Passive airflow supply (system) (PAS) units are used for the controlled supply of outside air into buildings and are part of ventilation concepts in accordance with DIN 1946-6. They operate passively and introduce outside air into living and occupied spaces depending on pressure differences – for example caused by wind or thermal buoyancy.
In combination with fan-assisted exhaust air systems (e.g. in kitchens, bathrooms or WCs), PAS units enable defined airflow within the building: while stale and humid air is mechanically removed, outside air flows in via the PAS units. This ensures the air exchange required for moisture protection.
This creates a directed airflow from supply air rooms to exhaust air rooms, reducing humidity, odours and pollutants.
What is a passive airflow supply (system) (PAS) unit?
A passive airflow supply (system) (PAS) unit is a passive ventilation component that introduces fresh outside air into a building without the use of electrical components. It provides the supply air function within a ventilation concept and ensures that extracted air is replaced by fresh outside air.
How does a passive airflow supply (system) (PAS) unit work?
PAS units use pressure differences between indoor and outdoor air. When air is removed from the building via exhaust air systems, a slight negative pressure is created. As a result, fresh outside air flows in through the PAS unit.
Typical ventilation principle:
Supply air (PAS) → living spaces → wet rooms → exhaust air
This interaction enables continuous air exchange within the building.
Passive airflow supply (system) (PAS) units in ventilation concepts
PAS units are often part of ventilation concepts according to DIN 1946-6. They ensure the required fresh air supply and support moisture protection within the building. They are particularly used:
- in combination with exhaust air systems
- in living and occupied spaces
- in renovations and retrofitting
- in buildings with airtight construction
Advantages of passive airflow supply (system) (PAS) units
PAS units offer a simple and cost-effective solution for fresh air supply:
- energy-efficient, as no electricity is required for air transport
- low maintenance, as there are no moving parts
- flexible use in new builds and renovations
- controlled air supply for exhaust air systems
- high sound insulation, suitable for noise-exposed locations
- flexible integration into facade and building structure
The AIR CONTROL series from Ventomaxx can be integrated into various facade and wall constructions – from ETICS to ventilated facade systems. Even with complex architectural requirements, special window shapes or limited space, suitable solutions can be implemented. The modular design simplifies installation and allows adaptation to different wall thicknesses and installation situations.
Solutions for challenging installation situations
For projects with limited space, special solutions are available that can also be used with small wall thicknesses or complex structural conditions. Space-saving variants allow integration into narrow facades, partition walls or demanding constructions without significantly altering the existing structure. This enables reliable implementation even in complex projects.
Installation and planning reliability
PAS units are easy and flexible to install. Components can be adapted on site or delivered preconfigured for specific projects.
Advantages in practice:
- adaptation to different wall thicknesses
- compensation of construction tolerances
- fast and simple installation
- high planning reliability
Application areas of passive airflow supply (system) (PAS) units
PAS units are suitable for a wide range of construction projects:
- single-family houses
- multi-family houses
- residential complexes
- office buildings
- renovation projects
They are used wherever controlled fresh air supply in combination with exhaust air systems is required.
Ventomaxx AIR CONTROL – PAS units as part of the system
The AIR CONTROL series from Ventomaxx offers modular passive airflow supply (system) (PAS) units for various requirements in planning and construction.
The systems provide:
- high sound insulation (up to 75 dB standard sound level difference D n,e,w)
- flexible adaptation to wall constructions
- discreet integration into the facade
- versatile installation options
In combination with Ventomaxx exhaust air systems, this creates a coordinated ventilation concept with controlled supply and exhaust air.
PAS units as key supply air components
Passive airflow supply (system) (PAS) units play an important role in ventilation concepts by enabling the supply of fresh outside air into buildings. In combination with fan-assisted exhaust air systems, they ensure continuous air exchange and support a balanced indoor climate.
Thanks to their simple, passive functionality, PAS units can be flexibly integrated into different building types and implemented economically. They are particularly suitable for solutions where supply air is provided via PAS units and exhaust air is handled mechanically.
Frequently asked questions
When are PAS units required?
PAS units are used when the supply of outside air must be ensured as part of a ventilation concept. They are often part of solutions according to DIN 1946-6, especially in combination with fan-assisted exhaust air systems. They are used whenever the required airflow rates – for example for moisture protection – cannot be ensured through building leakage or manual window ventilation.
How does a PAS unit work?
A PAS unit introduces fresh outside air into indoor spaces through the building envelope. The operation of exhaust air systems creates slight negative pressure, allowing outside air to flow in and enabling continuous air exchange.
Where are PAS units used?
PAS units are mainly used in living and occupied spaces such as bedrooms, living rooms or offices. They provide the supply air, while exhaust air systems remove air from wet rooms such as bathrooms or kitchens.
What are the advantages of PAS units?
PAS units operate without electricity and have no moving parts. This makes them energy-efficient, low-maintenance and durable. At the same time, they allow flexible integration into different construction projects and ensure controlled fresh air supply.
How is sound insulation ensured?
Modern PAS units are equipped with integrated sound insulation elements that significantly reduce external noise. Depending on the design, high standard sound level differences can be achieved, making them suitable for noise-exposed environments.
Can PAS units be used in renovations?
Yes, PAS units are suitable for both new buildings and renovations. Their flexible design allows adaptation to different wall constructions and installation situations, enabling easy retrofitting.
