to the various components such as the horizontal first modules105and the vertical second modules107that connected to the backplane103. The load sharing power supplies111may be cooled similarly to the rest of the components in the system100as described herein or else may contain their own integrated fans in order to help the load sharing power supplies111remain cool with front-to-rear airflow.

Control blades113may also be connected to the front of the backplane103in order to control the operation of the modular system during start-up and operation. For example, upon start-up the control blades113may be used to detect the presence or absence of components within the various connections on the backplane103, and may also determine the status of each component that is present. During operation of the backplane103, the control blades113may periodically scan the backplane103to determine if new components (e.g., a new first module105) have been added to the backplane103during operation and, if one has been added, power up and integrate the new component with the rest of the components on the backplane103. In some modular systems, the control blades113may simply be another of the horizontal first modules105.

As illustrated inFIG. 1A, two control blades113may be connected to the backplane103in order to provide a primary control blade along with a backup secondary control blade. In such an embodiment, the primary control blade may monitor and control the components connected to the backplane103while the secondary control blade may monitor the primary control blade. If the primary control blade fails or otherwise gives up control of the backplane103, the secondary control blade may immediately take over, thereby minimizing any disruption caused by the primary control blade failing.

Optionally, a mechanical stiffener115may be part of the chassis101to provide stronger mechanical support. The mechanical stiffener115may be used to provide additional support beyond the inherent structural support already present within the backplane103. The additional support can be used to ensure that there is no undesired deformation of the backplane103when the horizontal first modules105and the vertical second modules107, along with other components, are connected to the backplane103and begin to apply uneven forces to the backplane103.

FIG. 1Billustrates a rear view of the chassis101, which may house the vertical second modules107in vertical sections104supported by vertical rails112. The vertical second modules107may be attached to the backside of the backplane103through slots within the backplane103. In an embodiment in which the backplane103is an orthogonal backplane and the horizontal first modules105are arranged horizontally, the vertical second modules107are connected to the backplane103vertically.

The vertical second modules107may be, e.g., fabric blades that may be used to form functional interconnections between the various horizontal first modules105and other components. In an embodiment in which the horizontal first modules105are server blades, the vertical second modules107may provide interconnection between the individual horizontal first modules105, and/or network connectivity to an external network (not shown). Alternatively, if the horizontal first modules105are linecard blades, the vertical second modules107may provide interconnectivity between the individual horizontal first modules105as well as providing network aggregation function between multiple chassis.

Similar to the horizontal first modules105, the vertical second modules107may physically include the functional components that may be needed to provide the desired interconnectivity functionality. Other elements, such as the power supply and cooling components, may be located elsewhere within the chassis101and shared between the various components such as the horizontal first modules105and the vertical second modules107. This allows the shared components to be optimized for all of the components of the system while still providing for the functionality of each of the individual vertical second modules107.

Optionally, each of the vertical second modules107may include a first air flow opening119. This first air flow opening119provides a path for airflow to flow away from the surfaces of the vertical second modules107and, eventually, out of the chassis101. The first air flow opening119could be as simple as being an open space, an open space with a screen, a series of smaller openings, combinations of these, or the like, depending on the desired overall design. Further, the backplane103may, as illustrated inFIG. 1B, connect six vertical second modules107in a vertical configuration, although the precise number of vertical second modules107is not limited to six, and may be more or less depending upon the desired overall design.

Additional to the vertical second modules107, a number of management components may also be connected to the back side of the backplane103. For example, system management components126may be included in order to manage the operations of all other circuit boards, power supply modules and fans. The chassis101may also have additional air outlets122to exhaust hot air from power supplies111along with an external power entry opening125through the back side of the chassis101in order to allow for an external power source (not shown) to be connected to the chassis101. Air outlets122and power entry125may also be one part. Once connected, the external power source can supply power to the load sharing power supplies111located within the chassis101, which can then supply power to the individual components of the chassis101.

FIGS. 1A and 1Badditionally illustrate the placement of first fans127and second fans129around the chassis101. In the embodiment illustrated inFIGS. 1A and 1B, there are two first fans127located in the middle along the bottom of the front of the chassis101. The first fans127may be, e.g., two 80 mm fans, although any other suitably sized fan, such as 60 mm fans, 92 mm fans, 100 mm fans, or the like, may alternatively be utilized.

