Extractor Fan Mistakes to Avoid

Extractor Fans: Why Getting It Right Matters

If you’re dealing with mould in the bathroom, steamed-up windows, or musty smells in your home, there’s a good chance your extractor fan isn’t doing its job properly—or wasn’t installed correctly in the first place.

At Smart Ohm, we install high-performance extractor fans across Leeds and West Yorkshire with a focus on proper design, long-term performance, and Building Regulations compliance. This blog highlights what goes wrong in many homes—and how to get it right the first time.

The Most Common Extractor Fan Mistakes

1. Using Flexible Ducting

Flexible ducting may be cheap and easy to fit, but we avoid it whenever possible—and here’s why:

• It’s prone to kinks and crushing, which increases air resistance
• Condensation can pool inside the duct, leading to drips, mould, or corrosion
• It reduces airflow and can cause fans to underperform or fail

Instead, we install rigid or semi-rigid ducting with smooth internal walls that maintain proper airflow and last longer without sagging.

2. Choosing the Wrong Type of Fan

Not all extractor fans are the same. Installing a basic axial fan in a long duct run or an internal bathroom often leads to poor airflow. We choose fan types based on your property layout:

• Axial fans for short, direct external wall installations
• Centrifugal fans for longer duct runs
• Inline fans for loft and ceiling void use
• DMEV fans for continuous background ventilation

Each type is suited to a specific airflow requirement—and getting that wrong often means replacing the whole setup.

3. Poor Duct Routing

Long, twisted, or uphill duct runs can completely defeat even a good-quality fan. We always design systems with:

• Short, direct routes to external walls or soffits
• Proper fall angles to prevent water build-up
• Correct termination grilles with backdraft protection

Airflow is everything when it comes to ventilation, and poor routing can undo a perfectly good installation.

4. Lack of Isolation Switch or Incorrect Wiring

Bathroom and kitchen fans must be wired correctly and safely, with an accessible isolation switch—typically located outside the room. We install all extractor fans in accordance with:

• Part P of the Building Regulations (Electrical Safety in Dwellings)
• Zoning and IP rating rules for bathrooms
• Appropriate fusing and cable types

Poor wiring and missing isolation are not only non-compliant—they’re unsafe.

Types of Extractor Fans That Actually Work

At Smart Ohm, we don’t just install whatever’s in stock. We specify and fit the right type of fan for each job:

• Axial Fans - Simple fans suited to short, direct-through-wall installs—typically in ground-floor WCs or external bathrooms.
• Centrifugal Fans - More powerful units ideal for first-floor bathrooms, utility rooms, and other areas with longer duct runs or internal positions.
• Inline Fans - Fitted in lofts or ceiling voids, inline fans are perfect for discreet bathroom extraction with minimal noise in the room itself.
• Timer Fans - Great for WCs or bathrooms—these continue to run after the light is turned off, ensuring moisture is removed properly.
• Humidity Sensor Fans - React automatically to rising moisture levels—ideal for family homes or where users forget to switch the fan on.
• Silent/Low-Noise Fans - Essential for noise-sensitive areas like bedrooms or ensuites. These run quietly while maintaining consistent airflow.

What is DMEV? (And Why It Matters for Modern Homes)

DMEV (Decentralised Mechanical Extract Ventilation) systems run continuously at low speed, boosting when humidity rises. They’re ideal for:

• New builds and refurbishments
• Energy-efficient or airtight homes
• Meeting Part F of the Building Regulations

DMEV fans provide silent, consistent extraction that protects your home from damp and mould 24/7 without needing user input.

Why We Replace, Not Repair

We’re often asked about fan repairs—but in most cases, especially with older models, it’s simply not worth it. Modern fans are:

• More efficient
• Quieter
• Easier to maintain
• Often cheaper to replace than repair

At Smart Ohm, we don’t offer fan diagnostics or repairs—we focus on installing new, properly fitted extractor fans that meet today’s performance expectations.

Our Approach to Extractor Fan Installation in Leeds

Every installation we carry out includes:

• Fan selection based on your home’s layout and needs
• Proper ducting (rigid or semi-rigid wherever possible)
• Compliant wiring and isolation
• Advice on fan settings and usage
• Fully tested and guaranteed work by a registered electrician

We also install in line with Part F and Part P of the Building Regulations—ensuring your installation is both safe and legally compliant. Whether you’re replacing an outdated fan or planning a renovation, we offer expert advice and quality installation, every time.

Need a Proper Extractor Fan Installation in Leeds?

If you’re tired of ineffective fans, black mould, or condensation that just won’t shift—get it sorted properly. Smart Ohm offers professional extractor fan installation across Leeds and West Yorkshire, with proper ducting, the right fan type, and certified installation that’s built to last.