C054 -- Lab Home Validation of a Moisture Balance Model to Estimate Internal Moisture Generation Rates in Occupied Homes ✓ Most Recent

Internal moisture generation (IMG), or moisture generated by building occupants via activities such as respiration, cooking, bathing, and cleaning, is a critical contributor to the overall moisture load in a home. Other contributors to the moisture load include natural and mechanical ventilation, mechanical humidification/dehumidification, vapor diffusion, and sorption. Total moisture load is a critical input required for design and analysis of building enclosure and HVAC systems yet data quantifying IMG is scarce, and data that do exist show varied results. This discrepancy is largely due to the difficulty with making direct measurements of the moisture source(s) in occupied homes. Another approach to field determination of IMG rate involves measurement of other dominant moisture addition and removal mechanisms, and then applying a moisture balance model to calculate the internal generation. This paper describes a moisture balance model and efforts to validate the model in simulated occupancy laboratory homes. Empirical best-fit corrections resulted in a prediction error over a range of outdoor conditions and varying internal generation rates on the order of 1.5-2.0 kg/d (3.3-4.4 lb/d). See more