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

Overview

This article is the Turkish translation, published in the TTMD Journal, of an ASHRAE Journal piece that summarises points from the ASHRAE TC 9.9 water-cooled servers technical paper for Turkish facility engineers. It complements the full technical paper and does not replace it. The text compares coolant distribution units (CDUs) with direct (no-CDU) facility-water connection, and explains why supply water must stay above the room dew point, water quality, wetted-material compatibility, and filtration for plate heat exchangers and cold plates.

The introduction notes that air cooling worked well up to about 150 W processors, while GPUs at about 300 W and CPUs at about 205 W push toward liquid cooling. 28 water-cooled IT products announced 2010-2017 were analysed: the first seven allowed a maximum facility water of 10-24 C, and 8 of the remaining 21 allowed 40 C or more. The data show rising rack heat loads and increasing allowable facility-water temperatures.

The roles of a CDU are to transfer heat from the equipment loop (ESS) to the facility loop (TSS), circulate coolant, allow non-water coolants, keep supply above the room dew point and maintain coolant chemistry. No-CDU designs gain floor space, lower thermal resistance, shared pump redundancy and higher ΔT, but need stricter water quality, materials and filtration.

Supply water must stay above the room dew point; ASHRAE A1 allows a maximum room dew point of 17 C. Plate heat exchangers in CDUs typically have 2-8 mm passages, while cold plates may have fin gaps of only about 0.1 mm, which drives different filtration levels. The limit of the document is that it is a summary translation and contains no detailed calculation method.

Key points

1. Air cooling worked well up to about 150 W processors; GPUs at about 300 W and CPUs at about 205 W push toward liquid cooling.
2. Of 28 water-cooled IT products announced 2010-2017, the first seven allowed a maximum facility water of 10-24 C, and 8 of the remaining 21 allowed 40 C or more.
3. CDU roles: transfer heat from ESS to TSS, circulate coolant, allow non-water coolants, keep supply above room dew point and maintain coolant chemistry.
4. No-CDU designs gain floor space, lower thermal resistance, shared pump redundancy and higher ΔT, but need stricter water quality, materials and filtration.
5. Supply water must stay above the room dew point; ASHRAE A1 allows a maximum room dew point of 17 C.
6. Plate heat exchangers in CDUs have 2-8 mm passages, cold plates fin gaps of about 0.1 mm, driving different filtration levels.

Using it in design

• Require a CDU or an explicit water-quality and filtration specification when IT is connected to facility water.
• Check supply temperature against room dew point and warn below it.
• Catalogue cold-plate products with maximum facility-water temperature and required filtration (µm).
• Add wetted-material compatibility to the design checklist.

Who should read it

Turkish facility and cooling engineers connecting water-cooled servers to facility water.

Related standards

• ASHRAE TC 9.9 Water-Cooled Servers
• ASHRAE Liquid Cooling Guidelines for Datacom Equipment Centers
• ASHRAE Thermal Guidelines (A1)

Publication details

Authors

Roger Schmidt; Mark Steinke; Austin Shelnutt

Publisher

Türk Tesisat Mühendisleri Derneği (TTMD) - TTMD Dergisi

Year

2021

Document number

TTMD Dergisi Sayı 130 (Nisan-Haziran 2021), s. 38

Document language

English

Source type

Industry body

Access

Free to read

Licence

Copyright retained; citation only — the publisher’s terms apply to the original document

Citation