A 16 second seamless loop of a small room fan: a steady motor hum with a slow wobble, plus a wash of air being pushed around. Use it under voice-over, study videos, or any scene that needs to sound warm and slightly annoying. Lower and steadier than the rain loop, with a hum the room tone does not have.
motor: sine 108 Hz at 0.05, plus 216 Hz at 0.02, wobble 1/8 Hz (exactly 2 cycles in 16 s) air: white noise, band-pass 1.6 kHz, Q 0.55, level 0.55 blade: white noise, low-pass 260 Hz, Q 0.7, level 0.7 seam: 0.6 s rendered past the end and equal-power crossfaded (sin/cos) back onto the head noise seeds: 91 (air), 92 (blade)