气流分配在数据处理环境的重要性

Air distribution’s importance in data processing environments

Sep 27, 2022，JUSTIN HSIAO AND BEN OLEJNICZAK

译 者 说

数据中心气流遏制策略能够大幅提高传统数据中心制冷系统的可预测性和效率。但是，大多数已有数据中心由于受各种条件的制约，只能采用某些类型的气流遏制策略。由于IT 设备与局部送风气流分配（例如穿孔地板）的不匹配，在非均匀的高密度机柜环境中，很可能发生热排风再循环以及冷风气流旁通等现象。气流遏制技术可以有效地消除上述再循环现象，从而提高数据中心的可靠性并降低能耗。

数据中心洞察

Data center insights

为数据中心创建一个最优的配置需要大量思考空气如何分布在整个数据中心，同时还要创建一个节能系统。Creating an optimal setup for data centers requires a lot of thought in how the air is distributed throughout the data center while also creating an energy-efficient system.

ASHRAE TC9.9 – 数据处理环境的散热指南是一些想要了解服务器设备的用户的首选资源，包括服务器设备是否值得推荐以及是否必需等信息。ASHRAE TC9.9 – Thermal Guidelines for Data Processing Environments is a good first resource for users looking to understand what is and isn’t recommended and required for server equipment.

数据中心的设计不仅仅是在一个大型空间中安装冷却服务器。为了优化服务器寿命和最大限度地提高系统能源效率，人们已经对建立的离散运行范围进行了很多思考、学习和研究。如果没有适当的气流分配和策略遏制，设施将超出设计偏差，运行效率低下，在某些情况下还会损坏服务器设备。以下文章将讨论ASHRAE环境种类，讨论在设计条件下将冷空气输送到服务器基础设施的常见气流分配方式，并重点介绍解决封闭方案如何帮助维护所述环境。

Data center design is more than just cooling servers installed in a large spatial volume. Much thought, study and research has gone into the establishment of very discrete operating envelopes to optimize server life and maximize system energy efficiency. Without proper means of air distribution and containment strategies, facilities will fall outside of design tolerance, operate inefficiently and damage server equipment in some cases. The following article will discuss the ASHRAE environmental classes, discuss common air distribution methods to deliver cool air at design conditions to server infrastructure and highlight how containment solutions can aid in the maintenance of said environments.

ASHRAE TC9.9 -数据处理环境热指南由ASHRAE技术委员会(TC) 9.9于2004年首次发布，是数据中心行业中引用最多的文档之一，为数据中心环境搭建了指南，以确保信息技术设备(ITE)的可靠运行，以及标准化 ITE 制造商的设计要求。这些标准在全国数据中心项目中普遍遇到和使用，参与数据中心设计和运营的每个人都应该了解其中给出的运行范围。

First published in 2004 by ASHRAE Technical Committee (TC) 9.9, ASHRAE TC9.9 – Thermal Guidelines for Data Processing Environments is one of the most referenced documents within the data center industry and establishes guidelines for data center environments to ensure reliable operation of information technology equipment (ITE), as well as standardizing design requirements for ITE manufacturers. These standards are commonly encountered and used in data center projects nationwide and everyone involved in data center design and operations should be aware of the operating envelopes established within.

第二章中概述的指南在数据中心领域发挥着重要作用，通过提供标准化条件，将ITE和数据中心设计统一起来。该标准为ITE定义了几种环境级别，为每种级别给出了推荐和允许的进入空气温度和湿度范围(见表1)

The guidelines outlined in Chapter 2 play an important function in the data center space by unifying both ITE and data center design through providing standardized conditions for both. The standard defines several environmental classes for ITE, establishing both recommended and allowable entering air temperature and humidity ranges for each class (see Table 1).

