ASHRAE Journal - May 2024 - 22
COLUMN DATA CENTERS
towers, often with only a small increase in annual
energy consumption. Some require water evaporation
during extreme conditions, while others may allow for
air-cooling (with the associated energy penalty) yearround,
but with a preference for evaporative cooling if
available during peak ambient dry-bulb conditions.
Summary
This column examined several air-cooled chiller
systems and their ability to comply with the MLC of the
IECC 2021 in a hot climate. We found that a " standard "
ACC system, without economizers, will likely not
comply, even though the same system would comply
with Standard 90.4-2016, which is referenced by the
same code except for the MLC tables.
We then looked at several alternatives, including
an integrated closed-loop water economizer, and
the incorporation of direct airside free cooling at
temperatures at or below the high end of ASHRAE's
Recommended Range for ITE classes A1 to A4. We found
that IECC 2021 compliance would be challenging with
just the integrated closed-loop water economizer,
while the combination of ACCs for cooling and direct
airside free cooling for temperatures at or below the
recommended range would be compliant.
Direct airside free cooling is the type of use envisioned
by x-factor creators, as it allows cold aisle temperatures
to float within a certain range and for the higher failure
rate of relatively higher cold aisle temperatures to be
more than offset by the colder temperatures available
in the winter. In this column, all economizer/free
cooling scenarios studied had a lower x-factor (and
thus higher server availability) as well as reduced
energy consumption when compared to the constanttemperature
mechanically cooled baseline.
References
1. ANSI/ASHRAE Standard 90.4-2016, Energy Standard for Data
Centers.
2. International Code Council. 2021. 2021 International Energy
Conservation Code.
3. ASHRAE. 2021. Thermal Guidelines for Data Processing
Environments, 5th Edition. Atlanta: ASHRAE.
Improving Ventilation in Homes,
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ASHRAE Journal - May 2024
Table of Contents for the Digital Edition of ASHRAE Journal - May 2024
Contents
ASHRAE Journal - May 2024 - Intro
ASHRAE Journal - May 2024 - Cover1
ASHRAE Journal - May 2024 - Cover2
ASHRAE Journal - May 2024 - 1
ASHRAE Journal - May 2024 - Contents
ASHRAE Journal - May 2024 - 3
ASHRAE Journal - May 2024 - 4
ASHRAE Journal - May 2024 - 5
ASHRAE Journal - May 2024 - 6
ASHRAE Journal - May 2024 - 7
ASHRAE Journal - May 2024 - 8
ASHRAE Journal - May 2024 - 9
ASHRAE Journal - May 2024 - 10
ASHRAE Journal - May 2024 - 11
ASHRAE Journal - May 2024 - 12
ASHRAE Journal - May 2024 - 13
ASHRAE Journal - May 2024 - 14
ASHRAE Journal - May 2024 - 15
ASHRAE Journal - May 2024 - 16
ASHRAE Journal - May 2024 - 17
ASHRAE Journal - May 2024 - 18
ASHRAE Journal - May 2024 - 19
ASHRAE Journal - May 2024 - 20
ASHRAE Journal - May 2024 - 21
ASHRAE Journal - May 2024 - 22
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ASHRAE Journal - May 2024 - 24
ASHRAE Journal - May 2024 - 25
ASHRAE Journal - May 2024 - 26
ASHRAE Journal - May 2024 - 27
ASHRAE Journal - May 2024 - 28
ASHRAE Journal - May 2024 - 29
ASHRAE Journal - May 2024 - 30
ASHRAE Journal - May 2024 - 31
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ASHRAE Journal - May 2024 - 33
ASHRAE Journal - May 2024 - 34
ASHRAE Journal - May 2024 - 35
ASHRAE Journal - May 2024 - 36
ASHRAE Journal - May 2024 - 37
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ASHRAE Journal - May 2024 - 43
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ASHRAE Journal - May 2024 - 49
ASHRAE Journal - May 2024 - 50
ASHRAE Journal - May 2024 - 51
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ASHRAE Journal - May 2024 - 53
ASHRAE Journal - May 2024 - 54
ASHRAE Journal - May 2024 - 55
ASHRAE Journal - May 2024 - 56
ASHRAE Journal - May 2024 - 57
ASHRAE Journal - May 2024 - 58
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ASHRAE Journal - May 2024 - 60
ASHRAE Journal - May 2024 - 61
ASHRAE Journal - May 2024 - 62
ASHRAE Journal - May 2024 - 63
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ASHRAE Journal - May 2024 - 65
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ASHRAE Journal - May 2024 - 67
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ASHRAE Journal - May 2024 - 69
ASHRAE Journal - May 2024 - 70
ASHRAE Journal - May 2024 - 71
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ASHRAE Journal - May 2024 - 73
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ASHRAE Journal - May 2024 - 77
ASHRAE Journal - May 2024 - 78
ASHRAE Journal - May 2024 - 79
ASHRAE Journal - May 2024 - 80
ASHRAE Journal - May 2024 - Cover3
ASHRAE Journal - May 2024 - Cover4
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