Patent Publication Number: US-2022221916-A1

Title: Systems And Methods To Determine System Airflow Using Fan Characteristic Curves

Description:
FIELD 
     This invention relates generally to information handling systems and, more particularly, to cooling air flow within information handling systems. 
     BACKGROUND 
     As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems. 
     One or more cooling fans are typically employed within the electronic chassis enclosure of information handling system platforms, such as network servers, to supply airflow to cool components that are operating within the information handling system chassis. Examples of such components include Peripheral Component Interconnect Express (PCIe) cards that are plugged into mating PCIe slots within the chassis enclosure of the information handling system. 
     Multiple servers are often grouped and operated together within a data center. Airflow consumption for cooling individual servers within such a data center is tightly coupled to data center capacity and facility resources, and data center operators benefit from having access to real time reporting of estimated airflow from individual servers. In addition, system control algorithms also benefit from real-time estimated airflow reporting which may then be used for PCIe inlet and system exhaust temperatures (bulk) determination. 
     A conventional method for estimating volumetric airflow rate consumed by a single given server system platform configuration is to use a conventional predefined correlation of the system airflow as a function of the system cooling fan speed for the given server system platform configuration to estimate the server system volumetric airflow rate from the real time known system cooling fan speed. Such a conventional predefined correlation is developed in the laboratory from static data that is collected for a single given discrete system platform configuration that includes a particular combination of storage drive/s, rear input/output connections, processor types, number of processors, etc. 
     Using conventional techniques, each unique server system platform configuration must be separately characterized in the laboratory by the server system manufacturer or assembler in order to develop a conventional predefined correlation of volumetric system airflow rate versus cooling fan speed for that unique server system platform configuration. This characterization is made in the laboratory by measuring cooling fan speed (% pulse width modulation “PWM”) versus airflow (cubic feet per minute “CFM”) for each different type (e.g., different type, different size, different motor horsepower, etc.) of cooling fan that is present in the given server system platform, i.e., each unique server system platform configuration typically includes multiple different configurations of cooling fans that must be characterized. As shown in  FIG. 1 , this laboratory characterization process for a unique server system platform configuration must be performed multiple times (e.g., for a total of two to three times), once for each different configuration of cooling fan that is present in the given server system platform. The resulting correlation of cooling fan speed versus volumetric airflow rate for the unique server system platform configuration is then input into a table for the baseband management controller (BMC) to reference from. The resulting correlations of the conventional methodology are only valid for a single unique given server system platform configuration, which means that this conventional characterization process must be repeated (e.g., for a total of five to ten times), once for each other possible unique server system platform configuration that may be manufactured and deployed in the field. 
       FIG. 2  shows how the conventional laboratory characterization process of  FIG. 1  must be repeated by the server system manufacturer or assembler for any new unique server system platform configuration that is developed after product is officially released to the customer. The table for the BMC must then be updated to include the resulting correlation of cooling fan speed versus volumetric airflow rate that is obtained from the characterization of the new unique server system platform configuration. 
     Once developed, each given conventional correlation of cooling fan speed versus volumetric airflow rate that is developed as described above is only valid for estimating airflow from a server system that has the same unique discrete system configuration for which the given conventional predefined correlation was developed in the laboratory. Further, each given conventional predefined correlation is used to estimate airflow based only on system cooling fan speed. Development and use of such conventional correlations takes precious development time and expenses, and each developed correlation of cooling fan speed versus volumetric airflow rate is only valid for estimating volumetric airflow rate consumed by a single unique and discrete server configuration. 
     SUMMARY OF THE INVENTION 
     Disclosed herein are systems and methods that may be implemented in real time to determine the volumetric rate of airflow through a chassis enclosure of an information handling system platform directly from real time measured cooling fan power consumption in combination with standalone or system-level cooling fan power characteristics (e.g., expressed as cooling fan power curves) that relate cooling fan volumetric airflow rate to cooling fan power consumption at the current fan rotation speed. In one embodiment, distinct characteristics of individual cooling fan performance may be used in this manner to determine the real time volumetric airflow rate of each individual cooling fan from its respective measured individual real time power consumption at its current fan rotation speed while it is circulating air through a chassis enclosure of an information handling system platform. The individually-determined cooling fan volumetric airflow rates of all the separate system cooling fans may then be summed or added together to determine the total real time volumetric airflow rate that is currently passing through the chassis enclosure of the information handling system platform. This determined value of total real time volumetric airflow rate may then be used, for example, by individual system level thermal control algorithms and/or data center level thermal control algorithms. 
     In another embodiment, performance of all system cooling fans circulating air through a chassis enclosure of an information handling system platform may be considered together and used to determine total real time volumetric airflow rate that is currently passing through the chassis enclosure of the information handling system platform. In this embodiment, the real time total power consumption of all system cooling fans may be measured together while all system cooling fans are rotating at the same speed, e.g., in a case where individual cooling fan power measurements are not available. The total real time volumetric airflow rate that is currently passing through the chassis enclosure of the information handling system platform may then be determined at the current uniform fan rotation speed of all system fans from total system cooling fan power characteristics (e.g., expressed as total system power curves) that relate total system cooling fan volumetric airflow rate to total cooling fan power consumption of all system cooling fans at their current uniform fan rotation speed. 
     In one embodiment, the disclosed systems and methods may be implemented to provide increased flexibility for system and data center operations by allowing continuous measurement of real time volumetric airflow rate without using the conventional characterization methodology that requires collection of static data for each different discrete system platform configuration. Since no additional system platform characterization is required for each different system platform configuration, no additional system platform characterization steps are required to allow measurement of system platform volumetric airflow rate when new unique system platform configurations are introduced after product is officially released to the customer by a manufacturer or assembler of a system platform (e.g., for inclusion in a lookup table that describes a correlation between fan speed versus airflow versus PCIe inlet airflow matched to a given system configuration that may be accessed by a baseband management controller (BMC)). Each of such unique system platform configurations may have different combinations of chassis enclosure characteristics and/or internal system components (e.g., such as storage drive/s, processor type/s, number of processors, types of rear input/output connections, etc.). However, the disclosed systems and methods may be implemented to determine real time total volumetric rate of airflow through a chassis enclosure of an information handling system platform regardless of differences in specific information handling system platform configurations, such as different configurations of storage drive/s, rear input/output connections, processor type/s, number of processors etc. 