这意味着ITE制造商可以在特定环境中最大限度地提高其设备的可靠性。这也意味着数据中心设计专业人员了解优化其制冷系统的条件。数据中心设计者经常参考这些环境范围，以确保ITE的最大可靠性。ITE制造商通常使用给定等级的允许范围来设计和测试其设备，以确保在极端条件下运行的最大可靠性和能力。在设计过程中应谨慎行事，以确保数据中心或IT空间的设计考虑到预期的ITE分类，并遵守客户规定的范围要求。

This means ITE manufacturers can maximize their equipment’s reliability within a certain environment. It also means data center design professionals know the conditions to optimize their cooling systems around. Data center designers often reference these environmental ranges to ensure maximum ITE reliability. ITE manufacturers typically design and test their equipment using the allowable ranges for a given class to ensure maximum reliability and capability to operate under extreme conditions. Care should be exercised during the design process to ensure the data center or IT space is designed with the intended ITE classification in mind and any client-mandated envelope requirements are upheld.

ASHRAE TC9.9中建立的风冷设备环境等级旨在广泛代表典型的数据中心/IT环境。

The environmental classes for air-cooled equipment established in ASHRAE TC9.9 are intended to broadly represent typical data center/IT environments.

表 1：风冷 ITE的推荐和允许环境运行条件。友情提供：ESD，改编自 ASHRAE 技术委员会 （TC） 9.9，ASHRAE TC9.9 – 数据处理环境的热指南。

Table 1: Recommended and allowable environmental conditions for operating, air-cooled ITE. Courtesy: ESD, adapted from ASHRAE Technical Committee (TC) 9.9, ASHRAE TC9.9 – Thermal Guidelines for Data Processing Environments.

虽然所有风冷等级(H1除外)的推荐运行范围都是相似的，但允许范围的变化要大得多。A1类用于表示严格控制的关键任务数据中心环境。A2类的允许条件范围略宽松，旨在代表具有一定空气调节能力的IT机房或类似空间，但不一定达到专用数据中心的水平。

While the recommended operating ranges are similar for all the air-cooled classes (with exception to H1), there is much greater variation in the allowable ranges. Class A1 is intended to represent a tightly controlled mission-critical data center environment. Class A2, with its slightly looser range of allowable conditions, is intended to represent an IT room or similar space with some ability to condition air, but not necessarily to the level of a purpose-built data center.

2012年增加了A3和A4级别，以反映该行业对更多自然冷却和更节能冷却技术的需求，这些需求反映出更宽的允许范围。H1类代表高密度计算或设备，通常位于较大数据中心的单独区域。这类设备通常需要较低的进气温度，以满足组件的要求。

Classes A3 and A4 were added in 2012 to reflect the industry’s drive for more free cooling and more energy-efficient cooling technologies, with the wider, allowable ranges reflecting those desires. Class H1 represents high-density computing or equipment, typically located in a separate area within a larger data center. This class of equipment typically requires lower entering temperatures to meet component requirements.

自该文件首次出版以来，通过扩大现有环境类别的运行范围和设立新的环境类别，ITE的推荐和允许运行范围已经扩大。这些变化的驱动因素通常是来自数据中心运营商的压力，他们要求通过更多的节约/减少机械冷却来提高效率，以及调查各种条件对ITE可靠性影响的研究结果，包括低湿条件下的静电放电，以及环境中诱导腐蚀的催化剂元素的影响。

The recommended and allowable operating ranges for ITE have expanded since the document was first published, through both expanding the operational ranges of existing environmental classes and through the creation of new environmental classes. The driver for these changes was often a combination of pressure fromdata center operators for increased efficiency through greater economization/reduction of mechanical cooling, as well as results from studies investigating the effects of various conditions on ITE reliability, including electrostatic discharge in low humidity conditions, as well as effects of corrosion-inducing catalyst elements in the environment.

