The Xpelair Simply Silent Contour Timer (C4TSR, MPN 078346) is a near-silent 100mm axial bathroom extractor fan with a two-speed motor and adjustable overrun timer. Powered by Xpelair's proprietary Ghost™ Air Movement Technology, the fan uses precision-engineered impeller geometry and long-life, low-noise motors to achieve a remarkable 15 dB(A) at 3m on low speed — quieter than a whisper. Suitable for wall, ceiling, panel and window fitting, it comes supplied with both a contoured square and a round fascia, giving installers and homeowners a choice of aesthetics without purchasing extra parts. Complies with Building Regulations Parts F and L.
15 dB(A)
Low-speed noise
29 dB(A)
High-speed noise
54/76 m³/h
2-speed airflow
6.3/7W
Power draw
IPX4
IP rating
2 Years
Warranty
Wiring — 3-Core Required: The C4TSR Timer model requires a 3-core feed: Live (L), Neutral (N) and Timer wire (T). The fan is connected to the lighting circuit — the timer terminal keeps the fan running for the set overrun period after the switch opens. Always isolate the mains and verify the circuit is dead before commencing wiring. The protective fuse must not exceed 5A for fixed wiring installations.
Speed Selection at Installation: The two speed settings — Low (15 l/s / 52 m³/h) and High (21 l/s / 76 m³/h) — are selected by a link inside the fan body during installation. Set High for standard Part F compliance in bathrooms (minimum 15 l/s required); set Low for near-silent background running where the higher speed is not needed.
Ghost™ Air Movement Technology
Xpelair's Ghost technology addresses the two main sources of fan noise: motor noise and aerodynamic turbulence. The motor is optimised for low rotational speed and minimal vibration; the impeller blades are shaped to move air smoothly without the irregular flow patterns that generate broadband hiss in cheaper fans. The result — 15 dB(A) low speed — is measurably quieter than background conversation.
Adjustable Overrun Timer
The timer overrun is factory set at 15 minutes but can be adjusted from 30 seconds to 30 minutes using control T inside the fan body. Turn clockwise to increase; anti-clockwise to reduce. The overrun period keeps the fan running after the light turns off, removing residual humidity from the room — a key requirement under Approved Document Part F for intermittent extract systems.
Square and Round Fascias Supplied
The C4TSR is shipped with both a contoured square fascia (180×180mm) and a round fascia (200mm Ø). The chosen fascia simply clips onto the fan body — no screws, no tools. Swap between them at any time without specialist parts. The smooth contoured profile wipes clean and resists mould growth at the surface.
Built-In Backdraught Shutter
An integral backdraught shutter closes automatically when the fan stops, preventing cold downdrafts, condensation ingress and insect entry through the duct run. This is especially important in winter when unshuttered duct runs can become significant sources of draughts and heat loss in bathrooms.
Versatile Mounting Options
With a 44.5mm body depth and universal mounting holes, the C4TSR fits into walls, ceilings, panels, and window frames. The fan body accommodates the 100mm ducting spigot (98mm Ø) and can be oriented in any direction. The Xpelair 100mm Easy Fit Wall Kit (sold separately) simplifies external wall finishing from inside the room.
Part F & Part L Compliant
High speed (21 l/s / 76 m³/h) meets Approved Document Part F minimum extract rates for bathrooms and utility rooms. The low Specific Fan Power of 0.42/0.33 W/l/s (low/high) satisfies Part L energy efficiency requirements, making this an appropriate choice for new builds and extensions under current UK Building Regulations.
Technical Specifications
| Fan Performance |
| MPN |
078346 |
| Model |
C4TSR (Simply Silent Contour Timer) |
| Speeds |
2 (selectable at installation) |
| Extract Rate — Low Speed |
15 l/s / 52 m³/h |
| Extract Rate — High Speed |
21 l/s / 76 m³/h |
| Sound Level — Low Speed @ 3m |
15 dB(A) |
| Sound Level — High Speed @ 3m |
29 dB(A) |
| Electrical Power |
6.3W (low) / 7W (high) |
| Specific Fan Power (SFP) |
0.42 W/l/s (low) / 0.33 W/l/s (high) |
| Motor Type |
AC |
| IP Rating |
IPX4 (Zone 1 with 30mA RCD; Zone 2) |
| Timer & Controls |
| Timer Range |
30 seconds – 30 minutes |
| Timer Factory Default |
15 minutes |
| Wiring Cores Required |
3-core (L, N, T) |
| Dimensions & Fitment |
| Square Fascia Size |
180 × 180mm |
| Round Fascia Diameter |
200mm |
| Body Depth (fitted) |
44.5mm |
| Rear Spigot Diameter |
98mm |
| Mounting |
Wall, ceiling, panel or window |
| Supply Voltage |
230V AC, 50Hz |
| Max Fuse Rating |
5A |
| Backdraught Shutter |
Integral |
| Colour / Finish |
White / Gloss ABS |
| Compliance |
Building Regs Parts F & L |
| Warranty |
2 years (Xpelair UK) |
Frequently Asked Questions
How quiet is 15 dB(A) compared to everyday sounds?
15 dB(A) is at the threshold of human hearing — comparable to a very light rustle of leaves or the hum inside a sound-proofed room. For reference, normal conversation is around 60 dB(A) and a typical bathroom extractor fan is 30–45 dB(A). The Simply Silent Contour at low speed is effectively inaudible in all but the most acoustically silent spaces.
What speed should I select for my bathroom?
For compliance with Approved Document Part F, select High speed (21 l/s), which exceeds the 15 l/s minimum for bathrooms without opening windows. If the bathroom has adequate natural ventilation or if near-silent operation is the priority, Low speed (15 l/s) still meets the 15 l/s requirement at free air. For a shower room or combined bathroom/shower, High speed is recommended to ensure adequate moisture extraction.
Can I fit the round fascia instead of the square one?
Yes. Both fascias are supplied in the box. The round fascia (200mm Ø) simply clips onto the same fan body as the square one — no modification required. Swapping between them takes under a minute. This dual-fascia approach is particularly useful when replacing an existing round-faced fan, as the 200mm round cover matches most standard installation apertures.
Do I need a separate external grille for a wall installation?
Yes. The fan unit itself is installed on the interior side of the wall. For a through-wall run, a separate external grille or outlet is required — for example the Airvent Wall Outlet Gravity Flap (415454) or a Domus Cowled Outlet (4902W). Xpelair also offers a Simply Silent 100mm Easy Fit Wall Kit that provides the wall tube and outer grille, and is designed to be fitted entirely from inside the room.
Is the Contour Timer suitable for a shower enclosure (Zone 1)?
The C4TSR carries an IPX4 rating, confirming it can withstand water splashing from any direction. It can therefore be installed in Zone 1 of a shower room provided the circuit is protected by a 30mA RCD, as required by BS 7671. Without RCD protection, Zone 2 applies (outside the immediate spray area). Always confirm zone boundaries before installation.
