Problems caused by poor ventilation and their solution(Manrose extractor fans)

Being inspired by what Manrose advises regarding the siting of the fans and the problems created by the lack of ventilation, we have compiled some ideas and listed them below(the source can be found at the Manrose Fan Selection page). Read below about:

Some of the problems caused by poor ventilation

  • Poor ventilation: Stale Air
    The stale air is usually caused by the cooking smells, people smoking, the odours remaining in the bathroom, a general lack of ventilation around the house as well as by a damp atmosphere. All these problems can cause an certain level of discomfort(which can be avoided!) as well as the risk of respiratory illness and general poor health.
  • Poor ventilation: Condensation
    Problems can occur when the steam from the kitchen / the bathroom finds cooler surfaces around the house on which to condense. When we attempt to conserve the heat by sealing the windows – and therefore reducing the natural ventilation – we actually make this problem even worse. Condensation can cause some considerable problems from peeling wallpaper and mould growth to severe structural damage such as wood rot and damp.

Help in Solving the Problem Caused by the Lack of Ventilation

The Current Building Regulations

The Building Regulations Document F1 (2006 Edition) outlines the importance of ventilation and stipulates that mechanical ventilation must be installed in kitchens, bath/shower rooms and toilets. All the Manrose fans comply with or exceed current Building Regulations and are capable of extracting no less than 60 litres per second from kitchens and no less than 15 litres per second from bath/shower rooms. This means that the humidity is removed at source before it can reach the cooler part of the dwelling and cause damage.

Specific requirements of The Building Regulations Document F1 (2006 Edition) on ventilation

  • The Building Regulations about the Bathrooms/Shower Rooms:
    The Regulations require a fan capable of minimum extract capacity of 15 litres per second 54m3/hr (32CFM) when installed.
  • The Building Regulations about the Toilets (Separate from a Bathroom):
    The Regulations require a fan capable of a minimum extract capacity of 6 litres per second 21m3/hr (12CFM) when installed. N.B. If a room does not contain an openable window the fan should be fitted with a 15 minute over-run timer.
  • The Building Regulations about the Kitchens:
    The Regulations require a fan capable of extracting 60 litres per second 216m3/hr (127CFM) when installed.
  • The Building Regulations about the Utility Rooms:
    The Regulations require a fan capable of extracting 30 litres per second per second 108m3/hr (63CFM) when installed.

Where should we site the Manrose extractor fan?

  • A fan should always be sited in the furthest window or wall from the main source of air replacement to avoid short-circuiting the airflow. It should be located as high as possible in the window or wall nearest to smells or steam, but not directly above eye-level grills or cooker hoods.
  • If the room contains a fuel burning device (such as a gas boiler) with a non-balanced flue, it is essential that there is enough replacement air to prevent fumes being drawn down the flue when the fan is extracting to its utmost capacity.
  • The IEE Regulations (U.K.) require that a conventional mains voltage fan in a bathroom or shower must be located where it cannot be touched by a person using the bath or shower and well away from any water spray.
  • Alternatively, the new Manrose range of 12 volt S.E.L.V. (Safety Extra Low Voltage) fans are specifically designed for the safe ventilation of toilets, bathrooms and shower rooms and can be fitted within the splash area with absolutely no risk of electric shock.

Tips for Choosing the Right Manrose Fan

  • The Manrose Axial Fans are designed to move air over short distances i.e. window fixing or through mounting and are not suitable for ducting over 2 metres in length. Available in 4″, 5″, 6″, 9″ and 12″ sizes.
  • The Manrose Centrifugal Fans are designed to move air over longer distances and will perform well against the pressure caused by long lengths of ducting and resistance by grilles.
    Note: When ducting vertically it is recommended that a condensation trap is used.
  • The Manrose Humidistat Controls – Manrose has a complete range of integral Humidistat Controls on all their fans, they are also available with a pullcord the bathroom and off as it falls. It will continue to monitor the humidity 24 hours per day, thus preventing mould growth on walls and ceilings and drastically reduces condensation problems.