     In one respect, disclosed herein is an information handling system, including: a chassis enclosure; at least one cooling fan configured to operate at multiple rotational speeds to provide different flow rates of cooling air within the chassis enclosure to cool one or more heat-producing components within the chassis enclosure; and at least one programmable integrated circuit that is coupled to the at least one cooling fan. The programmable integrated circuit may be programmed to: determine a current real time rotational speed of the at least one cooling fan and a current real time value of electric power consumed by the at least one cooling fan; and determine a current real time volumetric airflow rate provided within the chassis enclosure by the at least one cooling fan as a function of the determined current real time value of electric power consumption of the at least one cooling fan and the determined current rotational speed of the at least one cooling fan. 
     In another respect, disclosed herein is a method including: operating at least one cooling fan to provide airflow within a chassis enclosure of an information handling system to cool one or more heat-producing components within the chassis enclosure; determining a current real time rotational speed of the at least one cooling fan and a current real time value of electric power consumed by the at least one cooling fan; and determining a current real time volumetric airflow rate provided within the chassis enclosure by the at least one cooling fan as a function of the determined current real time value of electric power consumption of the at least one cooling fan and the determined current rotational speed of the at least one cooling fan. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates conventional methodology. 
         FIG. 2  illustrates conventional methodology. 
         FIG. 3  illustrates a block diagram of an information handling system platform according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 4A  illustrates an overhead block diagram view of an exemplary embodiment of an information handling system chassis enclosure according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 4B  illustrates an overhead block diagram view of an exemplary embodiment of an information handling system chassis enclosure according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 5  illustrates a simplified representation of a data center and its components according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 6  illustrates methodology according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 7  illustrates an exemplary relationship according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 8  illustrates an exemplary empirical correlation according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 9  illustrates a correlation between an individual cooling fan power consumption and volumetric air flow rate according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 10  illustrates methodology according to one exemplary embodiment of the disclosed systems and methods. 
         FIG. 11  illustrates a correlation between total system fan power consumption and total system volumetric air flow rate according to one exemplary embodiment of the disclosed systems and methods. 
     
    
    
     DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
       FIG. 3  illustrates one exemplary embodiment of an information handling system platform  100  configured in this embodiment as a server platform, although the disclosed systems and methods may be implemented with other types of information handling system configurations such as desktop or tower computer configurations, workstation configurations, notebook computer configurations, etc. As shown, system platform  100  includes individual and discrete heat-producing electrical components (e.g., components  103 ,  106 ,  108 ,  109 ,  111 ,  117 ,  121 ,  140 ,  150 , etc.) and one or more variable speed cooling fans  190  (e.g., axial fans, centrifugal fans, blower fans, etc.) that are configured to cool at least a portion of these respective heat-producing components, e.g., based on sensed and reported real time temperature information provided from temperature sensor/s  124  that may be positioned within the airflow of the cooling fans  190  and/or that may sense the operating temperature of one or more of the heat-producing temperature sensors  124 . 
     In the illustrated embodiment of  FIG. 3 , each of the cooling fan/s  190 , temperature sensor/s  124  and individual heat-producing components are contained within a chassis enclosure  104  (e.g., plastic enclosure, sheet metal enclosure, etc.) that encloses internal components of the information handling system  100  therein. Examples of chassis enclosures  104  include, but are not limited to, 2U, 3U, 4U computer chassis, tower or desktop computer chassis, etc.). As shown, the cooling fan/s  190  are provided to cool the heat-producing components by circulating cooling air through the interior of chassis enclosure  104  from cooling air inlets  175  to cooling air outlets  177  that are defined through the walls of chassis enclosure  104 . One or more of the cooling fans  190  may be of different configuration (e.g., different type, different size, different motor horsepower, etc.) than one or more of the other cooling fans  190 , and/or may be rotating at different speeds from each other at any given time. 
     Examples of heat-producing components illustrated in the embodiment of  FIG. 3  include a host programmable integrated circuit  106 , video/graphics hardware (e.g., discrete graphics processing unit or video card/s)  109 , volatile memory (e.g., DRAM dual in-line memory module/s)  121 , system power supply and voltage regulator/s  111 , storage device/s (e.g., solid state drive “SSD”, hard drive, optical drive, etc.)  117 , persistent or non-volatile (e.g., non-volatile RAM) memory  140 , an out-of-band programmable integrated circuit  108  in the form of a baseboard management controller “BMC” (e.g., with other possible examples being a service processor, embedded processor, etc.), and a network interface controller (NIC)  103 . Together, BMC  108  and non-volatile memory  140  may be configured as a remote access controller  198 , e.g., such as an integrated Dell Remote Access Controller (iDRAC) available from Dell Technologies of Round Rock, Tex., etc., in which case non-volatile memory  140  may store, among other things, remote access controller component firmware. 
     Still referring to  FIG. 3 , power supply and voltage regulator/s (PSU and VR)  111  supplies power to all power-consuming components of system  100  within chassis enclosure  104  via power rails  183 , including cooling fan/s  190  and heat-producing electrical components of system  100 . It will be understood that other types and combinations of heat-producing components are possible, e.g., a given system  100  may be provided with two or more PSU&#39;s  111  for supplying all the power-consuming components of system  100  and/or two or more host programmable integrated circuits  106 . In one embodiment, out-of-band programmable integrated circuit  108  may be coupled and configured to monitor and/or control (and thus be aware of) total power provided by the one or more PSUs  111  to power all the power-consuming components of system  100 , and may also be coupled and configured to monitor and/or control (and thus be aware of) real time power consumption by individual power-consuming components (e.g., such as individual cooling fans  190 ). In this regard, programmable integrated circuit  108  may be configured to directly monitor power consumption of an individual power-consuming component and/or may be configured to receive reported component power consumption from another intervening component (e.g., chassis power manager) of system  100 , e.g., such as described in U.S. Pat. No. 8,156,358 which is incorporated herein by reference in its entirety for all purposes. 
