Hygro-thermal performance of imperfectly protected below-grade walls with interior insulation

In the United States, significant number of residential structures contains basements that are frequently habitable. The energy consumption to heat and/or dehumidify the below- -the-grade spaces is significantly affected by the ability of the envelope to resist moisture infiltration. Clearly, the energy consumption is directly impacting the sustainability of such systems. This study investigates the performance of three different types of insulation installed in the interior of a basement wall system in a below-grade situation. All boundary conditions were simulated in a controlled environment with the testing of nine segments simultaneously. Damage to the damp-proofing layer on the exterior surface of the wall was introduced and moisture was present to simulate saturated soil. Three tests were conducted in order to represent a winter, summer, and artificial condition. Data was analyzed to determine the response of the systems to an imperfect environment. No condensatio n was detected throughout each experiment, leading to the conclusion that each insulation type performed as intended by the manufacturer in a moist environment. The insulation with the highest permeability showed evidence of a higher drying capacity in the artificial test. The damage to the damp-proofing layer did not have a significant effect on the performance of the wall system.