I have just put in a new wetroom. It is 3m x 0.8m. At one end is a shower with a fixed head and a hand held head. In the middle of the wetroom is a washbasin and a wc at the other end. There is no splash screen between the washbasin and the shower, the floor is continuous tiles throughout. There is no window and I need to put in an extractor fan. I have seen one I like but it is not a SELV/zone 1 fan. It is a low profile ceiling fan. How close to the shower am I allowed to put the fan?