ENERPOS
Finally, large ceiling fans are installed in every room, even those using air conditioning. Ceiling fans ensure that even in the absence of the necessary breezes, the airflow needed to feel comfortable in the room is provided for the users. This solution significantly reduces the amount of energy consumed. The overall consumption of the ceiling fans and the split system (the latter used to cool the technical rooms) is only 3.7kWh/m².yr compared to a classic air conditioning system in a standard building consuming 80kWh/m².yr.
Thermal destratification
Because of their size, HVLS fans are normally installed in new construction, rather than retrofits, as the roof structure may have to be redesigned to accommodate the increased weight and size. It's not uncommon to require the relocation of lights, due to strobing as large fan blades pass under them, and sprinkler systems, which typically require unobstructed access to the floor to meet fire code. When used in the summer to encourage evaporative cooling, HVLS fans are run forward, blowing air at the floor. When used for destratification in the winter, the fans are run in reverse, blowing air towards ceiling which then circulates around the room. The height at which HVLS fans can be effective is limited compared to axial destratification fans.