Facilities Mechanical Engineer - Mission-Critical Facilities Design

Leidos is seeking a driven and detail-oriented Facilities Mechanical Engineer to support the planning, design, and analysis of mechanical systems-primarily Heating, Ventilation, and Air Conditioning (HVAC)-for secure, mission-critical operations. This is a growth-focused role where you’ll work alongside senior engineers to develop high-performance, energy-efficient, and code-compliant systems that support 24/7 operations. You will be expected to provide engineering level support for existing systems and work with other disciplines to resolve site issues.

We are able to sponsor the clearance process for qualified candidates; however, our preference is to onboard individuals who already hold an active clearance at any level. This role supports a TS/SCI with Polygraph, and Leidos can maintain that clearance for the position.

What You’ll Do

• Analyze the design and layout of HVAC systems, including ductwork, piping, ventilation, and equipment selection for high-availability environments.
• Collaborate with electrical, architectural, and structural teams to deliver integrated solutions.

• Prepare and maintain construction drawings and specifications using AutoCAD, Revit MEP, or similar tools.
• Support system load calculations, energy modeling, and equipment sizing using tools like Trace 700, HAP, or eQUEST.
• Participate in field surveys, site investigations, and facility condition assessments.

• Perform commissioning, testing, and balancing to ensure optimal system performance.

• Review submittals, respond to RFIs, and support construction administration activities.
• Ensure all designs meet applicable codes and standards (ASHRAE, NFPA, IBC, IMC, LEED).
• Maintain organized documentation including technical memos, reports, and as-built drawings.

• Manage Building Management Systems (BMS) for centralized control of HVAC, lighting, and life safety systems.

Basic Qualifications

• Ability to obtain a Top Secret/SCI with Polygraph clearance
• Bachelor’s degree in Mechanical Engineering

• 4+ years of relevant experience 

• Understanding of design specifications and documentation standards

• Experience with facilities HVAC equipment design, management, and support

• Strong communication skills and ability to work across multidisciplinary teams

• Excellent organizational skills and attention to detail

Preferred Qualifications

• Any level of active clearance.
• Active Top Secret/SCI with Polygraph.
• Mechanical Fundamentals of Engineering (FE) exam or Professional Engineers (PE) exam passed

• Experience with Siemens Insight, Siemens Desigo, Tridium, or Iginition

• Proficiency in CAD software (e.g. AutoCad, Revit)

• Ability to contribute independently to moderately complex engineering projects

• Ability to apply engineering standards and best practices in documentation and design

EC-DAS

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo - because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 - and moving faster than anyone else dares.

Original Posting:

Pay Range:

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.