Air conditioners cool and dehumidify. An oversized air conditioner can quickly cool a home, but it results in frequently cycling on and off, which doesn’t allow enough time to remove moisture and may make the house feel clammy. A properly sized AC will operate for a longer period of time during the hottest days, which will remove that uncomfortable moisture. Although a properly sized unit will run longer, it will be more efficient and use less energy. Oversizing a residential AC system by 50% will cause a 10% increase in energy consumption. Not only do oversized units consume more energy, but they also remove less moisture from your home.