While the first fans127are located in the front of the chassis101, the second fans129may be located in the back of the chassis101. In the embodiment illustrated inFIG. 1B, there is one second fan129in each group for every two slots in the front of the backplane103(shown inFIG. 1Aconnected to the horizontal first modules105, the mechanical stiffener115and the control blades113). As such, in this embodiment twelve second fans129may be arranged, e.g., vertically in two rows of six second fans129each along the outside edges of the chassis101adjacent to the vertical second modules107. Similar to the first fans127, the second fans129may be, e.g., 80 mm fans, or any other suitably sized fan, such as 60 mm fans, 92 mm fans, 100 mm fans, or the like, and more or less fans may alternatively be utilized if desired.

The first fans127and the second fans129are utilized to induce an air flow across the individual components within the chassis101(e.g., the horizontal first modules105and the vertical second modules107). As the air flows across the individual components, the difference in temperature between the air and the individual components will induce heat to transfer from the individual components into the air, thereby cooling the individual components. After being heated through the heat transfer, the air then continues to flow out of the chassis101, thereby completely removing the heat from the individual components.

FIG. 1Cillustrates a side view ofFIG. 1Aand illustrates a path for a first air flow (represented inFIG. 1Cby the dashed lines131) that is induced by the first fans127within the chassis101. As illustrated, the first fans127pull in external air from outside of the chassis101and routes the external air beneath the horizontal first modules105and through an opening134on the backplane103. As such, the external cool air is introduced across the vertical second modules107without the external air being significantly heated by the horizontal first modules105.

Once the external air has been routed to the back of the chassis101, the external air is directed vertically so that it passes over the vertical second modules107. The external air may be directed simply by hitting the back of the chassis101. However, as such an impact on a flat wall would reduce the overall efficiency of the cooling, the external air may optionally be directed vertically by an air turner128located at the back of the bottom of the chassis101. The air turner128may comprise a series of angled surfaces to gradually direct the first air flow131vertically without the first air flow131hitting a vertical wall. The air turner128may be, e.g., a piece of sheet metal that is placed to provide a series of smaller, angular surfaces, although any other suitable material may alternatively be utilized.

Additionally, it may be desirable to expand the first air flow131so as to more evenly direct the first air flow131across the vertical second modules107. For example, in the embodiment in which there are two first fans127, the first air flow131from the first fans127is initially flowing with a cross-section of about 160 mm (80 mm fans×2 fans). However, the vertical second modules107take up a cross-section of 9.6 inches (1.6 inches×6 modules) or about 244 mm. As such, a more efficient cooling across all of the vertical second modules107may be achieved by spreading out the first air flow131through, e.g., an air spreader134(not visible inFIG. 1Cbut shown inFIG. 1Dbeneath the vertical second modules107). The air spreader134may be, e.g., similar to the air turner128and may be a piece of sheet metal that is positioned at an angle to the air flow in order to spread the first air flow131more evenly across the vertical second modules107.

Once the external air has been introduced to the vertical second modules107, the external air flows vertically through the chassis101and across the vertical second modules107. As the external air flows across the vertical second modules107, heat is transferred from the vertical second modules107to the air, thereby heating the air while also simultaneously cooling the vertical second modules107. After the air has been heated, the air may then exit the chassis101horizontally through the first air flow openings119(seeFIG. 1A) located within the vertical second modules107. Optionally, another air turner128may be placed at the top of the second modules107in order to better direct the first air flow131out of the first air flow openings119.

As seen from the side view inFIG. 1C, the first air flow131from the front of the bottom of the chassis101to the top of the back of the chassis101resembles a backwards “Z” shape, with the first air flow131being directed horizontally along the bottom of the chassis101, vertically over the vertical second modules107, and then horizontally out of the first air flow openings119. Additionally, the first air flow131may be spread more evenly across the vertical second modules107(in a direction into and out ofFIG. 1C) through the use of the air spreader134. This first air flow131allows for the efficient entry, heating, and removal of the external air in order to cool the vertical second modules107.

FIG. 1Dillustrates a top-down view of the chassis101showing a second air flow (represented inFIG. 1Dby the dashed lines133) induced by the second fans129across the horizontal first modules105. As illustrated, the second fans129pull in external cool air from the front of the chassis101through, e.g., openings on the faceplates of horizontal first modules105and passes the external air over and around the horizontal first modules105(one of which is visible inFIG. 1D). The second air flow133may flow through third air flow openings135located on the backplane103, and the second air flow133is then expelled through the backside of the chassis101by the second fans129.

