Free HVAC tools
Free HVAC calculators
Superheat, subcooling, P/T charts and more. Free, fast on your phone, and no sign-up.
- Free, no sign-up
- Built for your phone
- Same math as the FieldLoom app
Refrigerant charge Check the charge from your gauge readings
Superheat calculatorSuction pressure + line temp → superheat, with TXV and piston targets.Open →Target superheat calculatorIndoor wet bulb + outdoor dry bulb → target superheat for piston systems.Open →Subcooling calculatorLiquid pressure + line temp → subcooling, with typical targets.Open →Approach temperature calculatorLiquid line temp minus outdoor ambient, to check condenser performance.Open →
P/T charts Saturation temperature at every 10 PSI
Refrigerant P/T chartAll refrigerants, pressure to temperature and back.Open →R-410A P/T chartFull table and lookup.Open →R-454B P/T chartFull table and lookup.Open →R-32 P/T chartFull table and lookup.Open →R-22 P/T chartFull table and lookup.Open →R-407C P/T chartFull table and lookup.Open →R-134a P/T chartFull table and lookup.Open →
Airflow and heating Splits, furnace rise and duct static
Delta T calculatorReturn and supply air temperature split across the evaporator coil.Open →Furnace temperature rise calculatorSupply minus return in heating, checked against the nameplate range.Open →Total external static pressure calculatorSupply + return static, compared with the rated maximum.Open →
Electrical Run capacitor checks
Built for the truck
Every calculator works on your phone, with no sign-up and nothing to install. The math and targets are the same ones the FieldLoom app uses on the job.
These tools are a reference. Always follow the equipment manufacturer's charging and installation instructions.