Affordable Access

Solutions to outdoor air intake

  • Korkala, Tapio
  • Siitonen, Veijo
Publication Date
VTT Publications Register


Obvious problems in outdoor air intake are the uneven distribution of air into rooms, the draught, the missing basis for design and the impact of weather on the air flows. The aim of the study "Controlled outdoor air intake through the building envelope" has been to find solutions to these problems in dwellings that have mechanical extract ventilation. In this report the performance and the development possibilities of the known air intake arrangements are estimated. The study concentrated on the airing shutter, different outdoor air inlets, permeable wall construction, flow cracks of the construction, supply air window and structural windshield positioned in the building envelope. Of these only the data of the supply air window has been evaluated sufficiently. This data is the air flow without draught, the flow resistance, the adjustability, the thermal economy and the liability to condensation. The data of the other air intake arrangements is insufficient, especially of the draught, so the designed use of them is not possible so far. To correct the situation a determined product development and testing is needed with the help of uniform instructions. The main principle to defend against the draught are the heating of the supply air, the highest possible discharge velocity along the wall surface or the direction of the air flow away from the point of stay. From the point of view of the air flow control the favourable design values of the flow paths can be evaluated with the help of calculation models. The use of the structural windshield and the constant flow inlet as an air intake path also seems to be promising in the elimination of the wind disturbances.

Report this publication


Seen <100 times