It’s a familiar story we hear from homeowners across Bournemouth, Poole, and the wider Dorset area. You’ve invested in modern, sealed windows—hoping for lower heating bills and a warmer, quieter home—only to be met with the frustration of daily window condensation and, eventually, patches of black mould.
We recently spoke to a homeowner whose experience perfectly illustrates this common challenge. They had an older property but had significantly improved its insulation and airtightness with new windows. The result? A home that, while warmer, was suffering from chronic moisture build-up. Their old, intermittent bathroom fan and kitchen extractor simply could not cope with the continuous moisture load being generated.
The problem isn’t the new windows; it’s the sudden, unmanaged shift in the home’s ventilation strategy. Older Dorset homes relied on air leaks to ‘breathe.’ When you seal those gaps, you create an efficient, yet ultimately sealed, box. To solve the resulting condensation and mould, you must replace that accidental ventilation with a professional, continuous mechanical system.
Why a Continuous Ventilation Strategy is Essential for Coastal Properties
The core of the issue for many homes near the Dorset coast is two-fold: high internal moisture combined with the local climate’s characteristics.
The Regional Challenge in Bournemouth and Poole
The properties in and around Bournemouth and Poole are often a mix of spacious Victorian and Edwardian terraces, as well as post-war estates. These types of housing present unique ventilation hurdles:
- Period Property Retrofits: Many older homes, especially those undergoing extensive renovation, had high air permeability. Sealing them up without introducing mechanical airflow traps all internally generated moisture, which quickly condenses on the coldest surfaces—the new, thermally-efficient windows.
- Coastal Humidity: Dorset’s coastal location means the ambient air often has naturally higher humidity levels compared to inland areas. When this moist air is drawn in or retained, it compounds the problem. Furthermore, sea fog and prevailing wet weather patterns demand a robust, continuous system to maintain a healthy internal environment.
A traditional, light-activated bathroom fan that only runs for minutes cannot control a -hour humidity problem. You need a transition to a system that provides continuous mechanical ventilation.
What a Decentralised Ventilation Upgrade Involves
For homeowners in Bournemouth and Dorset looking for a permanent solution, the decentralised ventilation system is the ideal retrofit strategy. It avoids the complex ductwork of a central system and is perfect for a supply-only project managed by your own contractor.
The strategy involves installing two types of high-performance units to create balanced airflow:
1. Continuous Extract in Wet Rooms with ARIA
The first step is upgrading the extract in high-moisture ‘wet rooms’—the bathroom, kitchen, or utility. This is achieved by installing a Decentralised Mechanical Extract Ventilation (dMEV) unit, such as the ARIA.
The ARIA Advantage: The ARIA is a smart, discreet unit that runs 24/7 at a whisper-quiet trickle speed. It features a built-in humidistat that constantly monitors the air. When it detects a spike in humidity (like a steamy shower), the ARIA automatically boosts to clear the damp air fast and prevent condensation from forming. This continuous, low-level extraction ensures that moisture is removed as it’s generated.
2. Balanced Fresh Air in Habitable Spaces with AUREN or FLUXO
For the rest of the house—bedrooms, living room, and study—you must introduce a continuous supply of fresh, filtered air, but without the heat loss of an open window. This is achieved using Single Room Heat Recovery (srMVHR) units like the AUREN or the FLUXO.
How AUREN or FLUXO Works: These units are installed through a single core-drilled hole in the wall and operate on an alternating cycle:
- Heat Recovery: They alternately extract stale, warm air (recovering up to of the heat with AUREN or with FLUXO using a ceramic core) and then supply fresh, filtered air back into the room.
- Energy Efficiency: This process ensures you get continuous fresh air while retaining your heat, protecting your energy bills (for example, the FLUXO costs around per year per unit to run).
- Simple Installation: Their decentralised nature makes them straightforward for your chosen electrician or contractor to fit, avoiding the complexity and mess of ducted systems in a retrofit environment.
How Proper Ventilation Prevents Recurring Problems
By switching to a continuous, smart, and balanced ventilation system, you address the root cause of the issue: trapped humidity.
The ARIA, AUREN, and FLUXO units work together to:
- Maintain Low Relative Humidity: By continuously exchanging air, the system maintains a consistent relative humidity level () that is too low for mould spores to thrive, typically below .
- Ensure Air Quality: It removes internal pollutants, odours, and dust particles, ensuring a healthier living environment—a significant benefit for families in coastal areas where damp can impact respiratory health.
- Protect Property Value: Eliminating mould and persistent condensation safeguards internal décor, plasterwork, and window frames, protecting your investment in your Dorset home.
Next Steps for Homeowners in Bournemouth and Dorset
If you’re in the Bournemouth, Poole, or Christchurch area and your new, sealed windows have unintentionally created a condensation and mould problem, VENTI is here to help.
The decentralised approach using ARIA, FLUXO, and AUREN is designed for your situation. We specialise in providing homeowners with a full ventilation strategy service, calculating the required airflow based on a simple floor plan to ensure you select the correct number and size of units to fully comply with Building Regulations Part F.
We can provide all the high-quality, energy-efficient units you need on a supply-only basis for your chosen qualified contractor to install.
To take the next step towards a permanently dry, healthy, and mould-free home, please contact the VENTI Group team for expert advice and to begin planning your custom ventilation solution.