Design Engineer (Mechanical)

As Design Engineer (Mechanical), you produce the mechanical design for OnZero's data centers, including the cooling and heat rejection systems that make dense AI compute possible. The solutions are scalable, cost-efficient and sustainable, and built to satisfy technical, safety and customer requirements. You maintain the mechanical content of our reference designs, including the mechanical services of the physical buildings.

You translate business, customer and operational needs into mechanical design principles and deliverables, including heat and mass balances, P&IDs, flow and pressure schedules and equipment specifications. You take part in multidisciplinary design reviews, work alongside the A&E (Architecture & Engineering) consultants who produce detailed design, and carry the mechanical scope through the Project Phases: from Site Selection handover to detailed design, and on through construction, flushing and commissioning.

Produce and develop mechanical design concepts across direct-to-chip liquid cooling, CDUs and the technology and facility water loops, heat rejection plant, and HVAC cooling of white space and support areasAssess and specify the mechanical technologies, systems, materials and installation methods used across cooling and heat rejectionPrepare heat and mass balances, P&IDs, flow, pressure and equipment schedules, and technical specifications to procurement qualityReview and comment on consultant and vendor mechanical deliverables, and follow non-conformances through to resolutionAct as technical responsible for mechanical systems across design, build and commissioning, supporting factory acceptance testing, flushing and thermal performance verificationMaintain the mechanical content of the reference designs, technical requirements and engineering frameworks that align with OnZero standardsPropose emerging technologies where they improve efficiency, sustainability and resilienceConfirm that mechanical design solutions meet their performance, sustainability, safety and environmental targets, including PUE and WUEPropose updates to the Design Requirements as lessons learned, field experience and new technologies accumulateKeep mechanical guidelines and best practice current so that designs stay consistent, high in quality and scalableTake part in multidisciplinary design reviews and coordinate the mechanical scope with the architectural, civil, electrical and ICT disciplinesWork alongside internal and external engineering teams and A&E partners on the mechanical scopeCarry the mechanical design through every phase of the Project Phases, from Site Selection handover through detailed design, and stay engaged through constructionSupport Site Selection, Project Managers and Procurement on mechanical feasibility, cost, lead times and quality, including long-lead equipmentContribute mechanical input to the assessment of brownfield and greenfield opportunities, and to Master Planning, including cooling water availability and heat reuse potentialProvide the mechanical basis for CAPEX estimates on new builds, expansions and retrofitsEvaluate existing mechanical installations when changes are planned, and support Operations through implementationApprove mechanical design deliverables and calculations within your assigned scope and delegated authorityRecommend equipment selections and technical platforms, consistent with engineering standards and sustainability requirementsRaise and disposition mechanical design changes and controlled deviations within delegated authority, escalating any that affect the reference designCertify mechanical design readiness as input to design freeze and other Gate Process decisions

Essential

A Bachelor's or Master's degree in mechanical, energy, or a related fieldExperience producing mechanical or HVAC design for data centers, industrial facilities or comparable building services, taken through to constructionWorking knowledge of hydronic systems and heat rejection: pumps, pipework, valves, flow balancing and pressure dropWorking knowledge of air-side cooling, white-space airflow, containment and thermal managementAbility to produce heat and mass balances, P&IDs and technical specifications to procurement qualityExperience on engineering and construction projects, including review of consultant or vendor deliverablesTechnical knowledge of product design, and the ability to understand client needs and translate them into solutionsDetailed design capability and strong technical problem solvingFluent in English. Finnish, German or Swedish a plus

Strong Advantage

Experience in data center design, build and commissioningDirect-to-chip or immersion liquid cooling experience, and exposure to GPU or HPC deploymentsHeat reuse or district heating interface experience, particularly in the NordicsThermal modeling, CFD or hydronic system simulation

Benefits

Competitive Compensation Package: We offer a competitive salary package based on your professional experience, qualifications and overall fit for the positionHybrid & Flexible Working: Benefit from a flexible working setup that combines remote work with on-site collaboration when required. As this is an international role, occasional travel to Vienna and future OnZero project locations will be part of the positionFlexible Working Hours: We support flexible working hours, giving you the flexibility to organize your working day while ensuring effective collaboration with your team and project stakeholdersCollaborative Working Culture: Join an international and technically driven team where close collaboration across disciplines is key. Your expertise, ideas and input will be valued, and you will have the opportunity to influence technical decisions and the development of our projectsGrowth Opportunity: As OnZero continues to expand, you will have the opportunity to take on broader responsibilities and play an active role in developing our technical standards, reference designs and future projectsLunch Allowance: Enjoy a monthly restaurant allowance via Edenred to treat yourself