Patent Publication Number: US-11039556-B2

Title: Data center cooling system

Description:
RELATED APPLICATION DATA 
     The present patent document is a continuation of U.S. patent application Ser. No. 15/611,879, filed Jun. 2, 2017, entitled “DATA CENTER COOLING SYSTEM”, the disclosure of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to data center cooling systems and, more specifically, to a modified data center cooling system having a relatively high chilled coolant temperature. 
     BACKGROUND 
     Large-scale computer systems and servers are crucial components of modern-day business. Many organizations rely on these systems to store and process data associated with that organization. Some organizations choose to own and maintain large-scale computer systems or servers on-site, either in a dedicated building or in a building that is also occupied by people, such as employees. However, as the need for computing power grows, many organizations instead may choose to pay for use of a third-party&#39;s computer system or server or to house their large-scale computer systems off-site. These off-site and third-party systems are generally located in massive data centers that can house hundreds, if not thousands, of individual server units. 
     Computer systems and, more specifically, computer processors generate heat when operating. This heat, if sufficiently concentrated, can harm the computer systems, decreasing computing efficiency and, in some cases, permanently damaging computer hardware. When many computer systems are within the same room or under the same roof, this heat generation issue is further exacerbated. Therefore, particularly in large data centers, it becomes necessary to cool the data center in order to dissipate this heat before it can cause damage. 
     Server rooms and data centers can use cooling techniques to facilitate cooling of the server machines housed therein. For example, in some server rooms and data centers, cool air is forced into the room to displace heated air and to absorb excess heat from server machines. These servers are typically stored on shelving-like racks to allow airflow through each server. The floor of a server room can also be raised to allow the cooler air to enter the room through holes in grates, perforated tiles, or other openings in the raised floor. The displaced heated air can be drawn out of the room through ventilation systems or similar systems. In some instances, cold water or another coolant can be used to chill the air before it is introduced into the server room. 
     SUMMARY 
     In general, embodiments described herein provide for cooling a data center with a cooling system having a relatively high coolant temperature. This cooling system is controlled by a building management system and includes piping through which coolant flows, an air cooling unit in thermal contact with the coolant, and a chiller to cool the coolant to a temperature between 18 and 22 degrees Celsius as instructed by the building management system. The building management system uses a chiller controller to vary the chilling of coolant within a range of 18 to 22 degrees Celsius, thereby controlling the air temperature within the data center to within a required temperature range. Because the building management system maintains the coolant temperature to between 18 and 22 degrees Celsius, the cooling system can be simplified by excluding typical cooling system components such as variable flow control valves and their controllers. This simplification decreases the need for maintenance and reduces operating cost. 
     One aspect of the present invention includes a system for cooling a data center, the system comprising: a cooling system comprising: a closed circuit of piping through which a coolant flows; a coolant chilling unit; an air cooling unit, wherein the coolant flows from the coolant chilling unit to the air cooling unit via the piping uninterrupted by any flow control mechanism; and a flow control mechanism; and a building management system comprising: a memory medium comprising program instructions; a bus coupled to the memory medium; and a processor, for executing the program instructions, that when executing the program instructions causes the building management system to cause the flow control mechanism to control the flow of coolant through the closed circuit of piping. 
     Another aspect of the present invention includes a method for cooling a data center with a cooling system, the method comprising: receiving a reading from a temperature sensor located in the data center; determining, based on the received reading, a set of adjustments to a flow of coolant to most efficiently return the data center to a desired temperature; and adjusting a flow of the coolant through the cooling system only though a control mechanism disposed downstream from the data center, between the data center and a chiller unit. 
     Yet another aspect of the present invention includes a computer program product for cooling a data center with a cooling system, the computer program product comprising a computer readable storage device, and program instructions stored on the computer readable storage device, to: receive a reading from a temperature sensor located in the data center; determine, based on the received reading, a set of adjustments to a flow of coolant to most efficiently return the data center to a desired temperature; and adjust a flow of the coolant through the cooling system only though a control mechanism disposed downstream from the data center, between the data center and a chiller unit. 
     Still yet, any of the components of the present invention could be deployed, managed, serviced, etc., by a service provider who offers to implement passive monitoring in a computer system. 
     Embodiments of the present invention also provide related systems, methods, and/or program products. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       These and other features of this invention will be more readily understood from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings in which: 
         FIG. 1  shows an architecture in which the invention may be implemented according to illustrative embodiments. 
         FIG. 2  shows a schematic of an implementation of a traditional data center or server cooling system. 
         FIG. 3  shows a three-dimensional model of the traditional data center or server cooling system of  FIG. 2 . 
         FIG. 4  shows a schematic of an implementation of a data center or server cooling system according to illustrative embodiments. 
         FIG. 5  shows a three-dimensional model of the data center or server cooling system of  FIG. 4  according to illustrative embodiments. 
         FIG. 6  shows a process flowchart for cooling a data center with a cooling system having a relatively high chilled coolant temperature according to illustrative embodiments. 
     
    
    
     The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the invention. The drawings are intended to depict only typical embodiments of the invention, and therefore should not be considered as limiting in scope. In the drawings, like numbering represents like elements. 
