Ready to shape the future of science and global health? ATCC, a leading nonprofit biological resources and standards organization, is seeking a Senior Mechanical Engineer for a full-time onsite role primarily based in Manassas, VA to provide engineering expertise for ATCC facilities (Manassas, VA, Gaithersburg, MD, and Germantown, MD), including a new Biomanufacturing facility at our campus in Manassas, VA. Prior experience in the biomanufacturing sector is not required for consideration. Relocation package may be available for this opportunity.

As a key contributor to ATCC’s critical infrastructure, the Senior Mechanical Engineer ensures the performance, reliability, and compliance of facility systems. This role involves the design and development of HVAC and refrigeration systems that support industrial processes and enable operational continuity. This position will apply expertise in thermodynamics, fluid mechanics, and heat transfer to deliver efficient solutions and optimize existing systems. From selecting equipment to creating detailed system designs and ensuring energy code compliance, this engineer plays a vital role in supporting ATCC’s scientific mission.

Join ATCC and be part of a team that supports the global scientific community with trusted, authenticated biological materials.

• Design & Engineering Excellence: Lead the development of HVAC and refrigeration systems by formulating design criteria, performing calculations, and producing detailed construction documents. Apply advanced knowledge in thermodynamics, fluid mechanics, and heat transfer to create efficient, code-compliant mechanical solutions.
• Project & Vendor Management: Oversee all phases of engineering and facilities projects—from feasibility to closure—ensuring alignment with safety standards, budgets, and timelines. Collaborate with contractors and vendors through meetings, site visits, and inspections to support seamless implementation of MEP, HVAC, and structural systems. Provide engineering expertise to drive commissioning and qualification of mechanical systems in ATCC's new Biomanufacturing facility at Manassas.
• System Optimization & Troubleshooting: Resolve complex design and operational issues through field investigations and root cause analysis. Manage and improve building and lab mechanical systems, including refrigeration equipment and Building Management Systems (BMS), while providing technical guidance for operations and maintenance.

• Bachelor's degree and 5 or more years' experience or equivalent experience.
• Proven ability to design HVAC and refrigeration systems, including load calculations and construction drawings and documents.
• Experience managing engineering projects across all phases, including commissioning and ensuring compliance with codes, standards, and safety requirements.
• Engineering experience with commisioning and qualification processes.
• Investigation and troubleshooting experience with HVAC refrigeration systems required.
• Strong troubleshooting skills for HVAC, MEP, and refrigeration systems.
• Proficient in using Building Management Systems (BMS) and asset management platforms like Maximo
• Effective communicator with strong leadership and coordination abilities across teams and vendors.
• Skilled in AutoCAD and/or Revit for mechanical system drawings
• Familiarity with building codes, energy standards, and regulatory compliance.

The expected salary range for this position is $140,000 annually with potential for relocation package. Actual compensation will be determined based on experience and qualifications as well as internal equity and alignment with market data. In addition to base salary, this role may be eligible for additional incentive compensation including regular merit increases and the corporate bonus program. We Invest in You 

• Health & Wellness: 
  • Comprehensive medical coverage and company paid Life Insurance, Disability Insurance, AD&D, & paid parental leave 
  • Work life balance with Paid Holidays and PTO
  • Fitness and cell phone subsidies, and additional benefits such as Aflac, legal services, and pet insurance
  • Employee Assistance Program offering around-the-clock counseling
• Financial security: 
  • 401(a) (6% employer contribution) and 403(b) (2% match) retirement plans
  • Exceptional career advancement opportunities, recognition, and rewards
  • Corporate bonus program
• Mission Focused:
  • Non-profit organization supporting critical life science research
  • We give scientists the tools they need to make discoveries that improve and save lives
  • Contribute to community involvement and social responsibility

Join ATCC, where we fuel your success, well-being, and development. We're a mission-focused non-profit Equal Opportunity Employer, celebrating a century of supporting global public health.  All qualified applicants will receive consideration for employment without regard to sex, race, color, religion, national origin, disability, protected Veteran status, age, or any other characteristic protected by law.  Shape the future of science with us.