Mechanical Engineer

Role Summary:

$90-95k annually

Under the direction of the Engineering & Estimating Manager -National, the Project Engineer is responsible for supporting the Engineering and Estimating team across the full project lifecycle, including load calculations, system design, bidding support, client presentations, field deployment, and post-project documentation. This is an engineering-track role with exposure to a wide variety of industries and applications. The day-to-day work is office-based, with travel for site visits, client meetings, and emergency response.

Essential Job Functions:

• Perform load calculations — cooling, heating, moisture, and ventilation — for temporary climate solutions across construction sites, industrial and manufacturing facilities, food production plants, automotive and battery plants, aerospace facilities, data centers, commercial buildings, and labs
• Perform psychrometric chart analyses and study weather to inform design decisions
• Design temporary systems from Polygon’s equipment fleet
• Develop project layouts, equipment schedules, and sequences of operation tailored to each client’s environment and process needs
• Support the estimating process: take-offs, equipment selection, scope development, and pricing inputs for bids and proposals
• Prepare and present engineered solutions to clients, general contractors, and internal sales teams
• Translate technical decisions into clear, client-friendly language
• Serve as the engineering resource for the field technician team during equipment deployment, startup, commissioning, and troubleshooting
• Travel to project sites on short notice when needed — for emergency response, project kickoffs, complex deployments, or field issues that require engineering oversight
• Translate field observations into improvements to design and project execution
• Develop and maintain Standard Operating Procedures (SOPs) for specific systems, applications, and key clients
• Create technical documentation, including system narratives, commissioning checklists, monitoring plans, and project closeout packages
• Build out engineering templates and reference materials to improve consistency and efficiency across the team

Job Qualifications:

• Bachelor’s degree in Mechanical Engineering or a related field
• Solid understanding of thermodynamics, heat transfer, and HVAC fundamentals
• Comfortable with psychrometric calculations
• Strong written and verbal communication skills, with the ability to explain technical concepts to engineers, salespeople, technicians, and clients
• MS Office proficiency across the board, with Excel as a particular strength
• Demonstrated CAD experience
• Willingness to travel on short notice, including occasional nights and weekends for emergency response
• Valid US driver’s license and the ability to work on construction and industrial job sites

Preferred Training Requirements and Competencies:

• EIT certification
• 1–3 years of experience in HVAC, mechanical contracting, temporary climate solutions, dehumidification, or a related field
• Exposure to construction sites, manufacturing facilities, food production, automotive or battery plants, aerospace, data centers, or controlled environments such as labs, cleanrooms, and pharmaceutical facilities
• Familiarity with building codes, OSHA site safety, and standard PPE requirements
• Experience supporting estimating, sales, or field service teams

Demonstration of the Polygon Values:

• Integrity
• Excellence
• Empathy