Field measurement of moisture-buffering model inputs for residential buildings

• Published in: Energy and buildings Vol. 117; pp. 91 - 98
• Main Authors: Woods, Jason, Winkler, Jon
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 01.04.2016; Elsevier
• Subjects: Air conditioners; Buildings; Computer simulation; Construction; Effective penetration depth; ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; Houses; Humidity; Infiltration; Mathematical models; Modeling; Moisture; Moisture buffering; Moisture capacitance; Moisture capacitance; Buildings; Modeling; Moisture buffering; Effective penetration depth
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2016.02.008

•We developed an experimental method to extract moisture buffering model inputs of a house.•We validated the method with measurements on materials in a laboratory chamber.•We used the method on two houses in the field.•The extracted parameters can be used in the effective moisture penetration depth model.•Tests on the houses with realistic internal loads validated this model and the derived inputs. Moisture adsorption and desorption in building materials impact indoor humidity. This effect should be included in building-energy simulations, particularly when humidity is being investigated or controlled. Several models can calculate this moisture-buffering effect, but accurate ones require model inputs that are not always known to the user of the building-energy simulation. This research developed an empirical method to extract whole-house model inputs for the effective moisture penetration depth (EMPD) model. The experimental approach was to subject the materials in the house to a square-wave relative-humidity profile, measure all of the moisture-transfer terms (e.g., infiltration, air-conditioner condensate), and calculate the only unmeasured term—the moisture sorption into the materials. We validated this method with laboratory measurements, which we used to measure the EMPD model inputs of two houses. After deriving these inputs, we measured the humidity of the same houses during tests with realistic latent and sensible loads and demonstrated the accuracy of this approach. These results show that the EMPD model, when given reasonable inputs, is an accurate moisture-buffering model.