The truth of the matter is that buying a bigger room air conditioner will not make you comfortable during the hottest months of the year. Any reputable HVAC contractor will tell you that having a big Air Conditioner in your small sized room will not perform efficiently or effectively compared to a smaller sized AC. The reason for this is that, a big AC will cool the room to your thermostat set position before de-humidification occurs. This will make the area feel uncomfortable as well as feeling clammy. Therefore, the central air conditioner has to be of the right size in relation to your room.