A fan curve shows how a specific fan configuration performs across a range of airflow and pressure. It should be used to confirm the operating point, not treated as a promise that every airflow and pressure value can occur at the same time.
Find the required duty point
Plot the required airflow against the required static or total pressure using matching units. The selected fan should operate close to this point with an appropriate margin for known system variation, without relying on an unstable or inefficient end of the curve.
Read the related values together
- Fan speed and impeller size for the plotted curve
- Efficiency near the intended operating point
- Absorbed power, not only the motor nameplate rating
- Sound data and test conditions when noise matters
- Air density, temperature, and altitude corrections if applicable
Compare curves on the same basis
Before comparing two proposals, confirm that both curves use the same airflow units, pressure definition, air density, speed, and test arrangement. A visually higher curve is not automatically the better or more efficient selection.