Similar to the cooling of the vertical second modules107, as the external cool air flows over the horizontal first modules105, the heat from the horizontal first modules105is transferred to the air, thereby heating the air while simultaneously cooling the horizontal first modules105. The heated air is then expelled from the chassis101through the second fans129, thereby cooling the horizontal first modules105within the chassis101.

The first air flow131and the second air flow133in combination form a hybrid air flow from the two separate air flows. This hybrid air flow is able to provide external air to both the horizontal first modules105and the vertical second modules107even if the horizontal first modules105and the vertical second modules107are connected to the backplane103in an orthogonal configuration. As such, the hybrid air flow is able to provide a more efficient cooling for each of the various types of components.

FIGS. 2A-2Billustrate a front-view and a back-view, respectively, of the chassis101in a second embodiment of the present invention, andFIGS. 2C-2Dillustrate the first air flow131across the vertical second modules107and the second air flow133across the horizontal first modules105in this embodiment, respectively. In this embodiment the second fans129are located in a similar position as the second fans in the embodiment described above with respect toFIGS. 1A-1D. As such, the second air flow133induced by the second fans129across the horizontal first modules105is similar to the second air flow133as discussed above with respect toFIGS. 1A-1D. As such, the second air flow133illustrated inFIG. 2Dis illustrated as being the same as the second air flow133illustrated inFIG. 1D.

However, in the second embodiment the first air flow131across the vertical second modules107is not pushed from the front of the chassis101but is instead pulled from the top back of the chassis101. In particular, the first fans127are removed from the bottom of the front of the chassis101and are replaced with a third air flow opening201in order to allow external air to enter the chassis101from the bottom of the front of the chassis. The first fans127, having been replaced by the third air flow openings201in the front of the chassis, are placed in the middle along the top of the back of the chassis101, as can be seen inFIG. 2B.

In order to accommodate the first fans127along the top of the chassis101, the chassis101may be extended upward a distance to accommodate the first fans127. This extension allows not only for the placement of the two first fans127along the back top of the chassis101, but also allows for additional fans to be included. For example, with the additional space, four first fans127may be included along the back top of the chassis101as illustrated inFIG. 2B.

By placing the first fans127along the top of the back of the chassis101, the first fans127, instead of inducing the external cool air by pushing the air across the vertical second modules107, are instead pulling the external air across the vertical second modules107. However, the first air flow131of the external air across the vertical second modules107is similar to the first air flow131as in the first embodiment (e.g., the reverse “Z” shape of air flow) in that the external cool air enters the chassis101through the bottom front of the chassis101, travels beneath the horizontal first modules105and through openings on the backplane103, then travels vertically over the vertical second modules107before entering the first fans127and exiting the chassis101outside the top of the back side of the chassis101.

Alternatively in this embodiment, the first fans127along the front of the chassis101are not removed and are simply left in place while additional first fans127are placed along the back of the chassis101as described above. As such, the external cool air may be both pulled through the chassis101by the first fans127at the back of the chassis101while also being pushed through the chassis101by the first fans127located at the front of the chassis101.

FIGS. 3A-3Billustrate a front-view and a back-view, respectively, of the chassis101in a third embodiment of the present invention, andFIGS. 3C-3Dillustrate the first air flow131and the second air flow133in the third embodiment, respectively. As illustrated inFIG. 3A, in this embodiment the positions of the first fans127and the load sharing power supplies111are reversed so that the first fans127are located along the edges of the chassis101along the bottom of the chassis101while the load sharing power supplies111are located in the center of the chassis101along the bottom of the chassis101.FIG. 3Billustrates that, in this embodiment, the position of the second fans129has been switched with the position of the vertical second modules107such that the second fans129are located in the center of the back of the chassis101while the vertical second modules107are located on the left and right sides of the back of the chassis101. In such a fashion, the vertical second modules107are kept in line with the first fans127located at the front of the chassis101.

Given this placement of the first fans127, the first fans127induce the external fresh cool air to flow as illustrated by the first air flow131inFIG. 3C. In particular, the first fans127induce the external air to flow horizontally beneath the horizontal first modules105and through openings134on the backplane103, vertically over the vertical second modules107and out of the chassis101through the first air flow opening119on the top of the faceplates of the vertical second modules107. This first air flow131follows the reversed “Z” pattern that may similarly be seen inFIG. 1C.