     Referring now in more detail to the embodiment of  FIG. 3 , host programmable integrated circuit  106  is configured in this embodiment as a central processing unit (CPU) that executes an operating system (OS) for system  100 . CPU  106  may include, for example, an Intel Xeon series processor, an Advanced Micro Devices (AMD) processor or another type of programmable integrated circuit. In  FIG. 3 , optional GPU  109  is coupled in signal communication with CPU  106  (e.g., by conductor including PCI-Express lanes, power supply bus, power, thermal and system management signals, etc.) to transfer instructions and data for generating video images from CPU  106  to the GPU  109 . Optional GPU  109  may be an NVidia GeForce series processor, an AMD Radeon series processor, or another type of programmable integrated circuit that is configured to perform graphics processing tasks and provide a rendered video image (e.g., as frame buffer data) by output digital video signals (e.g., HDMI, DVI, SVGA, VGA, etc.) to display device  185  (e.g., LED display, LCD display, or other suitable type of display device) of system  100 . It will be understood that in other embodiments CPU  106  may alternatively provide video images directly to display  185 , including in those cases where optional GPU  109  is not present. 
     Still referring to the exemplary embodiment of  FIG. 3 , CPU  106  is shown coupled to system memory  130  via a data channel. System memory  130  may include, for example, random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), and/or other suitable storage mediums. CPU  106  is also coupled to platform controller hub (PCH)  150 , which facilitates input/output functions for information handling system  100 . Local system storage  117  (e.g., one or more media drives such as solid state drives, hard disk drives, optical drives, etc.) are each coupled to PCH  150  to provide non-volatile storage for the information handling system  100 . Optional input/output devices  183  (e.g., a keyboard, mouse, touchscreen, etc.) may be coupled to PCH  150  as shown to enable a local system user to interact with components of information handling system  100  including application programs or other software/firmware executing thereon. Also shown coupled to PCH  150  is network interface controller (NIC)  103  that may be present to allow CPU  106  and/or BMC  108  to wired and/or wirelessly communicate with other remote information handling system devices such as data center administrative system  193  and client information handling systems  192  across network  191  which may be the Internet, corporate intranet or other suitable network communication medium 
     In the embodiment of  FIG. 3 , out-of-band programmable integrated circuit  108  is provided in the form of a baseboard management controller “BMC” (e.g., with other possible examples being a service processor, embedded processor, etc.). As shown, BMC  108  is coupled to non-volatile memory or persistent storage  140 . BMC  108  is also coupled to PCH  150  by a data bus and is configured to perform out-of-band and system tasks including, but not limited to, providing control signals to control cooling fan speed and to control operation of power supply/voltage regulation circuitry  111  that itself receives external power (e.g., such as alternating current from AC mains  101  as shown) and in turn provides suitable regulated and/or converted direct current power via power rails  183  for operating the system power-consuming components. As used herein, an out-of-band programmable integrated circuit is separate and independent from any in-band host central processing unit (CPU) that runs the host OS of the information handling system, and without management of any application executing with a host OS on the host CPU. 
       FIG. 4A  illustrates an overhead view of an exemplary embodiment of a chassis enclosure  104 A of an information handling system  100 A with its top wall removed. In  FIG. 2 , information handling system  100 A is configured with multiple heat-producing components within chassis enclosure  104 A. Information handling system  100 A also includes multiple expansion slots  201  (e.g., PCIe slots) that may be provided on system motherboard  250  within chassis enclosure  104 A, with a respective mating expansion card (e.g., mating PCIe card) that includes a heat-producing component inserted into each expansion slot  201  that in this embodiment includes a storage device  117  and NIC  103 . Other heat-producing components present within chassis enclosure  104 A of  FIG. 2  include CPU package  106  (received in corresponding CPU socket on motherboard  250 ), memory  121  (e.g., one or more dual in-line memory modules “DIMMs” received within corresponding DIMM slots on motherboard  250 ), and remote access controller  198  (e.g., including BMC  108  and its NVM  140 ) that may be integrated on the motherboard  250 . Not shown is PSU and VR  111  which may be present within chassis enclosure  104 A and cooled with one or more dedicated cooling fan/s integrated with the PSU/VR  111 . It will be understood that number and identity of heat-producing components illustrated in the embodiment of  FIG. 4A  are exemplary only, and that the number and location of expansion slots  201  and/or the identity of heat-producing components inserted within each expansion slot  201  may vary in other embodiments. For example, in an alternate embodiment, a PSU may be located external to the chassis enclosure  104 A and coupled to a VR and power rails that are integrated within chassis enclosure  104 A. 
     For purposes of illustration and example only, the expansion slots  201  and mating expansion cards will be described below as being Peripheral Component Interconnect Express (PCIe) slots and mating PCIe cards. However, it will be understood that in other embodiments, other types and configurations of expansion slots  201  and mating expansion cards (e.g., corresponding to different types of computer expansion bus configurations) may be similarly employed (or substituted) in place of PCIe slots and PCIe cards in the embodiments described herein. In such other embodiments, a given type expansion slot  201  may be coupled to a corresponding type of computer expansion bus for exchanging signals such as data, power, etc. 
