Senior Mechanical Engineer; onsite

What you will do

Johnson Controls is seeking a Senior Mechanical Engineer! In this role, you will be responsible for mechanical analysis, detailed design, subsystem integration, and overall mechanical performance of HVAC equipment across Enviro‑Tec air-handling, fan‑coil, and blower‑coil platforms. You'll support new‑product development, sustaining engineering, prototyping, laboratory validation, and manufacturing execution. You will have the opportunity to collaborate closely with electrical, controls, test lab, compliance, sourcing, product management, and operations teams to deliver market‑leading, safe, compliant, serviceable, and cost‑effective HVAC products.

You will lead complex and exciting mechanical development efforts—spanning sheet metal design, thermal/fluid performance, air‑moving systems, heat‑exchanger integration, mechanical safety features, A2L refrigerant adaptations, structural integrity, DFMEA, and field‑service considerations—while contributing technical leadership across NPD teams.

This position is onsite based in Largo, FL. Candidates must be commuting distance to the facility, or able to relocate. Johnson Controls offers various relocation packages depending on your needs.

• Mechanical Design & System Integration
• Perform mechanical analysis and detailed design for AHUs, FCUs, BCUs and related subsystems including sheet metal, enclosure structures, panels, fan/motor assemblies, coil integration, and airflow pathways.
• Develop innovative design solutions for custom HVAC equipment based on customer-specific requirements and product performance targets.
• Execute design improvements that optimize manufacturability, serviceability, acoustics, energy efficiency, and product quality.
• Create and maintain mechanical engineering standards, CAD models, technical documentation, and design specifications.
• Develop design rules and logic used in configurable/dynamic BOM generation.
• Mechanical Compliance, A2L Adaptation & Safety Requirements
• Interpret and implement UL 60335-2-40 mechanical safety and A2L refrigerant requirements for clearances, airflow paths, compartment construction, and enclosure integrity.
• Coordinate with compliance partners and agencies (e.g., Intertek/ETL) to validate mechanical requirements and securement tests.
• Ensure mechanical designs meet relevant safety, installation, and regulatory standards.
• Lab Validation, Prototypes & Testing
• Define and execute test plans in partnership with the Largo Test Lab (airflow performance, thermal testing, vibration, structural integrity).
• Lead prototype builds and fit‑up verification for assembly feasibility and service access.
• Oversee testing of fans, motors, mechanical components; analyze data and drive corrective actions.
• Manufacturing, Sourcing & Cross‑Functional Collaboration
• Support manufacturing engineering with BOMs, routings, assembly sequencing, and DFM/DFA improvements.
• Evaluate mechanical vendors and qualify new components including fans, bearings, heating elements, insulation materials, and assemblies.
• Provide mechanical guidance to marketing, applications, sales engineering, service, and field teams.
• Generate clear and accurate drawings, installation details, and mechanical instructions.
• Support PFMEA reviews, root‑cause analyses, corrective actions, and engineering change processes.
• Maintain consistency with Largo drafting/documentation standards and mentor drafters/designers.

• Bachelor’s Degree in Mechanical Engineering.
• 5+ years of mechanical engineering experience in product development.
• Understanding of thermodynamics, heat transfer, and airflow fundamentals.
• Experience designing sheet‑metal assemblies. Preferably fan/motor systems, coil integration, heater assemblies, and structural components.
• Familiarity with mechanical aspects of UL 1995.

• HVAC industry experience
• Experience with lab testing, vibration/structural analysis, acoustics, or CFD.
• Knowledge of sheet-metal fabrication, brazing/welding, fastening, gasketing, and insulation.
• Understanding of DFMEA, DFM/DFA, cost modeling, and value engineering.
• Experience with configurable platforms and dynamic BOM logic.
• Cross‑functional…