Senior Mechanical Engineer - PE (HVAC)

NELSON is seeking a Senior Mechanical Engineer (HVAC) to lead the design and delivery of complex mechanical systems for a variety of facility and infrastructure projects. This role will provide technical oversight, serve as Engineer of Record, and drive engineering quality from initial design through construction administration. The ideal candidate brings extensive experience with complex HVAC systems, central plant design, and specialized building environments, along with the ability to mentor engineering teams, lead multidisciplinary coordination, and provide innovative solutions to challenging engineering requirements. Attributes to support the NELSON culture: Go All In. Own the Outcome. We go all in—with urgency, follow-through, and pride in the result. Be Direct. Be Respectful. Be Authentic. We keep it real—with clarity, candor, and care. Grow with Purpose. We embrace growth—through learning, coaching, and continuous improvement. Think Bold. Execute Smart. We think boldly—and pair ambition with discipline. Make Space for Everyone. We value you—and build a culture where people can thrive and do their best work. Qualifications To perform this job successfully, an individual must be able to perform each essential duty and responsibility satisfactorily. The requirements listed below are representative of the knowledge, skill, and/or ability required. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential functions. Critical features of this job are described under the headings below. They may be subject to change at any time due to reasonable accommodation or other reasons. Essential Duties and Responsibilities include the following. Other duties may be assigned: Lead mechanical engineering design efforts on large, technically complex facility and infrastructure projects. Serve as Engineer of Record, providing technical oversight, quality control, and signing and sealing construction documents. Independently develop complex HVAC systems, including unitary equipment, chilled water and heating hot water plants, steam and condensate systems, and specialized ventilation. Perform and critically evaluate advanced engineering calculations, including psychrometrics, hydronic design, equipment sizing, and system performance under varying operating conditions. Develop central plant configurations, pumping arrangements, equipment staging, and comprehensive HVAC control sequences. Lead designs involving critical environments, humidity control, building pressurization, and specialized ventilation requirements. Perform comprehensive technical quality control reviews, identify design deficiencies, and resolve complex engineering challenges. Manage and mentor mid-level engineers, EITs, and designers while overseeing project deliverables. Demonstrate the ability to independently perform hands on mechanical design and drafting using Autodesk Revit when required. Lead interdisciplinary coordination, client communication, construction administration, and assist with project planning and staffing. Education, Experience