We are often asked about the positioning of fans in bathrooms and wet rooms. As with any fan that is mounted in the room itself, there is the potential for water coming into contact with the unit. And as the best place for a fan is to be positioned as close to the main source of moisture, usually the shower, it may cause some people to worry about the safety implications.
The following guidance is based on the 18th Edition IET Wiring Regulations as guidance for you to both understand the requirements and help you to choose the correct fan unit for you. As always, we strongly advise that any electrical installation be undertaken by a qualified electrician; however, many electricians are still unaware of IP ratings and insist on installing overly expensive low-voltage fan units, which come supplied with an additional step-down transformer. This is a perfectly sensible way to install a fan for safety, however, the designs and technology have moved forward, and there are now many fans on the market that do not require a low-voltage supply to be safely installed in the bathroom. So, before you capitulate to your electrician's teeth-sucking, get them to read this article so that you can install the fan you want rather than the ugly, old-school fan they recommend! So what are these IP ratings all about?
Understanding IP Ratings
All electrical products - including extractor fans - come with an IP (Ingress Protection) rating, which tells you how well the item is protected against solids and, more importantly, water.
With bathrooms, we focus on the second digit in the IP code (e.g. IPX4), which relates specifically to water ingress:
• IPX0 - no protection from liquids
• IPX1 - protection against vertically falling drops of water (e.g. condensation)
• IPX2 - protection against direct sprays of water up to 15 degrees from vertical
• IPX3 - protection against direct sprays of water up to 60 degrees from vertical
• IPX4 - protection against water sprayed from all directions - limited ingress permitted
• IPX5 - protected against low-pressure jets of water from all directions - limited ingress permitted
• IPX6 - protected against high-pressure jets of water (use on ship deck) - limited ingress permitted
• IPX7 - protected against the effects of immersion between 15cm and 1m
• IPX8 - protected against long periods of immersion under pressure
Now let’s take a closer look at the bathroom zones themselves.
Zone 0
This is the area inside the bath or shower basin — anywhere that can hold standing water. Only SELV (Safety Extra Low Voltage) equipment up to 12V is permitted here, and it must be rated IPX7 or higher.
Zone 1 - The main contender for the best extractor fan position
Located above Zone 0, this extends up to 2.25m from the floor and includes the area directly above the bath or shower. In a wet room, this includes the floor area within a 1.2m radius of the drain. Any extractor fans installed in this zone must be at least IPX4 rated and be connected to a 30mA RCD or RCBO-protected circuit.
Zone 2
This is the area stretching 0.6m horizontally beyond the edge of the bath or shower and also up to 2.25m in height. IPX4 or higher rated fans are again required, and all connections must be RCD/RCBO protected. Note: Wet rooms do not have a Zone 2, instead going straight from Zone 1 to Outside Zone.
Outside Zone
Beyond Zones 1 and 2, this area includes all spaces above 2.25m and any area more than 0.6m away from a water source. Extractor fans placed here do not require an IP rating, provided they are installed outside the splash zones and on a compliant protected circuit.
Important: Portable appliances are not permitted in bathrooms, even in Outside Zones. All installations must be hardwired by a qualified professional.
By understanding bathroom zones and IP ratings, you can choose the right extractor fan for your installation with confidence, ensuring compliance, safety, and long-term reliability. As always, consult with a certified electrician to determine what’s suitable for your specific layout.