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When bathroom ventilation is poor, the room can feel continually damp and musty or remain steamy for some time after showering. If this sounds like your bathroom, then it may just be a sign to consider buying a new bathroom exhaust fan.
Good ventilation in your bathroom is essential to prevent mould, mildew, and excessive humidity. And as we enter the summer season, there’s never been a better time to address ventilation issues, ensuring a healthy space when winter time comes around. 
Here at The Bathroom Showroom, we discuss just why good bathroom ventilation is so important, offer expert tips on how to improve ventilation in your bathroom and highlight the many benefits of ventilating this most important room in the home.

Why is Bathroom Ventilation Important?

Proper ventilation in your bathroom helps to remove excess moisture from the air. When you take a hot shower, the steam created can lead to condensation on the walls, ceilings, and mirrors.
This excess moisture can create the perfect environment for mould and mildew to grow. Not only can mould and mildew be unsightly, but they can also pose a health hazard, especially for those with allergies or asthma.

Why Summer is a Good Time for Bathroom Ventilation

It’s a great idea to think about getting your bathroom ventilation sorted this summer. While there's no single "best" time of year, summer actually offers some distinct advantages for this type of home improvement project, including:
  • Existing Humidity Relief: The UK can experience humid summers. So, if your bathroom already feels stuffy or you're seeing signs of condensation or mould, upgrading your ventilation now will provide immediate relief and make your bathroom much more comfortable throughout the warmer months.
  • Optimal Drying Conditions: If any plastering or minor building work is involved with the installation, the warmer, drier air of summer allows materials to dry much faster. This can speed up the overall project and prevent issues like trapped moisture.
  • Better Airflow During Work: With windows and doors more likely to be open for longer during summer, there's better natural airflow throughout your home during the installation process, which helps dissipate any dust or fumes more quickly.
  • Reduced Disruption (potentially): If you're planning a full bathroom renovation, summer can be a popular time for home improvements. By tackling the ventilation now, you might be able to slot it in before a potential rush for other services later in the year.
  • Preventing Future Problems: Investing in good ventilation now will help prevent mould, mildew, and dampness from taking hold, which can be particularly problematic in winter when windows are often kept closed.

Choose The Best Bathroom Exhaust Fan Type

  • Type of Extractor Fan:
Axial Fans: Common for through-the-wall installations, generally quieter for smaller bathrooms.
Centrifugal Fans: More powerful, often used with longer ducting runs (e.g. to the roof or outside wall) and for larger bathrooms. They can be mounted in the loft to reduce noise in the room itself.
Humidity Sensing Fans: Automatically turn on when humidity reaches a certain level, saving energy.
Timer Fans: Run for a set period after the light switch is turned off.
  • Choose the Right Size Bathroom Extractor Fan
The right size extractor fan depends primarily on your bathroom's size and the amount of moisture generated. Fan capacity is measured in CFM (Cubic Feet per Minute) or L/s (Litres per Second) in the UK.
  • For bathrooms less than 50 sq. feet: A minimum of 50 CFM is recommended.
  • For bathrooms 50-100 sq. feet: Aim for at least 1 CFM per square foot of floor space.
  • For bathrooms over 100 sq. feet: You may need to add CFM requirements for each fixture, So, for a toilet: 50 CFM, a shower: 50 CFM, a bathtub: 50 CFM, and a jetted tub: 100 CFM
Top Tip: The Bathroom Showroom sells a selection of ventilation fans all designed to promote a healthy bathroom space all year round. With the most popular brand names, from HiB to Airflow, we have the perfect bathroom exhaust fan to suit the size and style of your bathroom. Take a look at our bathrooms brochure for the entire range of models we sell. 

 How to Improve Ventilation in Your Bathroom

  1. Install a Ventilation Fan: One of the most effective ways to improve ventilation in your bathroom is to install a ventilation fan. A ventilation fan helps to remove moist air from the bathroom, preventing mould and mildew growth. Make sure to run the fan during and after showering to ensure proper ventilation.
  2. Open Windows: If your bathroom has a window, open it during and after showering to let in fresh air and allow excess moisture to escape. This can help to improve ventilation and reduce humidity levels in the bathroom.
  3. Use a Dehumidifier: If your bathroom is particularly prone to humidity, consider using a dehumidifier to remove excess moisture from the air. This can help to prevent mould and mildew growth and keep your bathroom feeling fresh and dry.
  4. Keep Bathroom Door Open: Keeping the bathroom door open when showering can help to improve air circulation and ventilation. This can prevent excess moisture from getting trapped in the bathroom and causing mould and mildew issues.

