Jerald Allen Atchley

Field Testing of Low-Cost Bio-Based Phase Change Material

A test wall built with phase change material (PCM)-enhanced loose-fill cavity insulation was monitored for a period of about a year in the warm-humid climate of Charleston, South Carolina. The test wall was divided into various sections, one of which contained only loose-fill insulation and served as a control for comparing and evaluating the wall sections with the PCM-enhanced insulation. This report summarizes the findings of the field test.

Evaluation of Experimental Parameters in the Accelerated Aging of Closed-Cell Foam Insulation

The thermal conductivity of many closed-cell foam insulation products changes over time as production gases diffuse out of the cell matrix and atmospheric gases diffuse into the cells. Thin slicing has been shown to be an effective means of accelerating this process in such a way as to produce meaningful results. Efforts to produce a more prescriptive version of the ASTM C1303 standard test method led to the ruggedness test described here. This test program included the aging of full size insulation specimens for time periods of five years for direct comparison to the predicted results. Experimental parameters under investigation include: slice thickness, slice origin (at the surface or from the core of the slab), thin slice stack composition, product facings, original product thickness, product density, and product type. The test protocol has been completed and this report provides a detailed evaluation of the impact of the test parameters on the accuracy of the 5-year thermal conductivity prediction.

An Experimental and Analytical Evaluation of Wall And Window Retrofit Configurations: Supporting the Residential Retrofit Best Practices Guide

A Retrofit Best Practices Guide was developed to encourage homeowners to consider energy conservation issues whenever they modify their siding or windows. In support of this guide, an experimental program was implemented to measure the performance of a number of possible wall siding and window retrofit configurations. Both thermal and air-leakage measurements were made for a 2.4 x 2.4 m (8 x 8 ft) wall section with and without a 0.9 x 1.2 m (3 x 4 ft) window. The windows tested were previously well-characterized at a dedicated window test facility. A computer model was also used to provide information for the Best Practices Guide. The experimental data for walls and windows were used in conjunction with this model to estimate the total annual energy savings for several typical houses in a number of different locations.

Effect of Steel Framing in Attic/Ceiling Assemblies on Overall Thermal Resistance

Experiments have been performed to assess the impact of cold-formed-steel framing on the thermal performance of attic/ceiling assemblies. Test configurations duplicated features of full-sized, truss-based and conventional joist-and-rafter assemblies away from the edges of the ceiling. Steady-state tests were done at winter conditions in a climate simulator. In truss systems, strong thermal bridges due to framing members that penetrated through the insulation to the bottom chords persisted as the insulation level increased. Without penetrations, the effect of steel framing eventually disappeared as insulation level was increased. For negligible effect of the framing, framing spaced 41 cm oc required greater insulation depth than did framing spaced 61 cm oc. Without penetrations but with enough insulation to cover framing with depths of 8.9 cm, 20.3 cm and 30.5 cm, greater framing depth yielded slightly poorer thermal performance. In some tests, a continuous layer of extruded polystyrene foam insulation was placed between the C-shaped bottom chords of trusses and the gypsum board ceiling. System R-values improved slightly more than the R-value of the foam insulation. A three-dimensional model of the thermal behavior of the assemblies was used to extend the test results to the entire range of steel-framed attic/ceiling configurations. Equations generated from this and related work can be the basis for changes in codes and standards that reflect the effect of steel framing on the thermal performance of attic/ceiling assemblies and discourage allowing steel framing to extend beyond insulation in the assemblies.