HVAC & Refrigeration
Intermediate

Fan Power

Power a fan needs to move air against a pressure drop.

Formula

P=Q ΔpηP = \frac{Q \, \Delta p}{\eta}

Variables

PPower (W)
QAirflow (m³/s)
\Delta pPressure rise (Pa)
\etaEfficiency

Example

Q=2, Δp=300, η=0.7: P = 857 W

Did You Know?

Fan power rises with the cube of speed, so trimming airflow 20% can cut power roughly in half.

hvacfanpower

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Heat absorbed or released when moisture condenses or evaporates — the hidden load air conditioners fight.

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Cooling delivered per unit of work input — higher is more efficient.

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Cooling capacity in BTU/h per watt of power — a common AC rating.

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