     Computer expansion card slots  201  and computer expansion cards configured for mating with expansion slots  201  may include, for example, high-speed serial computer expansion bus slots such as Peripheral Component Interconnect Express (PCIe) slots and mating PCIe cards configured according to PCIe 1.0, 2.0, 3.0 4.0, 5.0, etc. standards available from the Peripheral Component Interconnect Special Interest Group (PCI-SIG). In one PCIe embodiment, possible form factors for PCIe slots  201  include, but are not limited to, x1, x2, x4, x8 and x16 sized PCIe slots, in which the “x” prefix identifies the lane count (or number of differential signaling pairs) present in a particular PCIe slot  201 , e.g., “x16” represents a 16-lane card or slot. In this regard, a given PCIe card will fit into a PCIe slot  201  that has its same physical size (i.e., its same lane count) or a larger size. In other embodiments, a PCIe slot  201  may be configured with other form factors that utilize a PCIe high speed serial computer expansion bus standard, e.g., such as PCI Express Mini Card form factor. 
     In the embodiment of  FIG. 4A , chassis enclosure  104 A may be, for example, a rack mount 1U or 2U server chassis, although a chassis enclosure  104 A may be configured in other sizes and shapes, e.g., including larger server chassis (e.g., 3U, 4U, 5U, 6U, 7U, etc.), desktop or tower chassis enclosure, etc. As shown in  FIG. 4A , multiple cooling fans  190   1  to  190   N  (e.g., provided as a gang of cooling fans  190   1  to  190   N ) may be present to draw in cooling air though air inlets  175  from outside chassis enclosure  104 A and pass the cooling air past and in contact with the heat-producing components within chassis enclosure  104 A, then to be expelled out of chassis enclosure  104 A through air outlets  177  in the direction of the arrows as shown. In one embodiment, each of the given PCIe slots  201  may be an enclosed slot, e.g., with solid slot enclosure walls and open ends or otherwise defining an enclosed airflow path due to adjacent structures, adjacent-mounted PCIe cards, etc. In  FIG. 2 , each of PCIe slots  201  has an open inlet end  271  and an open outlet end  273  that allow cooling air to pass through the enclosed airflow path (e.g., between the slot enclosure walls) of the respective slot  201  over its inserted PCIe card (which are each shown in dashed hidden line outline in  FIG. 2 ). The enclosed airflow path through each of PCIe slots  201  is illustrated by the dashed arrows in  FIG. 4A . 
     Still referring to  FIG. 4A , exemplary inlet vents  175  and outlet vents  177  are shown defined in the enclosure wall of chassis enclosure  104 A. Inlet vents  175  are provided to allow fan/s  190  to draw ambient cooling air into chassis enclosure  104 A from the atmosphere surrounding outside chassis enclosure  104 A so that it may be circulated by fan/s  190  across the heat-producing components within the enclosure  104 A. Outlet vents  177  are provided to allow this air that has been heated by transfer of heat from the heat-producing components fan/s  190  to be exhausted back to the outside atmosphere around chassis enclosure  104 A. It will be understood that the illustrated number and configuration of vents  175  and  177  (and their relationship to fan/s  190  and fan zones  105 ) is exemplary only, and that any other number and/or configuration of inlet and outlet vents  175  and  177  is possible that is suitable for allowing circulation of cooling air across the heat-producing component/s of each cooling fan zone  105 , and that each fan  190  does not need to have an exclusive designated vent  175  or  177 . 
     Also shown in  FIG. 4A  are rear input/output connections  210 A that provide connectivity for data and power signals between components within chassis enclosure  104 A of information handling system  100 A and external devices, regulated power supply, AC mains, etc. 
     In  FIG. 4A , each of PCIe cards (e.g.,  103  and  117 ) of  FIG. 4A  may or may not have integrated temperature sensors that are configured to sense real time operating temperature of the respective heat-producing component of each PCIe card. As further shown in  FIG. 4A , a respective temperature sensor  124  may optionally be positioned at (or adjacent) the boundary of the inlet  271  of each respective PCIe slot  201  to sense and report real time current temperature at the inlet boundary of each of PCIe slots  201 . One or more data buses or other suitable communication media path may also be provided (e.g., as shown in  FIG. 3 ) for allowing communication of data (e.g., sensed temperature data, component operational power consumption data, fan speed data, digital fan speed control signals) between the various components of information handling system  100 A. 
     Further examples of types and configurations of heat-producing components, temperature sensors, and cooling fan configurations may be found, for example, in United States Patent Application Publication Number 2014/0032011; United States Patent Application Publication Number 2013/0176680; United States Patent Application Publication Number 2012/0224322; and in U.S. Pat. No. 9,785,208; each of which is incorporated herein by reference in its entirety for all purposes. 
       FIG. 4B  illustrates an overhead view of another exemplary embodiment of a chassis enclosure  104 B of an information handling system  100 B with its top wall removed. In  FIG. 4B , information handling system  100 B is provided with a second configuration of multiple heat-producing components (e.g., including two local system storage devices  117   a  and  117   b ) within chassis enclosure  104 B that is different from the first configuration of heat-producing components within chassis enclosure  104 A of information handling system  100 A of  FIG. 4A . In the embodiment of  FIG. 4B , chassis enclosure  104 B is also provided with rear input/output connections  210 B that are configured differently than the rear input/output connections  210 A of  FIG. 4A . Chassis enclosure  104 B is also provided with a different number and configuration of air outlets  177  than is chassis enclosure  104 A of  FIG. 4A . 
     Due to the different configuration of heat-producing components, rear input/output connections and air outlets, a conventional cooling fan speed versus volumetric airflow rate correlation for the embodiment of  FIG. 4A  would be different from a conventional cooling fan speed versus volumetric airflow rate correlation for the embodiment of  FIG. 4B . This means that a conventional cooling fan speed versus volumetric airflow rate correlation for the chassis enclosure embodiment  104 A of  FIG. 4A  cannot be used to estimate cooling fan airflow for the chassis enclosure embodiment  104 B of  FIG. 4B  (and vice-versa). Thus, if using conventional cooling fan air flow estimation techniques, a separate and different conventional cooling fan speed versus volumetric airflow rate characterization process must therefore be performed in the laboratory for each of chassis enclosure  104 A and chassis enclosure  104 B. In contrast, embodiments of the disclosed systems and methods advantageously do not require performance of such separate characterization processes to allow determination of cooling fan airflow for the separate embodiments of  FIGS. 4A and 2B . 