However, differently from the first air flow131as shown inFIG. 1C, the first air flow131in the third embodiment travels along the outside edge of the chassis101instead of being directed down the middle of the chassis101as in the embodiment described above with respect toFIGS. 1A-1D. Once at the back of the chassis101the first air flow131is expanded to more evenly flow over the vertical second modules107(using, e.g., air spreaders134shown inFIG. 3D), directed vertically over the vertical second modules107(using, e.g., air turners128), and then directed horizontally out of the first air flow openings119in the vertical second modules107.

With this placement, the second fans129induce the external air to flow as illustrated inFIG. 3D. In particular, the second fans129induce the external air to flow from the front of the chassis101through openings on the faceplates of the horizontal first modules105, through the horizontal first modules105, through the third air flow openings152located in the middle of the backplane103, through the second fans129located in the middle of the back of the chassis101, and out the back of the chassis101. However, instead of routing the second air flow to the outside edges of the chassis101, the second fans129will pull the second air flow133into the middle of the chassis101before expelling the second air flow133out of the chassis101. As such, the external air is used to cool the horizontal first modules105and the heat is ultimately removed from the chassis101.

FIG. 4A-4Billustrate a front-view and a back-view, respectively, of the chassis101in yet another embodiment of the present invention, withFIGS. 4C-4Dillustrating the first air flow131and the second air flow133associated with this embodiment, respectively. In this embodiment the second fans129, similar to the third embodiment discussed above with respect toFIGS. 3A-3D, are located in the middle of the back of the chassis101as illustrated inFIG. 4B. As such, the second air flow133across the horizontal first modules105as illustrated inFIG. 4Dis similar to the second air flow133described above with respect toFIG. 3D.

In this fourth embodiment, however, the first fans127are placed along the top of the back of the chassis101while the third air flow opening201are placed in the front of the chassis101in order to allow external air to enter the chassis101from the bottom of the front of the chassis101. However, instead of being located in the middle of the back of the chassis101(which would be similar to the embodiment described above with respect toFIG. 2A-2D), the first fans127are split into two groups located along an outside edge of the chassis101, such as the two groups of two first fans127each illustrated inFIG. 4B. Power supply modules401may provide power to the horizontal first modules105and vertical second modules107in the chassis101.

FIG. 4Cillustrates the first air flow131through the chassis101with the first fans127located along the top of the chassis101at the sides. Similar to the first air flow131described above with respect toFIG. 2C, the first air flow131in this embodiment follows the reverse “Z” shape, wherein the first air flow travels along the bottom of the chassis101beneath the horizontal first modules105and through opening134on the backplane103, vertically across the vertical second modules107, and then is pulled horizontally through the first fans127before being expelled from the chassis101. However, while the first air flow131inFIG. 4Cis similar toFIG. 2C, the first air flow131inFIG. 4Cis pulled by the first fans127along an outer edge of the chassis101in order to flow across the vertical second modules107located along the outer edge of the chassis101.

By providing for the first air flow131across the horizontal first modules105and the second air flow133across the vertical second modules107(in the reverse “Z” shape of air flow), a hybrid air flow may be realized that is especially efficient when used with an orthogonal backplane in which some blades are positioned horizontally and other blades are positioned vertically. Such a hybrid air flow allows for the efficient cooling of all components embodied within the chassis101even as the speed of the components and, therefore, their generation of heat, is increased into future generations of data transfer.

FIG. 5Aillustrates yet another embodiment in which the second fans129may be replaced with two liquid cooling heat exchangers501to pull and cool the hot air from the horizontal first modules105before it is exhausted out of the chassis101for higher data center cooling efficiency.

FIG. 5Billustrates yet another liquid embodiment in which the second fans129may be replaced with two liquid cooling tanks503in order to provide cooling fluid to the horizontal first modules105in the front of the chassis101. The cooling fluid may be routed from one of the liquid cooling tanks503to the horizontal first modules105using suitable tubing that routes the cooling fluid through the openings in the backplane103to the horizontal first modules105, and back to the second liquid cooling tank503. Such routing of the cooling fluid allows the horizontal first modules105to be cooled beyond the cooling capacity of the external air or the liquid cooling heat exchangers501.

Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. For example, many different types of blades may be connected to the backplane. As another example, it will be readily understood by those skilled in the art that connections and positions may be varied while remaining within the scope of the present invention.