Central pressuring fan with bottom inlets for notebook cooling

A cooling system may include a fan which may be placed near the center of the system board. The fan may include bottom inlet and may draw air through an opening in the bottom skin of the computer system and may generate a positive pressure within the computer system. Exhaust vents may be positioned at the periphery.

FIELD OF THE INVENTION

The present invention generally relates to cooling systems. More specifically, the present invention relates to cooling computer systems using a central pressuring fan.

BACKGROUND

As computer systems become faster, electronic components in the computer systems generate more heat requiring more efficient cooling techniques. There are different techniques to provide cooling. They may be classified generally as passive cooling or active cooling. Passive cooling techniques are typically quieter as compared to active cooling techniques since they don't generally include an air moving device such as a fan or a liquid moving device such as a pump. Active cooling techniques on the other hand may be more effective than the passive cooling techniques. In the active cooling techniques, many different factors may affect their cooling capacity and application. These factors may include fan size, placement, noise, etc.

DETAILED DESCRIPTION

For one embodiment, an apparatus and a method for cooling electronic components in a computer system is disclosed. The cooling system may include a fan which may be placed near the center of the system board. The fan may include bottom inlet and may draw air through an opening in the bottom skin of the computer system and may generate a positive pressure within the computer system. Exhaust vents may be positioned at the periphery.

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures, processes and devices are shown in block diagram form or are referred to in a summary manner in order to provide an explanation without undue detail.

As used herein, the term “when” may be used to indicate the temporal nature of an event. For example, the phrase “event ‘A’ occurs when event ‘B’ occurs” is to be interpreted to mean that event A may occur before, during, or after the occurrence of event B, but is nonetheless associated with the occurrence of event B. For example, event A occurs when event B occurs if event A occurs in response to the occurrence of event B or in response to a signal indicating that event B has occurred, is occurring, or will occur.

Reference in the specification to “one embodiment” or “an embodiment” of the present invention means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase “for one embodiment” or “in accordance with one embodiment” appearing in various places throughout the specification are not necessarily all referring to the same embodiment.

Cooling System with Fan Positioned Near Edge of System

FIG. 1Ais a block diagram illustrating an example of a typical cooling system of a computer system, in accordance with some embodiments. System board100may be included in an enclosure190(illustrated inFIG. 1B) associated with a computer system. The system board100may include many different electronic components which may be capable of generating heat when in operation. For example, some of these components may include processor105, hard disk drive110, optical drive115, battery cell120, etc. A remote heat exchanger (RHX)125may be used to provide cooling. As illustrated, a heat pipe may be coupled to the processor105at one end and to the RHX125at the other end. The RHX125may be coupled to fan130which may be used to draw air into the enclosure190and cause the air to flow across the system board100for cooling.

The fan130may typically be a single outlet blower fan with top and bottom inlets. The air may enter the enclosure190through air vent openings150A-150B. It may pick up heat as it flows across the system board100and the remote heat exchanger125, and it may exit the enclosure190through exhaust air vent opening150C. The air may also enter the enclosure190through bottom air vent opening172(illustrated inFIG. 1B) located underneath the fan130.

The dotted lines illustrate air flow paths as the air travels across the system board100. The airflow paths include airflow path140A and airflow path140B. In a typical cooling configuration, the RHX125and the fan130are positioned at or near the edge of the enclosure190(or system board100) adjacent to the exhaust air vent opening150C. The cooling system illustrated inFIG. 1Ais typically known as an evacuative system.

One disadvantage of the typical cooling system illustrated inFIG. 1Ais the long flow paths of the air flow paths140A and140B from the air vent openings150A and150B to the air vent opening150C, respectively. This may mean that air may need to flow across the entire length of the system board100before it reaches an exhaust air vent opening. The long air flow paths may reduce cooling effectiveness of the cooling system since the air may be warmer toward the end of the air flow paths. For example, by the time the air following the air flow paths140A and140B reaches the RHX125, the air may already be warm and therefore may not be able to cool the RHX125or the processor105effectively.

