Fans
Choosing replacement fans for open-air frames
When a bearing sings, the shopping reflex is to buy whatever lists the highest CFM. On open-air mining frames that shortcut creates new problems: wrong thickness, mismatched connectors, and airflow arrows that disagree with the shelf design.
Start with the physical envelope
Measure frame cutouts and screw spacing before you order. A 120 mm label means little if the hub height collides with a neighboring board. Keep the old fan until the new one seats—labels rub off, and voltage print on the sticker is your ground truth.
Voltage and connectors
Many shelves mix 12 V fans with adapters that look interchangeable until a pin sits proud. In the Fan Replacement Clinic we practice seating without levering against the PSU harness. If your loom uses proprietary plugs, budget for pigtails rather than forcing a fit.
Direction beats bravado
Confirm intake versus exhaust with a ribbon or tissue after install. A powerful fan blowing the wrong way raises board temperatures while sounding “strong.” Noise after a swap is a clue: new bearings should settle, not scream. If chirp returns within days, revisit mounting torque and whether the blade scrapes a warped shroud.