Forced Circulation Units (FCU) can be used for heating and cooling. They are simple devices consisting of a heating/cooling pipe coil where water circulates and a fan to push air through. They can be used both in offices and homes. Modern fan coils operate quietly, with individual thermostats and air flow adjustment capacity. They come in various sizes, either for floor or celling placement. They can be combined with solar hot water supply systems during cold days, for greater energy savings.