       FIG. 5  illustrates a simplified representation of a data center  300  according to one exemplary embodiment of the disclosed systems and methods. As shown in  FIG. 5  data center  300  is an enclosed space that contains multiple information handling systems  100  (e.g., mounted in multiple server racks  303   a ,  303   b  and  303   c ) which may be configured in different manner from each other, e.g., such as illustrated and described in relation to  FIGS. 2A and 2B  as well as other configurations. In  FIG. 5 , the multiple racks of information handling systems  100  are cooled by an air-conditioning system  310  (e.g., refrigeration unit) that blows refrigerated cooling air into the data center  300  and recirculates the air heated by the server systems  100  via a cooling air return intake  312 . As shown by arrows in  FIG. 5 , cooling fans  190  of each of information handling systems  100  intakes and exhausts cooling air that is heated by internal heat-producing components within a respective chassis enclosure  104  of each information handling system  100 . Since air-conditioning system  310  must effectively cool each of the individual information handling systems  100  of  FIG. 5 , the design, capacity, operation and optimization of air-conditioning system  310  is dependent on the cumulative volumetric airflow rate that passes through each of the chassis enclosures  104  of the multiple information handling systems  100  of  FIG. 5 . 
     A data center administrative information handling system  193  is also shown present in data center  300  that is communicatively coupled to monitor and control operation of each of the individual information handling systems  100  shown in  FIG. 5 , and may receive and/or monitor volumetric airflow rate measured within each of the chassis enclosures  104  of information handling systems  100  using the methodology described further herein. Data center administrative information handling system  193  may also be communicatively coupled to control operation of air-conditioning system  310  including, for example, set point temperature for data center  300 . In one embodiment, a data center administrative information handling system  193  may be configured with similar components as described herein for an information handling system  100 , and a display device  185   D  may be coupled as shown to data center administrative information handling system  193  to display monitored information from each of information handling systems  100  in server racks  303   a ,  303   b  and  303   c . It will be understood that the illustrated configuration of data center  300  (e.g., server racks  303 , information handling systems  100 , air-conditioning unit  310  and return air path from vent  312 , data center administrative information handling system  193 , etc.) is exemplary only, and that other configurations are possible (e.g., including provisioning of a data center administrative information handling system  193  outside and/or remotely located from data center  300 ). 
       FIG. 6  illustrates methodology  400  that may be employed in one exemplary embodiment to determine real time volumetric airflow rate produced by individual cooling fans  190  through a chassis enclosure  104  of an information handling system  100  such as described and illustrated herein. Methodology  400  may be implemented using a correlation of volumetric airflow rate (e.g., cubic feet per minute “CFM”) such as shown in  FIG. 9 , and that may be developed for a single standalone blower fan  190 , for example, as illustrated in  FIGS. 5 and 6 . 
     It will be understood that the data of the following examples and figures ( FIGS. 7, 8, 9 and 11 ) is exemplary and hypothetical only. This data is illustrative and may not represent an actual system&#39;s performance. Further, data for a given system will vary based on the system&#39;s actual configuration. 
       FIG. 7  illustrates an exemplary fan curve of pressure versus airflow (PQ) for a given configuration of standalone blower-type cooling fan  190  (i.e., that includes a stator, impeller and motor mechanically coupled to the impeller). The data for a relationship such as  FIG. 7  may be developed (e.g., in a laboratory setting) by characterizing the given configuration of cooling fan  190  at a given speed control setting, which is 70% PWM in the embodiment of  FIG. 7 . At a given speed control setting, the cooling fan  190  operates at a fixed rotational speed (e.g., RPM) as shown in  FIG. 7 . At the fixed rotational speed of  FIG. 7 , there is a direct relationship between power consumption in watts [W] and a given operating point of static pressure (e.g., inches of water [inH2O]) and volumetric airflow rate (cubic feet per minute [CFM]) on the PQ curve as shown in  FIG. 7 . Using the PQ relationship of  FIG. 7 , the volumetric airflow rate produced at the fixed rotational speed by the given configuration of cooling fan  190  may be determined as a function of the operating power consumption of the given configuration of cooling fan  190 . 
       FIG. 8  illustrates an exemplary empirical correlation that may be created for the three dimensions of fan control speed [% PWM], power [W], and output airflow [CFM] from multiple PQ relationships that are obtained by laboratory characterization of a given configuration (e.g., type, size, motor horsepower, etc.) of cooling fan  190  of information handling system  100  at multiple different fan speed control settings. Curve fitting techniques for laboratory data (e.g., such as least squares analysis, total least squares analysis, polynomial regression, polynomial interpolation, etc.) may be employed to develop curves for the correlations herein, and software tools (e.g., such as MATLAB) may also be employed. In one embodiment, such a correlation may be stored as cooling fan power characteristics  151  in non-volatile memory  140  and used by airflow determination logic  161  of BMC  108  to determine real time volumetric airflow output from a given configuration (e.g., type, size, motor horsepower, etc.) of cooling fan  190  as a function of current power consumption (e.g., measured from the given control fan  190  by BMC  108 ) and fan control speed (e.g., provided to the given cooling fan  190  by BMC  108 ). A respective separate and different empirical correlation may similarly be created for the three dimensions of control speed [% PWM], power [W], and output airflow [CFM] from multiple PQ relationships for each other given configuration (e.g., type, size, motor horsepower, etc.) of cooling fan  190  of information handling system  100  by characterizing each other configuration of cooling fan  190  at multiple different speed control settings. Each separate and different empirical correlation may also be stored as cooling fan power characteristics  151  in non-volatile memory  140 . 
