Water

Consulting-Specifying Engineer · 2021

How to design data centers: HVAC systems (roundtable)

Offer integrated-free-cooling chillers as a catalogue option with the free-cooling changeover ambient field.

• NREL ESIF: water-cooled racks with thermosyphon plus towers achieved PUE 1.04 and halved water use.

Schneider Electric · 2015

Humidification Strategies for Data Centers and Network Rooms

Accept humidity limits as dew point plus RH in the environmental envelope settings, default to current ASHRAE recommended values rather than the 2011 ones quoted here, and recommend dew-point control mode for multi-CRAC rooms.

• Static buildup: 250 V at 80% RH vs 12,000 V at 20% RH on a raised-floor tile; 1,500 V vs 35,000 V on synthetic carpet.

Cundall (for Iceotope Technologies) · 2021

Iceotope Engineering Review - Desktop Study Report: Liquid and Air-Cooling Compared

Catalogue liquid-cooled IT and CDUs with ASHRAE W-class and supply temperature fields, and use these to decide whether compressor cooling can be omitted for the site climate.

• Per kW IT versus air baseline: water use down up to 96%, power about 40% lower, CO2 about 39.5% lower.

Vertiv · 2020

Indirect Evaporative Cooling Technologies in the Data Centre: Using Hyperscale Technology for Retail Data Centres in Tropical Climates

Use hourly climate data (dry-bulb and wet-bulb) in cooling selection to estimate IEC mode hours.

• IEC is estimated to cut cooling energy by up to 50% versus traditional approaches.

ISO/IEC · 2022

Information technology - Data centres key performance indicators - Part 9: Water usage effectiveness (WUE)

In the water module, derive WUE (L/kWh_IT) from the hourly cooling model (evaporation, blowdown, humidification) and tag it with its measurement category.

• Edition 1, published 2022-03-24, 19 pages.

Cundall · 2024

Is power or water best for cooling?

When a user selects a cooling topology, show a three-way comparison of energy (PUE), water (WUE) and carbon (CUE using local grid intensity) for the chosen site.

• Danish hyperscale project with Fjernvarme Fyn: heat pumps lift to 70-75 C, expected 165,000 MWh/yr of heat at full build-out.

Lawrence Berkeley National Laboratory, Center of Expertise for Energy Efficiency in Data Centers · 2023

IT Equipment Energy Assessment Tool (IT Efficiency Tool), Version 2.5 (October 2023)

In IT-refresh scenarios, propagate savings through cooling losses, power losses and water (WUE), as the DOE tool suite does.

• Related standard: ISO/IEC 30134-9 (WUE).

TMMOB Makina Mühendisleri Odası (MMO) · 2009

Energy efficiency in HVAC systems with dry-cooler free-cooling applications (Kuru Soğutuculu Doğal Soğutma Uygulamaları ile İklimlendirme Sistemlerinde Enerji Verimliliği)

Use the paper's mode thresholds (approach of about 2 C for partial and about 5 C for full free cooling) as defaults in a free-cooling-hours estimator, fed by city bin data for Turkish sites.

• Targets 24/7 loads such as server rooms and data centres.

WSP · 2026

Liquid cooling in African data centres: A turning point in efficiency, resilience and future-ready design

For TCS loops, add coolant fields (demineralised water, PG percentage).

Communications of the ACM (Association for Computing Machinery (ACM)) · 2025

Making AI Less 'Thirsty': Uncovering and Addressing the Secret Water Footprint of AI Models

Separate withdrawal from consumption in water outputs, and default cooling-tower consumption to about 80% of withdrawal when water quality is good.

• GPT-3 'drinks' a 500 ml bottle for roughly 10-50 medium-length responses.

The Green Grid · 2009

North American Water-Side Economizer Map (2009)

Use the map only as a visual cross-check.

• Related standard: ASHRAE 90.4.

U.S. DOE Federal Energy Management Program / National Renewable Energy Laboratory · 2012

NSIDC Data Center: Energy Reduction Strategies - Airside Economization and Unique Indirect Evaporative Cooling (FEMP brochure, 2012)

Offer indirect evaporative cooling and airside economizer options in the cooling selector with climate-driven hours.

• Since September 2011 monthly PUE stayed below 1.35 due to airside economization.

Beca · 2026

Part 2: Designing next-generation data centres - Principals for efficiency and resilience

Let users set the cold-aisle supply temperature and recompute free-cooling hours from the site weather file.

• A PUE of about 1.4 is described as a common target; going lower needs more than conventional air cooling.

arXiv (UC Riverside / RIT / Caltech preprint) · 2026

Small Bottle, Big Pipe: Quantifying and Addressing the Impact of Data Centers on Public Water Systems

Add a peak-day water demand output (annual average times peaking factor, default at least 2.2 for cooling towers, configurable up to about 6-10 for evaporative assist used only on hot days), and compare it with utility supply capacity in site screening.

• With a 10% compound annual WUE reduction, the need drops to 227-604 MGD.

Nortek Air Solutions · 2021

Solutions to Water and Power Availability that Challenge the Future of Data Centers

In a site/sustainability module, estimate annual water (m3), WUE and cooling energy for alternative plant types at a chosen SAT, using local water and power tariffs.

• Case prices: water ~USD 2/m3, power ~USD 0.10/kWh.

Türk Tesisat Mühendisleri Derneği (TTMD) - TTMD Dergisi · 2021

Mitigating the impacts of integrating water-cooled servers into data centres (Turkish translation, TTMD)

Require a CDU or an explicit water-quality and filtration specification when IT is connected to facility water.

• Supply water must stay above the room dew point; ASHRAE A1 allows a maximum room dew point of 17 C.

Patterns (Elsevier BV) · 2025

The carbon and water footprints of data centers and what this could mean for artificial intelligence

Use location-specific grid water-intensity factors (L/kWh), not a national average, when calculating indirect water.

• Reported operator average WUE values include 0.15, 0.19, 0.30 and 1.61 m3/MWh.