Energy Efficient Ceiling Fans
Ceiling fans are perhaps the most energy efficient active cooling solution available, using about 2% of the electricity of an equivalent air conditioner. Combining ceiling fans with air conditioners and heaters improves their efficacy and efficiency and has been estimated by the Cademus Group of the U.S. to reduce summer cooling bills by up to 46% and winter heating bills by up to 15%. Australian research by Dr. Tony Isaacs of RMIT focused on just the cooling benefits of ceiling fans has produced similar results. Read more about Ceiling Fan Energy Star Ratings.
So how much electricity does an efficient ceiling fan use?
The CSIRO says in their book ‘The CSIRO Home Energy Saving Handbook’ that “An efficient fan producing 140 cubic metres of airflow a minutes typically has a power of 75 watts.” At Spinifex we think this is about 20% less efficient than we would expect from our fans, but it is a good benchmark.
The table below summaries Spinifex’s estimates of energy consumption for a 132cm diameter fan using a conventional AC motor. Annual operating costs for a fan that is run for 12 hours a day throughout the 3 months of summer are also shown.
| Speed | Energy consumption (watts) |
Air movement (m3 / minute / watt) |
Running cost per fan* ($ / yr) |
Running cost for a house of 5 fans ($ / yr)* |
|---|---|---|---|---|
| High | 65 | 2.5 | $12.07 | $60.33 |
| Medium | 35 | 3.3 | $6.50 | $32.49 |
| Low | 17 | 4.1 | $3.15 | $15.78 |
| CSIRO Benchmark on ‘High’ | 75 | 1.87 | $13.93 | $69.50 |
* Assumes 1kwh costs $0.17
What about DC motors?
DC motors are possibly the way of the future, using about 30% of the electricity of a conventional AC motor. At Spinifex we are experimenting with them but to date have not been satisfied that they meet our quality standards; but watch this space as new innovations are likely to drive quality up and price down. In the meantime you might be happy in the knowledge even the most inefficient ceiling fan is a big step in the right direction and the incremental benefit of a DC motor is only about $4.00 a year on a ‘high’ speed setting.
Energy efficient lighting
A number of fans in the Spinifex range can be fitted with energy efficient compact fluorescent lamps (CFLs) giving you an environmentally friendly lighting option. Learn more about ceiling fans with lights.