A database, spanning two years in a cold, Zone 7 climate, that describes the measured transient energy and hygrothermalperformance of insulated hollow CMU basement walls, has been published in the public domain. The database includes experimentaldata from walls with IECC 2012-compliant full-wall interior and half-wall exterior insulation and data from vapor-sealedrim joist cavities. The database has been used to test the temperature and heat flux predictions of a three-dimensional thermalsimulation program yielding an average root mean square error of 1.22°C for soil temperatures and 0.42 W/m²·K for CMU wallinterior heat fluxes for the particular experimental wall system simulated. The data allowed insight to the heat transport effectsof hollow CMU wall buoyant cavity flow loops and their impact on the wall heat fluxes and soil temperatures and showed thatthese loops cannot be ignored in basement thermal simulations. If it exists, the importance of a sub-slab water table and its effecton the soil temperatures adjacent to CMU walls with interior insulation was demonstrated. Heat transport from the sub-slab watertable in a cold climate was the dominant heat source affecting the observed soil temperatures adjacent to interior-insulated foundationwalls while heat loss through the footing and wall below the interior insulation had no measured impact. Including ambientand ground interface phase change in a snow model is necessary to accurately simulate the observed ground temperatures within12 in. of grade. A solid CMU wall bond beam with a permeance of 0.1 to 1 U.S. perms (Class II) was sufficient to isolate a vaporsealedrim joist cavity from vapor saturated CMU cores so that condensation on the rim board interior face was avoided withand without exterior insulation.
Citation: Thermal Performance of Exterior Envelopes of Whole Buildings XIII, Conference Papers
Product Details
- Published:
- 2016
- Number of Pages:
- 11
- Units of Measure:
- Dual
- File Size:
- 1 file , 3.9 MB
- Product Code(s):
- D-BldgConf16-11
