How to Prevent Mould in Ventilation Ducts
Mould in ventilation ducts isn’t just a problem to look past.
It’s a potential health hazard and a threat to the efficiency of your ventilation system.
It can cause musty odours, compromise air quality, and lead to expensive repairs.
To prevent mould, it’s essential to understand what causes it and how to address the risks effectively.
Let’s dive into it.
What Causes Mould in Ventilation Systems?
Mould thrives in environments where moisture and poor airflow combine.
Ventilation ducts can become damp due to high humidity, condensation, or leaks in the system.
This is especially problematic for ventilation ducting, where stagnant air allows moisture to linger.
Dust and dirt trapped inside the ducts makes the situation worse, providing the nutrients mould needs to grow.
Even with smooth or flexible ducting materials, regular maintenance is necessary to keep the system clean and mould-free.
1. Keep Humidity Under Control
One of the best ways to stop mould in its tracks is to control indoor humidity levels.
Ideally, the humidity in your building should stay between 30% and 50% depending on the season (according to Checkatrade)
High humidity not only makes the environment uncomfortable but also increases the likelihood of condensation forming inside the ventilation ducts.
Dehumidifiers can help in areas prone to dampness, such as basements or bathrooms.
If your system includes underground ducting, it’s especially important to monitor moisture levels, as these environments are naturally more humid.
2. Clean and Inspect Your Ducts Regularly
Dust, dirt, and organic debris inside the ducts create an ideal environment for mould.
Regular inspections allow you to identify early signs of trouble, such as musty odours or visible patches of mould.
Cleaning the ducts periodically ensures airflow isn’t obstructed and removes potential mould food sources.
For systems using rectangular ventilation ducting, specific cleaning tools may be needed to reach every surface effectively.
Proper cleaning methods extend the lifespan of your ducting and keep it functioning efficiently.
3. Design and Install Ducts Correctly
Proper design and installation play a critical role in mould prevention.
Poorly sized or installed systems can restrict airflow, creating areas where moisture builds up.
This is particularly relevant for round ventilation ducting, which needs to maintain smooth airflow throughout the system to minimise condensation risks.
To avoid these issues, ensure the duct connections are tightly sealed and that insulation is used where necessary.
This helps reduce temperature fluctuations and prevents moisture from forming inside the ducts.
Additionally, where possible, it is recommended to use smooth bore rigid ventilation pipe instead of flexible ducting.
Flexible underground ducting contains peaks and troughs due to the helix running through it, which can lead to water pooling inside the duct.
This trapped moisture increases the risk of mould growth and airflow restriction.
To minimise these issues, flexible ducting should only be used for short connection pieces of up to 300mm when necessary, while the majority of the system should be rigid ducting.
4. Address Leaks and Condensation Promptly
Water leaks or condensation in ductwork can lead to rapid mould growth if not addressed.
Regularly inspect your system for any signs of leaks, especially around joints and fittings.
Repair any damage as soon as it’s spotted to prevent further moisture from entering the ducts.
Insulation is your best defence against condensation.
By maintaining consistent internal temperatures, insulated ducts significantly reduce the risk of water build-up, keeping the system dry and mould-free.
5. Use the Right Materials
The materials used in your ducting system can make a big difference in mould prevention.
Smooth-surfaced ducts, such as those used for ventilation ducting, are easier to clean and less likely to trap debris.
Some ducting materials also come with anti-microbial coatings that provide additional protection against mould and bacteria.
Investing in high-quality materials ensures your system remains efficient and easier to maintain over time.
6. Don’t Skip Professional Maintenance
While regular cleaning and inspections go a long way, professional maintenance ensures a deeper level of care.
Specialists have the tools and expertise to clean the system thoroughly and identify potential problems early.
This is particularly important for larger systems, such as those with rectangular ventilation ducting, where hidden issues can develop over time.
