Thick insulation changes the meaning of cross ventilation.

Although most new houses in the Hokuriku region are equipped with air conditioners, some people living in farmhouses still feel that cross ventilation is more desirable. Comparative measurements were made between a new house and a farmhouse. Simplified simulations were also carried out to clarify the effects of thermal insulation and earth floors on cross ventilation in summer. The role of thermal insulation in hot and humid regions is different from that in cold regions, where there is a large difference between outside and inside air temperatures. Insulation against solar heat by the use of awnings or "sudare" on windows and thick roof insulation is important for effective cross ventilation. Solar-heat insulation greatly enhances the cooling effect of an earth floor, and slight changes in air movement due to cross ventilation generate a comfortable feeling. These combined effects would enhance the wisdom of farm inhabitants, and would also add a regional feature to their houses and life-style.