Abstract
Research report submitted to Peter Francis, President, MAGO Building Products Ltd in April 2016. Passive humidity control in buildings can be achieved by incorporating materials with moisture buffering potential in that these materials absorb moisture at peak times and give off the stored up moisture at low moisture production times thereby stabilizing the interior relative humidity. Some of the advantages of this phenomenon include but are not limited to energy savings, improvement of thermal comfort and perceived air quality. As such, it is necessary to investigate different materials for their moisture buffering capabilities. As part of product development, the moisture buffering characteristics of Magnesium oxide board (Magnesia board) is experimentally investigated. Other considerations such as the impact of surface finishing and ventilation are also assessed. The experiment is done by monitoring twin buildings termed the Whole Building Performance Research Laboratory (WBPRL) while measuring the relative humidity evolution in time. One is set as the reference building and finished with gypsum wallboard owing to its wide industry use. The other is set as the reference building and covered with the Magnesia board. Both buildings are first validated under non-hygroscopic conditions to ensure similar hygrothermal loading and operation of both buildings. Next, four tests are conducted to simulate surface treatments, ventilation effects, and occupancy density. For each test run, four cases are created for different surface treatment configurations. From the test, it is found that magnesia board and gypsum demonstrate similar moisture buffering characteristics. In the as-in service case where the gypsum wallboard is painted with latex paint, as it is the current common practice, and magnesia board with the company specified paint, the later demonstrates slightly better moisture buffering due to the high permeability surface treatment.,Research report,Published.