Abstract
A recent development in heat insulating materials offers a decrease in the energy consumption by air-conditioning in the summer and an improvement in the thermal performance of the insulating glass in windows and the openings of houses and buildings in the winter. A resin spacer in the insulating glass is useful for improving the insulation efficiency instead of an aluminum spacer, but water vapor is still transmitted inside the air space of the insulating glass and leads to dew condensation and decreased transparency. The lifetime of the resin spacers is predicted by the diffusion coefficient of water vapor without knowing of the dew point of the insulating glass. The amount of water adsorbed on various resin spacers made of polyisobutylene with zeolite 4A was measured at temperatures of 40-80°C, humidities of 15-95 %RH, and atmospheric pressure, for 1 h-1 month. In this study, the relationship between the lifetime of the insulating resins, the adsorbed amount of water, and the optimum component of the resin spacers for a long lifetime is discussed. The diffusion model for the transmission of water into the air space is proposed.