     Although the plot of  FIG. 8  illustrates an exemplary empirical correlation developed for a finite number of discrete cooling fan control speed points [% PWM], it is alternatively possible to use characterization of a given configuration (e.g., type, size, motor horsepower, etc.) of cooling fan  190  at multiple different speed control settings to develop a continuous equation that expresses volumetric airflow output ([CFM] or CFM) as a function of any given combination of power ([W] or PWR) and cooling fan control speed ([% PWM] or PWM) for a given configuration of cooling fan  190 , e.g., of the form: CFM=f(PWR,PWM). Curve fitting techniques for laboratory data (e.g., such as least squares analysis, total least squares analysis, polynomial regression, polynomial interpolation, etc.) may be employed to develop curves for the correlations herein, and software tools (e.g., such as MATLAB) may also be employed. These continuous equations may also be stored as cooling fan power characteristics  151  in non-volatile memory  140 , and used by airflow determination logic  161  of BMC  108  to determine real time volumetric airflow output from a given configuration (e.g., type, size, motor horsepower, etc.) of cooling fan  190  as a function of current power consumption (e.g., measured from the given control fan  190  by BMC  108 ) and fan control speed (e.g., provided to the given cooling fan  190  by BMC  108 ) 
     Two example possible continuous equations [1] and [2] are provided below that may be so developed to determine volumetric airflow output ([CFM] or CFM) for a single standalone cooling fan configuration (e.g., cooling fan type, size, motor horsepower, etc.). It will be understood that different equations having different coefficients and/or form may be similarly developed by cooling fan characterization of other different cooling fan configurations. 
       CFM=17.18+0.65*PWR−0.32*PWM  Equation [1]:
 
       OR 
       CFM=348.95*(PWR 1.34 )*(PWM −1.81 )  Equation [2]:
 
     Returning to  FIG. 6 , method  400  begins in step  402  with each of the cooling fans  190  of the information handling system  100  operating with a particular given fan speed setting, e.g., as set by BMC  108  using a percent pulse wave modulation [% PWM] control signal that corresponds to a given desired fan rotational speed (RPM). In one embodiment, all cooling fans  190  of system  100  may be currently operating with the same rotation or rotational speed, although in another embodiment one or more of cooling fans  190  may currently be operating with a rotational speed that is different from the current rotational speed of one or more of the other cooling fans  190 . 
     In step  402 , airflow determination logic  161  of BMC  108  determines the current fan speed setting [% PWM] for each individual cooling fan  190 . In this regard, BMC  108  has knowledge of the current particular fan speed setting for each individual cooling fan  190  when the cooling fan speed is set by BMC  108 , or BMC  108  may alternatively determine the current fan speed setting for each individual cooling fan  190  from a different programmable integrated circuit of information handling system  100  (e.g., in the case that the current cooling fan speed of each cooling fan  190  is set by the different programmable integrated circuit). 
       FIG. 9  illustrates an example embodiment of a correlation between an individual cooling fan power consumption and volumetric air flow rate that may be first selected from stored cooling fan characteristics  151  for use by BMC  108  for the configuration (e.g., type, size, motor horsepower, etc.) of a first one of the cooling fans  190  when operating at a given cooling fan rotational speed or fan speed power setting [% PWM]. This selected correlation of  FIG. 9  may be used to determine current fan volumetric airflow rate from measured power consumption of the first cooling fan  190  when the determined current fan speed control setting of step  402  for the first cooling fan  190  is a discrete fan speed control setting of 70% PWM (as denoted by the circled number “1” in  FIG. 9 ). Other correlations may be selected from stored cooling fan characteristics  151  for use by BMC  108  for the different configurations and current fan speeds of each of the other of the cooling fans  190  of information handling system  100 . However, in another embodiment, a respective continuous equation (e.g., such as of the type of Equation [1] or Equation [2] described herein) may alternatively be selected and used by BMC  108  for each of the different configurations (e.g., different fan types, different fan sizes, different fan motor horsepowers, etc.) of cooling fans  190  to continuously calculate the current fan volumetric airflow rate for any current fan speed of each respective cooling fan  190  based on the current cooling fan power setting and measured cooling fan power consumption that respective cooling fan  190 . 
     Next, in step  404 , airflow determination logic  161  of BMC  108  separately reads or measures the power consumed by each individual cooling fan  190  of information handling system  100  (e.g., by using current monitor “IMON” circuitry to measure each individual cooling fan current at the existing cooling fan voltage). In the present example,  FIG. 9  illustrates a case where airflow determination logic  161  of BMC  108  determines a current real time electric power consumption of 33 Watts by the first one of the cooling fans  190  of information handling system  100  (as denoted by the circled number “2” in  FIG. 9 ). Airflow determination logic  161  of BMC  108  performs a similar real time power consumption determination of step  404  for each of the other cooling fans  190  of information handling system  100 . 
     Next, in step  406  airflow determination logic  161  of BMC  108  determines the volumetric airflow rate currently produced by each individual cooling fan  190  of information handling system  100 . In the present example,  FIG. 9  illustrates a case where airflow determination logic  161  of BMC  108  determines a current real time power consumption of 33 Watts by the first one of the cooling fans  190  of information handling system  100  (as denoted by the circled number “2” in  FIG. 9 ). Airflow determination logic  161  of BMC  108  then determines a corresponding current volumetric airflow rate of 19 cubic feet per minute (CFM) that corresponds to the 33 Watts power consumption of the first cooling fan  190  at the current discrete fan speed control setting of 70% PWM for the first cooling fan  190  (as denoted by the circled number “3” in  FIG. 9 ). Airflow determination logic  161  of BMC  108  performs a similar real time volumetric airflow rate determination in step  406  for each of the other cooling fans  190  of information handling system  100 , i.e., using an appropriate corresponding correlation between fan power consumption and volumetric air flow rate that is selected for use by BMC  108  for each of the other cooling fans  190  of information handling system  100 . 
