Mission Critical Facilities, Data Centers, Technology Spaces and Electronic Equipment
ASHRAE Technical Committee 9.9


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Upcoming TC Meetings

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Location: Atlanta, GA
Sunday, 1/13/2019  Room
5:00 PM - 7:00 PM - Programs, Handbook and Research


Monday, 1/14/2019  
2:15 PM - 7:30 PM - Main Committee


TC 9.9 sponsored seminars, conference paper session, data center related topics, etc. will be posted for each conference in the Meetings section of this website.



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Committee Chair

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Jason Matteson TC0909@ashrae.net

Committee Scope

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TC 9.9 is concerned with all aspects of mission critical facilities, data centers, technology spaces, and electronic equipment/systems.


Upcoming Society Conferences

2019 Winter Conference
January 12–16, 2019
Atlanta, GA


Conference Badges

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Latest TC Activities

If you would like to get involved in this TC's activities you can contact the appropriate Point of Contact in the TC 9.9 Work Items listing, attend the biannual meetings, or contact our committee chair at tc0909@ashrae.net.


ASHRAE 90.1 Publication Public Review

SSPC 90.1 has issued 2 addenda for Publication Public Review (PPR) that are of major interest to the members of TC 9.9, which are:

1)  Addendum be: This addendum revises and expands the CRAC equipment covered under Standard 90.1.
(45-Day Public Review Period from November 16, 2018 to December 31, 2018)

2)  Addendum bv: This addendum removes all exceptions related to computer rooms ( part of the original 2010 Standard) and removes the Alternative Compliance Path PUE (added in 2013) and replaces it with with Standard 90.4-2016.
(30-Day Public Review Period from November 16, 2018 to December 16, 2018)


The new ASHRAE Standard 90.4-2016, Energy Standard for Data Centers, establishes the minimum energy efficiency requirements of data centers for design and construction and for creation of a plan for operation and maintenance, and for utilization of on-site or off-site renewable energy resources.  Through publication of its Datacom series, ASHRAE has emerged as a leader in the data center field.  Standard 90.4 draws upon the collective expertise of the industry to promote stable and sustainable data centers.  To learn more about this standard, click on this link for an overview presentation.

Overview Presentation
As committed at the Orlando meeting, the overview presentation for TC 9.9 has been updated and is now available on this site.  This overview can be used by members to understand what TC 9.9 does and the resources available from TC 9.9.  Please consider this as ASHRAE’s material and always follow appropriate use considerations.


August 27

To Members and Parties Interested in SSPC 90.4, the following addenda to ANSI/ASHRAE Standard 90.4-2016, Energy Standard for Data Centers will be out for a 30 day public review:

30 day Public Review
August 25th, 2017 – September 24th, 2017

1st Public Review of BSR/ASHRAE Addendum to ANSI/ASHRAE Standard 90.4-2016, Energy Standard for Data Centers

This addendum deletes the definition of alteration from Section 3 of Standard 90.4, thereby reverting to the definition of alteration in Standard 90.1 (which is reproduced in Standard 90.4 Annex 1).

1st Public Review of BSR/ASHRAE Addendum to ANSI/ASHRAE Standard 90.4-2016, Energy Standard for Data Centers

This addendum clarifies the exception in Section that addresses the case where existing HVAC systems and equipment serve an addition, and adds parallel criteria to Section 8.1.3 for electrical equipment.


The paper, “Data Center Power Equipment Thermal Guidelines and Best Practices” contains an overview of data center power distribution and how changes in the data center thermal environment can affect power distribution equipment.  The paper includes recommendations on how to improve power equipment thermal compatibility with IT equipment particularly where power equipment shares the same physical space and air stream as IT equipment.



An error was discovered in the latest edition of the ‘Thermal Guidelines’ book. ASHRAE has produced the attached errata and it can be downloaded by everyone from the following webpage (You do not have to have purchased the book to download the errata page.)


 Please check out this errata which addresses the humidity levels for all ASHRAE air classes.  Anyone can print out the material and insert it into their copy of the Thermal Guidelines book.  The PDF will not be updated until the next reprint which may take some time.


TC 9.9 Approved Definitions for Data Centers, ITE, and ITE Enclosures

TC 9.9 is recognized as a leader in driving the data center environmental knowledge and best practices in the industry. At the ASHRAE Annual Meeting in Orlando, TC 9.9 discussed one area where we must help to align our industry. Previously TC 9.9 has not provided definitions for ITE and locations where it is housed. It is essential that we do this to meet our mission "To be recognized by ALL areas of the datacom industry as the unbiased engineering leader in HVAC and an effective provider of technical information for the datacom industry."

It is important for data centers to be excluded from codes written for human occupancy. Even an IT server rack does NOT fit human occupancy codes. Racks that belong in human occupancy codes are ones supporting building services such as fire, security, HVAC, audio / video, etc. These racks are typically far less than 2 KW per rack. There might be occasional exceptions but those are minor compared to human occupancy codes requiring economizers on 2 KW IT server racks.

TC 9.9 has approved the following definitions for use by those needing to quantify data center related terms. Please consider them as the position of TC 9.9 as we move forward in developing standards, codes and general communications for our industry.

1) Data Center: A room or building, or portions thereof, with one or more ITE enclosures greater than 2 KW.
2) Information Technology Equipment (ITE): Computers, data storage, servers and network / communication equipment.
3) ITE Enclosure: A rack, cabinet, or chassis that is designed to mount ITE.


TC 9.9 Presentations
Past presentations given at the ASHRAE annual and winter meetings are now available.  They can be found on the Documents page under the 'Other Publications' section.

New Whitepapers

Data Center Storage Equipment - Thermal Guidelines, Issues and Best Practices

This paper defines thermal guidelines best practices for storage equipment. The intended audience is both storage hardware designers and storage equipment users. The thermal guidelines were written by a team of storage subject matter experts from many different companies and the recommendations are industry-wide best practices which are agnostic of the point of view of any one company.

Clarification to ASHRAE Thermal Guidelines

There has been some confusion of ASHRAE's definition in the Thermal Guideline Datacom Book of the Temperature Rate of Change specified in the table for Equipment Environmental Specifications for Air Cooling. This addendum helps describe in detail examples of air inlet that are either non-compliant or compliant to ASHRAE's temperature rate of change requirements for data centers.

ASHRAE Bookstore

A bulk quantity discount for the Datacom Series Products applies to purchases of 10 or more copies of one title or any combination of titles.

TC 9.9 Datacom Books

Quantity discounts are available for purchases of 10 or more books (mix & match).  Please contact the Manager of Inventory and Subscriptions for instructions on receiving your discount.

Visit the ASHRAE Bookstore Now!