Interxion BRU 3 & 4

Project Description

Located on the same campus in Brussels, Interxion BRU 3 and BRU 4 represent two interconnected data centre projects designed to meet high resilience, operational continuity, and efficiency standards.

BRU 3 involved the critical upgrade of an existing live data centre facility nearing the end of its operational life, with an IT capacity of 1.4MW. The project was delivered with zero disruption to ongoing operations by designing all new systems to be installed and commissioned live.

Adjacent to BRU 3, BRU 4 is a new-build facility with a significantly larger IT capacity of 13.6MW. It spans three floors and contains 12 data halls. The building was developed as a high-density, high-efficiency data centre with robust mechanical and electrical infrastructure designed to operate to strict client and regulatory requirements.

Ethos Input

Ethos Engineering served as the lead consultant for both BRU 3 and BRU 4, providing complete project management, mechanical and electrical design services, and the coordination of sub-consultants across architecture, civil, and structural disciplines. Ethos also acted as LEED AP assessors for the BRU 4 data centre project, supporting this development to achieve LEED Silver certification.

Both projects were developed to RIBA Stage 3, and Ethos successfully managed the submission of full planning packages to the local authority within extremely aggressive programme timelines. Ethos led the technical strategy across both facilities, ensuring cohesive infrastructure design despite the differing operational contexts of retrofit and new build. A high level of coordination ensured seamless system integration and full compliance with local regulations and Interxion’s governance protocols.

Unique / Key Features

Electrical Systems
• Both facilities were designed with single utility connections and MV/LV step-down transformers (11.0/0.4kV).
• BRU 4 incorporated 4MVA transformers and a 2286kVA/1829kW diesel generator system with 11kV alternators and remote dry-cooled radiator systems, along with bulk fuel storage and site-wide power backbone distribution.
• BRU 3 featured 1.6MVA transformers, integrated with full UPS distribution, TN-C/TN-S earthing systems, and site switching and PMS monitoring systems.
• Both sites included comprehensive safety systems: emergency lighting, fire detection and suppression (Inergen and water mist), leakage detection, CCTV, access control, and structured cabling.

Mechanical Systems
• CGMs (Cooling Generation Modules) with both water-cooled chiller and dry cooler integration.
• CRAH units provided efficient cooling across all data halls with forced air ventilation and humidity control systems.
• Office spaces were conditioned using VRF systems, and DX systems were included for battery room cooling.
• StruxureWare BMS was deployed across both sites for centralised building management and control.
• Inergen and water mist systems were specified for advanced fire suppression, enhancing safety without compromising equipment.

Sustainability & Resilience
• The BRU 3 refurbishment was carefully designed to maintain full operational continuity throughout construction, with sustainability considerations included at every stage.
• BRU 4, although a new build, leveraged design learnings from BRU 3 to implement optimised energy and cooling systems aligned with modern efficiency standards, achieving LEED Silver.