Water cannot be added to the bottom case of this fan.
The box under most electric fans is not used to add water. This housing is generally used to filter and add humidity. If you add water, although it will improve the cooling effect in a short time, it is not safe to add too much or for a long time.
In order to avoid safety issues, it is recommended not to pour water into uninstructed areas. When in doubt, it's best not to add water or run an electric fan randomly. This prevents accidents that could affect the performance of the device.