Models of Manrose Fans

  • Manrose Standard Fans: For remote switching through wall light or separate switch;
  • Manrose Timer models: with built-in adjustable time delay operated by the light switch;
  • Manrose Pullcord models: with built-in pullcord switch;
  • Manrose Humidity controlled models: with built-in adjustable sensor which operates the fan automatically;
  • Manrose P.I.R. model: sensitive to movement Switches on when room is entered and off when room is vacated.

To purchase online Manrose Extractor fans for kitchens, bathrooms, showers, etc – visit the Heating & Ventilation section, the Ventilation Solutions.


  1. I live in Lincoln and would like to know the nearest stockist to the city. Also whether replacement parts can be obtained as the shutters on our kitchen extractor are not working any more – the main fan is OK.
    Not really a comment I know – just information wanted.
    Thank you.

  2. If you are within the UK, we deliver via courier – all you need to do is just order online the desired item.
    About replacement shutters – did you check on our website at the section of Extractor Fans – the model that you currently own? Usually we sell the whole fitting, but there may be some accessories for some fans(you just need to visit, the section of Heating and Ventilation, and select the right model you own).

  3. Thank you for your prompt reply but regret the site quoted deals only with lighting, no mention of extractor fans which is where my problem is.
    Can you help?

  4. Please ignore my email of the 23rd…have located the fan on your site that we have a problem with. Now tell me are you able to supply the front only of Fan No. XF150T? The shutters no longer open…seems the spring mechanism has given up.
    Hoping to hear from you.
    Mrs. E. Cross

  5. Many thanks for your reply this morning, however, the fan we have fitted bears the identifying number XF150.A. The only fan I can find that looks the same as ours carrys the number XF.150.T.
    Now if I order the front casing of the latter will it fit the fan I have.
    Sorry if I seem to be making heavy weather of this.
    Thankyou in advance.
    E. Cross.

    1. What we have in stock is just the XF150T and XF150AP. And one more thing: we don’t sell the COVER by itself – we sell the entire fitting, as listed on the website.

    1. yes, by the “entire fitting” we mean the whole fan, not just the cover. We don’t recommend changing just the cover actually. After a while, it is good to change the whole fan.

  6. Hello,

    I would like to replace my existing Manrose fan (standard model) with the humidity control. Currently there is plenty of condensation in the bathroom and I have discovered some moulds on the wall too. I am thinking a model with the humidity control will help.

    Can you please advise me which model I should order? I am not sure about the difference between model xf 100H and xf 100MH. Ideally the fan should operate itself automatically it the humidity of the room reaches/rises to certan perset level.

    I look forward to your recommendation.

    Thank you in advance.


    1. Hello, regarding your enquiry, we would recommend you would go for the XF100H, since it is the model that automatically turns on the fan with the adjustable humidistat included, while the XF100MH is the version with the MANUAL turning on of the device. M – stands for Manual.

  7. I have a problem with the damp walls in the house that we renovated last year. We replaced the new PVC windows and renovated the fasade using external thermo render.
    We do noit live in the house and use it only during summer holidays. Over the winter, all the windows were closed and when we walked in the furniture and walls were wet and we had teh mould on the walls and at the back of the furniture in the living room and bedrooms.
    Can someone please advise if the extractor fan with humidity control (XF100H) shoudl be installed in all the rooms in order to switch on ventilation automatically when humidity level in the air increases.

  8. I have a manrose extractor above the shower but it does not take the steam away in my small bathroom, I have checked the hose it is clear and the vent is working but not as it should. Any ideas anyone ?

  9. @ John, the legislation states that the fans above the showers need to extract min. 15l/s, and it has no relevance to the size nor the distance it has to transport the air through. Most builders will go for the cheapest option available, regardless whether the fan is capable of doing the job or not. You need to know the size of the bathroom and how is the air extracted – does it have to travel a distance before it is being expelled, or whether it is through the wall.

    To work out the volume and the kind of fan that you need to have in the bathroom, you need to calculate length x width x height, and take a look at for

    Unfortunately with ventilation you get what you pay for. There are many good value fans that do the job for you. If you want us to recommend a fan for you, please let us know – either here or by email at sales @ What model of Manrose fan are you using?

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