     DETAILED DESCRIPTION 
     Illustrative embodiments will now be described more fully herein with reference to the accompanying drawings, in which illustrative embodiments are shown. It will be appreciated that this disclosure may be embodied in many different forms and should not be construed as limited to the illustrative embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of this disclosure to those skilled in the art. 
     Furthermore, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, the use of the terms “a”, “an”, etc., do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. Furthermore, similar elements in different figures may be assigned similar element numbers. It will be further understood that the terms “comprises” and/or “comprising”, or “includes” and/or “including”, when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless specifically stated otherwise, it may be appreciated that terms such as “processing,” “detecting,” “determining,” “evaluating,” “receiving,” or the like, refer to the action and/or processes of a computer or computing system, or similar electronic data center device that manipulates and/or transforms data represented as physical quantities (e.g., electronic) within the computing system&#39;s registers and/or memories into other data similarly represented as physical quantities within the computing system&#39;s memories, registers or other such information storage, transmission, or viewing devices. The embodiments are not limited in this context. 
     As stated above, embodiments described herein provide for cooling a data center with a cooling system having a relatively high coolant temperature. This cooling system is controlled by a building management system and includes piping through which coolant flows, an air cooling unit in thermal contact with the coolant, and a chiller to cool the coolant to a temperature between 18 and 22 degrees Celsius as instructed by the building management system. The building management system uses a chiller controller to vary the chilling of coolant within a range of 18 to 22 degrees Celsius, thereby controlling the air temperature within the data center to within a required temperature range. Because the building management system maintains the coolant temperature to between 18 and 22 degrees Celsius, the cooling system can be simplified by excluding typical cooling system components such as variable flow control valves and their controllers. This simplification decreases the need for maintenance and reduces operating cost. 
     With reference now to the figures,  FIG. 1  depicts a computerized implementation  100  that performs embodiments of the present invention. Computerized implementation  100  is only one example of a suitable implementation and is not intended to suggest any limitation as to the scope of use or functionality of embodiments of the invention described herein. Regardless, computerized implementation  100  is capable of being implemented and/or performing any of the functionality set forth hereinabove. 
     In computerized implementation  100 , there is a computer system/server  102 , which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server  102  include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like. 
     As shown, computer system/server  102  can be deployed within a computer infrastructure  104 . This is intended to demonstrate, among other things, that embodiments can be implemented within a network environment  106  (e.g., the Internet, a wide area network (WAN), a local area network (LAN), a virtual private network (VPN), etc.), a cloud-computing environment, or on a stand-alone computer system. Communication throughout the network can occur via any combination of various types of communication links. For example, the communication links can comprise addressable connections that may utilize any combination of wired and/or wireless transmission methods. Where communications occur via the Internet, connectivity could be provided by conventional TCP/IP sockets-based protocol, and an Internet service provider could be used to establish connectivity to the Internet. Still yet, computer infrastructure  104  is intended to demonstrate that some or all of the components of computerized implementation  100  could be deployed, managed, serviced, etc., by a service provider who offers to implement, deploy, and/or perform the functions of the present invention for others. 
     Computer system/server  102  is intended to represent any type of computer system that may be implemented in deploying/realizing the teachings recited herein. Computer system/server  102  may be described in the general context of computer system/server executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on, that perform particular tasks or implement particular abstract data types. In this particular example, computer system/server  102  represents an illustrative system for performing embodiments of the present invention. It should be understood that any other computers implemented under various embodiments may have different components/software, but can perform similar functions. As shown, computer system/server  102  includes a bus  116  and device interfaces  118 . 
     Bus  116  represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus. 
     As shown, computer system/server  102  includes a processing unit  108  capable of operating with a controller  110  stored in a memory unit  112  to perform embodiments of the present invention, as will be described in further detail below. Processing unit  108  refers, generally, to any apparatus that performs logic operations, computational tasks, control functions, etc. A processor may include one or more subsystems, components, and/or other processors. A processor will typically include various logic components that operate using a clock signal to latch data, advance logic states, synchronize computations and logic operations, and/or provide other timing functions. During operation, processing unit  108  collects and routes signals representing inputs and outputs between external devices and input devices (not shown). The signals can be transmitted over a LAN and/or a WAN (e.g., T1, T3, 56 kb, X.25), broadband connections (ISDN, Frame Relay, ATM), wireless links (802.11, Bluetooth, etc.), and so on. In some embodiments, the signals may be encrypted using, for example, trusted key-pair encryption. Different systems may transmit information using different communication pathways, such as Ethernet or wireless networks, direct serial or parallel connections, USB, Firewire®, Bluetooth®, or other proprietary interfaces. (Firewire is a registered trademark of Apple Computer, Inc. Bluetooth is a registered trademark of Bluetooth Special Interest Group (SIG)). 
     In general, processing unit  108  executes computer program code, such as program code for operating controller  110 , which is stored in memory unit  112  and/or storage system  114 . While executing computer program code, processing unit  108  can read and/or write data to/from memory unit  112  and storage system  114 . Storage system  114  may comprise VCRs, DVRs, RAID arrays, USB hard drives, optical disk recorders, flash storage devices, and/or any other data processing and storage elements for storing and/or processing data. Although not shown, computer system/server  102  could also include I/O interfaces that communicate with one or more hardware components of computer infrastructure  104  that enable a user to interact with computer system/server  102  (e.g., a keyboard, a display, a camera, etc.). 