     It will be understood that the example current real time power consumption value of 33 Watts and the corresponding current volumetric airflow rate value of 19 CFM of  FIG. 9  are only exemplary values for a hypothetical first cooling fan  190 , and are given for purposes of illustration only. It will also be understood that airflow determination logic  161  of BMC  108  may determine current real time power consumption values of greater or lesser than 33 Watts (and corresponding volumetric airflow rate values of greater of lesser than 19 CFM), depending for example, on the particular characteristics and configuration and/or type of each different given cooling fan  190 . Further, the determined current real time power consumption value and corresponding volumetric airflow rate value for each given cooling fan  190  may be different for different cooling fans  190 . 
     Next, in step  408  airflow determination logic  161  of BMC  108  sums together the real time volumetric air flow rates determined for all of the respective different cooling fans  190  of information handling system  100  to determine (or predict) the single total current volumetric airflow rate (e.g., in CFM) that is currently flowing from all of the cooling fans  190  added together through chassis enclosure  104 . In the case where an information handling system  100  includes only a single cooling fan  190 , step  408  may be skipped since the determined current volumetric air flowrate of the single fan  190  is equal to the total current volumetric airflow flowing through chassis enclosure  104 . 
     Next, in step  410  airflow reporting logic  163  may optionally report the determined total current volumetric airflow rate of step  408  that is currently flowing through chassis enclosure  104  to one or more end users and/or administrators, e.g., by displaying the total current volumetric airflow rate as a value in a graphical user interface (GUI) on display device  185  of information handling system  100  and/or via network  191  on display device  185   D  of data center administrative system  193 . 
     In step  412 , thermal control logic  165  of BMC  108  may execute one or more thermal control algorithms that utilize the total current volumetric airflow rate of step  408  to thermally balance current determined volumetric airflow rate generated by cooling fan/s  190  through chassis enclosure  104  with the amount of total heat currently produced by heat-producing components within chassis enclosure  104 . As one example, thermal control logic  165  of BMC  108  may increase or decrease the rotational speed [% PWM] of one or more of cooling fans  190  as needed to provide a total current volumetric airflow rate that is calculated to maintain a current target temperature (or temperature range) within chassis enclosure  104 . In another example, thermal control logic  165  of BMC  108  may increase or decrease the rotational speed [% PWM] of one or more of cooling fans  190  as needed until cooling fan/s  190  produce a determined volumetric airflow rate through chassis enclosure  104  that falls within a predefined target range of total volumetric airflow rate that is specified for sufficiently cooling the current configuration of heat-producing components within the chassis enclosure  104 . In another example, thermal control logic  165  of BMC  108  may perform energy balance thermal control by fixing the total current volumetric airflow rate determined in iterations of step  408  to a selected airflow rate value, and then power capping one or more of the heat-producing components of information handling system  100  in order to control airflow temperature inside the chassis enclosure  104  of information handling system  100 . 
     Additionally or alternatively in step  412 , data center administrative system  193  may receive the reported value of current total volumetric airflow rate reported in step  410  from each of separate server systems  100  of  FIG. 5 , and take one or more control or design operations based on the combined total volumetric airflow rate consumed by all of the server systems  100 , e.g., such as by increasing or decreasing the cooling capacity of air conditioning system  310  (e.g., by decreasing or increasing temperature set-point or system blower speed of air conditioning system  310  and/or by planning for needed air conditioning system capacity and performing air flow sizing of air conditioning system  310  to match the combined total volumetric airflow rate consumed by all of the server systems  100 ) based on the total volumetric airflow rate consumption of all the server systems  100 . Methodology  400  may then optionally repeat to step  402  and repeat as shown. 
       FIG. 10  illustrates methodology  1000  that may be employed in one exemplary embodiment at a system level to determine real time total volumetric airflow rate produced by all cooling fans  190  through a chassis enclosure  104  of an information handling system  100  such as described and illustrated herein. Methodology  1000  may be implemented using a correlation of total system volumetric airflow rate (e.g., cubic feet per minute “CFM”) versus total system cooling fan power consumption for a given cooling fan rotational speed, such as shown in  FIG. 11 . Such a system-level correlation may be developed and defined at a system level for all cooling fans  190  simultaneously operating within chassis enclosure  104  at the same cooling fan speed, but otherwise using the same techniques as previously described in relation to  FIGS. 6 and 7  for developing a correlation for a single standalone cooling fan  190 . 
     Method  1000  of  FIG. 10  begins in step  1002  with all of the cooling fans  190  of the information handling system  100  controlled by BMC  108  using [% PWM] control signals to operate at the same given rotational fan speed setting. At this time BMC  108  may have knowledge of the current given fan speed setting for all cooling fans  190  when the cooling fan speed is set by BMC  108 , or BMC  108  may alternatively determine the current given fan speed setting for all cooling fans  190  from a different programmable integrated circuit of information handling system  100  (e.g., in the case that the current given fan speed setting for all cooling fans  190  is set by the different programmable integrated circuit). 
       FIG. 11  illustrates an example embodiment of a correlation between total system fan power consumption and total system volumetric air flow rate that may be stored with one or more other correlations as cooling fan power characteristics  151  in non-volatile memory  140 . In step  1002  the correlation of  FIG. 11  may be first selected from the stored cooling fan characteristics  151  for use by BMC  108  for the current configuration of chassis enclosure  104  (e.g., chassis enclosure dimensions, types and positions of internal components, configurations of cooling fans  190 , etc.) for a given cooling fan rotational speed or fan speed setting [% PWM] for all system cooling fans  190 . In this embodiment, the correlation of  FIG. 11  may be used for a determined current uniform fan speed control setting (e.g., 70% PWM as denoted by the circled number “1” in  FIG. 11 ). Other correlations may be selected from stored cooling fan characteristics  151  for use by BMC  108  for different chassis enclosure configurations and/or uniform fan speed power setting for all cooling fans  190  of information handling system  100 . 
