Free HVAC Tools & Calculators
Fast field calculators for working HVAC and refrigeration techs — superheat, subcooling, delta T, airflow, static pressure, electrical, and unit conversions. Free to use, right on your phone. No account required.
Refrigeration
Superheat Calculator
Calculate measured superheat from suction line temperature and saturation temperature, with TXV and fixed-orifice target guidance.
RefrigerationSubcooling Calculator
Calculate measured subcooling from liquid saturation temperature and liquid line temperature, with TXV charging targets.
RefrigerationTarget Superheat Calculator
Find the target superheat for a fixed-orifice system from indoor wet-bulb and outdoor dry-bulb temperatures.
Airflow
Delta T Calculator
Calculate the temperature split (Delta T) across the evaporator coil from return and supply air temperatures.
AirflowCFM & Tonnage Calculator
Find required CFM from sensible heat and Delta T, apply the 400 CFM/ton rule, and convert tons, BTU/h, and kW.
AirflowStatic Pressure Calculator
Add supply and return static pressure readings to get TESP and compare it to the equipment's rated maximum.
These calculators are provided for quick field reference and estimation. Always follow equipment manufacturer specifications and applicable codes. FieldPad is not a substitute for professional engineering or manufacturer charging data.
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