What is an extractor fan?
An extractor fan is a functional and practical ventilation device that is essential to all homes. It works by drawing moisture out of a room and venting it outdoors through a duct system. It is perfect for ensuring proper ventilation in your home by controlling excess humidity, smoke, heat removal, and unwanted odours. This is important for maintaining a healthy indoor environment and occupant health.
Additionally, extractor fans are imperative in homes as they help you meet UK Building Regulations.
In summary, the regulations state that:
- A UK bathroom must be ventilated by either a window or an extractor fan.
- However, if a bathroom only has a toilet, it is fine to use only a window as your source of ventilation.
- In modern bathrooms with a bath and shower, mechanical ventilation i.e., extractor fan. This is because these modern bathrooms are designed to be more airtight, hence natural ventilation is much lower.
- The ventilation requirements for a standard domestic bathroom are a minimum of 15 litres per second/ 54m3 per hour air exchange rate.
What is the benefit of an extractor fan?
Aside from meeting UK building regulations, extractor fans come with a wide range of home and occupant benefits.
For instance, it helps improve the air quality of a room, allowing drier, fresher air to circulate throughout the room. This also helps reduce the excess build-up of mould or mildew which can cause damage to walls, ceilings, fixtures, and furniture in the home. Excess build-up of mould is also harmful to individuals’ health and can release allergens which can lead to respiratory problems such as asthma, as well as skin irritation.
Another benefit of an extractor fan is that the circulation of air can help ensure a comfortable temperature is maintained especially during summer/warm weather.
How effective are extractor fans?
The effectiveness of an extractor fan is dependent on several variables, such as the location it is situated in, where you intend to use it, and the volume of moisture you need to be extracted (this will also depend on where you plan to use the extractor fan).
The most important thing to note, regardless of the type of extractor fan you want etc, is that extractor fans are generally better suited as high as possible near an air source such as a window or door or vented to an exterior wall to allow maximum circulation.
With kitchens, it is best to place it over the stove or heat source in order to allow steam to be drawn directly upwards rather than around the room.
It is also important to place the extractor fan in a place that is easily accessible for regular and periodic cleaning and servicing to ensure all aspects of the extractor fan continue to function properly and in compliance with regulatory requirements.
Ultimately, ensure the fan exits outside or else you would simply be recirculating the extracted air back to your home. So, ensuring the fan exits outside allows you to more effectively avoid/minimise dampness and mould in the home.
Types of extractor fans:
There are three main types of extractor fans: inline, axial, and centrifugal.
Inline Extractor Fans:
These are situated within the run of ducting, often fitted in the loft space or ceiling void. They can be used in installations which require long duct runs, or for rooms with a large volume of airflow/moisture that need to be removed quickly and efficiently. In addition, inline extractor fans can provide a great extraction rate which is ideal for rooms where condensation or mould are a serious problem.
- The National Ventilation UMDTK Monsoon 100mm 4″ 240V Mixed Flow Bathroom Inline Duct Shower Fan Kit with Adjustable Timer is a 17-19W, 230V inline extractor fan kit.
National Ventilation UMDTK | Monsoon 100mm 4″ 240V Mixed Flow Bathroom Inline Duct Shower Fan Kit with Adjustable Timer, White & Chrome
The kit contains: 1x UMD100T mixed flow extractor fan, 2x internal diffusers (white and chrome), 1x 6m PVC flexible ducting, 1 externally fitted grille and 4x cable ties, and a motor equipped with standard thermal overload protection (STOP). The kit is made of premium packaging with an easy carry handle and wipe-clean polymer case that saves onsite time and simplifies the home installation process.
The 1 x UMD100T mixed flow extractor fan is ideal for air exhaust and supply ventilation system rooms that require high-pressure, powerful airflow, and low noise levels, with high humidity levels such as the bathroom and kitchen.
It is designed to be ceiling void or loft mounted – can be used with rigid and flexible ducting, and longer duct runs as well – with two-speed motors that are attached to the fan body by two quick-release clips that ensure ease of installation. It also features a long-life ball bearing for a long maintenance-free life.
In addition, the inline extractor fan is fully speed controllable, high-performing and low-power consuming with an airflow extraction rate of 198m³/h, at a relatively low noise level of roughly 28 dB(A) at 3 metres. It is IPX4 rated and complies with Parts F and L of the latest building regulations. The extractor fan has dimensions of H 190mm x W 246mm x Dia 96mm x Base 167mm.
The integral overrun timer allows for operation between 2-30 minutes after a room is vacated.
We also offer the National Ventilation UMDTKLED which comes complete with everything in the National Ventilation UMDTK as well as an LED light.