     Moving on, before embodiments of the present invention are described in greater detail, it will be necessary, with reference to  FIG. 2  and  FIG. 3 , to provide a general overview of data center cooling systems as found in the current art. Accordingly, referring to  FIG. 2 , a schematic of a traditional data center or server cooling implementation  200  is shown. Referring to  FIG. 3 , the same traditional data center or server cooling implementation is shown as a three-dimensional model  300 . Traditional cooling implementation  200  generally relies on controlling several environmental variables, including air supply or return temperature, air flow, chilled coolant supply temperature, chilled coolant flow, and room humidity, in order to cool servers or other computer systems. While the design of traditional cooling implementation  200  can be very complex, generally the goal of such a system is to minimize energy costs while adjusting the environmental variables to cool computer systems. 
     Servers and other computer systems are typically housed in one or more rooms within a building, such as a data center. Traditional cooling implementation  200  may be incorporated into a building&#39;s building management system (BMS)  210  and may use components of BMS  210 . BMS  210  may be a computer system and/or computer infrastructure, such as that shown in  FIG. 1 , which controls operates components of a cooling system  230 . 
     BMS  210  may be in contact with a chilled water (CHW) or other chilled coolant temperature controller  220  for controlling a chiller  212  which chills coolant  214 . Coolant  214  may be any coolant material, such as a refrigerant, water, distilled water, air, or any other liquid or gas used for cooling. BMS  210  may instruct CHW temperature controller  220  to chill coolant  214  to a specified temperature  222 . In traditional cooling implementation  200 , coolant  214  is generally chilled to a temperature between 6 and 10 degrees Celsius (or between 42 and 50 degrees Fahrenheit). Accordingly, CHW temperature controller  220  may control the environmental variable of chilled coolant supply temperature. 
     BMS  210  may further, through a set of valves and/or pumps, control flow of coolant  214  through a set of coolant pipes  216  connected to chiller  212  that transport coolant  214  to traditional cooling system  230 . Coolant  214  may be moved through pipes  216  by a flow control mechanism, such as a variable frequency drive (VFD) pump, that creates and maintains a pressure differential. Pipes  216  generally form a closed system that both transports coolant  214  to traditional cooling system  230  and returns coolant  214  back to chiller  212 . At the least, an outflow coolant pipe  216 A of coolant pipes  216  is protected by insulation  236  to eliminate condensation and to minimize pre-warming of the coolant and, depending on whether returning coolant  214  is expected to be warmer or colder than ambient temperature, a return coolant pipe  216 B may also be protected by insulation  236  to decrease the cost of re-cooling coolant  214 . 
     BMS  210  may include a variable flow controller  224  that operates a VFD pump  218  that controls the flow of coolant  214 . VFD pump  218  may be used to reduce or increase flow of coolant  214  through chiller  212  in order to maintain a minimum flow required by chiller  212 . Pressure differential sensor  226  monitors and provides feedback to BMS  210  on a pressure drop of coolant  214  within traditional cooling system  230 , thereby allowing traditional cooling system  230  to adjust flow accordingly. In other words, in response to this feedback, BMS  210  instructs variable flow controller  224  to modulate a pump speed of VFD pump  218  to keep the pressure differential within traditional cooling system  230  constant. Therefore, variable flow controller  224  may control the environmental variable of chilled coolant flow. 
     A chiller bypass safety valve  228  may, in some instances, be placed in parallel with chiller  212 . Chiller bypass safety valve  228  may be used to reduce pressure within traditional cooling system  230 . For example, in the case that all other valves in traditional cooling system  230  are closed, pressure differential sensor  226  will register an increase in pressure within traditional cooling system  230 . In response to this increased pressure, BMS  210  may instruct chiller bypass valve  228  to open. Alternatively, chiller bypass safety valve  228  may be configured to automatically open in response to a pressure reading above a certain threshold. 
     Moving on, traditional cooling system  230  of traditional cooling implementation  200  may be, for example, a Computer Room Air Conditioning (CRAC) system, an Air Handling Cooling Units (AHCU) system, and/or any other type of Heating, Ventilation and Air Conditioning (HVAC) system. Traditional cooling system  230  may be controlled by a control module  240 , which may be connected to BMS  210 . Control module  240  may have several components for controlling functions within traditional cooling system  230 . 
     Control module  240  may include a flow controller  242  that operates flow control valve(s)  232  that controls the flow of coolant  214  within traditional cooling system  230 . In some instances, flow control valve  232  may work in tandem with or separately from VFD pump  218 . As stated above, pressure differential sensor  226  monitors and provides signal feedback to BMS  210  on a pressure drop of coolant  214  within traditional cooling system  230 . BMS  210  may instruct flow controller  242  to adjust flow control valve  232  to keep the pressure differential within traditional cooling system  230  constant. In other words, flow control valve  232  may also be used to normalize a pressure drop between pipe  216 A coming into traditional cooling system  230  and pipe  216 B leaving the cooling system. Flow control valve  232  may further be used to increase or decrease a rate at which coolant  214  enters traditional cooling system  230 . Accordingly, flow controller  242  may control the environmental variable of chilled coolant flow. 
