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New Efficiency Standards in India Could Push More Ceiling Fans Towards BLDC Motors

BEE Star Rating

Ceiling fans are a big part of everyday life in tropical regions like India. Even in spaces where air conditioners are present, keeping the ceiling fans on can enhance the cooling effect. Energy consumption of a ceiling fan may not seem to be much compared to the humming AC compressor, but running it for long hours can add up to a significant electricity bill.

The Bureau of Energy Efficiency (BEE) uses a Star Rating system to promote energy efficiency in electrical appliances, and ceiling fan gets its own category. The new IS 374:2019 standard for ceiling fans sets the bar much higher than the previous version. For example, a ceiling fan with a 1400 mm blade span that has a service value (details below) of 4.1 would get a 5-Star top rating under the earlier standard. Under IS 374:2019, that same fan now only gets a 1-Star lowest rating.

The new standard applies to all ceiling fans driven by squirrel cage induction motors and brushless direct current (BLDC) motors. According to Bijli Bachao, an initiative promoting residential energy saving, in order for a ceiling fan to achieve a 5-Star rating under IS 374:2019, it would most likely need to be powered by the much more efficient BLDC motor.

One of the biggest changes made with the new standard is that it factors in fan blade size instead of considering a default size of 1200 mm. The following table shows the required minimum performance value that ceiling fans need to comply with:

Fan Blade Size (mm) Minimum Air Delivery (m3/min) Minimum Service Value (m3/min/Watt)
900 130 3.1
1050 150 3.1
1200 210 4
1400 245 4.1
1500 270 4.3

Air delivery represents the amount of air swept by the fan with air velocity measurement up to 15m/min. Service value is what the star rating is based on. It indicates the amount of air delivered per watt of energy consumed. The rating breaks down like this:

Star Rating Service Value (m3/min/Watt)
Blade Size Smaller than 1200 mm Blade Sizes 1200 mm to 1500 mm
1 Star ≥ 3.1 to < 3.6 ≥ 4.0 to < 4.5 for 1200 mm
≥ 4.1 to < 4.5 for 1400 mm
≥ 4.3 to < 4.5 for 1500 mm
2 Star ≥ 3.6 to < 4.1 ≥ 4.5 to < 5.0
3 Star ≥ 4.1 to < 4.6 ≥ 5.0 to < 5.5
4 Star ≥ 4.6 to < 5.1 ≥ 5.5 to < 6.0
5 Star ≥ 5.1 ≥ 6.0

The majority of ceiling fans on the market in India feature blades longer than 1200 mm. The 6.0 service value required for a 5-Star rating would be very difficult to achieve by fans running on induction motors. This is especially true for ceiling fans that require extra headroom in available power to support features like remote control or smart home connectivity, making BLDC motors the ideal solution for high efficiency ceiling fans.

Learn more about Power Integrations’ BridgeSwitch half-bridge motor driver ICs, which simplify the development and production of high-voltage inverter driven single-or multi-phase BLDC motor drives.

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