Every architect and engineer knows that venting relief in a bathroom begins with an exhaust vent/fan being located above the shower alcove and not in the middle of the room, irrespective of what anyone says about their multi function product, because in the end, the homeowner is the one that ends up with the problem.
And if you think mould and mildew are easy to get rid of once created…think again!
There are two forms of venting required in a bathroom, or any wet area for that matter.
Positive (fan) venting and trickle venting ( slow continuous venting)
In order for either of these to occur a means of external air ingress needs to be present. as the efficiency of either is dependent just that. External means atmospheric and not air coming from adjacent rooms in the house.
The fan is always located above the shower alcove, not next to it, and not in the centre of the room. Above the shower alcove the steam is removed almost as quickly as it’s created.
Fan efficiency is based on ease of ingress to remove the moisture laden volume efficiently and avoid precipitation which is easily evident on mirrors and glass.
Trickle venting is continuous and just as essential as this is what keeps the bathroom walls dry and odour free.
Multi function products, as the one pictured above, are designed for perception and illusion of performance, and therein lays the trap for the unaware or unsuspecting.
Moreover they are manufactured in plastic and therefore have a guaranteed short life span.