     When coolant enters traditional cooling system  230  through coolant pipes  216  in traditional cooling implementation  200 , pipe  216 A may also be covered in insulation  236  to prevent premature warming and condensation. Likewise, pipe  216 B returning to chiller  212  may be covered in insulation  236  depending on the temperature of coolant  214  in pipe  216 B. In any case, as coolant  214  flows from outflow pipe  216 A to return pipe  216 B, it passes through cooling coil  238 , picking up heat energy and carrying this heat energy back to chiller  212 . This permits cooling coil  238  to act as a heat sink with respect to traditional cooling system  230 . In some instances, an air handler may be used in place of cooling coil  238 . 
     Control module  240  may further include an air flow controller  244  that operates a fan or blower  234 . In some traditional cooling systems  230 , blower  234  blows or otherwise pushes air over cooling coil  238 . In some instances, control of blower  234  can be based on a reading from a sensor that measures a pressure differential of the air. By controlling operation of blower  234 , air flow controller  244  may control the environmental variable of air flow. Moreover, as comparatively warmer air passes over cooling coil  238 , heat energy from the warmer air is absorbed by cooling coil  238  and passed to coolant  214 . This process lowers the temperature of air flowing over cooling coil  238 , resulting in cooled air  252  and an air inlet server temperature  258  typically at a temperature between 12 and 20 degrees Celsius. Accordingly, air flow controller  244  may also control the environmental variable of air supply temperature. 
     Blower  234  may furthermore push cooled air  252  into, within, and/or around data center/server room  250  where one or more computers/servers  254  (e.g., a rack of servers) are located and operating. When cooled air  252  comes into contact with computers/servers  254  that are at a higher temperature than cooled air  252 , some of the heat from computers/servers  254  is absorbed by cooled air  252  and carried away from computers/servers  254 . This exposure to cooled air  252  allows computers/servers  254  to be cooled through the removal of excess heat energy. After cooled air  252  is warmed by contact with heated computers/servers  254 , the air may be routed (e.g., by an intake duct) back to blower  234  for re-cooling. In  FIG. 3 , the flow of cooled air  252  from blower  234  and cooling coil  238  of traditional cooling system  230 , into data center/server room  250 , through computers/servers  254  (e.g., a server rack), and then back to traditional cooling system  230  is more clearly shown. 
     Control module  240  may further include a humidity controller unit  246  that operates a humidifier (not shown) to add humidity to the air around traditional cooling systems  230  and/or in data center/server room  250 . The main reason for adding humidity within data center/server room  250  is a low supply temperature of chilled coolant  214  between 6 and 10 degrees Celsius can cause air to lose its moisture. Liquid condensation can form when warmer and humid air comes into contact with cooler surface materials (e.g., outflow coolant pipe  216 A or cooling coil  238 ). Therefore, to prevent air from becoming too dry or too moist, upper and lower humidity control parameters are desirable in data center/server room  250  where electrical machinery is located (particularly if human beings are inhabiting the same space as data center/server room  250 ). Therefore, humidity controller unit  246  may prompt a humidifier to add moisture into the air at blower  234  and/or within data center/server room  250  when the comparatively colder cooling coil  238  removes humidity from the surrounding air. Traditional cooling system  230  may also include a condensation pan  248  ( FIG. 3 ) for collecting and removing condensed moisture. Accordingly, humidity controller unit  246  may also control the environmental variable of room humidity. 
     Control module  240  may further receive readings from one or more temperature and/or humidity sensors  256 A-N, which may be located at the return, supply, and/or intake of blower  234 . These sensors form a chilled coolant variable flow control system by generating feedback to permit control module  240  or BMS  210  to control temperature and/or humidity in data center/server room  250  by adjusting speed of coolant  214  or speed or temperature of cooled air  252 . (In traditional cooling system  230 , temperature  222  of coolant  214  is typically stable and therefore is not typically adjusted.) For example, if one of sensors  256 A-N detects that the air in data center/server room  250  is too warm, BMS  210  may respond by instructing variable flow controller  224  to increase a speed of VFD pump  218  or by instructing control module  240  to instruct flow controller  242  to increase the flow of coolant or blower  234  to increase the speed at which cooled air is supplied. If, in the opposite case, one of sensors  256 A-N detects that the air in data center/server room  250  is too cold, BMS  210  or control module  240  may respond, for example, with instructions to decrease the flow of coolant or to decrease the speed cooled air is supplied. In some instances, control module  240  may provide feedback to BMS  210 , which then instructs one or more controllers to respond accordingly. 