虽然作为行业内的基准是必要的，但为每个环境类别提供的指南并不是强制性的。该文件提供了关于超出推荐范围的评论，指出这是节能和ITE运行可靠性之间的平衡。每个所有者/经营者都需要找到一个符合他们业务需求的解决方案。

While necessary as a baseline within the industry, the provided guidelines for each environmental class are not mandatory. The document provides commentary regarding going outside of the recommended ranges, noting it is a balance between energy savings and ITE operational reliability. Each owner/operator needs to find a solution congruent with their business needs.

值得注意的是，ASHRAE TC9.9中给出的范围是针对进入设备的空气。自首次发布以来，该文件一直围绕着ITE进气温度是影响设备功能和可靠性的唯一温度这一理念构建。离开ITE的热排风不影响ITE的性能或可靠性，除非它与进入的空气相互作用。数据中心设计人员的主要任务是完成以下工作:

It is important to note the ranges presented in ASHRAE TC9.9 are for air entering the equipment. Since it was first published, the document has been built around the idea the ITE inlet air temperature is the only temperature that matters for equipment functionality and reliability. The heated exhaust air leaving the ITE does not impact the performance or reliability of the ITE unless it interacts with the entering air. The primary task of the data center designer is to do the following:

确保冷却ITE所需的适当空气量符合ITE要求的标准。Ensure an appropriate quantity of air required to cool the ITE is conditioned to the standards required by the ITE.

确保步骤1中的空气到达所有ITE的进气道。Ensure the air in step 1 reaches the inlet of all ITE.

尽可能减少第2步中离开ITE的热排风对空气的影响，以保持所需的ITE运行范围。Minimize the effect of the heated exhaust air leaving the ITE on the air in step 2 as much as possible, to maintain the required ITE operating envelope.

执行、维护运行范围

Execute, maintain operating envelopes

现在已经建立了运行范围的概述, 那么必须讨论用于建立和维护这些环境围护结构系统的设计方法。为此，第5章介绍了常见的空气气流分配和遏制策略。该方案由两部分组成:将送风分配到位于或接近且不超过设计热范围的所有服务器机架位置;分开的服务器送风(冷)和排气(热)通道，以保存所述的热范围。

Now that an overview of operating envelopes has been established, ways to design systems for establishing and maintaining these environmental envelopes must be discussed. To accomplish this, Chapter 5 introduces common air distribution and containment strategies. The idea is comprised of two parts: Distribute supply air to all server rack locations at or close to and not beyond the design thermal envelope; separate server supply air (cool) and exhaust air (warm) pathways to preserve said thermal envelope.

通过在设计中实施这些项目，用户可以减少数据中心内热点的产生，减少再循环和/或过早混合的机会，并确保合理的空气状态进入ITE。不这样做通常会导致气流需求增加和更高的风扇功耗。如果规划时不注意空间内的气流分配、服务器送风和排气路径和ITE配置，那么将这些概念整合到设计中通常是困难的。然而，通过最佳实践和一些有用的技巧，用户可以部署一个在定义的热范围内有效运行的系统。

By implementing these items into a design, users can mitigate the generation of hot spots within the data center, reduce the chance of recirculation and/or premature mixing and ensure proper entering air conditions at the ITE. Not doing so will often lead to increased airflow requirements and higher fan power consumption. Consolidating these concepts into design is often difficult if care is not taken when planning out the air distribution methods, server supply and exhaust pathways and ITE configurations within the space. However, through best practice and a few helpful tips, users can deploy a system that operates efficiently within the confines of the defined thermal envelope.

第 1 部分：向服务器基础设施分配送风

Part 1: Distribution of supply air to server infrastructure

两种主要的空气分配策略将是重点:吊顶和高架地板。每个选择都有优点和缺点，正确的选择是由许多因素决定的，这里就不再讨论。对于每种方法，将讨论常见的设备类型，并解释一些高级设计注意事项。要确保设计送风分配到服务器机架和维护运行环境，下一步是了解空气分配方法的类型和设备的选择。

Two main air distribution strategies will be the focus: Overhead and underfloor. Each option has advantages and disadvantages and the right choice is determined by many factors that will not be discussed here. For each method, common equipment types will be discussed and some high-level design considerations will be explained. Understanding the types of air distribution methods and the equipment options at one’s disposal is the next step in ensuring design supply air is distributed to server racks and the operating environment is maintained.

