HVAC Engineers in India design, size, and commission the heating, ventilation, air-conditioning, and refrigeration systems that keep commercial towers, data centres, hospitals, pharma cleanrooms, and manufacturing facilities within precise temperature and humidity bands. Day-to-day work spans cooling-load calculations in HAP / E20-II / Trace 700, psychrometric analysis, duct sizing by Equal Friction and Static Regain methods, chiller selection (centrifugal, screw, absorption), VRF and VAV system design, compliance to ECBC and ASHRAE 90.1/62.1, BMS integration, and Test-and-Balance commissioning. The Indian market is driven by Voltas, Blue Star, Daikin India, Carrier India, and Mitsubishi Heavy Industries on the OEM side, and by MEP consultants — Aircon Engineers, Spectral Consultants, Vintech Consultants — plus global firms (Arup, WSP, Mott MacDonald) and EPC contractors (L&T, Shapoorji Pallonji, Tata Projects, Cushman & Wakefield). Data-centre cooling is the fastest-growing specialisation as hyperscalers (AWS, Azure, Google, Reliance Jio) and Indian colocation providers expand capacity across Mumbai, Pune, Chennai, and Hyderabad.