There is no one-size-fits-all number, but hotels should think about spare inventory based on property size, occupancy patterns, lead times, and how critical each item is to room availability. PTAC unit failures can quickly make a room unserviceable, so those often deserve more contingency planning than smaller accessories. TV and appliance spares may also be worth keeping if model consistency matters for brand or guest experience reasons. The goal is to balance storage costs against the revenue risk of out-of-service rooms.