Despite significant advances in home insulation and energy-saving design, one persistent issue continues to affect many UK households: mould and damp.
Despite significant advances in home insulation and energy-saving design, one persistent issue continues to affect many UK households: mould and damp.
You might assume that upgrading your home with double glazing, added insulation, or new doors would eliminate condensation problems. In reality, many of these improvements actually trap moisture indoors, worsening the conditions for mould growth. Without proper ventilation, moisture has nowhere to go—and in modern airtight homes, this quickly becomes a serious health and structural concern.
This is where Mechanical Ventilation with Heat Recovery (MVHR) comes in. MVHR doesn’t just manage airflow—it actively removes moisture from your home’s most humid areas while retaining valuable heat. If you’ve been battling black spots on the ceiling, musty smells, or condensation on windows, an MVHR system could be the long-term solution you need.
Today’s homes are better sealed and insulated than ever before. While this helps reduce energy use, it also limits natural ventilation. The problem? Every day, we release litres of water vapour into the air through:
Without a system to continuously extract this humid air and replace it with fresh, filtered air, moisture begins to build. The result?
According to the NHS, exposure to indoor damp and mould can worsen asthma, allergies, and respiratory infections[1].
MVHR systems solve this problem by constantly extracting moist air from your home’s wet rooms (bathroom, kitchen, utility) and supplying clean, filtered air into living areas and bedrooms. All while recovering up to 90% of the heat from the outgoing air.
Here’s how it works:
With MVHR, you no longer need to rely on extractor fans, open windows, or dehumidifiers.
In 2023, a homeowner in South West London contacted ClimateWorks after ongoing mould problems in their two-bedroom flat. Despite repainting, treating surfaces, and running a dehumidifier, the issue persisted—particularly in the bathroom and main bedroom.
The property had recently been upgraded with new windows and insulation, which had reduced energy bills but worsened condensation.
Many households rely on extractor fans in bathrooms or portable dehumidifiers to combat moisture. These can help temporarily—but they’re often:
MVHR is the only system that provides whole-house, continuous, and balanced ventilation—ensuring every room is kept dry, healthy, and well-ventilated at all times.
When damp is already present, it’s essential to install MVHR correctly:
ClimateWorks designs each MVHR installation around your home’s specific layout and problem areas, ensuring the system solves rather than shifts the issue.
Even the best MVHR system needs regular upkeep to perform effectively:
Neglecting maintenance can reduce airflow, allowing humidity to rise again and putting your home at risk.
If you’re dealing with recurring mould or condensation issues—especially after upgrading insulation or windows—MVHR could be the permanent fix.
It’s not just about air movement. It’s about smart ventilation, designed to improve your indoor environment, reduce health risks, and protect your property from hidden moisture damage.
To speak to a specialist or arrange a no-obligation home survey, contact the team at https://www.climateworks.co.uk
Dr. Julian Carter is a highly experienced thermal systems expert with over 15 years in the field, holding a PhD in thermal systems. His career spans academic research, consulting, and teaching, focusing on air conditioning and refrigeration systems. Dr. Carter bridges the gap between theoretical advancements and practical applications, providing expert insights to organisations like ClimateWorks, where his guidance informs decision-making and industry best practices. Notably, he has worked on international projects with organisations such as Daikin Industries, the International Institute of Refrigeration (IIR), and the United Nations Environment Programme (UNEP). Currently a lecturer at Edinburgh University, Dr. Carter combines his expertise with a passion for educating the next generation of engineers and advancing climate control technologies.
[1] NHS. (2023). Health risks of damp and mould in homes. Retrieved from https://www.nhs.uk/conditions/damp-and-mould
[2] UK Government. (2022). Approved Document F – Ventilation. Retrieved from https://www.gov.uk/government/publications/ventilation-approved-document-f
[3] Energy Saving Trust. (2024). How to Reduce Humidity in Your Home. Retrieved from https://energysavingtrust.org.uk