The northern end of Siesta Key falls inside the city limits, and much of the housing there is rented by the week. Systems in vacation properties sit idle between bookings, then run hard for a few days at a time, which is a pattern that finds weak capacitors and clogged filters quickly. Guests report a cold bedroom long before an owner would notice anything.
Two bridges serve the key, Siesta Drive at the north end and Stickney Point Road at the south, and the housing changes character between them: cottages and small condominiums around the village, larger houses and mid-rises further down. Weekly turnover asks a system to pull a closed, humid house down to temperature in a few hours, which is a load no residential unit was sized for. Repeated short cycles are usually what ends a compressor's life on the island.
Salt is the other constant. Outdoor units corrode at the coil fins and along the cabinet seams, and a unit that looks sound from the ground can have very little fin left behind the grille. On Siesta Key the outdoor section is inspected as closely as the air handler, because a repair that ignores a corroded coil is a repair that comes back. Lanais converted to living space are common here and normally need a supply and a return of their own.