Mechanical EngineerIrving, Texas, United StatesUnder 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 labsPerform psychrometric chart analyses and study weather to inform design decisionsDesign temporary systems from Polygon's equipment fleetDevelop project layouts, equipment schedules, and sequences of operation tailored to each client's environment and process needsSupport the estimating process: take-offs, equipment selection, scope development, and pricing inputs for bids and proposalsPrepare and present engineered solutions to clients, general contractors, and internal sales teamsTranslate technical decisions into clear, client-friendly languageServe as the engineering resource for the field technician team during equipment deployment, startup, commissioning, and troubleshootingTravel to project sites on short notice when needed — for emergency response, project kickoffs, complex deployments, or field issues that require engineering oversightTranslate field observations into improvements to design and project executionDevelop and maintain Standard Operating Procedures (SOPs) for specific systems, applications, and key clientsCreate technical documentation, including system narratives, commissioning checklists, monitoring plans, and project closeout packagesBuild out engineering templates and reference materials to improve consistency and efficiency across the teamJob Qualifications:Bachelor's degree in Mechanical Engineering or a related fieldSolid understanding of thermodynamics, heat transfer, and HVAC fundamentalsComfortable with psychrometric calculationsStrong written and verbal communication skills, with the ability to explain technical concepts to engineers, salespeople, technicians, and clientsMS Office proficiency across the board, with Excel as a particular strengthDemonstrated CAD experienceWillingness to travel on short notice, including occasional nights and weekends for emergency responseValid US driver's license and the ability to work on construction and industrial job sitesPreferred Training Requirements and Competencies:EIT certification1–3 years of experience in HVAC, mechanical contracting, temporary climate solutions, dehumidification, or a related fieldExposure to construction sites, manufacturing facilities, food production, automotive or battery plants, aerospace, data centers, or controlled environments such as labs, cleanrooms, and pharmaceutical facilitiesFamiliarity with building codes, OSHA site safety, and standard PPE requirementsExperience supporting estimating, sales, or field service teamsDemonstration of the Polygon Values:IntegrityExcellenceEmpathy