When selecting a Bathroom fan it’s important to consider where the fan will be installed.
There are Zones 0,1,2, which decide which fan is suitable for the job.
Bathroom Zone 0
The inside of the bath, or the inside of the shower that can physically hold or contain water. Electrical items installed into these areas must be low voltage, SELV (Safety Extra Low Voltage – no higher than 12V), and rated no lower than IPX7.
Bathroom Zone 1:
The area directly above zone 0, limited to a height of 2.25m above the bath or shower. Electrical items installed in this area must have an IP rating of IPX4 or higher. Items installed into zone 1 can be mains voltage, but if so must be fitted to a 30ma RCD. Low voltage items can also be installed in this area, but the transformer must be located outside of zone 2.
Bathroom Zone 2:
This is the zone beyond zones 0 and 1, continuing 0.6m horizontally and up to 2.25m vertically. As with zone 1, mains voltage items must be fitted to an RCD, and low voltage items’ transformers must be installed outside of zone 2. IPX4 or higher protection is required. Sink areas are classified as being in zone 2.
Bathroom Zone 3:
Any extractor fan can be installed in this area, as it does not have an IP rating. Apart from shavers and toothbrushes though, no electrical equipment is allowed in this area.