Senior Mechanical Design Engineer; onsite

Johnson Controls,a global leader in thermal management, mission-critical building systems, energy efficiency, and decarbonization, helps customers use energy more productively, reduce carbon emissions, and operate with the precision and resilience required in rapidly expanding industries such as datacenters, healthcare, pharmaceuticals, advanced manufacturing, and higher education.

For more than 140 years, Johnson Controls has delivered performance where itreally matters. Backed by advanced technology, lifecycle services and an industry-leading field organization, weelevatecustomer performance,turn goals into real-world results andhelpmove society forward.

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Johnson Controls is seeking a Senior Mechanical Design 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…