About RHAELM
RHAELM is the sovereign AI cloud built to accelerate secure AI deployment at scale, combining power and infrastructure pipelines with global capability and local, in-country operations. Headquartered in London, with deployments across Europe and APAC, we deliver ring-fenced compute, networking, and storage infrastructure alongside a sovereign platform and flexible Bare Metal, Kubernetes, and AI-as-a-Service models. Focused on regulated and mission-critical sectors including Government, Defence, Healthcare, and Financial Services, we give organisations sovereign control over their AI infrastructure, platform, and data.

This Role
This role is based in Tokyo, Japan, leading mechanical design across RHAELM's Japan data centre programme.

As DC Mechanical Design Engineer, you will develop and design the cooling, HVAC, and mechanical infrastructure that keeps RHAELM's data centres running reliably and efficiently.

You will work across concept through detailed design, collaborating with electrical, structural, and ICT teams to deliver high-density cooling solutions that meet the demands of mission-critical, sovereign infrastructure.

Key Responsibilities

• Develop concept and detailed designs for HVAC, cooling, fire protection, plumbing, and ventilation systems

• Design high-density cooling solutions for critical facilities, including air and liquid cooling strategies

• Conduct thermal load calculations, CFD analysis, and airflow optimisation

• Optimise critical cooling systems for energy efficiency, redundancy, and sustainability

• Review and approve Basis of Design (BOD), technical specifications, and compliance reports

• Collaborate with electrical, structural, and ICT teams to ensure seamless multidisciplinary integration

• Guide equipment selection, ensuring adherence to reliability and redundancy requirements

• Provide technical support during construction, installation, and commissioning phases

Experience

• Proven mechanical design experience, with a strong emphasis on data centre or critical facility projects

• Experience with chilled water systems, CRAC/CRAH units, and mechanical cooling plant design

• Familiarity with Tier Standard Topology and relevant international standards (ASHRAE, ISO, NFPA)

• Experience supporting design reviews at key project milestones

• Experience working with BIM technicians and reviewing coordinated design output

• Experience operating within Japan's construction, engineering, or regulatory market context advantageous

Skills

• Strong knowledge of HVAC, critical cooling, and mission-critical mechanical systems

• Proficiency in CFD analysis, thermal modelling, and energy simulation tools

• Hands-on experience with 3D modelling software (AutoCAD, Revit MEP, Navisworks)

• Effective cross-discipline coordination and stakeholder communication

• Strong problem-solving and analytical capability

Qualifications

• Degree in Mechanical Engineering or a related discipline

• Professional Engineer status or working towards chartership advantageous

• Relevant design software certifications a plus

• Based in Tokyo, Japan; business-level English required, Japanese language skills advantageous