We sound-test samples of our Pro Grow Dragon Series silenced fans so the figures we publish come from real measurements, not estimates.

• Test setup: the fan runs at full speed (10 V control signal, 230 V supply), fitted with ducting as it would be in a real installation.
• Two microphones, two distances: we measure sound at the same time from 1 m and 3 m away from the fan, using a calibrated two-channel sound level meter.
• A-weighted decibels, dB(A): the meter weights the reading toward the frequencies the human ear actually hears. That gives a truer picture of how loud the fan sounds in a room than a raw decibel figure.
• LEQ, the average over time: fan noise rises and falls slightly from moment to moment. LEQ (equivalent continuous sound level) averages the readings across the whole test, so one brief peak doesn’t skew the result.

Example: Dragon Series silenced fan, 200 mm

• 1 m from the fan: 51.3 dB(A)
• 3 m from the fan: 47.4 dB(A)

Why distance matters
Sound spreads out as it travels, so the same fan reads lower the further away you stand. When you compare fans from different brands, check what distance each figure was measured at. A 3 m figure will always look quieter than a 1 m figure for the same fan.

Figures are from sample testing. Real-world noise depends on your setup, including ducting, mounting, room size and fan speed.