Ventilation

Ventilation: single flow or double flow? Comparative guide 2025

Complete comparison of VMC ventilation systems for your home: operation, advantages, disadvantages, price and grants in Belgium.

· 13 min read · VCN Energy

Mechanical ventilation: single flow or double flow? The definitive guide

Indoor air quality has become a major concern, particularly since our homes are better and better insulated. Effective ventilation is essential to renew the air, evacuate humidity and pollutants, while preserving thermal comfort.

Why is ventilation essential?

Indoor air, more polluted than we think

Contrary to popular belief, indoor air in our homes is often 5 to 10 times more polluted than outdoor air. Without sufficient air renewal, these pollutants accumulate and can cause health problems.

Single flow ventilation

The single flow VMC extracts stale air from humid rooms thanks to a centralized extractor. Fresh air enters passively through air intakes in living rooms.

Advantages:

  • Moderate installation cost: €500 to €1,500
  • Simple maintenance
  • Low electrical consumption

Double flow ventilation

The double flow VMC simultaneously provides extraction of stale air AND supply of fresh air with heat recovery up to 90%.

Advantages:

  • Heat recovery: 15% to 25% heating savings
  • Increased thermal comfort
  • Air filtration

Conclusion

The choice between single flow and double flow depends on your specific situation.

Contact VCN Energy at 0470 27 16 08 for a personalized study of your ventilation needs.

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