Measurement of Flow Characteristics of a Ceiling Fan with Varying Rotational Speed

This paper conducts an experimental measuring of the airflow generated by a modern ceiling fan that has an electronic device to vary the instant rotation speed for simulating natural winds. The measuring results are then used to calculate the mean air velocity, standard deviations, turbulence intensity, equivalent frequency, power spectrum, and other comfort evaluation parameters. The results have shown that, by adopting the natural wind mode, even at a lower mean air velocity, a substantial comfort level can be achieved while consumes much less electric energy. In the consideration of achieving a sustainable built environment, this finding is of great importance. This study also completes a so-called 1/f power spectrum analysis to identify the feature of natural wind generated. It seems that we can achieve environmental sustainability by further exploring the characteristics of natural environment.