ASHRAE Journal - February 2023 - 52

FEATURE
energy conservation and, as already stated, data centers
were basically an unregulated niche responsible
for an increasingly disproportionate consumption of
electric power. But forcing data centers to comply with
Standard 90.1 was seen as something of a " round peg
in a square hole " situation. So if not in 90.1, something
still had to be done to ensure data center energy efficiency.
ASHRAE responded by asking TC 9.9 to spearhead
the creation of a new Standards Committee
tasked with developing a data center efficiency standard.
The ASHRAE Board of Directors approved creation
of Standard Project Committee 90.4 (SPC 90.4) in late
2012 with the goal to aggressively expedite development
of a new standard for data centers. Committee membership
was approved and the first meeting was held
in January 2013 chaired by a past ASHRAE president,
Ronald Jarnagin, Fellow/Life Member ASHRAE, who had
also been a past chair of SSPC 90.1. The original SPC 90.4
committee membership included longtime representatives
from both SSPC 90.1 and TC 9.9 as well as other
industry stakeholders including the Edison Electric
Institute, National Renewable Energy Lab, various engineering
firms, general contractors and equipment suppliers.
After four drafts and public reviews, the ASHRAE
Board of Directors approved the standard for publication
at the June 2016 Annual Conference.
ASHRAE is an American National Standards Institute
(ANSI) certified Standard Development Organization,
which means its standard development process is compliant
with ANSI requirements. Like other ASHRAE standards
such as 90.1, Standard 90.4 is written in " enforceable "
language suitable for adoption by jurisdictions as
federal, state and/or local building codes and regulations.
As previously noted, Standard 90.4 is incorporated into
Standard 90.1 and is also being adopted independently
by some states and jurisdictions. Unfortunately, it could
not be adopted in May 2019 by the International Code
Council (ICC) due primarily to administrative issues.
But there were also ICC concerns regarding ambiguities
on how AHJs demarcate where Standard 90.1 and
Standard 90.4 apply in mixed-use buildings. These
concerns were addressed through more collaboration
between SSPC 90.1 and SSPC 90.4, wherein Standard
90.1-2019 included Standard 90.4 as an alternate compliance
path where applicable. This also ensured that
Standard 90.4 would be adopted by normative reference
wherever Standard 90.1-2019 or later versions are
52
ASHRAE JOURNAL ashrae.o rg
F E B R U A RY 2023
adopted as code. Standard 90.4-2019 and approved
addenda were adopted by the ICC in 2021.
Another important decision made in the development
of Standard 90.4 was to create new metrics suitable for
the design industry. The Green Grid had already created
the power usage effectiveness or " PUE " metric, and
there were many who thought this should be used in the
new energy efficiency standard since it was being widely
adopted and used. However, PUE is an operational metric,
relying on actual hour-by-hour and day-to-day measurements
to compute. The committee recognized that
attempting to compute a realistic PUE in the design stage
would involve many thousands of computations and
would further assume that facilities would actually operate
exactly as the designers had assumed. Considering
that the actual complement of ITE is never fully known
during design, and that it changes even as the facility
is being constructed, attempting to predictively calculate
a PUE was considered unrealistic, onerous for the
designer, unconfirmable by the AHJ, and misleading
to the owner since the calculated number would likely
never actually be realized in practice.
The result was development of two design metrics: the
mechanical load component or MLC, and the electrical
loss component or ELC. These can be readily calculated
from available design information, compared with
simple tables in the standard and realistically verified by
the AHJ. Moreover, when facility upgrades involve only
the mechanical or the electrical, the components can be
separated so that the standard does not force unjustifiable
investment to meet the total tandard requirements.
Summary
Standard 90.4 meets the needs of the data center industry
primarily because it is a performance-based standard,
intended to be used by designers and constructed
for realistic verification by AHJs. It also encourages
innovation by focusing on overall system performance
and allowing offsets between mechanical and electrical
system efficiencies to achieve overall site infrastructure
efficiency goals. And in keeping with overall energy conservation
goals, it enables credits for both on-site and
off-site renewable energy sources, as well as process heat
recovery designs for on-site or export to adjacent sites.
In short, it ensures energy efficiency achievement while
also being specifically geared to the highly unusual and
very demanding data center industry.
http://ashrae.org

