Moisture Buffering Effect of Gypsum Board in a Marine Climate: A Field Experimental Study

Abstract:

Durability, acceptable indoor air quality, energy efficiency and aesthetics are all pillars of good design in healthy buildings. A new approach for optimizing all four of these pillars is whole-building performance design. This approach involves the consideration of heat, air and moisture (HAM) transfer and control of a building, specifically, how the coupled relations between different transient systems (mechanical system, building envelope, indoor environment, outdoor environment, and occupants) affect the building performance and operation. Ventilation is one of the means of controlling indoor humidity in buildings. Its effectiveness depends on the supply air moisture level and the ventilation rate. The drier the supply air is, the higher its capacity to remove indoor humidity. In a marine climate where the outdoor air is relatively moist, higher ventilation rate is required to achieve the same level of indoor humidity in a cold and dry climate. In this study, the potential benefit of interior gypsum finishing in lowering indoor humidity peaks, through the moisture buffering process, and thereby reducing ventilation rates are investigated. A field experimental study is conducted using two identical test facilities at the Whole Building Performance Research Laboratory in Burnaby, British Columbia to test this hypothesis in a marine climate. Initial benchmarking of the recently commissioned test buildings was undertaken to ensure they behaved similarly under identical conditions. Each building was outfitted with an occupant simulator unit, which provided the humidification that would be produced by occupants. The occupants simulators were programmed based on moisture production data analysis from a real high-occupancy apartment suite, to provide two different moisture generation profiles representing typical and high intensities, scaled down to the size of the test buildings. Following benchmarking, three tests were conducted to evaluate the effect of ventilation rate, moisture generation intensity, and moisture buffering ability of finishing surfaces on indoor moisture levels. Preliminary experimental test results are presented. Future tests will be undertaken to consider other factors such as indoor air quality based on carbon dioxide concentration, heating and ventilation energy consumption, and alternative finishing materials.

• Periodical: Advanced Materials Research (Volume 1051)
• Pages: 763-773
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1051.763
• Online since: October 2014
• Authors: Shahrzad Pedram, Fitsum Tariku
• Keywords: Drywall, Gypsum Board, Indoor Humidity, Moisture Buffering, Moisture Production, Ventilation

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