scope:

ABSTRACT

Vinyl siding is the most widely used cladding type on residential buildings, with a 37% share. An air cavity behind the vinyl siding within the building envelope provides an approach to mitigating moisture-related issues. However, most existing studies assume the air cavity to be rectangular and thus neglect the effects of geometric irregularity and complexity on the drying performance in the air cavities behind vinyl siding. Therefore, in this study, after analyzing the irregular and complex configuration of air cavities behind siding for a one-story residential building, a mathematical model was developed to evaluate the drying performance of the air cavity. The results show that the shape of vinyl siding plays a major role in the airflow rate, and an increase in air cavity depth has a positive effect on the drying potential of vinyl siding. Furthermore, it shows that the airflow rate rapidly increases and converges at a constant value as the air cavity depth increases. The cavity's airflow rate reaches its maximum value when the cavity depth is 20% of a siding panel projection for a triple Dutch lap siding. Based on the optimal cavity depth that is no less than the water droplet diameter, a new design of vinyl siding is proposed.