Moderating indoor conditions with hygroscopic building materials and outdoor ventilation

This paper contains a numerical study of the indoor temperature, humidity, and comfort and indoor air quality conditions in a bedroom located in Saint Hubert, Belgium. The performance of the bedroom is presented for a range of constant outdoor ventilation rates (0.1 ach to 1 ach) with and without hygroscopic materials. The results show that the conditions in the bedroom improve significantly as the ventilation rate increases and when hygroscopic materials replace nonhygroscopic materials. In general, increasing the ventilation has a stronger impact on the average indoor conditions than applying hygroscopic materials, but the impacts of ventilation and hygroscopic materials can be similar during certain operating conditions. These results suggest that the ventilation rate could be decreased slightly in a room with hygroscopic materials without degrading the indoor humidity, comfort and air quality conditions. The possible decrease typically ranges from 20% to 50% depending on the variables and criteria chosen.