Calculation of air infiltration in buildings and the movement of the air inside buildings corrected by heat transfer.

The purpose of this work is to evaluate the air infiltration through the high buildings and in the same time to determine the exchange of the air between the rooms and the influence of the heat transmission for these exchanges. The method of approach for this problem is a network model. This is a grid system in which the nodes are the rooms or zones of the building and the connection between two nodes simulates a flow path of a given resistance. It was built a computer program for predicting the interactions between different zones which was applied for a given case of a building. The results obtained generate a complete image of the air flow in the building. The values of the flow rates infiltrated into the building give an average of 0.16 h-1 for the number of changes of fresh air I hour. This only value demonstrates, clearly, the importance of the airtightness of a building envelope. We save energy by insulating better the buildings but how far we can go as we could pay this with our health because of the lack of fresh air. More, the cost of a ventilation system would be very important when rehabilitation works are made in order to increase the insulation.