Another disadvantage of the typical cooling system illustrated inFIG. 1Ais the requirement of the inlet gaps above and below the fan130. These inlet gaps may be used to allow air to be drawn into the fan130, as illustrated inFIG. 1B. These inlet gaps are between the top and/or bottom of the fan130and the top and bottom surfaces of the enclosure of the computer system.FIG. 1Billustrates an example of a cross section of the computer system having a typical cooling system, in accordance with some embodiments. Top side inlet gap107and bottom side inlet gap108may limit the fan130to a maximum height170. The inlet gaps107and108may typically be between one and three millimeters (mm). The inlet gaps107and108may enable air from the air vent openings150A and150B to be drawn into the enclosure190toward the fan130. Air may also be drawn in by the fan130through bottom vent172. The requirement to have the inlet gaps107and108may limit the size and capacity of the fan130.

Pressurized Cooling System with Bottom Inlet Fan

FIG. 2is a block diagram illustrating one example of an improved cooling system, in accordance with some embodiments. System board200may include similar electronic components as the system board100, except for the cooling system. The system board200may be included in enclosure such as, for example, enclosure690(illustrated inFIG. 6). For some embodiments, the system board200may include fan135which may be a positioned near the center and slightly toward the rear of the system board200. Placement of the fan135in this manner may facilitate acoustic damping of fan noise by the enclosure of the computer system and the electronic components, or by added muffling elements. With the fan135being near the center of the system board200, the exhaust air from the fan135may need to flow only approximately half the length of the system board200before it reaches an exhaust air vent opening.

The fan135may be different from the fan130in that the inlet gaps between the top and the bottom of the fan135and the top and bottom surfaces of the enclosure690may be reduced. For some embodiments, there may be no inlet gaps. This may enable the fan135to be larger than the fan130, and therefore may increase air flow to provide greater cooling capacity. The improvement in the cooling capacity may be approximately linear with the increase in height of the fan135.

The fan135may draw air from a bottom inlet. The bottom inlet may be placed at or near bottom opening605(illustrated inFIG. 6) in the bottom of the enclosure690. The fan135may not have any other inlet, and it may have two or more outlets, illustrated by air flow paths240A-240C.

The fan135may generate a positive pressure within the enclosure690. For some embodiments, exhaust air vent openings may be positioned at the periphery (e.g., side or rear) of the enclosure690. Depending on the layout of the system board200, the location of the exhaust air vent openings may vary. It may be possible to have exhaust air vent openings at the top or bottom of the enclosure690.

Referring toFIG. 2, exhaust vent openings250A,250B and250C are positioned at various places near the edges of the enclosure690(or of the system board200). The air drawn by the fan135from the bottom opening705may flow across the system board200, as illustrated by air flow paths240A,240B and240C. It may be noted that the average of the air flow paths240A-240C may generally be shorter than the average of the air flow paths140A-140B illustrated inFIG. 1. The shorter air flow paths may result in more effective cooling. It may be noted that the cooling system illustrated inFIG. 2generally reverses the airflow paths140A-140B (illustrated inFIG. 1) into the air flow paths240A-240C.

For some embodiments, RHX225may be positioned adjacent to the fan135and may be coupled to the processor105via a heat pipe. In this configuration, cool air drawn in by the fan135may follow the air flow path240C and may first flow across the RHX225and then across the processor105in series. This may enable more effective cooling of the RHX225due to the short distance that the cool air has to travel from the bottom opening705to the RHX225.

The enclosure690may not include any inlet on the interior except for the inlet at the bottom opening705. This may allow for a pressurized cooling environment. In this environment, flow impedance of the RHX225and flow impedance of the enclosure690may be separated. This may allow the fan135to drive these two flow resistances in parallel, rather than in series. This may reduce the overall system impedance and hence increase air flow. For some embodiments, when the fan135includes a greater than 90 degrees outlet which may cause the exhaust air to exit the fan135on two or more of its radial sides, there may be an increase in airflow in a low impedance system (flatter fan curve). This may enable reduction in fan noise. Using a radial blower fan such as, for example, the fan135may allow for an increase in the number of components on a system board and an increase in system powers.

Cooling System with Ducted Air Flow Path

FIG. 3Ais a block diagram illustrating another example of an improved cooling system, in accordance with some embodiments. System board300may include similar electronic components and may be housed in an enclosure similar to the enclosure690, except for the cooling system. The enclosure690may include air vent openings350A-350C. As inFIG. 2, the fan135and may be a positioned near the center and slightly toward the rear of the system board300.

