What is summer bypass on MVHR?
Understanding Summer Bypass in MVHR Systems
How Summer Bypass Works
MVHR systems typically recover heat from stale indoor air to warm incoming fresh air. However, during warmer months, this heat recovery becomes counterproductive. Summer bypass solves this by using a valve to divert incoming air around the heat exchanger when outdoor temperatures are cooler than indoors. This ensures fresh, cool air enters the home directly, reducing reliance on air conditioning and improving comfort .
Key components:
- Temperature sensors: Monitor indoor/outdoor conditions to trigger bypass activation.
- Bypass valve: Redirects airflow, bypassing the heat exchanger.
- Control logic: Automates the process for seamless operation.
Why Summer Bypass Matters in the UK
The UK’s temperate climate sees summer nights cool enough to leverage natural ventilation. With rising energy costs and sustainability goals, summer bypass offers:
- Energy savings: Reduces cooling costs by up to 15% in well-insulated homes .
- Improved air quality: Maintains continuous filtered ventilation, critical for urban areas with pollution.
- Mould prevention: Balances humidity levels, reducing condensation risks in kitchens and bathrooms .
Summer Bypass vs. Summer Purging
While both strategies cool homes, they serve different purposes:
| Feature | Summer Bypass | Summer Purging |
|---|---|---|
| Method | Automated MVHR valve adjustment | Manual window opening |
| Use Case | Mild cooling during cooler nights | Rapid cooling during heatwaves |
| Energy Impact | Low (uses existing system) | None (passive) |
| Air Quality | Maintains filtration | Depends on outdoor pollution levels |
For optimal results, combine both: use bypass for consistent nighttime cooling and purging for extreme heat .
Choosing the Right MVHR System
Centralised systems (e.g., VENTI RESPIRO) suit new builds with ductwork, offering whole-house efficiency. Decentralised units (e.g., VENTI FLUXO) are ideal for retrofits, providing room-specific control without ducts .
Key considerations:
- Automatic bypass: Look for models with integrated sensors.
- Noise levels: Ensure <30 dB for bedrooms.
- Filters: HEPA filters enhance air quality in polluted areas.
Upgrade your home’s ventilation with a summer bypass-equipped MVHR system to save energy, improve air quality, and stay comfortable year-round.
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