ASHRAE Journal - February 2023

Table of Contents for the Digital Edition of ASHRAE Journal - February 2023

Contents
ASHRAE Journal - February 2023 - Intro
ASHRAE Journal - February 2023 - Cover1
ASHRAE Journal - February 2023 - Cover2
ASHRAE Journal - February 2023 - 1
ASHRAE Journal - February 2023 - Contents
ASHRAE Journal - February 2023 - 3
ASHRAE Journal - February 2023 - 4
ASHRAE Journal - February 2023 - 5
ASHRAE Journal - February 2023 - 6
ASHRAE Journal - February 2023 - 7
ASHRAE Journal - February 2023 - 8
ASHRAE Journal - February 2023 - 9
ASHRAE Journal - February 2023 - 10
ASHRAE Journal - February 2023 - 11
ASHRAE Journal - February 2023 - 12
ASHRAE Journal - February 2023 - 13
ASHRAE Journal - February 2023 - 14
ASHRAE Journal - February 2023 - 15
ASHRAE Journal - February 2023 - 16
ASHRAE Journal - February 2023 - 17
ASHRAE Journal - February 2023 - 18
ASHRAE Journal - February 2023 - 19
ASHRAE Journal - February 2023 - 20
ASHRAE Journal - February 2023 - 21
ASHRAE Journal - February 2023 - 22
ASHRAE Journal - February 2023 - 23
ASHRAE Journal - February 2023 - 24
ASHRAE Journal - February 2023 - 25
ASHRAE Journal - February 2023 - 26
ASHRAE Journal - February 2023 - 27
ASHRAE Journal - February 2023 - 28
ASHRAE Journal - February 2023 - 29
ASHRAE Journal - February 2023 - 30
ASHRAE Journal - February 2023 - 31
ASHRAE Journal - February 2023 - 32
ASHRAE Journal - February 2023 - 33
ASHRAE Journal - February 2023 - 34
ASHRAE Journal - February 2023 - 35
ASHRAE Journal - February 2023 - 36
ASHRAE Journal - February 2023 - 37
ASHRAE Journal - February 2023 - 38
ASHRAE Journal - February 2023 - 39
ASHRAE Journal - February 2023 - 40
ASHRAE Journal - February 2023 - 41
ASHRAE Journal - February 2023 - 42
ASHRAE Journal - February 2023 - 43
ASHRAE Journal - February 2023 - 44
ASHRAE Journal - February 2023 - 45
ASHRAE Journal - February 2023 - 46
ASHRAE Journal - February 2023 - 47
ASHRAE Journal - February 2023 - 48
ASHRAE Journal - February 2023 - 49
ASHRAE Journal - February 2023 - 50
ASHRAE Journal - February 2023 - 51
ASHRAE Journal - February 2023 - 52
ASHRAE Journal - February 2023 - 53
ASHRAE Journal - February 2023 - 54
ASHRAE Journal - February 2023 - 55
ASHRAE Journal - February 2023 - 56
ASHRAE Journal - February 2023 - 57
ASHRAE Journal - February 2023 - 58
ASHRAE Journal - February 2023 - 59
ASHRAE Journal - February 2023 - 60
ASHRAE Journal - February 2023 - 61
ASHRAE Journal - February 2023 - 62
ASHRAE Journal - February 2023 - 63
ASHRAE Journal - February 2023 - 64
ASHRAE Journal - February 2023 - 65
ASHRAE Journal - February 2023 - 66
ASHRAE Journal - February 2023 - 67
ASHRAE Journal - February 2023 - 68
ASHRAE Journal - February 2023 - 69
ASHRAE Journal - February 2023 - 70
ASHRAE Journal - February 2023 - 71
ASHRAE Journal - February 2023 - 72
ASHRAE Journal - February 2023 - Cover3
ASHRAE Journal - February 2023 - Cover4
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FFRDES
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WMMDFY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_HTDEWQ
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FYONLJ
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2024november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2024november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_BDMHLG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WJDGRY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ATMAHK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VHQRAW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XGMDXI
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_YELQLJ
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QJLWMC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_MCDEBX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WNYSQY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XATVOD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FJSHSS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CCBZDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XDEFVG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2023november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2023november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VHGNBL
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WPKBNJ
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_UUVCDE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTGDEW
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2023
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LKRFXS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_AZSOFG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ERCDBH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QWDFRV
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JHGVDF
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPUYHG
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SREIBM
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LRTGLK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OKRFGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2022november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2022november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TZSERA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_LVRUIX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RPTVYZ
https://www.nxtbook.com/nxtbooks/ashrae/mini_pub_catalog
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XIYTGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2022
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RFGDOB
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PABXNU
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_REMKLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PICVBT
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_AOYTVW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JQOPLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_IOYTBC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SGAJJF
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_IGHYER
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_PDRKLS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2021november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2021november_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_XCODFR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QSLFGO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ILKVNM
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2021
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OPDJKD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_VJKSRY
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDHUTC
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JPPKRR
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SDLTTH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_CKLLES
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_SLDOX
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_HJETUK
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_OLUHGE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2020october_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ZERDGH
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_QVMNEO
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_RTPOKE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_BBATRE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_STUBMW
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TPEMPE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_JNMKDS
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_FBTTPA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_WQMMNE
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_TVBRYN
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2020
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_KTUZMA
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_ABEDGD
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201910
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201909
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019septmeber_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2019september
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201908
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201907
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201906
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201905
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201904
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019april
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201903
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2019march
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201902
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201901
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_showguide2019
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018december
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018november
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2018fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_2018october
https://www.nxtbook.com/nxtbooks/ashrae/ashraemexico_2018
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201810
https://www.nxtbook.com/nxtbooks/ashrae/ashraeinsights_201806
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201805
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201804
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201803
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201712
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201711
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201710
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2017fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201709
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201705
https://www.nxtbook.com/nxtbooks/ashrae/ashrae_meetinginsert_201610
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2016fall
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acrexindia
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_amca_2015summer
https://www.nxtbook.com/nxtbooks/amca/2014summer2
https://www.nxtbook.com/nxtbooks/amca/2014summer
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acma_2014summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201311
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201309
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_acmasupp_2013fall
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201305
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201303
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2013winter
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201211
https://www.nxtbook.com/nxtbooks/ashrae/achr_expo_mexico2012
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201209
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v3
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201208_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201205
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201203
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2012winter
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201111_v2
https://www.nxtbook.com/nxtbooks/ashrae/ashraejournal_201109_v2
https://www.nxtbook.com/nxtbooks/ashrae/pubcatalog_2011summer
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201105
https://www.nxtbook.com/nxtbooks/ashrae/meetingplanner_201103
https://www.nxtbookmedia.com