KW =  Weight of material (KG) x Specific Heat (Kcal/Kg °C) x Temperature rise (°C)
860 x  Heat-up time (hrs.)

Wattage required to heat Liquid:

KW =  Weight of Liquid (KG) x Specific Heat (Kcal/Kg °C) x Temperature rise (°C)
860 x Heat-up time (hrs.)

Wattage required  to Heat Air

For free flow air:

KW =  CFM x Temperature Rise (°F)
3000

Use the maximum anticipated airflow.

For compressed air:

KW = CFM* x Density*(lbs/cu. ft.) x Temperature rise (°F)
228

Note:  Please add Heat Loss, Factor of Safety, and if any.

To convert Temperature in Centigrade to Fahrenheit

• T(^oF) = [T(^oC)](9/5) + 32

• 1 kW (kJ/s) = 102.0 kpm/s = 859.9 kcal/h = 3,413 Btu/h = 1.360 hk = 1.341 hp = 738 ft lb/s = 1,000 J/s = 3.6x10⁶ J/h

• 1 hp (English horse power) = 745.7 W = 0.746 kW = 550 ft lb/s = 2,545 Btu/h = 33.000 ft lb/m = 1.0139 metric horse power ~= 1.0 KVA

• 1 atm = 1.01325 bar = 101.3 kPa = 14.696 psi (lb_f/in²)= 760 mmHg =10.33 mH₂O = 760 torr = 29.92 inHg = 1013 mbar = 1.0332 kg_f/cm² = 33.90 ftH₂O