For some embodiments, the RHX325may be positioned adjacent to an exhaust vent opening such as, for example, vent opening350C. The RHX325may be coupled to the processor105via a heat pipe. The processor105may be positioned in between the RHX325and the fan135. In this configuration, cool air drawn in by the fan135may follow the air flow path340C and may first flow across the processor105and then across the RHX325in series. This may enable more effective cooling of the processor105due to the short distance that the cool air has to travel from the bottom opening705of the fan135to the processor105.

For some embodiments, air movement caused by the fan135may be directed toward the RHX325using internal duct.FIG. 3Billustrates one portion of a system board illustrated inFIG. 3Awhere a duct may be used to direct air flow, in accordance with some embodiments. Duct370(illustrated in solid lines) may extend from the fan135to the RHX325. In this configuration, the air flow path340C from the fan135to the RHX325may be mostly within the duct370. It may be noted that the fan135may accommodate ducted air flow path340C and non-ducted air flow paths340A and340B concurrently.

FIG. 4illustrates another example of an improved cooling system, in accordance with some embodiments. System board400may include similar electronic components and may be housed in an enclosure similar to the enclosure690, except for the cooling system. The enclosure690may include exhaust air vent openings450A-450C. As inFIG. 3A, the RHX425may be positioned near exhaust air vent opening450C. The RHX425may be coupled to the processor105via a heat pipe. For some embodiments, the fan135may be positioned in between the RHX425and the processor105. In this configuration, cool air drawn in by the fan135may follow air flow path440C and flow across the RHX425. Cool air drawing in by the fan135may also follow the air flow path440A and flow across the processor105. This configuration may enable both the RHX425and the processor105to be cooled in parallel. It may be noted that the fan135in the configuration illustrated inFIG. 4may also generate airflow paths440B and440D. Air associated with the air flow path440D may exit the enclosure690via openings related to the installation of the optical disk drive115.

Cooling System with Ducted Side Inlet

FIG. 5illustrates another example of an improved cooling system, in accordance with some embodiments. System board500may include similar electronic components and may be housed in an enclosure similar to the enclosure690, except for the cooling system. The enclosure690may include exhaust air vent openings for exhaust air. Fan535may include an inlet at its bottom similar to the fan135. For some embodiments, the fan535may also include a side inlet510. The side inlet510may be coupled to a duct to draw air into the fan535.

Using the duct may enable the air drawn into the enclosure690to remain at a relatively similar temperature before it is exhausted by fan535. Thus, there may be air flow path520A associated with the bottom inlet (and bottom vent505) and air flow path520B associated with the side inlet510flowing toward the fan535and air flow path520C flowing away from the fan535. In the current example, a keyboard525may occupy some spacing from the top surface of the enclosure690, and there may be an inlet gap515between the top surface of the enclosure690and the top of the fan535.

FIG. 6illustrates an example of a cross section of the computer system having an improved cooling system, in accordance with some embodiments. The cooling system illustrated inFIG. 6may be similar to the improved cooling systems illustrated above in that they all employ a fan that has a bottom inlet. System board650may be included in the enclosure690. The height645of the fan135may be as much as the space between the top surface and the bottom surface of the enclosure690. Air may be drawn into the enclosure690by the fan135through bottom vent605. Air may be exhausted by the fan135according to airflow paths610and615.

FIG. 7is a block diagram that illustrates an example of a process that may be used to cool computer systems, in accordance with some embodiments. At block705, a bottom inlet fan may be used to draw air into an enclosure of a computer system. The fan may be a radial blower fan that may generate two or more exhaust air flow paths. At block710, the fan is to be positioned near middle area of a system board. This may enable short exhaust air flow paths from the fan to the air exhaust vent openings. At block715, duct may be used to direct one or more air flow paths to components that need cooling. At block720, if the fan includes a side inlet, a duct may be connected to the side inlet to draw air from outside the enclosure directly to the fan.

Although the present invention has been described with reference to specific exemplary embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the invention as set forth in the claims. For example, the bottom inlet fan may be used with or without any duct. When used with a duct, the duct may be used to cool one or more components located any where on the system board. Furthermore, even though the improved cooling system may be described with notebook or portable computer systems, it may also be applied to non-portable computer systems. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.