FAQs About Bathroom Ventilation

What Are the Signs I Need Better Ventilation in the Bathroom?
  • Condensation: Water droplets on mirrors, windows, and walls after a shower.
  • Visible Mould and Mildew: Growth on walls, ceilings, grout, or shower curtains.
  • Peeling Paint or Wallpaper: Caused by excessive moisture.
  • Musty Odour: A persistent damp smell.
  • Stuffy or Humid Feeling: Lingering humidity that makes the bathroom feel consistently damp and warm.
  • Foggy Mirrors: Mirrors that stay clouded long after a shower.
  • Excessive Noise: from an old or failing fan.
  • Water stains: Patches on walls or ceilings.
Why Do I Need Ventilation in My Bathroom?
  • Moisture Removal
  • Mould and Mildew Prevention 
  • Odour Control
  • Protection For The Rest of The Home
  • Improved Air Quality
How Noisy Are Bathroom Extractor Fans?
Fan noise is measured in sones. Lower sones mean a quieter fan.
  • 1.0 sones is similar to rustling leaves or a refrigerator.
  • Anything under 30 dB (decibels) is generally considered quiet.
Do I Need a Bathroom Fan If I Have a Window?
UK building regulations state that for bathrooms without windows, an extractor fan is required. However, for a bathroom with just a toilet, a window may be considered adequate ventilation.
While a window provides some ventilation, a mechanical extractor fan offers more consistent and effective moisture removal, especially after showers when the air is heaviest with humidity. It's generally recommended to have a fan even with a window for optimal ventilation.
What Are the UK Building Regulations for Bathroom Ventilation?
  • Extract Rate: The fan should extract at least 15 litres per second (L/s) or 54 m3/hr for bathrooms.
  • Placement: Fans should be installed as high as possible in the room, ideally no more than 400mm below the ceiling, and often opposite the internal bathroom door to aid airflow.
  • Electrical Safety (Bathroom Zones): Extractor fans must have an appropriate IP rating for their zone (e.g. IPX4 minimum for splash protection in areas around showers/baths) All electrical work must comply with Part P of building regulations and should be carried out by a qualified electrician.
  • Ducting: Ducts should vent directly to the outside, not into attics or crawlspaces.
What Are the Ducting Requirements for a Bathroom Fan?
  • Vent to the Outside: Always vent outside the home, not into a loft, attic, or wall cavity, as this can lead to moisture build-up and mould in those spaces.
  • Duct Material: Rigid ducting (solid PVC) is generally preferred over flexible ducting due to its smoother interior, which promotes better airflow and reduces noise. If flexible ducting is used, it should be pulled taut to avoid sagging, which can restrict airflow.
  • Length and Bends: Keep duct runs as short and straight as possible. Long runs and multiple bends significantly reduce fan effectiveness. As a rough guide in the UK, total duct length shouldn't exceed 6 metres for a standard fan, with deductions for bends (e.g. 1 metre for a 90-degree bend).
  • Insulation: If the ducting runs through an unheated space (like a loft), it should be insulated to prevent condensation from forming inside the duct, which can drip back into the bathroom or damage the fan.
  • Slope: If the duct must run downward, ensure a slight slope back towards the bathroom to allow any condensation to drain and evaporate, rather than pooling in the duct.
How Often Should I Clean My Bathroom Exhaust Fan?
Regular cleaning is important for optimal performance.
  • Monthly: Wipe down the surface of the fan grille to remove dust and debris.
  • Every Six Months: Perform a more thorough cleaning, which may involve removing the grille and cleaning the fan blades and housing.
Can You Over-Ventilate a Bathroom?
In terms of preventing moisture and improving air quality, there's generally no such thing as "too much" ventilation from an extractor fan. A more powerful fan will simply clear the air more quickly.
However, an excessively oversized fan for a small bathroom might be unnecessarily loud or use more energy than needed. The primary goal is effective moisture removal, and meeting or slightly exceeding the recommended CFM/L/s for your bathroom size is usually ideal.

Get Your Bathroom Into Shape This Summer

By proactively addressing your bathroom ventilation this summer, you'll be creating a healthier, more comfortable, and more durable bathroom environment for your home.
Ensuring your bathroom has the correct ventilation for its size now means that by the time the colder and wetter weather arrives, your space can handle it all while remaining in tip-top condition throughout. 
If you’re considering a new bathroom extractor fan, book an appointment with The Bathroom Showroom. Experts in all things bathrooms, we can help turn your dream bathroom into a reality.