Engineering Calculator HVAC is a professional unit converter and engineering calculator designed for HVAC engineers, mechanical engineers, plumbers, and building services professionals.

UNIT CONVERTER — 10 categories:
• Pressure: Pa, kPa, MPa, kgf/m², kgf/cm², mmHg, mmH2O, bar, mH2O
• Flow rate: m³/s, m³/min, m³/h, L/s, L/min, L/h
• Power: W, kW, MW, kcal/h, Mcal/h, Gcal/h, BTU/h, hp
• Energy: J, kJ, MJ, cal, kcal, BTU, kWh
• Temperature: °C, °F, K
• Length: mm, cm, m, km, in, ft
• Area: mm², cm², m², km², in², ft²
• Volume: mL, L, m³, cm³, gal, bbl
• Mass: g, kg, t, lb, oz
• Velocity: m/s, km/h, mph, knot

ENGINEERING CALCULATORS — 5 tools:
• Pipe Velocity — calculate water/fluid velocity and flow rate in pipes of various diameters
• Thermal Power — compute heating/cooling power from flow rate and temperature difference, with antifreeze concentration support
• Valve Pressure Drop — determine pressure loss through control valves using Kv coefficient
• Expansion Tank — size membrane expansion tanks for heating and cooling systems
• Insulation Area — calculate pipe insulation surface area for material estimation

KEY FEATURES:
• Clean Material Design 3 interface
• Bilingual: English and Russian (auto-detect or manual switch)
• Swap units with one tap
• Instant conversion as you type
• Works fully offline — no internet required
• No ads, no in-app purchases
• Lightweight and fast

Perfect for daily engineering work, on-site calculations, project estimation, and quick reference. Built by an HVAC engineer for real-world use.