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Back to Knowledge Hub14.04.2026
Supply and exhaust air ventilation is no longer an optional comfort feature, but a central component of modern building planning. Airtight building envelopes, increasing energy efficiency requirements and clear regulatory specifications mean that natural air exchange via leakages is no longer sufficient.
For planners, architects and contractors, this creates a clear task: indoor air quality, moisture protection and energy efficiency must be ensured technically. This is exactly where supply and exhaust air ventilation systems come into play.
This article explains how supply and exhaust air ventilation works, what system types exist and what really matters in planning and implementation. A particular focus is placed on when centralised solutions make sense and where decentralised systems offer clear advantages.
Modern buildings are designed to be almost airtight. While this is beneficial from an energy perspective, it quickly leads to indoor problems without controlled ventilation.
A functioning supply and exhaust air ventilation system fulfils three key tasks:
Especially in residential buildings, large amounts of moisture are generated daily through showering, cooking and normal usage. Without continuous air exchange, this moisture cannot be reliably removed.
Missing or insufficient supply and exhaust air ventilation repeatedly leads to the same issues in practice:
Traditional window ventilation is not a reliable solution. It depends on user behaviour, is inconsistent and often insufficient in practice.
With increasing energy efficiency requirements, construction methods have changed significantly. Airtight building envelopes are now standard in both new builds and renovations.
This means:
For planners, the consequence is clear: supply and exhaust air ventilation must be integrated early into the overall concept and cannot be treated as an afterthought.
Supply and exhaust air ventilation describes the controlled exchange of used indoor air with fresh outside air, while simultaneously removing moisture and pollutants. This is achieved either naturally or via technical systems.
A supply and exhaust air ventilation system follows a clear principle: air is supplied and extracted in a controlled manner.
Two airflows perform different functions:
Air exchange takes place continuously and independently of user behaviour, ensuring consistent ventilation throughout the building.
In systems with heat recovery (HRV), a large portion of the heat contained in the exhaust air is transferred to the incoming supply air. This significantly reduces energy losses.
In practice, two basic approaches are distinguished:
Natural ventilation:
Controlled supply and exhaust air ventilation:
For modern buildings, controlled ventilation is often the only way to reliably ensure moisture protection and indoor air quality.
Choosing the right system is one of the key planning decisions.
Centralised ventilation systems
Primarily used in new builds due to early planning requirements.
Decentralised ventilation systems
Especially in renovations, decentralised systems offer clear advantages.
Result: preheated fresh air enters the building without additional heating energy.
Heat recovery is particularly beneficial in energy-efficient buildings and renovations.
New build
Existing buildings / retrofitting
Roof ventilation
Room-based ventilation
Supply air areas:
Exhaust air areas:
There is no general legal obligation in Germany, but standards apply.
DIN 1946-6
Requires a ventilation concept for residential buildings to ensure:
In practice, this often leads to the need for technical ventilation systems.
Key parameters:
Airflow concept:
Centralised:
Decentralised:
Centralised:
Decentralised:
New build
Centralised systems often preferred
Renovation
Decentralised systems usually more efficient
Hybrid solutions
Combination of both systems possible
Supply and exhaust air ventilation is an essential part of modern building design. Airtight construction, energy requirements and regulations make controlled air exchange indispensable.
For planners: Ventilation must be integrated early.
For contractors: Clear planning ensures efficient implementation.
In practice, decentralised ventilation systems with heat recovery (HRV) often provide the most efficient and flexible solution, especially in existing buildings.
Working with an experienced manufacturer specialising in decentralised ventilation systems, sound insulation and modular solutions helps ensure reliable planning and smooth execution.
Those who would like to explore individual aspects of supply and exhaust air ventilation in more depth will find additional expert articles in our blog with a clear practical focus. Particularly useful is the comparison between centralised and decentralised ventilation systems, which provides a solid basis for decision-making across different project types. In addition, an article on ventilation levels according to DIN 1946-6 offers clarity on regulatory requirements and their practical implementation in planning.
Furthermore, overview articles on various ventilation systems as well as ventilation planning by building type provide a structured insight into technical possibilities and demonstrate how solutions can be specifically adapted to usage and building conditions. This creates a deeper overall understanding that can be directly applied in both planning and execution.
Contact
We provide architects and technical planners tailored solutions to address every ventilation challenge with precision. Whether it is sound insulation, energy efficiency, or optimising facade aesthetics, our expert technical teams are equipped to provide you with the ideal solutions.
With Ventomaxx, you gain access to comprehensive hybrid ventilation concepts that seamlessly combine passive and active systems from a single, trusted source. Our mission is to improve indoor air quality in the most efficient way.
We provide architects and technical planners tailored solutions to address every ventilation challenge with precision. Whether it is sound insulation,
energy efficiency, or optimising facade aesthetics, our expert technical teams are equipped to provide you with the ideal solutions.
With Ventomaxx, you gain access to comprehensive hybrid ventilation concepts that seamlessly combine passive and active systems from a single, trusted source. Our mission is to improve indoor air quality in the most efficient way.
