Sr. Mechanical Engineer - Site Development

Prattwhitney; Sudbury (MA); On-site; USD 110,000 - 160,000; Full time

Job summary

RTX in Marlborough, MA is seeking a Sr. Mechanical Engineer to provide site development and integration expertise. This onsite role focuses on HVAC design and complex building systems for military and commercial facilities.

You will work with senior staff to collect and analyze data, assess site conditions, develop mechanical plans, and apply standard HVAC technologies and digital controls to deliver future-ready solutions.

Qualifications

• HVAC design experience required.
• Experience with site development and integration.
• Ability to analyze field data and drawings.
• Knowledge of building codes and standards.

Responsibilities

• Provide assistance with collecting, compiling, and analyzing data from the physical work site, surveys, blueprints, schematics, technical drawings, HVAC load calculations, system performance reports, and other engineering inputs used for HVAC system design and construction.
• Apply mechanical engineering techniques and HVAC design principles in working with senior engineering staff to identify improvements across project phases including concept development, preliminary design, final design, and construction administration.
• Perform HVAC engineering design work in a professional manner, and conduct field assessments of proposed and existing site conditions, mechanical rooms, HVAC equipment, and system distribution to determine conformance with applicable codes, industry standards, for team review against project performance goals.
• Aid in preparing overall mechanical plans and updates to infrastructure layouts requiring coordination with owners, architects, electrical engineers, sub‑consultants, clients and other in‑house senior staff.
• Develop and incorporate standard HVAC design technologies, digital controls, and building systems strategies to aid senior staff in developing future‑ready design solutions.
• Verify site characteristics and provide mechanical/HVAC technical assistance related to documenting existing building conditions – including automatic temperature control systems, air distribution systems (supply, return, exhaust), hydronic systems (chilled water, heating water), and general building mechanical equipment.
• Work with cross‑functional teams of engineers, designers, and technical professionals to execute HVAC‑focused project work,

Skills

HVAC design

Site development

Data analysis

Cross-functional teamwork

Education

BS in Mechanical Engineering

Tools

AutoCAD

Revit

Job description

Date Posted: 2026-07-22 Country: United States of America Location: US-MA-MARLBOROUGH-MA1 ~ 1001 Boston Post Rd ~ BLDG 1 Position Role Type: Onsite U.S. Citizen, U.S. Person, or Immigration Status Requirements: The ability to obtain and maintain a U.S. government issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance Security Clearance Type: DoD Clearance: Secret Security Clearance Status: Active and existing security clearance required after day 1

At RTX, the world's largest aerospace and defense company, 185,000 great minds are united by purpose and inspired to make a difference solving the world’s most complex problems. With our three market leading businesses, world‑class operations and investments in research and development, we offer capabilities and opportunity no one else can. Together, we push the boundaries of known science and find new ways to connect and protect our world. Raytheon brings the strength of more than 100 years of experience and renowned engineering expertise to meet the needs of today’s mission and stay ahead of tomorrow’s threat. We deliver solutions that help our nation and allies defend freedoms and deter aggression, creating a safer, more secure world. Join us and help shape the future of aerospace and defense. At Raytheon, the foundation of everything we do is rooted in our values and a higher calling – to help our nation and allies defend freedoms and deter aggression. We bring the strength of more than 100 years of experience and renowned engineering expertise to meet the needs of today’s mission and stay ahead of tomorrow’s threat. Our team solves tough, meaningful problems that create a safer, more secure world.

Raytheon Mechanical Engineering (ME) is the premier organization for mechanical hardware design, development, production, and research. ME strives to minimize total systems cost, while maximizing production. This is achieved through commitment, training and continuous improvement using common tools and processes. The capabilities encompass a broad range of technical disciplines which include engineering, operations, technical services, materials and processes, analysis and test and documentation.

The Tactical Radars and Effectors department within Raytheon Hardware Engineering supports the development, production, and deployment of multiple defense products including radars, missiles, command and control systems, and naval electronics. The products support US Government and international customers.

The Mechanical Engineering Department is seeking an Sr. Mechanical Engineer to provide Site Development and Integration expertise. The Site Development & Integration section performs large scale, complex site development and onsite support. Engineers will perform research, design, support construction and development of military and commercial facilities.

The position is for the Marlborough, Massachusetts location. This position is an onsite role.

What You Will Do

Provide assistance with collecting, compiling, and analyzing data from the physical work site, surveys, blueprints, schematics, technical drawings, HVAC load calculations, system performance reports, and other engineering inputs used for HVAC system design and construction. Apply mechanical engineering techniques and HVAC design principles in working with senior engineering staff to identify improvements across project phases including concept development, preliminary design, final design, and construction administration. Perform HVAC engineering design work in a professional manner, and conduct field assessments of proposed and existing site conditions, mechanical rooms, HVAC equipment, and system distribution to determine conformance with applicable codes, industry standards, for team review against project performance goals. Aid in preparing overall mechanical plans and updates to infrastructure layouts requiring coordination with owners, architects, electrical engineers, sub‑consultants, clients and other in-house senior staff. Develop and incorporate standard HVAC design technologies, digital controls, and building systems strategies to aid senior staff in developing future‑ready design solutions. Verify site characteristics and provide mechanical/HVAC technical assistance related to documenting existing building conditions – including automatic temperature control systems, air distribution systems (supply, return, exhaust), hydronic systems (chilled water, heating water), and general building mechanical equipment. Work with cross‑functional teams of engineers, designers, and technical professionals to execute HVAC‑focused project work,