Instructions

35
Sprog
4.1. Minimum diameters
For the diameters of air pipes from the outside, the following must be taken into account:
- No kinks in the pipe since this reduces the diameter
- Maintain a constant diameter
- The free air passage through the air grate must not be less than the recommended dia-
meter/dimension.
- Underpressure must not be allowed to occur at the entrance to the air duct in high
winds.