I agree with begerm, there should be a noticeable difference!

hello, I would say that the product is faulty, I can feel the differences very well at home. On 1 the flux is indeed weaker, but it's enough for me at 2.5 m, facing my bed for example. What's more, I find it relatively quiet. On 5, up to 4 m away, you can feel the coolness of the ventilation.

When I switch through the 5 levels, there is a noticeable difference between the levels. From a breeze to almost a small storm ;-)
If the strength remains the same for you, this is probably a defect.