Wall air intakes are intended for drawing fresh air from outside of the wall.
Wall intake vents are made of steel sheets protected with the paint coatings.
Presentation of % participation of fresh air, for which wall intakes of dimensions equal with intake boxes meet the condition of air inlet velocity less than 2,5 m/s it means: they will not suck the rain.
ERM 0&1 units can operate totally on the outdoor air with the wall intakes dimensions equal with the cross-sections of the intake boxes.
For the TERM 2, 3 and 4 units and operated totally on the outdoor air the wall intakes are selected by the manufacturer (wall intakes will have the bigger surfaces area).