MVHR Systems provide controlled ventilation with slow but constant air movements. Therefore it is recommended to install such systems only in properties with relatively good air tightness. We recommend an air tightness of at least 5 m3/(m2*h) at the pressure test (q50), ideally below 3 m3/(m2*h). Air tightness targets should always be set for new built and refurbishment properties.
e.g. in a refurbishment project where windows are exchanged and other measures to increase the insulation and air tightness are being undertaken, MVHR system can definitely be a beneficial addition in the aim to increase the energy efficiency.
Passivhaus projects and Enerphit projects (refurbishment) rely on best performing MVHR systems due to their high demands on energy efficiency.
Other criteria are
1. Noise: if a property suffers from noise, e.g. traffic or airport, MVHR systems with adequate silencers will provide a good solution for ventilation without the need to open windows. Additionally noise reduced glazing will help.
2. High condensation: MVHR systems will actively dehumidify when it is outside colder than inside.
3. Air quality: if the air quality is problematic, various kind of filtration in MVHR systems can deal with pollen, rural and industrial smells.
If in doubt, please do contact us to discuss your project.