     Moreover, it may be, in some instances (e.g., during a dehumidification process), necessary to reheat or mitigate continued cooling of data center/server room  250  and adjust the flow of coolant  214 . Because temperature  222  of chilled coolant  214  in traditional cooling implementation  200  is typically between 6 and 10 degrees Celsius, the humidity of data center/server room  250  may fall below an acceptable humidity and/or the temperature of data center/server room  250  may fall below an acceptable temperature (e.g., below typical “room temperature” of 18 degrees Celsius or 64 degrees Fahrenheit, considered the minimum recommended temperature for IT equipment). This may also cause the room environment to be uncomfortable for human operators. Reheating the room can be used to remove excess moisture from the air caused when cooling coil  238  becomes very cold and prompts an increase in humidity. Therefore, sensible heat is added to data center/server room  250  using a heating coil (also called reheat coil) or similar heating device (not shown). This process of cooling and reheating is very inefficient. 
     Unfortunately, the attempt of traditional cooling system  230  (and overall traditional cooling implementation  200 ) to minimize energy costs causes the system to be highly complex and in need of constant monitoring and adjustment. Changes in a load on computers/servers  254  can cause the production of heat by computers/servers  254  to vary. This therefore necessitates BMS  210  and/or control module  240  to compensate for the varying computer/server temperatures by adjusting corresponding environmental variables, including air supply temperature, air flow, chilled coolant supply temperature, chilled coolant flow, and room humidity. 
     This level of complexity increases installation costs of traditional cooling system  230  and/or BMS  210  due to, for example, many control mechanisms (e.g., VFD pump  218 , flow control valve  232 , pressure independent control valves, or other modulating pumps or valves), BMS mechanisms to control chilled coolant flow through various load side components (e.g., cooling coil  238 ) and generation side components (e.g., chiller  212 , which requires at least a minimum flow), various controllers within traditional cooling system  230  (e.g., flow controller  242 , air flow controller  244 , and humidity controller  246 ), and other system components (e.g., blower  234  and coolant pipes  216 ). 
     Furthermore, this level of complexity increases capital expense and operational costs of traditional cooling system  230  and/or BMS  210 . For example, the several control pumps and/or valves throughout traditional cooling system  230  and BMS  210  and the increased chilled coolant pressure drop caused by the chilled coolant  214  bypass to chiller  212  causes the system to require regular maintenance, increasing energy consumption and maintenance costs. 
     However, as increased demand is placed on data centers, which in turn consume more power, information technology budgets remain relatively fixed. Therefore, pressure is mounting for information technology providers to reduce the costs associated with data center construction, operation, and maintenance, while also making data centers more efficient. Moreover, because data centers are becoming more virtualized, cooling requirements are becoming higher and more unpredictable. In response, standards bodies, such as the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE), have adopted more relaxed environmental standards for data centers, which allow for higher server air inlet temperatures. 
     The inventors of the present invention have found that, unlike other types of building environments, data centers can have extremely low latent loads (i.e., the amount of energy necessary to dehumidify air within a building environment). This is because most modern data centers have very few humans occupying the data center space who, if present, would add humidity to the data center by breathing out moist air. Therefore, latent cooling and fresh air within a data center building are typically very low. Instead, data centers tend to have mostly and primarily sensible cooling requirements. The inventors have discovered that, given the low latent load within most data centers, it is possible to raise the temperature of the chilled coolant (e.g., water) to about 19 degrees Celsius (66 degrees Fahrenheit) or even higher, while maintaining an air inlet temperature to servers/computers in a data center within the temperature zone recommended by ASHRAE. 
     Some of the inventors of the present invention have previously described methods for separating latent cooling from sensible cooling with respect to data center room cooling in United States patent application publication 2014/0053588, entitled “High-Efficiency Data Center Cooling” and having filing date Aug. 22, 2012. Accordingly, these methods will not be reiterated here. 
     Embodiments of the present invention, as will be described in more detail below, offer several advantages for improving computer technology. In one instance, embodiments remove the need to control the flow of coolant through a cooling coil (or another type of cooling structure). Furthermore, embodiments of the present invention remove the need for pipe insulation or drainage (e.g., a drainage pan) within a cooling system by preventing the formation of condensation. This allows for the elimination of several components and their controllers from cooling systems already known in the art, such as a CRAC system. Accordingly, these modifications simplify the complexity of existing cooling systems, and therefore, a cooling system, as modified by embodiments of the present invention, will require less maintenance and offer improved operational reliability and availability. Furthermore, embodiments of the present invention will lower capital expenses and overall operation and maintenance costs associated with data center cooling systems. Meanwhile, it will still be possible to control the environmental conditions within the server room or data center. 
     Referring now to  FIG. 4  and  FIG. 5 , with references to  FIG. 2  and  FIG. 3 , a simplified data center cooling system according to illustrative embodiments of the present invention is shown.  FIG. 4  shows a schematic of an implementation  400  of a simplified data center or server cooling system (also referred to as a KaPa cooling system) according to illustrative embodiments, while  FIG. 5  shows a three-dimensional model  500  of the simplified data center or server cooling system of  FIG. 4  according to illustrative embodiments. It should be understood that implementation  400  of a simplified data center or server cooling system contains several components and features in common with traditional data center or server cooling implementation  200 . Some of these components and features will only be discussed in passing below. Therefore, it should be understood that, unless otherwise stated, any component or feature shown in implementation  400  has the same characteristics and function as its counterpart component shown in implementation  200 . Counterpart components may be indicated with 2XY and 4XY nomenclature in  FIG. 2  and  FIG. 4 , respectively. In some embodiments, building management system (BMS)  410  can be computer system/server  102  of  FIG. 1 . 
