Dividing a home into independently controlled temperature areas, via duct dampers with multiple thermostats or via multiple ductless heads. It solves the classic 'freezing downstairs, roasting upstairs' pattern of multi-story homes.
Around Baltimore, Annapolis, and the DC metro, cooling decisions revolve around humid Mid-Atlantic summers, correct sizing for row houses and older homes, SEER2 efficiency, and whether a repair or a planned replacement is the smarter long-term spend.