     Next, in step  1004 , airflow determination logic  161  of BMC  108  measures total real time power simultaneously consumed by all system cooling fan  190  of information handling system  100  (e.g., by using current monitor “IMON” circuitry to measure total cooling fan current at the existing cooling fan voltage). In the present example,  FIG. 11  illustrates a case where airflow determination logic  161  of BMC  108  determines a current total real time power consumption of 120 Watts by simultaneous operation of all the cooling fans  190  of information handling system  100 . It will be understood that 120 Watts is only an exemplary value given for purpose of illustration and that determined values of current total real time power consumption may be greater or lesser than 120 Watts depending, for example, on the particular characteristics and configuration of a group of multiple cooling fans  190 . 
     In step  1006 , airflow determination logic  161  of BMC  108  determines (or predicts) the current total volumetric airflow rate (e.g., in CFM) that is produced together by all of cooling fans  190  of information handling system  100 , which equals the current total volumetric airflow rate that is flowing through chassis enclosure  104 . In the present example,  FIG. 11  illustrates a case where airflow determination logic  161  of BMC  108  has determined a current total real time power consumption of 120 Watts by simultaneous operation of all the cooling fans  190  of information handling system  100  (as denoted by the circled number “2” in  FIG. 11 ). Airflow determination logic  161  of BMC  108  then determines a corresponding current total volumetric airflow rate of 65 cubic feet per minute that corresponds to the 120 Watts power consumption of all cooling fans  190  at the current fan speed control setting of 70% PWM for all cooling fans  190  (as denoted by the circled number “3” in  FIG. 11 ). 
     Next, in step  1008  airflow reporting logic  163  may optionally report the determined total volumetric airflow rate of step  1006  that is currently flowing through chassis enclosure  104  to one or more end users and/or administrators, e.g., in a manner similar to described for step  410  of  FIG. 12  by displaying the total current volumetric airflow rate as a value in a graphical user interface (GUI) on display device  185  of information handling system  100  and/or via network  191  on display device  185   D  of data center administrative system  193 . 
     In step  1010 , thermal control logic  165  of BMC  108  may execute one or more thermal control algorithms that utilize the total current volumetric airflow rate of step  1006  to thermally balance current determined volumetric airflow rate generated by cooling fan/s  190  through chassis enclosure  104  with the amount of total heat currently produced by heat-producing components within chassis enclosure  104 , e.g., in a manner as described previously in relation to step  412  of  FIG. 6 . Additionally or alternatively in step  1010 , data center administrative system  193  may receive the reported value of current total volumetric airflow rate reported in step  1008  from each of separate server systems  100  of  FIG. 5 , and take one or more control or design operations based on the combined total volumetric airflow rate consumed by all of the server systems  100 , e.g., in a manner as described previously in relation to step  412  of  FIG. 6 . Methodology  1000  may then optionally repeat to step  1002  and repeat as shown. 
     It will be understood that the particular steps of methodology  400  are exemplary only, and that any combination of fewer, additional and/or alternative steps may be employed that are suitable for determining, reporting and/or using real time volumetric airflow rate produced by individual cooling fans through a chassis enclosure of an information handling system. Likewise, it will be understood that the particular steps of methodology  1000  are exemplary only, and that any combination of fewer, additional and/or alternative steps may be employed that are suitable for determining, reporting and/or using real time total volumetric airflow rate produced by all cooling fans through a chassis enclosure of an information handling system 
     It will understood that one or more of the tasks, functions, or methodologies described herein (e.g., including those described herein for components  103 ,  106 ,  108 ,  109 ,  117 ,  119 ,  121 ,  140 ,  150 ,  193  etc.) may be implemented by circuitry and/or by a computer program of instructions (e.g., computer readable code such as firmware code or software code) embodied in a non-transitory tangible computer readable medium (e.g., optical disk, magnetic disk, non-volatile memory device, etc.), in which the computer program comprising instructions are configured when executed on a processing device in the form of a programmable integrated circuit (e.g., processor such as CPU, controller, microcontroller, microprocessor, ASIC, etc. or programmable logic device “PLD” such as FPGA, complex programmable logic device “CPLD”, etc.) to perform one or more steps of the methodologies disclosed herein. In one embodiment, a group of such processing devices may be selected from the group consisting of CPU, controller, microcontroller, microprocessor, FPGA, CPLD and ASIC. The computer program of instructions may include an ordered listing of executable instructions for implementing logical functions in an information handling system or component thereof. The executable instructions may include a plurality of code segments operable to instruct components of an information handling system to perform the methodologies disclosed herein. It will also be understood that one or more steps of the present methodologies may be employed in one or more code segments of the computer program. For example, a code segment executed by the information handling system may include one or more steps of the disclosed methodologies. It will be understood that a processing device may be configured to execute or otherwise be programmed with software, firmware, logic, and/or other program instructions stored in one or more non-transitory tangible computer-readable mediums (e.g., data storage devices, flash memories, random update memories, read only memories, programmable memory devices, reprogrammable storage devices, hard drives, floppy disks, DVDs, CD-ROMs, and/or any other tangible data storage mediums) to perform the operations, tasks, functions, or actions described herein for the disclosed embodiments. 
     For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, an information handling system may be a personal computer, a PDA, a consumer electronic device, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price. The information handling system may include memory, one or more processing resources such as a central processing unit (CPU) or hardware or software control logic. Additional components of the information handling system may include one or more storage devices, one or more communications ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     While the invention may be adaptable to various modifications and alternative forms, specific embodiments have been shown by way of example and described herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Moreover, the different aspects of the disclosed adapters, systems and methods may be utilized in various combinations and/or independently. Thus the invention is not limited to only those combinations shown herein, but rather may include other combinations.