There are many types of motors and various sizes of motors available in the ceiling fan industry. There are direct drive motors which come in different sizes measured by (mm) millimeters. There are energy efficient DC Motors which are the most cost efficient ceiling fans on the market. And there are 220 volt motors which are specifically made for international use.
The most air movement you are going to get from a ceiling fan is from some of the largest direct drive motors that exist. With a large blade span and a high degree blade pitch combined with a large direct drive motor you will get one powerful ceiling fan as a result.