White Paper - Data center climate control: An air-to-water exchange provides cooling efficiencies

Overview

The paper cites cooling as the largest energy user after servers (37 %) and notes that US data centres used about 61 billion kWh in 2006, roughly 1.5 % of US electricity and about USD 4.5 bn. It then shows close-coupled units scaling per enclosure: LCP units remove up to 60 kW per enclosure, the LCP Inline takes 12 in between racks (about 0.36 m2), and all 42U of a 2000 mm enclosure stay available for IT.

The redundancy section is built around the T3+: with two power feeds and two water circuits, one unit provides 2N-style redundancy and each circuit can carry the full load. So 2N can be achieved by internal dual circuits rather than two separate units, though the dual piping and feeds must still be provided by the facility.

Efficiency is argued through EER: an EER of 5 means 1 kW of electricity yields 5 kW of cooling, and EC fans cut consumption versus AC fans. Small DX variants use R410a with useful outputs up to 10 kW and reject heat to an outdoor condenser. The paper is a manufacturer publication, so comparisons favour its own product family.

Key points

1. Cooling is the largest energy user after servers (37 %); US data centres used about 61 billion kWh in 2006 (about 1.5 % of US electricity, about USD 4.5 bn).
2. LCP units remove up to 60 kW per enclosure; the LCP Inline takes 12 in between racks (about 0.36 m2).
3. Close-coupled units keep all 42U of a 2000 mm enclosure free for IT.
4. LCP T3+ gives 2N-style redundancy in one unit with two power feeds and two water circuits, each able to carry full load.
5. EER of 5 means 1 kW electrical yields 5 kW of cooling; EC fans use less than AC fans.
6. DX variants use R410a, deliver up to 10 kW and need an outdoor condenser.

Using it in design

• Model cooler redundancy explicitly: 2N may come from two units or one unit with dual independent power and water feeds, so catalogue entries need an 'internal redundancy' field.
• When a rack's cooling is 2N, verify either duplicate units or a dual-supply unit plus dual piping and feeds.
• Show EER/COP as a per-unit field in energy calculations.

Who should read it

Designers comparing air-to-water cooler options and rack-cooling redundancy.

Publication details

Authors

Rittal

Publisher

Rittal

Year

2013

Document number

4_7695

Document language

English

Source type

Manufacturer

Access

Free to read

Licence

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

Citation