AC Blower Belt Noise — Package / Ducted Systems

Check belt tension, alignment, pulley wear

Check: Tension: press at belt midpoint, deflection ≈12 mm (finger-width). Alignment = ruler or laser tool to verify pulley parallelism. Wear = shiny surface, cracks, flipping. Pulley V-groove = wears from V to U shape. Direct-drive (DD) systems have no belt, only bearings/motor vibration.

What to do: Belt tension = 12 mm deflection at midpoint. Alignment = verify pulley parallelism with ruler/laser. Worn = replace with same-spec belt. Pulley V-groove worn = replace pulley too. Inspect yearly, replace belt every 2–3 years. Direct-drive (DD) systems have no belt.