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.
Fan coil unit
Speed control of the fan motors within a fan coil unit is partly used to control the heating and cooling output desired from the unit. Some manufacturers accomplish speed control by adjusting the taps on an AC transformer supplying the power to the fan motor. Typically this would require adjustment at the commissioning stage of the building construction process and is therefore set for life at a fixed speed. Other manufacturers provide custom-wound Permanent Split Capacitor (PSC) motors with speed taps in the windings, set to the desired speed levels for the fan coil unit design. A simple speed selector switch (Off-High-Medium-Low) is provided for the local room occupant to control the fan speed. Typically this speed selector switch is integral to the room thermostat, and is set manually or is controlled automatically by the digital room thermostat. Building Energy Management Systems can be used for automatic fan speed and temperature control. Fan motors are typically AC Shaded Pole or Permanent Split Capacitor. More recent developments include brushless DC designs with electronic commutation. Compared to units with asynchronous 3-speed motors, the fan coil units with brushless motors will reduce the power consumption up to 70%.