Absorption properties of common interior finishes

10 December 2013 — As the weather heats up, sustainability conscious people may wonder how they can cope with rising temperatures without more airconditioning powered by the thing that will keep the temperatures rising in the first place:coal.

With this in mind, Building Green has provided some advice on how interior building materials can be used to control humidity, a core element of indoor comfort and indoor air quality.

“As our buildings get tighter, the need to manage relative humidity increases – and energy use from ventilation and dehumidification may increase as well,” the article states. “Just as thermal mass can be used in passive design to redistribute heat, it is possible to use certain interior finishes to redistribute moisture – a strategy known as moisture buffering or humidity buffering.

“All porous building materials have hygric capacity; they can take on and release moisture. Gypsum wallboard, conventional plaster, and clay finishes, although they have very different vapor permeabilities and absorption properties, have relatively high hygric capacities.

“Conversely, many coatings significantly reduce moisture-buffering potential. Researchers are just starting to learn more about the suitability of different materials for passive moisture management.

“Interior finishes that take up moisture and decrease interior relative humidity can have significant comfort and energy implications. They can increase daytime comfort by storing moisture during the day and, when tied to nighttime cooling and active dehumidification, make it cheaper to deal with that load overnight.”

Read the full article at Building Green