Energy Efficiency Services Limited
Most households in India are cooled by fans, and less than 10% of households have air conditioning. The average rating of the fans installed and sold in the market is between 75-80W, whereas energy efficient fans provide the same level of comfort at about 45-50W. Considering that almost 30 million fans are sold every year, the potential to reduce demand is significant. Replacing the country's 35 crore inefficient ceiling fans in with BEE 5-Star-rated ceiling fans could save 47 billion KWh and reduce load by over 12,250 MW.
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.