National Ventilation UMDTKLED | Monsoon 100mm 4″ 240V Bathroom Inline Duct Shower Fan Kit with LED Light & Timer, White & Chrome
Axial Extractor Fans:
These are generally less powerful than inline and centrifugal (we will touch on these shortly) extractor fans as they transport air over shorter distances. They are designed for mounting into a window or installation directly through an external wall with a short duct run. This makes axial extractor fans particularly suited for rooms where the air doesn’t need to be moved long distances, perfect for standard-sized family bathrooms. It is the most common type of extractor fan used in homes.
- The National Ventilation MER100S Monsoon MER Series 100mm 4″ 15W 240V IP44 Kitchen/Bathroom Extractor Axial Ceiling/Wall Fan is a 100mm mains voltage standard axial, domestic bathroom/kitchen extractor fan with an 85m³/h high air extraction rate that is ideal for remote switching and wall/ceiling mounting.
National Ventilation MER100S | Monsoon MER Series 100mm 4″ 15W 240V IP44 Kitchen/Bathroom Extractor Axial Ceiling/Wall Fan, White
It has a long maintenance-free life as it features a single-phase 15W motor with long-life ball bearings. It also features a large terminal block and spirit level bubble that make wiring easier and ensure a straighter installation respectively.
In addition, the National Ventilation MER100S casing and impeller are made from a durable, high-quality UV-resistant ABS thermoplastic material designed to prevent degradation and discolouration of the fan over a long period of time. The stylish white profile of the extractor fan also makes it suitable for installation in most modern interiors.
With an IP45 rating, the National Ventilation MER100S is protected against tools and wires over 1mm in size as well as, low-pressure water jets from all directions. It also complies with Parts F and L of the latest building regulations.
*Please note, it is advised to switch off the mains supply prior to any electrical connections.
We offer a range of axial extractor fan options from the axial kitchen/bathroom extractor fan with a pull cord or, one with an adjustable timer, one with an adjustable timer and humidistat, and an option with a pullcord, timer AND humidistat.
- The National Ventilation MONS100PCA Monsoon 100mm 4″ IP45 Silent Axial Flow Bathroom Extractor Fan with Pullcord – Dimensions of H 136mm x W 158mm x D 133mm x Spigot Dia 99mm.
- The National Ventilation MONS100TA Monsoon 100mm 4″ IP45 Silent Axial Flow Kitchen/Bathroom Extractor Fan with Adjustable Timer (2-30mins) – Dimensions of H 158mm x W 158mm x D 107mm x Hole Size 99mm.
- The National Ventilation D100HT Monsoon D-Series 100mm 4″ 240V Kitchen/Bathroom Extractor Axial Flow Ceiling/Wall Fan with Humidistat & Adjustable Timer – Dimensions of L 150mm x W 150mm x D 100mm.
- The National Ventilation MONS100HTA Monsoon 100mm 4″ IP45 Silent Axial Flow Bathroom Extractor Fan with Pullcord, Humidistat & Adjustable Timer – Dimensions of H 136mm x W 158mm x D 107mm.
Pull cord: Models with pull cords are available for you to control as you like.
Adjustable timer: They are very practical features that allow for operation between chosen time settings after a room is vacated; without you worrying about having to go back and turn it off.
Humidistat: These have a humidity sensor which automatically detects when moisture levels (heat or humidity) in the air rise to a set level, causing the fan to switch ‘on’ or to a higher ‘boost’ speed.
Centrifugal Extractor Fans:
Centrifugal fans are designed to draw air into the fan intake, and then extract it at a 90-degree angle to allow for greater pressure to be generated. It is ideal for long duct runs as it can move more air at longer distances thanks to the pressure created by the fan wheel that is mounted to the shaft. Since it can move more air over long distances along ducting, centrifugal fans generally have a more powerful extraction rate. However, this brings with it a higher decibel level, i.e., a noisier appliance. Centrifugal fans are often ceiling mounted, so even if you have a bathroom without external walls, you can still be assured of proper airflow.
- The National Ventilation MONCF100T Monsoon 100mm 4″ Centrifugal Bathroom Fan with Adjustable Timer is an adjustable (2-30minutes) timer centrifugal bathroom fan with a 122m³/hr air extraction rate.
It is designed for surface mounting or flush fitting with a mounting plate provided. In addition, it features ball-bearing energy-efficient motors that ensure a long maintenance-free life. It also features specially designed vibration dampers, a dust filer as standard and an optional filer (not supplied). In addition, it also features forward curved blades offering maximum performance even against high-pressure long ducting and resistance by grilles (low noise levels).
