Overview

We're Hiring: Mechanical Services HVAC Design Engineer

Location: Bordon / Sunbury-on-Thames / London – Hybrid working | Hours: Mon–Fri, 9am–5pm

What You’ll Do

Join Johnson Controls as a Mechanical Services Design Engineer and help shape the future of sustainable infrastructure. You’ll design mechanical systems including ventilation, heating, air conditioning, chillers, and air source heat pumps—focusing on fluid designs for decarbonisation projects. You’ll size ductwork and pipework, select plant equipment, and calculate building heat losses and gains using AC Calc software. Site surveys and client meetings are part of the role, along with producing technical submissions and ensuring compliance with industry standards.

• Design mechanical systems including ventilation, heating, air conditioning, chillers, and air source heat pumps with a focus on decarbonisation.
• Size ductwork and pipework; select plant equipment; calculate building heat losses and gains using AC Calc software.
• Conduct site surveys and client meetings; produce technical submissions; ensure compliance with industry standards.

What We Offer

• Competitive salary
• 25 days holiday + bank holidays + sick pay
• 7% matched pension, free life assurance, employee assistance programme
• Discounts on high street brands and Johnson Controls security products
• Cycle-to-work scheme and referral incentives
• Hybrid working and structured career development
• Extensive training and a collaborative team culture
• Commitment to safety through our Zero Harm policy

Due to the nature of this position, we are only able to consider applicants who currently have the unrestricted legal right to live and work in the UK. We are unable to provide sponsorship or assist with visa applications for this role.

What You’ll Bring

Required:

• Expertise in fluid designs, especially ASHPs, chillers, and decarbonisation systems
• Experience conducting site surveys and preparing reports
• Knowledge of CIBSE, BESA, and Water Regulations
• Willingness to travel (1–2 site visits per week)
• Strong communication skills and customer-facing experience

Preferred:

• 10+ years in mechanical building services (ventilation, heating, domestic services, AC, chillers, ASHPs)
• Proficiency in AutoCAD and technical submissions
• Familiarity with NHS HTM specifications
• Experience in healthcare and local government decarbonisation projects
• Background in project-based environments with design-to-delivery handovers

Specialist Division Within Johnson Controls

This role sits within a specialist team formed through Johnson Controls’ acquisition of H&C Contracts Ltd—an established provider of mechanical services for healthcare environments. Since joining JCI in 2019, the H&C team has continued to deliver high-performance solutions for critical spaces such as operating theatres, MRI suites, and pharmaceutical facilities. You’ll be part of a legacy of precision and innovation, backed by the global strength of Johnson Controls.

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