Measurements and Two-Dimensional Computer Simulations of the Hygrothermal Performance of a Wood Frame Wall

Knowledge of the expected long-term performance of building envelopes subjected to simultaneous heat and moisture transport is critical during the design stage. In the past thirty years researchers have concentrated their efforts in extensive laboratory experiments. These experiments have been expensive as well as time consuming to conduct due to the slow moisture transport phenomena. This paper critically investigates a set of experimental results generated from laboratory controlled measurements on a wood frame wall construction, by employing a state of the art hygrothermal model. The analysis was carried out using the LATENITE model, a three-dimensional heat and moisture transport program tailored specifically for building envelope investigations. For the present simulations this model was adapted for two-dimensional conditions and hourly hygrothermal performances were predicted for a laboratory instrumented wood frame wall section. The investigation showed three main advantages of combining measurements and simulations. By carrying out simulations early in the design stage of laboratory experiments the experimental design will probably yield better quantification of data, placement and types of sensors, and assessment of workmanship influences, etc. Measurements can calibrate, adapt, or check calculated results. Finally, simulations can be performed to explain and interpret experimental results. Marrying experi ments and modeling allows researchers to generate effective hygrothermal perfor mance guidelines.