Description
The Knightsbridge EX1TBK is a 100mm (4-inch) extractor fan in black ABS with an adjustable overrun timer preset to 2 minutes and an adjustable range of 2-30 minutes. Rated at 24 l/s (87m³/hr) extraction, it operates at 28.5-30dBA at 3 metres, making it one of the quieter options for bathroom, ensuite and utility ventilation where continuous operation or post-shower moisture extraction is needed without intrusive noise.
Designed for wall and ceiling installation in Zone 1 (IP45 rating), the fan fits a 102mm cut-out and has a 49.9mm projection from the wall once fitted, with 78.5mm recessed depth behind the mounting surface. The built-in back draft shutter closes when the fan is off, reducing cold air ingress through short ducting runs. The overrun timer continues to extract after the light or pull-cord switch is turned off, clearing residual moisture without needing to leave the switch on manually.
The black finish provides a low-visibility alternative to white in dark-tiled bathrooms, utility rooms and commercial washrooms. The ABS construction is double-insulated (Class II), so no earth terminal is required during installation. The fan complies with Building Regulations Part F (ventilation rates) and Part L (energy efficiency) at 0.404W/l/s SFP, making it a compliant choice for new-build and retrofit projects requiring certified extraction.
Specification
| Height |
157.6mm |
| Width |
157.6mm |
| Depth |
127.2mm |
| Projection |
49.9mm |
| Recessed Depth |
78.5mm |
| Cut-out Diameter |
102mm |
| Construction |
ABS |
| Finish |
Black |
| IP Rating |
IP45 |
| Class |
II |
| Primary Voltage |
230V 50Hz |
| Earth Terminal |
No |
| Noise Levels |
28.5 - 30dB @ 3m |
| Airflow |
Airflow: 24l/s [86.93m3/hr] |
| SFP |
0.401W / (l/s) |
| Overrun Timer |
Overrun timer settings: 2-30mins (Preset: 2mins) |
| Warranty |
3 Year Guarantee |
Downloads
Product Specification Sheet
Frequently Asked
How does the overrun timer work?
The fan connects to a switched live (typically the bathroom light switch or a separate pull-cord). When the switch is turned on, the fan runs immediately. When the switch is turned off, the timer keeps the fan running for a preset period (default 2 minutes, adjustable 2-30 minutes) before it stops. This clears residual moisture without needing to leave the switch on manually.
Is it suitable for use in a bathroom shower area?
Yes. The IP45 rating allows installation in Zone 1 (directly above a bath or shower enclosure), provided the fan is installed according to wiring regulations and at the correct mounting height. It is not suitable for Zone 0 (inside a shower cubicle or bath).
How quiet is it in practice?
At 28.5-30dBA at 3 metres, the EX1TBK is quieter than most extractor fans in the 100mm class, which typically run at 35-40dBA. In a typical domestic bathroom, the noise is comparable to a quiet refrigerator hum rather than the louder whirr of standard extraction fans.
Does it need to be earthed?
No. The fan is double-insulated (Class II), so it does not require an earth terminal. You need only a permanent live, a switched live (for the overrun timer control), and a neutral connection.