What is MVHR and How Does It Work?

Ben from Earthwise delivering MVHR - mechanical ventilation with heat recovery - training to students in collaboration with The Green Register and Retrofit West

Mechanical Ventilation with Heat Recovery (MVHR) is a state-of-the-art whole-house ventilation system designed to provide continuous fresh air while minimising heat loss. If you’ve ever wondered, “What is MVHR?”, this guide will explain how it works and why it’s an excellent choice for modern buildings.

How Does an MVHR System Work?

At its core, an MVHR system extracts stale air from inside a building and replaces it with fresh outdoor air. But what makes it special is its ability to recover heat from the outgoing air and transfer it to the incoming air via a heat exchanger. This ensures that valuable heat energy isn’t wasted, making it a highly efficient system.

Interestingly, the system works equally well in summer by helping to retain cooler indoor temperatures when the outside air is warmer. Here’s a detailed breakdown of its operation:

  1. Air Extraction: MVHR systems remove stale air from areas where moisture and odours are common, such as kitchens, bathrooms, and utility rooms. This air is ducted to the heat recovery unit for processing.
  2. Heat Recovery: Inside the heat exchanger, the outgoing stale air transfers its heat energy to the incoming fresh air. Importantly, the two air streams do not mix, ensuring clean and fresh air is supplied indoors.
  3. Air Distribution: Once pre-warmed (or pre-cooled in summer), the fresh air is distributed to habitable rooms like living rooms and bedrooms via a network of ducts and valves.
  4. Balanced Ventilation: MVHR systems maintain a balanced airflow by ensuring that the rate of air extraction matches the rate of air supply. This prevents draughts and ensures even distribution of fresh air throughout the building.
  5. Filtration: Many MVHR systems include high-quality filters that remove dust, pollen, and other airborne particles from the incoming air. This is especially beneficial for allergy sufferers and improves overall indoor air quality.
  6. Advanced Controls: MVHR units are equipped with intelligent controls to optimise performance. These systems monitor factors like indoor air quality, outdoor temperature, and humidity levels, adjusting operation to maintain comfort and energy efficiency. Some units even offer mobile app controls for added convenience.

Exploring Ventilation Solutions: Retrofit Skills in Action

The photos above are from an insightful day at the Earthwise MVHR Showroom with The Green Register team for the Retrofit Skills Ventilation Module (7). Ben from Earthwise guided participants through the pros and cons of ventilation systems, including MVHR, MEV, and DCV, with hands-on training and a final test.

This session is part of The Green Register’s new Retrofit Skills Course, offering attendees a Level 2 qualification to enhance their knowledge of ventilation in retrofit projects.

Credit: West of England Mayoral Combined Authority

Find out more: www.greenregister.org.uk/news/introducing-the-retrofit-qualification/

Why Choose an MVHR System?

By continuously exchanging stale indoor air with fresh outdoor air and recovering heat, MVHR systems deliver numerous benefits:

  • Enhanced Indoor Air Quality: Filters remove allergens and pollutants, ensuring clean, fresh air for occupants.
  • Energy Efficiency: The heat recovery process minimises energy loss, reducing heating and cooling costs.
  • Year-Round Comfort: Balanced ventilation and temperature regulation maintain a pleasant indoor environment regardless of the season.
  • Sustainability: By reducing energy consumption, MVHR systems contribute to environmental preservation and lower carbon footprints.
  • Healthier Living Spaces: Proper ventilation reduces condensation and mould, creating healthier spaces for you and your family.

Conclusion

If you’ve been asking, “What is MVHR?”, the answer lies in its innovative approach to ventilation and energy efficiency. MVHR systems are a game-changer for modern buildings, offering a comprehensive solution for maintaining optimal indoor air quality and energy efficiency. By seamlessly integrating ventilation, heat recovery, filtration, and intelligent controls, they ensure a comfortable, healthy, and sustainable indoor environment. Whether you’re building a new home or upgrading an existing property, investing in an MVHR system is a step towards better living and environmental stewardship.

For help choosing the right MVHR solution for your project please contact our friendly team.