Senior Mechanical Engineer

About You

We are ARCO, a family of construction companies. We seek a Senior Mechanical Engineer to lead the full mechanical scope for hyperscale colocation and enterprise data center projects in Downers Grove, Illinois. You will guide system development, collaborate with construction partners, and support mission‑critical data centers.

• Industry‑leading performance‑based bonus program
• Employee Stock Ownership Plan (ESOP)
• Traditional and Roth 401k
• Tuition reimbursement for associates
• Scholarship for associates’ children up to $28,000 per child
• 1‑month paid sabbatical after every five years of employment, plus $5,000 for travel
• 1‑week paid volunteer leave each year
• 100% charitable match
• Medical, dental, and vision insurance coverage
• Paid parental leave

• Lead the mechanical design process for mission‑critical data centers, including chilled water systems, DX systems, CRAH/CRAC, heat rejection, and white‑space cooling.
• Guide system development from early concept and basis‑of‑design through construction documentation, commissioning, and turnover.
• Apply ASHRAE TC 9.9 guidance and critical environment standards to ensure reliability and efficiency.
• Perform cooling load calculations, CFD coordination, and mechanical equipment sizing.
• Coordinate with electrical, controls, and architectural teams to ensure system integration supporting N, N+1, and 2N redundancy.
• Generate design and construction documents using Revit and AutoCAD.
• Support construction by reviewing RFIs, submittals, and field conditions.

• 7–20 years of mechanical engineering experience with data centers or mission‑critical systems
• Bachelor’s degree in Mechanical Engineering, Architectural Engineering, or related field
• Proficiency with Revit and AutoCAD
• Strong understanding of critical cooling systems and redundancy strategies
• Ability to manage multiple fast‑paced projects
• Experience in design/build is a plus
• Willingness to travel to project sites as required (e.g., 10‑30%)
• Familiarity with engineering deliverables in a GC setting (i.e., design‑build or EPC support) is a plus

EOE, including disability/vets