     According to embodiments of the present invention, coolant  414  is chilled to a temperature  422  between 18 and 22 degrees Celsius (or between 64 and 72 degrees Fahrenheit) and supplied to a simplified cooling system  430  to cool a data center/server room  450 . This can be accomplished by a chilled water (CHW) or other chilled coolant temperature controller  420  (which may be controlled by BMS  410 ) instructing a chiller  412  to chill coolant  414  to a temperature between 18 and 22 degrees Celsius. Coolant  414  can travel through coolant pipes  416  (which can be uninsulated pipes  416 C and  416 D within simplified cooling system  430 ) to a cooling coil  438  or a similar cooling apparatus, before returning to chiller  412 . 
     It should be understood that although embodiments of the present invention will be described primarily with a temperature  422  of coolant  414  between 18 and 22 degrees Celsius, in some embodiments, temperature  422  can be higher than 22 degrees Celsius. The ASHRAE recommended zone for IT equipment is likely to rise in the future as methods are developed for manufacturing computerized equipment to be more resilient to heat. Therefore, in some embodiments, coolant  414  may have a temperature of, for example, 25 degrees Celsius (77 degrees Fahrenheit). 
     Using a coolant inlet temperature of between 18 and 22 degrees Celsius at cooling coil  438  allows a desired room temperature of data center/server room  450  within the ASHRAE recommended zone for IT equipment to be achieved more easily, simply, and consistently as compared with using a coolant inlet temperature of between 6 and 10 degrees Celsius in traditional cooling system  230 . In traditional cooling system  230 , BMS  210  and/or control module  240  must continuously monitor and adjust environmental variables to maintain a desired room temperature. Heat from computers/servers  254  must be compensated with cooled air  252 , resulting in sinusoid-like temperature fluctuations which may dip or peak outside of an acceptable temperature range. Dips below the acceptable temperature range can trigger undesirable condensation and/or humidity. By contrast, when coolant  414  is set at a temperature of 18-22 degrees Celsius, such that the resulting air inlet server temperature  458  of cooled air  452  at cooling coil  438  is the same as the desired temperature of data center/server room  450 , temperature  422  of coolant  414  becomes the lower limit of the temperature of data center/server room  450 . Therefore, regardless of a quantity of heat produced by computers/servers  454 , the room temperature of data center/server room  450  will always return, asymptote-like to that lower limit. Moreover, the room temperature of data center/server room  450  cannot dip below temperature  422 , which thereby prevents both condensation and wasting energy cooling and reheating data center/server room  450 . In some embodiments, the air of data center/server room  450  can be held in a closed system, such that the air continuously cycles between being cooled by cooling coil  438  and cooling computers/servers  454 . 
     Furthermore, because temperature  422  of coolant  414  supplied to simplified cooling system  430  and data center/server room  450  is at the ASHRAE recommended zone for IT equipment and higher than temperature  222  of coolant  214  supplied to traditional cooling system  230  and data center/server room  250 , it is possible to eliminate several components that would normally be found in traditional cooling system  230 , thereby forming simplified cooling system  430 . 
     To begin with, insulation  436  can be eliminated from portions of coolant pipes  416 . While, according to embodiments of the present invention, outflow coolant pipe  416 A and return coolant pipe  416 B can be insulated to help maintain temperature  422  of coolant  414 , cooling system pipes  416 C and  416 D can be uninsulated. This is because, as discussed above, the desired temperature of data center/server room  450  is the same as temperature  422  of coolant  414 . Accordingly, permitting coolant  414  to come into thermal contact with the air of data center/server room  450  allows coolant to better return or maintain the desired temperature of data center/server room  450 . In other words, no insulation is required on coolant pipes inside the controlled data center/server room environment, while all pipes outside this environment remain insulated to prevent condensation and thermal loss. 
     Further, chilled coolant flow control mechanisms can be eliminated from simplified cooling system  430 . In embodiments of the present invention, there is no need to increase or decrease the flow of coolant  414  to adjust the temperature of data center/server room  450 , and adjustments to coolant flow may simply be used to optimize power usage of VFD pump  418  versus power usage of chiller  412 . Therefore, flow control valve(s)  232  of traditional cooling system  230  can be eliminated from simplified cooling system  430  of the present invention, and instead, only VFD pump  418  is used to move coolant  414  through simplified cooling system  430 . As needed to optimize power usage, variable flow controller  424  can instruct VFD pump  418  to adjust the flow of coolant  414  anywhere between a minimum flow required for chiller  412  and a maximum required flow for the load of data center/server room  450 . Minimum and maximum flows can be adjusted as system components or loads are added or reduced from data center/server room  450 . Eliminating flow control valve  232  from simplified cooling system  430  reduces the cost of manufacturing simplified cooling system  430 . Furthermore, VFD pump  418  does not, in contrast to the combination of flow control valve  232  and VFD pump  218 , cause a pressure drop between different portions of pipes  416 . (Although a pressure differential sensor  426  and a chiller bypass safety valve  228  may be included in some simplified cooling systems  430 .) Accordingly, eliminating flow control valve  232  from simplified cooling system  430  also reduces operating and maintenance costs of simplified cooling system  430  and permits more efficient operation of simplified cooling system  430 . 
