Inline Fans

Our best selling inline fan is the Manrose MF100T which features a longlife motor, 20 minute timer, a powerful extraction rate of up to 245m³/hr and a 3 year warranty.

Our best budget inline fan is the Envirovent SILMV160/100T a compact, ultra-quiet inline fan with a timer and two-speed motor which provides an extraction rate of up to 180m³/hr.

An inline fan is an extractor fan that is installed directly inside a duct run rather than at the end.

Inline fans are powerful and very discreet as the fan is installed in the roof or loft space above the bathroom, meaning the only visible evidence is a small flush mounted grille. Ducting runs from the ceiling grille to the fan and then from the fan to an external grille which is generally installed discreetly under the eaves of the roof.

Installing the fan unit outside of the bathroom means that the internal grille can be located anywhere in the bathroom - even directly above a shower. Inline fan grilles can also be combined with lighting. Kits such as National Ventilation UMDTKLED and Airflow AV100T, provide an attractive and practical feature to the bathroom.

Reduced Noise Levels - Because the fan is located in the roof noise levels are greatly reduced. There is also a range of silent inline extractor fans on the market which ensure you will not hear the fan running at all.

Powerful Extraction & Suitable for Long Ducting Runs - Inline fan motors are more powerful than those in axial fans. This makes inline fans suited to longer ducting runs in which other standard extractor fans would struggle.

Extract from Anywhere - Whereas standard axial fans must be installed according to the bathroom zone regulations, the extraction point of an inline fan can be placed anywhere in the bathroom as the fan itself will be installed far enough away from any water sources to be safe.

Multiple Inlet Points - Inline fans can be joined to several inlet/outlets via Y junctions or BTOs. This means that one inline fan can be used to service multiple rooms or one large room.

An inline fan works similarly to a standard wall mounted axial fan, removing stale or moisture laden air from a room to reduce the risk of mould and damp problems.

The difference between axial and inline fans is that inline fans are much more powerful. An inline fan’s impellers are designed to create a “mixed flow” by combining the features of centrifugal and axial impellers to create a higher extraction rate. This allows the extracted air to be pushed through longer ducting runs of up to 10m without a loss in pressure or a drop in performance.

To understand what size inline fan you need and to work out what ventilation rates are required for your room, see the table below.

Please see What Size Inline Fan Do I Need? for a more detailed guide and calculations to help you buy the best fan for your requirements.

Inline fans do not cost much to run, especially when you compare their running cost to the cost of redecoration or repairs required due to damage caused by mould or damp.

The fans are not constantly running, operating only when activated by the remote switch and stopping once the switch has been turned off or the set time on models with an overrun timer has passed.

To work out how much it costs to run an inline fan follow this simple equation:

Wattage of Fan ÷ 1000 x cost per unit of electricity = Cost to run fan for 1 hour

Installation of an inline fan requires working with electrical wiring and must be building regulation compliant; because of this inline fans should be installed by a qualified electrician to ensure that the installation is both safe and efficient.

Unless you have bought your inline fan as part of a kit it is likely you will also require the following accessories:

Intake vent - An internal vent which will be at the point of extraction. These grilles come available in a range of shapes, sizes, materials and finishes to suit

Ducting - Ducting connects the vent to the fan and the fan to the external vent. Flexible ducting is most commonly used for inline fan installations as it is easier to work around beams and other obstacles in lofts.

Ducting Clamps - Ducting clamps are required to securely attach the ducting to the fan and keep it taught

Backdraught Shutter - Prevents outside air from causing cold draughts in the property

External Vent - A grille which is installed in the external wall

Inline fans are typically better at pulling air out of a room than they are at pushing it out, therefore it is better to install the fan closer to the external exhaust point than to the internal extraction point.

The optimum ducting length for inline fans is 6-10m. This length, along with the correct placement of the fan will not only provide better extraction performance but also reduces stress on the fan’s motor ensuring it will last as long as possible.

Yes, extractor fans must be vented outside of a building to avoid problems with mould and rot. If moist air is removed from the bathroom but is not then pushed outside it will cause moisture to build up elsewhere in the building which could prove both costly and dangerous.

Much quieter than axial/wall fans since they are situated away from the room they draw moisture from. Noise is also absorbed by ducting.

Inline mixed-flow fans balance airflow and pressure for medium to long duct runs. Centrifugal fans use higher pressure for very long or complex ducting runs but tend to be noisier and higher powered.