Energy saving and carbon footprint effect of waste-heat use in data-centre AHU test laboratories (Veri Merkezi Klima Santrali Test Laboratuvarlarında Atık Isının Kullanımı Yöntemiyle Enerji Tasarrufu ve Karbon Ayak İzine Etkisi)

Overview

This paper, in the TMMOB Chamber of Mechanical Engineers' TESKON 2023 proceedings, describes a Turkish manufacturer's factory test laboratory for indirect evaporative cooling (IEC) data-centre air handling units up to 500 kW. The laboratory has climatic and room-simulation cells, chillers for summer and winter simulation and a heat-recovery loop. Fan performance and heat-exchange tests follow ASHRAE 143-2015. The authors argue that every data-centre cooling unit should be performance-tested before shipment.

The paper shows that reusing chiller condenser heat to supply the room-simulation heat load cuts test energy sharply. Simulating the -5 °C winter condition at a 500 kW load, the test chillers (integrated COP 3.12) reject about 735 kW of waste heat that can supply the room-simulation cell. Waste-heat reuse saved about 75% versus a natural-gas boiler and about 94% versus electric heating for the test heat load. Operating cost and life-cycle carbon are compared for gas boiler, electric heater, electric boiler and waste-heat options.

Life-cycle GWP100 results for the four scenarios were 20.43, 41.87, 354.03 and 364.57 kg CO2-eq per test functional unit. Cooling is cited as historically about 50% of data-centre operating cost, reduced to about 34% with improved equipment. The climate cell uses a 7/12 °C chiller and a -10/-5 °C chiller to reproduce transitional and severe-winter conditions. The paper is useful background on how IEC data-centre units are rated and witness-tested.

Key points

1. The lab tests IEC data-centre AHUs up to 500 kW cooling capacity; fan and heat-exchange tests follow ASHRAE 143-2015.
2. Simulating -5 °C winter at 500 kW, test chillers (integrated COP 3.12) reject about 735 kW of waste heat.
3. Waste-heat reuse saved about 75% versus a natural-gas boiler and about 94% versus electric heating for the test heat load.
4. Life-cycle GWP100 results for four scenarios: 20.43, 41.87, 354.03 and 364.57 kg CO2-eq per test functional unit.
5. Cooling is cited as historically about 50% of data-centre operating cost, reduced to about 34% with improved equipment.
6. The climate cell uses a 7/12 °C chiller and a -10/-5 °C chiller for transitional and severe-winter conditions.
7. Related standards: ASHRAE 143-2015, EN 308, ISO 14044, ISO 14064-1.

Using it in design

• In the catalogue, add test-standard and witness-test fields for IEC/DC AHUs: ASHRAE 143 rating, tested capacity, factory witness test yes/no.
• In the commissioning checklist, prompt for a factory acceptance test of each data-centre cooling unit at site design conditions, including winter mode.
• Evaluate waste-heat recovery in test or manufacturing facilities for energy and carbon.

Who should read it

Mechanical engineers and manufacturers who specify, rate and commission data-centre cooling units.

Related standards

• ASHRAE 143-2015
• EN 308
• ISO 14044
• ISO 14064-1

Publication details

Authors

Ahmet Murat Tunç; Nadide Asuman Yaraş

Publisher

TMMOB Makina Mühendisleri Odası (MMO)

Year

2023

Document number

TESKON 2023 Bildiriler Kitabı, s. 944

Event

15. Ulusal Tesisat Mühendisliği Kongresi (TESKON 2023), İzmir

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