A well-established UK contractor specialising in high-specification controlled environments is seeking a mid-level HVAC Design Engineer to strengthen its in-house design capability. The business delivers technically demanding cleanroom and critical ventilation projects across life sciences, healthcare and advanced manufacturing sectors. This is a performance-led design role focused on precision airflow, environmental stability and compliance-driven engineering. This role would suit a technically capable mid-level engineer currently operating as a Mechanical Design Engineer, Building Services Design Engineer, HVAC Design Engineer, Cleanroom Design Engineer, Ventilation Design Engineer or Environmental Control Engineer looking to step into a more specialist, performance-led environment. You will take responsibility for the mechanical design of HVAC and ventilation systems within controlled and cleanroom environments, translating performance briefs into engineered solutions. Duties will include: Heat loss, heat gain and cooling load calculations Psychrometric analysis and humidity control strategies Airflow modelling and air change rate calculations Design of pressure cascades and contamination control strategies Specification of AHUs, HEPA filtration systems, ductwork and associated plant Production of ventilation schematics and technical design documentation Technical liaison with Project Managers and site teams through installation Providing technical support during commissioning and client handover Requirements 4-5 years' experience in HVAC / mechanical building services design Strong understanding of psychrometrics, airflow and heat load calculations Ability to independently size and specify HVAC plant and ventilation systems Confident interpreting technical briefs and performance specifications Experience working within a contractor-led, project delivery environment Cleanroom, laboratory, healthcare or other critical environment experience advantageous Package Competitive salary (dependent on experience) Hybrid working flexibility Exposure to technically complex, high-specification projects Long-term progression within a growing specialist contractor WR HVAC | M&E are 1 recruitment partner for HVAC jobs. Our customers include a range of large and small M&E companies, manufacturers and suppliers of heating, ventilation, air conditioning and refrigeration equipment. We recruit UK wide for sales, management and technical jobs. WR is acting as an Employment Agency in relation to this vacancy.