     Additionally, several control modules can be eliminated from simplified cooling system  430 . For example, because simplified cooling system  430  of embodiments of the present invention does not require, as discussed above, flow control valve(s)  232  as found in traditional cooling system  230 , simplified cooling system  430  also does not require a flow controller  242 . Furthermore, humidity controller  246 , a humidifier/dehumidifier system, a reheat system, and a condensation pan  248  or other condensation collector, as found in cooling system  230 , can be eliminated from simplified cooling system  430 . This is because temperature  422  of coolant  414  is 18-22 degrees Celsius and data centers that are not inhabited by human beings tend to have little to negligible latent loads, thereby making these components unnecessary. In some embodiments of the present invention, humidity control is performed by a system such as that described in United States patent application publication 2014/0053588, referenced above. Such a system may have a scaled-down humidity controller and/or a smaller condensation pan, as compared to humidity controller unit  246  and condensation pan  248  of traditional cooling system  230 . In any case, elimination or reduction of these control modules will further reduce operating and maintenance costs of simplified cooling system  430  and permit more efficient operation of simplified cooling system  430 . 
     Moreover, simplified cooling system  430  can be simplified such that a blower or fan  434 , which pushes/pulls air through cooling coil  438 , is the only component of simplified cooling system  430  remaining that may be associated with some form of control logic. In some embodiments, simplified cooling system  430  may have an airflow controller  444  (in communication with control module  440  and/or BMS  410 ) that controls and adjusts blower  434 . In other embodiments, control of blower  434  can be handled directly by control module  440  or BMS  410 . More specifically, in some embodiments, BMS  410  can directly control all components of data center/server cooling system implementation  400 , including simplified cooling system  430 , coolant chilling, and coolant flow. 
     Furthermore, several feedback sensors of the chilled coolant variable flow control system can be eliminated. However, in some instances it may be desirable to retain in simplified cooling system  430  the several temperature/humidity sensors  256 A-N of cooling system  230  in order to, for example, make a diagnostic in the case of a malfunction of simplified cooling system  430 . In traditional cooling system  230 , each of temperature/humidity sensors  256 A-N can provide feedback to a corresponding component of the load side or the generation side. However, in embodiments of the present invention, an area temperature sensor  456  can be placed at just one of a coolant return, a coolant supply, or an air intake of blower  434  or coiling coil  438 . Single temperature sensor  456  can read air inlet server temperature  458  and provide feedback directly to BMS  410 , which in turn can vary the temperature of coolant  414  using temperature controller  420 , based solely on the air inlet server temperature  458 , through both the load side and generation side of data center/server cooling system implementation  400 . In some instances, BMS  410  can also first vary the flow of coolant  414  using variable flow controller  424  because a relatively small reduction in pump speed can reduce power usage significantly (e.g., a 20% reduction in pump speed can reduce power consumption of the pump by about half). These processes allow BMS  410  to control the temperature of center/server room  450 . In some embodiments, single temperature sensor  456  can be an array of temperature sensors in data center/server room  450  and the air inlet temperature used by BMS  410  can be the worst air inlet temperature (i.e., the hottest) or an average temperature within an aisle or room of data center/server room  450 . 
     Accordingly, embodiments of the present invention permit BMS  410  to vary temperature  422  of coolant  414  between 18 and 22 degrees Celsius, in addition to varying the flow of coolant  414 , while maintaining a maximum server air inlet temperature of, for example, about 25 degrees Celsius, or any other desired temperature within ASHRAE recommended or allowable temperature zones. Accordingly, BMS  410  can directly control the temperature of data center/server room  450 , temperature  422  of coolant  414 , and the flow of coolant  414 . This offers the benefits of reducing balancing efforts requiring multiple components due to flow and temperature variations, as well as improving operation of chiller  412  by providing constant coolant flow through chiller  412 , which allows chiller  412  to have better, more consistent control over temperature  422  of coolant  412 . 
     To operate simplified cooling system  430 , BMS  410  first starts VFD pump  418 , which eventually reaches full speed, and chiller  412  to chill coolant  414  to a set temperature, such as 18 degrees Celsius. Unless data center/server room  450  has a full load, temperature in data center/server room  450  should be lower than the set point, in which case BMS  410  can reduce the speed of VFD pump  418 . For example, a 20% reduction in pump speed can reduce power consumption of a typical pump by about half while not having any significant impact on the capacity of simplified cooling system  430 . If the temperature in center/server room  450  still remains under a desired temperature, then BMS  410  can increase temperature  422  of coolant  414  (e.g., up to 22 or 23 degrees Celsius). When the temperature in data center/server room  450  begins to increase or raise above an upper temperature threshold (e.g., when data center/server room  450  has a full load), BMS  410  can perform these steps in reverse, lowering temperature  222  of coolant  414  and increasing the speed of VFD pump  418  up to its maximum. 