还有几种方法可以冷却数据中心。小型设施可以使用基本设备进行冷却，但在这种情况下，将专注于专门构建的关键任务系统的解决方案。

There are several ways to cool a data center. Smaller installations can be cooled with basic equipment provisions, but in this case, solutions for purpose-built, mission critical systems will be focused on.

吊顶分配概述

Overhead distribution overview

通过将数据中心本身的单元或远程设施中的单元空气导入吊顶方式来完成的。此应用程序的常用单元类型包括：

Overhead distribution is often accomplished by means of ducting air from a unit either in the data center itself or remotely in the facility. Common unit types for this application include:

上回风机房空气处理装置（CRAHs）-基于冷冻水Upflow computer room air handlers (CRAHs) – Chilled water based.

上回风机房空调装置—基于风冷或水冷冷凝器的直接膨胀（DX）设备Upflow computer room air conditioners (CRACs) – Packaged direct expansion (DX) equipment with either air-cooled or water-cooled condensers

带包装的屋顶设备。多种系统类型可供选择(冷冻水型、DX、直接蒸发、间接蒸发或它们的组合)Packaged rooftop equipment – Many system types available (chilled water, DX, direct evaporative, indirect evaporative or a combination thereof).

气流通过管道系统上升到服务器机架入口位置。送风位置要么是下送风，要么是延伸到更低的位置，这样才能确保精确送风。选择不同导致了气流速率的不同。如果在较高的位置，必须注意到从开口流出的空气速度，以确保冷空气进入服务器的进口。太高的位置会使空气穿过进风口，导致进入设备的空气量不足。过低的位置，导致空气可能过早地与服务器的排气空气混合，如果不采取封闭措施，就会导致入口温度过高。稍后将详细介绍。如果送风口向下延伸，应考虑降低速度，从而最大限度地允许服务器有效吸收送风。

Air leaves the unit of choice and travels via ductwork elevated above finished floor to server rack inlet locations. Supply locations are either positioned to discharge air downward or extended to a lower elevation to precisely deliver air. Velocity considerations vary with each option. If at high elevation, one must be cognizant of the air velocities exiting the opening to ensure cool air will make it to the server inlet. Too high and the air will shoot past the inlet, resulting in an insufficient air quantity entering the equipment. Too low and the air may prematurely mix with server exhaust air, resulting in excessive inlet temperatures if containment measures are not pursued. More to come on this later. If supply outlets are extended downward, decreased velocities should be considered to minimize throw and allow the servers to efficiently ingest the supply air.

总体而言，吊顶分配是有效的，但在施工时使多学科协调复杂化。电信电缆桥架、电气母线槽、配电导管、火灾报警和消防管道是通常在数据中心内吊顶布线的基础设施的例子。

Overall, overhead distribution is effective but complicates multidisciplinary coordination when it comes time for construction. Telecommunications cable tray, electrical busway, power distribution conduit, fire alarm and fire protection piping are examples of trade infrastructure typically routed at elevation within the data center.

高架地板下分布概述

Underfloor distribution overview

高架地板下的分配通常通过将送风送至高架地板下方的地板空腔来实现。此应用程序的常见单位类型如下：

Underfloor distribution is typically accomplished by means of supplying air into an underfloor cavity below a raised access floor. Common unit types for this application are as follows:

下送风空气处理装置（CRAHs）-基于冷冻水Downflow computer room air handlers (CRAHs) – Chilled water based下送风房间级空调（CRACs）-基于风冷或水冷冷凝器的成套直接膨胀 （DX） 设备Downflow computer room air conditioners (CRACs) – Packaged direct expansion (DX) equipment with either air cooled or water-cooled condensers.

