The impact of climate parameters on air movement in ventilated roofs air gap

Abstract

For the detailed analysis of the climate factors' impact on the air movement in the roof ventilated air gap, the calculation method has been compiled with the corresponding software. The air movement velocity in the ventilated air gap, air temperature alteration at the air outlet vent due to the heat exchange in the gap, indoor air temperature, outdoor air temperature and wind speed, building height and aerodynamic building parameters, dimensions of the ventilated air gap and materials, pressure losses in the ventilated air gap are estimated in the suggested calculation method. The pressure difference required to cause the air movement in the ventilated air gap depends on the wind action. This depend on the dominant wind speed and direction in the location. When the air movement in the air gap stops, the moisture accumulation process in the roof construction occurs. It makes the negative influence to the heat transfer and durability of the roof construction. The presented method for calculation of pressure losses in ventilated roofs gaps can be used for correct prediction of the moisture movement process in gable roof construction.