A ductless air exchanger, often referred to as a decentralised MVHR (Mechanical Ventilation with Heat Recovery) system, is a ventilation device designed to supply fresh air and extract stale air from individual rooms or small spaces without requiring ductwork. It operates by alternating airflow streams through a single wall-mounted unit, recovering heat from the extracted air and transferring it to the incoming air. This process typically achieves heat recovery efficiencies of 80-90%.
Key Features
- Ductless Design: Eliminates the need for complex ducting, making it ideal for retrofitting older UK homes where installing traditional ducted systems may be impractical or costly.
- Single-Room Application: Often used in kitchens, bathrooms, or extensions, providing localised ventilation and heat recovery.
- Energy Efficiency: Reduces heating demand by recovering waste heat, aligning with UK Building Regulations Part L (Conservation of Fuel and Power).
Practical Examples
- Retrofit Projects: In UK terraced houses, units like the FLUXO 100 or AUREN 160 are installed through external walls to improve indoor air quality without structural modifications.
- Compliance: Helps meet Part F (Ventilation) requirements in renovations, particularly in airtight homes post-insulation upgrades.
Real-World Applications
- A 1930s semi-detached house in London retrofitted with decentralised MVHR units in wet rooms to combat condensation while preserving historic features.
- Small-scale new builds (e.g., garden offices) using ductless systems to achieve near-passivehaus performance with minimal space requirements