地板空腔是通过在高架地板上安装服务器基础设施并由结构网格支撑来创建的。空气通过下送风的方式离开所选设备，并通过穿孔的特殊地砖向上穿过地板空腔，将空气输送到服务器机架位置。地砖有多种变化（阻尼器、无阻尼器、风扇辅助等）和可变的无孔区域。地板下分配的精妙之处在于，压力分布可以均匀，从而实现良好的空气分配效果。

The underfloor cavity is created by installing server infrastructure atop floor tiles elevated and supported by a structural grid. Air leaves the unit of choice in a downward direction and passes through the underfloor cavity up through special floor tiles that are perforated, strategically delivering air to server rack locations. Floor tiles come in many variations (damper, no damper, fan-assist, etc.) and in variable, perforated free area. The beauty of underfloor distribution is when it’s ideally deployed, the pressure distribution can be uniform, allowing for good air distribution effectiveness.

在实践中，通过审查旧设施通常遇到的一个主要缺点是，这种巨大的高架地板下空隙为安装其他设施提供了充足的空间。与吊顶分配一样，如果其他分配方式选择通过此空隙放置相应的基础设施，则协调可能会变得困难。地板下更多的障碍物会产生高度可变且不可预测的地板压力分布（见图1）。这使得整个数据中心的地砖排出的空气量和速度变得复杂。

One major downside, which is commonly encountered in practice through review of older facilities, is this large, underfloor void introduces ample volume for installation of other trade utilities. Like overhead distribution, coordination may prove to be difficult if other disciplines opt to route their infrastructure through this void. More obstructions underfloor yield a highly variable – and unpredictable – underfloor pressure distribution (see Figure 1). This complicates how much air and how fast it exits the floor tiles across the data center.

为了更好地预测这个问题，建议通过计算流体动力学建模来验证设计，以确保设计人员对地板下压力分布以及随后分配到服务器机架的气流特性和条件有很好的了解。

To better anticipate this concern, it is advisable to validate a design by means of computational fluid dynamics modeling to ensure that the designer has a good understanding of the underfloor pressure distribution and subsequent airflow characteristics and conditions distributed to server racks.

图 1：位于现有数据中心内高度拥挤的地板空腔的照片。友情提供：ESD服务器机架位置的重要性

Figure 1: Photograph of a highly congested underfloor cavity located within an existing data center. Courtesy: ESD

服务器机架位置的重要性

The importance of server rack positioning

第5章还涉及服务器机架定位和数据中心内相对位置的重要性。服务器机架通常按以下方向布置：

Chapter 5 also touches on the importance of server rack positioning and relative location within the data center. Server racks typically are arranged in the following orientations:

从前到后 – 空气从前方进入，通过后部存在。Front to rear – Air enters through the front, exists through the back.

从前到上 – 空气从前部进入，从顶部排出。Front to top – Air enters through the front and exits through the top.

从前到上和后 – 空气从前部进入，从顶部和后部排出。Front to top and rear – Air enters through the front and exits through the top and rear.

服务器机架通常并排放置在数据中心内。为了优化服务器性能并保持目标操作范围，服务器机架按背对背和从前到前排列成行排列。这样，冷的送风可以通过一个通道（冷通道）发送到服务器入口，而热排风可以收集并归入到另一个通道（热通道）。如果服务器机架从前到后放置，则一个服务器机架的排气将与到另一个服务器机架的入口空气混合，人为引入设计偏差。不建议使用此方法。

Server racks are often positioned side by side within the data center. To optimize server performance and maintain targeted operating envelopes, server racks are arranged in rows positioned back-to-back and front-to-front. This way, cool, supply air can be sent to server inlets through one aisle (cold aisle) and warm, exhaust air can be collected and relegated to another (hot aisle). If server racks are positioned front to back, the exhaust air from one server rack would mix with the inlet air to another, artificially elevating the inlet air to that server rack and introducing a deviation from the thermal envelope design. This approach is not recommended.

