Before you start...
In order for you to fit an extractor fan or ventilation system in your house you will need to conform to current building and electrical installation regulations. Here, we have set out a simple DIY guide to give a few tips on what you should be considering before starting your project.
When undertaking any electrical work in your home, be aware that new electrical wiring regulations may allow you to undertake some electrical work yourself without notifying building control. However, it is almost certain that building control will need to be informed if you are attempting most kinds of electrical work. More importantly, you will probably need to employ a certified electrician. Please click here for general guidelines on what the regulations will allow you to undertake.
Extract Rates for Kitchens (minimum)...
- 30 l/s (litres per second) adjacent to a hob.
- 60 l/s (liters per second) elsewhere.
Extract Rate for Utility Rooms (minimum)...
- 30 l/s (litres per second).
Extract Rate for Bathrooms, Shower Rooms & Wet Rooms (minimum)...
- 15 l/s (litres per second).
Extract Rate for Sanitary Accomodation (minimum)...
- 6 l/s (litres per second).
Air Change Rates...
When installing an extractor fan in your kitchen, bathroom, toilet or wet room, it is important to know that Part F of The Building Regulations stipulates a minimum intermittent air extract rate for each of these areas:
Fitting an extractor fan in a bathroom or shower room...
Fitting an extractor fan in a bathroom or shower room is a real issue because of the increased risk of electric shock, a room containing a bath or shower is now considered a special location as outlined in the new 17th edition IEE Wiring Regulations. If you have the space, fit an in-line fan in your void or loft space as this area isn't considered a special location, therefore saving a lot of time, hassle and money.
Recommended in-line fans for bathrooms, shower rooms & wet rooms:
In line extractor fans with short duct runs click here
In line extractor fans with longer duct runs click here
If you can't fit an in line extractor fan and you have no alternative but to fit a fan in the room then please read on as the new regulations pay special attention to the zones in and around a bath or shower in the room.
These areas can be briefly explained, as can their effect on the type of extractor fans which can be used.
Wiring Regulations, The Building Regulations and any further compliancy that may be required. If in doubt, consult professional help from a qualified person or company.
- Zone 0 for a bathroom is the area inside the bath.
- Zone 0 for a shower room is the area inside the shower basin. If there is no shower basin, zone 0 is 10cm high from the finished floor level and extends to 1.2m around the fixed shower head.
- It is not practical to mount extractor fans in zone 0.
- Zone 1 for a bathroom is the same width as zone 0 (the width of the bath) extending to 2.25m above the finished floor level.
- Zone 1 for a shower room is 2.25m from the finished floor level or the height of the fixed shower head from the finished floor level if more than 2.25m, and the width of the shower basin. If the shower has no basin then zone 1 extends to 1.2m around the fixed shower head.
- Zone 1 does not include zone 0.
- The space under the bath tub or shower basin is considered to be zone 1. However, if the space under the bath or shower basin is only accessable with a tool, it is considered to be outside the zones.
- Extractor fans installed within zone 1 must be at least IPX4.
- Extractor fans installed within zone 1 must be fitted with 12v SELV motors with the SELV transformers and isolators fitted outside of zone 0, 1 & 2.
- Zone 2 for a bathroom is the same height as zone 1 (2.25m) extended to 0.6m around the bath.
- Zone 2 for a shower room is the same height as zone 1 extended to 0.6m around the shower basin. If there is no shower basin zone 2 is replaced by zone 1 extended to 1.2m around the fixed shower head.
- Extractor fans installed within zone 2 must be at least IPX4.
- Extractor fans installed within zone 2 must be fitted with 12v SELV motors with the SELV transformers and isolators fitted outside of zone 0, 1 & 2.
The extent of the zones in a bath or shower room can be limited by floors, ceilings and walls. For more detailed information see BS 7671 diagrams 701.1 & 701.2. Any electrical equipment installed on the surface of floors, ceilings and walls that limit a zone is subject to the requirements of that zone.
RCDs are required for all circuits in locations that contain a bath or shower. The requirements for local supplementary bonding have been relaxed if certain conditions are met.
Please note that this guide is only to be used as general reference. Please ensure that you are fully aware that any electrical and installation work must be carried out in accordance with IEE Wiring Regulations, The Building Regulations and any further compliancy that might be required. If in any doubt, consult professional help from a qualified individual or company.
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