Residential Buildings: Installing or upgrading ventilation systems

Installing or upgrading ventilation systems in residential buildings is not only important for comfort and air quality, but also a key element of energy-efficient construction. Self-installation is generally allowed, but specific technical minimum requirements must be met – particularly regarding heat recovery. Compliance with these requirements must be confirmed by a specialist contractor’s declaration.

Technical Requirements for the Ventilation System
According to DIN 4701 Part 10, energy-related product data are used to determine the so-called system performance number. The stated values apply only to non-wind-exposed locations with average wind speeds below 5 m/s.
A key parameter is the heat recovery efficiency (ηₙWRG), which indicates how effectively a ventilation system recovers heat from exhaust air. For certain systems – e.g., centralised, decentralised or room-based units with heat exchangers – the following minimum requirements apply:

• ηₙWRG ≥ 80% at a specific electrical power consumption ≤ 0.45 W/(m³/h)
  or
• ηₙWRG ≥ 75% at a specific electrical power consumption ≤ 0.35 W/(m³/h)
  These requirements ensure energy-efficient operation. In typical applications (20–58 m³/h), values such as ηₙWRG = 0.78 and 0.3 W/(m³/h) consumption may be achieved – meeting the required standards.
  Important: Heat recovery values do not apply when the system operates solely in cross-ventilation mode (i.e., without active ventilation).

Funding Requirements for Ventilation Systems
To be eligible for government subsidies, additional proof is needed:

• The system’s air volume flows must be measured, set and documented according to EN 12599 (commissioning protocol).
• Alternatively, the requirement is fulfilled if the system achieves a specific energy consumption (SEC) < -26 kWh/(m²a) according to Ecodesign Directive 1253/2014 (corresponds to SEC class B for an average climate).

Conclusion
Those installing or upgrading a residential ventilation system can save energy and benefit from subsidies if they choose efficient products and follow proper installation practices.

Commissioning Protocol Download

To document your system properly, we provide a sample commissioning protocol as a downloadable PDF.
Note: The sample may not cover all project-specific details. Use the designated fields to add any necessary additional information.