How long it takes for the area to fill with the scent?

This depends on characteristics of the premises, namely on climatic conditions, height of the ceiling, aeration, size of the area etc.

You must consider that different models are suitable for different space area. In larger area, smaller device will have a lesser effect (according to characteristic). In such cases, you can use multiple devices or choose a spot where you will achieve maximum effect with your SG. (Example: the department store Nama placed it at the entrance of the department.) For ideal effect we also suggest that you switch the device on half an hour before the desired effect.