虽然正确的摆放服务器的位置可以增加气流分配和热操作环境的维护，但仍然存在两个问题：再循环和后混合。如果没有完全将送风和排风分开的方法，肯定会发生再循环和混合。来自服务器机架的排风将与进入的送风混合。这种混合人为增加了直接进入冷通道的送风温度和进入ITE的空气温度。如果发生这种情况，ITE 的可靠性可能会受到不利影响。

While proper server positioning can increase the air distribution and maintenance of the thermal operating environment, two problems remain: recirculation and subsequent mixing. Without a means to fully separate the supply and exhaust airstreams, recirculation and mixing will most certainly occur. Exhaust air from the server rack will make its way back into the space where it will mix with incoming supply air. This mixing artificially increases the supply air temperature directed into the cold aisle and the temperature of the air entering the ITE. If this occurs, the reliability of the ITE may be adversely affected.

第二部分：遏制策略可以作为分隔服务器气流的手段

Part 2: Containment as the means to separate server airstreams

通过再循环和混合来减少对运行范围的变化，遏制策略以物理方式将服务器送风与服务器排风分开。遏制策略主要有两种类型：

To mitigate alterations to the operating envelope by means of recirculation and mixing, containment strategies are deployed to physically separate server supply air from server exhaust air. There are two main types of containment strategies:

从根本上说，遏制策略是气流之间的物理屏障。这种屏障可以像基于聚合物的窗帘墙一样简单，也可以像服务器机架附近的内置体积一样坚固。遏制策略的目标是为通过的每种气流建立一个“控制体积”。通过管理两种分开的气流，可以最大限度地减少再循环和环境偏差，并提高服务器的性能和效率。通过将遏制解决方案集成到设计中，由于减少了通过混合或再循环改变送风的机会，可以更优化地维护设计操作范围。

Fundamentally, containment is a physical barrier between airstreams. This barrier could be as simple as a wall of polymer-based curtains or as robust as a built-out volume adjacent to the server racks. The goal of containment is to establish a “control volume” for each air stream to pass through. By managing the two airstreams and keeping them separated, recirculation and environmental deviations are minimized and server performance and efficiency is enhanced. By integrating containment solutions into a design, the design operating envelope is more optimally maintained because the opportunity for alteration of supply air by means of mixing or recirculation is reduced – but not eliminated.

图2 高架地板下带冷通道封闭系统的送风方式说明

Figure 2: Graphic illustrating underfloor, supply air distribution with cold aisle containment. Courtesy: ESD

图3 高架地板下带热通道封闭系统的送风方式说明

Figure 3: Graphic illustrating underfloor, supply air distribution with hot aisle containment. Courtesy: ESD

减少泄露

Leakage mitigation

即使制定了遏制策略，空气泄漏和偏差范围仍然存在。这里所讨论的遏制策略和分配方法不是100%密不透风的。正因为如此，空气仍有可能从一个气流迁移到另一个气流，从而提高ITE入口空气温度。泄漏以多种方式出现。将重点关注的三个问题是服务器机架的泄漏，遏制解决方案中的泄漏以及高架地板下分布网络中的泄漏。

Even with containment strategies in place, the opportunity for air leakage and envelope deviation remains. Containment strategies and the distribution methods discussed are not 100% airtight. Because of this, there still exists a possibility air can migrate from one airstream into another, raising the ITE inlet air temperature. Leakage presents itself in many ways. The three that will be focused on are leakage at the server rack, leakage within the containment solution and leakage in an underfloor distribution network.

