To determine the right air conditioner capacity for a room, start by measuring the floor area in square meters and use it as the basis for selecting the appropriate horsepower rating. As a general guide used in the Philippines, a 0.5 HP unit suits rooms up to 12 square meters, 1.0 HP covers up to 22 square meters, 1.5 HP is suited for up to 35 square meters, and 2.0 HP handles up to 52 square meters. Adjust the capacity upward if the room receives direct sunlight throughout the day, has high ceilings, is frequently occupied by many people, or contains multiple heat-generating appliances such as computers, ovens, or large televisions.