There are primarily two kinds of air conditioners — refrigerate ACS provides only a cooling service, while reverse cycle air conditioners have each cooling and heating capability. As the name might suggest, central air conditioning unit work primarily via a sequence of ducts to maintain you cool. Ducted A/C has an internal fan coil unit installed in the roof area of the home. From this central location, a collection of ducts run from it and into as many rooms in the home as the proprietor wishes.