     It should be understood that embodiments of the present invention can have many applications, which will not be described exhaustively here, but should be apparent to a person trained in the relevant art in light of this disclosure. For example, data center cooling systems, such as a Computer Room Air Conditioning (CRAC), an Air Handling Cooling Units (AHCU) system, or any other type of Heating, Ventilation and Air Conditioning (HVAC) system, can be manufactured to follow the features of embodiments of the present invention. In other words, a simplified CRAC unit can be made of a CRAC box, a cooling coil, and a fan, without the need for coolant flow control valves, controllers or control logic for fluid control mechanisms, a reheating system, a traditional drain pan, insulation, or traditional humidifiers. In another example, a simplified data center cooling systems can be built up from an existing cooling system or built off of a building management system, again using a CRAC box, a cooling coil, and a fan, while removing or not including coolant flow control valves, controllers or control logic for fluid control mechanisms, a reheating system, a traditional drain pan, insulation, or traditional humidifiers. 
     Moreover, in another example, a building management system can be programed and/or configured to control the temperature of a cooling system&#39;s coolant to between 18 and 22 degrees Celsius based on an IT load requirement and/or a room temperature of a data center or server room. It should also be understood that, in some embodiments, the building management system can be programed and/or configured to control coolant temperature to a temperature above 22 degrees Celsius if so desired to maintain server inlet temperature within ASHRAE mandated allowable zones. The building management system can also be programed and/or configured to control coolant flow within both the cooling and the building systems to between a minimum flow required by a coolant chiller and a maximum flow associated with a full IT load within the data center or server room. 
     As depicted in  FIG. 6 , in one embodiment, a system (e.g., computer system/server  102 ) carries out the methodologies disclosed herein. Shown here is a process flowchart  600  for cooling a data center with a simplified cooling system having a relatively high chilled coolant temperature. At  602 , BMS  410  receives a reading from temperature sensor  456  located in data center  450 . At  604 , BMS  410  determines, based on the received reading, a set of adjustments to temperature  222  of coolant  414  to most efficiently return data center  450  to a desired temperature. At  606 , BMS  410  instructs coolant chiller controller  420  to chill coolant  414  at chiller unit  412  to a selected temperature, based on the determination, between 18 and 22 degrees Celsius. 
     Process flowchart  600  of  FIG. 6  illustrates the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     Some of the functional components described in this specification have been labeled as systems, units, or controllers in order to more particularly emphasize their implementation independence. For example, a system, unit, or controller may be implemented as a hardware circuit comprising custom VLSI circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A system, unit, or controller may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. A system, unit, or controller may also be implemented in software for execution by various types of processors. A system, unit, or controller or component of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified system, unit, or controller need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the system, unit, or controller and achieve the stated purpose for the system, unit, or controller. 
     Further, a system, unit, or controller of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices and disparate memory devices. 
     Furthermore, systems/units may also be implemented as a combination of software and one or more hardware devices. In a further example, a system, unit, or controller may be the combination of a processor that operates on a set of operational data. 
     As noted above, some of the embodiments may be embodied in hardware. The hardware may be referenced as a hardware element. In general, a hardware element may refer to any hardware structures arranged to perform certain operations. In one embodiment, for example, the hardware elements may include any analog or digital electrical or electronic elements fabricated on a substrate. The fabrication may be performed using silicon-based integrated circuit (IC) techniques, such as complementary metal oxide semiconductor (CMOS), bipolar, and bipolar CMOS (BiCMOS) techniques, for example. Examples of hardware elements may include processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), logic gates, registers, semiconductor devices, chips, microchips, chip sets, and so forth. However, the embodiments are not limited in this context. 
     Any of the components provided herein can be deployed, managed, serviced, etc., by a service provider that offers to deploy or integrate computing infrastructure with respect to a process for performing embodiments of the present invention. Thus, embodiments herein disclose a process for supporting computer infrastructure, comprising integrating, hosting, maintaining, and deploying computer-readable code into a computing system (e.g., computer system/server  102 ), wherein the code in combination with the computing system is capable of performing the functions described herein. 
     In another embodiment, the invention provides a method that performs the process steps of the invention on a subscription, advertising, and/or fee basis. That is, a service provider, such as a Solution Integrator, can offer to create, maintain, support, etc., a process for performing embodiments of the present invention. In this case, the service provider can create, maintain, support, etc., a computer infrastructure that performs the process steps of the invention for one or more customers. In return, the service provider can receive payment from the customer(s) under a subscription and/or fee agreement, and/or the service provider can receive payment from the sale of advertising content to one or more third parties. 
     Also noted above, some embodiments may be embodied in software. The software may be referenced as a software element. In general, a software element may refer to any software structures arranged to perform certain operations. In one embodiment, for example, the software elements may include program instructions and/or data adapted for execution by a hardware element, such as a processor. Program instructions may include an organized list of commands comprising words, values, or symbols arranged in a predetermined syntax that, when executed, may cause a processor to perform a corresponding set of operations. 
     The present invention may be a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     It is apparent that there has been provided herein approaches to performing embodiments of the present invention. While the invention has been particularly shown and described in conjunction with exemplary embodiments, it will be appreciated that variations and modifications will occur to those skilled in the art. Therefore, it is to be understood that the appended claims are intended to cover all such modifications and changes that fall within the true spirit of the invention.