Craig Cundey from Ubbink UK looks at a recent installation of MVHR by Byfield Damp Solutions in Buckinghamshire, and how the technology can fight against black mould:
Ubbink UK supported a residential ventilation project in Oxfordshire after a homeowner experienced persistent damp and black mould problems. The issue had been ongoing for years. The homeowner had previously invested in high-end triple glazing throughout the property, the windows had been installed without trickle vents, significantly reducing natural airflow.
With limited ventilation and a highly airtight building envelope, humidity levels increased, and mould began to develop across several areas of the home. The homeowner first approached Byfield Damp Solutions in October 2024, at which point it was obvious that the remedy was going to be MVHR, but the installation was going to be extremely difficult with a run of the mill MVHR / ducting solution. The customer was considering his options for over a year and finally decided to proceed in early 2026.
The Challenge
Working alongside Byfield Damp Solutions, Ubbink supplied a Mechanical Ventilation with Heat Recovery (MVHR) system together with its market leading ducting and distribution boxes to restore healthy indoor air quality and eliminate the mould problem.
The final specification comprised of over 200 metres of ducting, a great deal of which was installed through the loft spaces. Two of the loft spaces had reduced heights of under a metre which made the project particularly difficult. Three lintols also had to be installed to get the ducting through brick walls within the property.
Black mould is becoming increasingly common in modern homes, particularly where insulation and airtightness improvements have been made without adequate ventilation.
In this case:
- The property measured approximately 260 m²
- Ventilation rates were far below requirements
- The building had evolved over time with two large extensions and four loft spaces
- Airflow throughout the house was almost non-existent
Under UK Building Regulations Part F, homes should achieve 0.3 litres of airflow per second per square metre of floor area. For this property, that requirement was not being met.
As a result, moisture from everyday activities such as cooking, bathing, and drying clothes accumulated inside the property, leading to significant black mould growth.
The Solution: MVHR Ventilation System
Byfield Damp Solutions knew from the outset that an MVHR system was going to be required but would be difficult to install, and Craig Cundey from Ubbink, provided substantial technical support which meant that the project could proceed to installation.
The system was turned on in February 2026, by the 11th March 2026 was consistently registering a relative humidity at sub 45%. This was despite the fact that Byfield Damp Solutions had also installed “room in roof” insulation to the entire first floor so it had been re-plastered.
Despite the complexity of the property layout, the installation was made possible thanks to the flexible design of Ubbink’s ventilation systems, which are engineered to adapt to challenging retrofit environments.
Once installed and commissioned, the system now operates almost silently while delivering approximately 250 m³ of fresh air per hour throughout the home.
The result has been a complete transformation of the indoor environment, with humidity levels stabilised and black mould eliminated.
Why MVHR Systems Help Prevent Black Mould
Modern homes often prioritise energy efficiency and airtight construction, but without proper ventilation this can lead to moisture build-up and mould growth. MVHR systems provide a long-term solution by delivering continuous, controlled airflow while recovering heat energy.
Key Benefits
Mould Prevention
MVHR systems reduce indoor humidity and condensation, significantly lowering the risk of mould formation.
Healthier Indoor Air
Stale air, pollutants, allergens, and excess moisture are continuously removed, improving indoor air quality.
Energy Efficiency
Heat recovery technology can retain up to 95% of heat energy, helping reduce heating costs while maintaining comfort.
Regulatory Compliance
Balanced ventilation supports compliance with UK Building Regulations Part F.
The Result
Following installation of the Ubbink MVHR system, the property now benefits from:
- Continuous fresh airflow throughout the home
- Stable humidity levels
- Improved indoor air quality
- Quiet, energy-efficient ventilation
- Complete elimination of black mould
This project demonstrates how effective mechanical ventilation can transform indoor environments, particularly in modern airtight homes where natural ventilation is limited.
Find out more at: Roofing Solutions- Building, Ventilation and Energy- Ubbink uk | Ubbink
