The ideal height is 2.4 to 2.7 meters from the floor. The minimum safe height is 2.1 meters.
For rooms with high ceilings, use an extension downrod to bring the fan to the optimal height. For low ceilings, Tub models are a good choice because of their compact design.
If the main function of your fan is to help with heat distribution in winter (using reverse mode), and you're installing it in a mezzanine or architectural void, it’s best to mount the fan closer to the ceiling. This will improve the circulation of warm air.