## Airflow Formulas

Watts to btu’s = watts x 3.413

Btu’s to watts = btu’s / 3.413

Three phase resistive watts  = (Amps1 x Volts1) + (A2 x V2) + (A3 x V3) / 1.732 (which is the square root of 3)

Single phase resistive watts = volts x amps

Three phase inductive watts (motors) = (Amps1 x Volts1) + (A2 x V2) + (A3 x V3) / 1.732 x power factor

Single phase inductive watts (motors) = volts x amps x power factor

Ohms Law: E/IR: Ohms = volts / amps (R=E/I), amps = volts / ohms (I=E/R), volts = amps x ohms (E=IR)

# How to convert kilowatts to amps

### DC kilowatts to amps calculation formula

The current I in amps is equal to 1000 times the power P in kilowatts, divided by the voltage V in volts:
I(A) = 1000 × P(kW) / V(V)

So amps are equal to 1000 times kilowatts divided by volts
amps = 1000 × kilowatts / volts

### AC single phase kilowatts to amps calculation formula

The current I in amps is equal to 1000 times the real power P in kilowatts, divided by the power factor PF times the voltage V in volts:
I = 1000 × P / (PF × V )

So amps are equal to 1000 times kilowatts divided by power factor times volts.
amps = 1000 × kilowatts / (PF × volts)

### AC three phase kilowatts to amps calculation formula

The current I in amps is equal to 1000 times the real power P in kilowatts, divided by square root of 3 times the power factor PF times the line to line RMS voltage VL-L in volts:
I = 1000 × P / (√3 × PF × VL-L )

So amps are equal to 1000 times kilowatts divided by square root of 3 times power factor times volts.
amps = 1000 × kilowatts / (√3 × PF × volts)

The Calculating tool uses both quantitative data and qualitative information covering HVAC design, installation and operation to benchmark energy efficient performance and identify potential areas for improvement. Calculator  