Carbon dioxide permeability of building materials and their impact on bedroom ventilation need

This research determined the carbon dioxide permeabilities of different materials and cellulose-insulated wall structures without a vapour barrier as well as the CO2 balance of bedroom air. Material tests have indicated that the CO2 permeabilities of building materials correlate closely with their water vapour permeabilities. Thus, the more permeable the external wall structures are, the bigger their impact on the CO2 content of indoor air. Yet, higher permeability allows more water vapour to pass through the structures, which make them more at-risk for condensation and mould growth. Some calculations on the CO2 balance of bedroom air were also made which indicated that the need of ventilation is not reduced by the use of gas permeable structures.