With the latest ventilation technology, the 4-inch centrifugal fan provides a powerful, low-noise, and vibration-free ventilation system that can move air continuously over long distances in kitchens, bathrooms, toilets, cloakrooms, and utility rooms. – continuously running and periodic exhaust ventilation.
The 100mm National Ventilation MONCF100T is manufactured using high-impact ABS thermoplastics for strength and durability with a white polish finish that is aesthetically pleasing for most modern installations.
We also offer the National Ventilation MONCF100PC Monsoon 100mm 4″ Centrifugal Bathroom Fan pull cord option. This is designed to be easy to use and install, offering a convenient way to turn the fan on and off with just a simple pull of a cord.
Envirovent Fans
Aside from the main type of extractor fans, we also offer Envirovent fans that are designed to ensure a continuous air supply to the home or area where it is located, eliminating or reducing condensation, excess humidity, heat, or unwanted odours. They are unique in that they feature silent elastic blocks that ensure completely noise-free running. Not only are they quiet running but come complete with a range of incredible ventilation features that support a high-performance ventilation system.
- An example of this is the Envirovent SIL125T Silent 125mm Ultra Quiet Toilet/Bathroom Extractor Fan with Timer which is a high-performing and ultra silent extractor fan with a 125mm spigot.
It is highly energy-efficient, resulting in big energy savings, a luxury with the high energy bills and cost of living crisis economy we’re in.
In addition, it features silent elastic blocks, an internal membrane backdraught shutter, airflow guide vanes, and sealed-for-life ball bearings. It also comes complete with a 1 to 30-minute adjustable overrun timer. As previously noted, a key benefit of the Envirovent SIL125T is that it offers impressive ultra-silent running.
Overall, the Envirovent extractor fan is ideal for use in toilets and bathrooms.
We also provide extractor fans in a practical kit that encompasses the important appliances and accessories to ensure you fully maximise the benefits of your ventilation device.
Shop our extractor fan kits:
National Ventilation UMDTK Monsoon 100mm 4″ 240V Mixed Flow Bathroom Inline Duct Shower Fan Kit
- 1x UMD100T mixed flow extractor fan
- Adjustable Timer
- 2x internal diffusers (white and chrome)
- 1x 6m PVC flexible ducting
- 1 externally fitted grille
- 4x cable ties
- A motor equipped with standard thermal overload protection (STOP)
- Dimensions of H 212m x W 230mm x L 252.5mm.
National Ventilation UMDTKLED Monsoon 100mm 4″ 240V Bathroom Inline Duct Shower Fan Kit
- 1x UMD100T mixed flow extractor fan
- LED light
- Adjustable Timer
- 2x air internal diffusers (white and chrome)
- 1x 6m PVC flexible ducting
- 1 external fitted grille
- 4x cable ties.
- Dimensions of H 212mm x W 230mm x D 252.5 x Ducting Size 100mm.
How long should ducting length be? i.e. What is the max for each fan?
Ducting is a ventilation accessory that carries extracted air to the external vent. It is generally recommended that the duct size be the same as the fan i.e., a 100mm extractor fan using a 100mm ducting run. And for maximum performance, flexible ducting should be installed fully extended to help eliminate sags and bends.
As a general guide, with axial fans use no more than 1.5 metres of ducting, and centrifugal fans should be used for ducting runs longer than 2 metres. However, axial fans are also suitable for installations up to 3 metres in a straight run, or 2 to 2.5 metres with a 90-degree angle bend.
The further the room your extractor fan is situated from the external wall, the longer the duct run will be required. This also applies to extractor fans fitted in the ceiling. Hence, centrifugal fans are better suited for longer ducting runs, whilst axial fans are better suited for shorter ducting runs.
In conclusion, before choosing an extractor fan, there are a few variables that are important to consider:
- The location/room you require the extractor fan.
- The volume of moisture/condensation you need extracted.
- The size of the room you plan to fit it in.
- How long the ducting will be.
This is because these factors all affect the effectiveness of your extractor fan.
For instance, if you plan to situate it in a large room, then you will need a larger, more powerful fan whereas if it is located in a smaller room, then a small, standard sized and low-voltage extractor fan is more appropriate. This is also because using a large fan for a small room may not only end up extracting the clean air needed, but is also a waste of energy, and with the current cost of living crisis and high energy bills, every penny counts. Likewise, if you use a small fan in a large fan, it will not be as effective against the likely excessive moisture/condensation/smoke etc and so, you will not be able to fully grasp the benefits of an extractor fan. This is just one example of why considering these variables is important in maximising the benefits of your new extractor fan.
This blog also outlines the different types of extractor fans, the type and size of rooms they are most suited for, the length of ducting required, and the best products we have to offer for each variable to assist you in taking full advantage of the incredible benefits of extractor fans.