Principle of the system
The non-permeable duct is made of a material through which the air is not allowed to enter the room. Therefore, all incoming air is supplied only through the perforations in the duct. These perforations can be DFC perforations or plastic nozzles.

Because a non-permeable material is used here, there may be a situation where the air inside the duct becomes much cooler than on the surface, which causes condensation to appear on the surface of the duct.

The most suitable applications
Beacuse the air is only supplied through the perforations in the duct, the systems are best suited for areas without strict cleanliness requirements. This makes the system ideal for areas such as logistics centers, industrial halls, or car repair shops.

On the other side, the systems are not suitable for environments demanding people's comfort, such as offices or other public spaces, due to the fact that all the air is distributed through the perforations at high velocity.

Cooling
The systems are designed to provide maximum air velocity through the distribution elements. Cooling with these systems is thus efficient but at the expense of area comfort.

For cooling, it is also necessary to ensure that the supply air temperature is above the dew point to prevent condensation.

Ventilation
In the case of ventilation, the supplied air is the same temperature as the actual air in the room. The ventilation process here is provided by distribution elements at the duct and therefore the supply air is distributed more quickly throughout the space.

Heating
For heating, purposes are non-permeable systems a good solution, because thanks to the high velocity of the air from the duct it is easily transported to the lower part of the room.