In my office there is an air conditioning unit that has a knob that adjusts the temperature with a grayscale bar with the shades getting darker from left to right above it but no other indication (such as numbers, a snowflake, etc). Sort of like this image:
This is very confusing to me. Typically I would think that temperature indicators would go from left to right (cold -> warm). But what if this isn't temperature but rather intensity where a higher intensity blast of air would result in colder temperatures? (off -> full blast)
Is white cold and black warm? Or white low intensity and black high intensity? Is it a badly designed indicator or are my intuitions off?
Bonus: What would be an idea for a better but just as minimalist design? How universal is this current design? Would snowflakes make more sense and how well understood would that be in climates with no snow? I don't think numbers would help unless they are associated with temperatures explicitly.
I took a photo of the knob. It doesn't look exactly like my illustration (in my defense it was dark inside the grid :-P )