减少机架层的泄露

Mitigating leakage at the rack level

实际上，数据中心在某个时间点始终在服务器机架内有开放的服务器区域。无论是新建数据中心内的早期服务器部署，还是旧硬件的日常维护和/或更换，始终都会有服务器的开放区域。服务器机架通常由许多插槽组成，用于滑入不同高度的服务器。最终用户可以根据其特定的硬件需求混合和匹配服务器类型。

In practice, data centers will always have open server positions within a server rack at one point in time or another. Whether it is an early server deployment within a newly-built data center or routine maintenance and/or replacement of older hardware, open server locations will surface. Server racks are typically comprised of many slots for servers of varying heights to be slid into. The end user can mix and match server types based on their specific hardware needs.

使用专门设计的空白面板阻挡机架内的这些开放服务器位置至关重要，以最大程度地减少服务器废气离开机架机箱的开放区域。这样，气流可以更有效地分离，并减缓设计送风温度变化。

It is critical these open server locations within a rack be blocked with specially designed blank-off panels to minimize open area for server exhaust air to exit the rack enclosure. This way, airstreams are more effectively separated and design supply air temperature variation is mitigated.

减少密闭层面的泄露

Mitigating leakage at the containment level

根据遏制策略和结构的不同，泄漏率会有所不同。确保遏制解决方案尽可能密闭。常见的泄漏点如下：安全壳连接点、其他基础设施的贯穿件和紧固件连接点。在上述所有位置，可以通过适当的垫圈、安装紧固件垫圈和在贯穿件周围密封等预防措施来减轻泄漏。

Depending on the containment strategy and construction, leakage rates will vary. Ensure containment solutions are as airtight as possible. Common points of leakage are as follows: containment panel connection points, penetrations for other trade infrastructure and fastener points of connection. Leakage can be mitigated at all mentioned locations with precautions such as proper gasketing, installation of fastener grommets and sealing around penetrations.

减少高架地板下的分布网络的泄露

Mitigating leakage in an underfloor distribution network

高架地板下经常出现泄露的情况。泄露通常出现在未安装正确的地砖或地板内。通常将贯穿件切割成地砖，以便电信布线和/或电线导管通过。同样，为了减少泄漏，通过在地砖/结构支撑网格接口处安装适当的垫圈并在所有地板贯穿件上安装密封垫圈来解决这些问题。根据经验，ASHRAE Applications 2019（见第20.15节）建议可接受的泄漏率不得超过系统设计流量要求的2%。

Leakage presents itself often in underfloor distribution networks. It is quite common to see leakage at improperly installed floor tiles or penetrations within the floor. Often penetrations are cut into floor tiles for telecommunications wiring and/or electrical conduit to pass through. Again, to mitigate leakage, these issues are remedied by installing proper gasketing at the floor tile/structural support grid interface and installing sealing grommets at all floor penetrations. As a rule of thumb, ASHRAE Applications 2019 (see section 20.15) recommends acceptable leakage rates shall not exceed 2% of the system design flow rate requirement.

保持数据中心内的效率和优化

Maintain efficiency, optimization within data centers

ASHRAE TC9.9是数据中心设计行业中使用的管理文档之一。了解建议和允许的运行范围以及如何执行和维护它们对这些设施及其系统的设计至关重要。通过设置这些环境阈值，结合各种分布方法和控制策略，并注意一些非常常见的泄漏因素，数据中心设计着可以确保保持适当的环境范围，同时最大限度地减少能源使用和对ITE的负面影响。

ASHRAE TC9.9 is one of the governing documents used in the data center design industry. Understanding the recommended and allowable operating envelopes and how to execute and maintain them is critical to the design of these facilities and their systems. By deploying these environmental thresholds, incorporating various distribution methodologies and containment strategies and being mindful of some very common contributors of leakage, a data center designer can ensure the maintenance of a proper environmental envelope while minimizing energy usage and negative impacts to ITE.

深 知 社

翻译：

黄洁晨

DKV（DeepKnowledge Volunteer）计划成员

校对：

贾梦檩

阿里云 暖通工程师

DKV（DeepKnowledge Volunteer）计划精英成员

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