HVAC Calculators

Target Superheat Calculator

For fixed orifice systems (piston or capillary tube). Enter whole numbers.

Indoor Wet Bulb (°F)Outdoor Dry Bulb (°F)

Formula: [(3 × WB) − 80 − DB] ÷ 2. If the result is N/A the target superheat is too low to calculate — see Target Superheat.

RefrigerantLiquid Tube ODVapor Tube ODTotal Line Set Length (ft)Feet Included in Factory Charge

Manufacturer charts supersede these values. Full tables on Refrigerant Weights.

Bottle WC — Water Column Capacity (lb)Bottle TW — Tare Weight (lb)Actual Scale Weight (lb)

A bottle may be filled to 80% of WC. Worked through on Recovery Bottle.

Input BTU/HRCombustion Efficiency (decimal, e.g. 0.9 for 90%)Delta T (°F)

Formula: CFM = (BTU/HR × Efficiency) ÷ (1.08 × Delta T)

VoltsAmpsDelta T (°F)

Formula: CFM = (Volts × Amps × 3.413) ÷ (1.08 × Delta T)