Prediction of dew condensation of windows with airflow

Thermal insulating performance of windows is often poor. Thus, effective windows are important for sustainable buildings. In this study, we propose using a dynamic insulation (DI) window that uses indispensable ventilation effectively. The principle of the DI system is that airflow opposite to the direction of heat loss recovers part of the heat that would be lost. Another merit of DI windows is that they decrease the risk of dew condensation. In this paper, we report evaluation of humidity using a non-dimensional index: humidity index (HI), and dew condensation frequency for DI window frames, at several locations in Japan.