Editorial: Special issue IBPC2021

the determination of thermal resistances (R-values) for reflective insulation by considering multi-dimensional radiative exchange between all surfaces. Results are presented for varied aspect ratios (width/depth) to characterize the geometry and effective emittance (E) variation from 0 to 0.82. Additionally, the use of CFD to evaluate convective heat transport allows the evaluation of installation defects that impact the R -value. R -values calculated for single and double air spaces show the greatest variation with aspect ratio for E \ 0.05. Modeling of assemblies with non-parallel surfaces has also been evaluated. Double airspaces with gaps that permit air flow between regions show that installation with unin-tended gaps at one end of a cavity results in small reductions in R-value while gaps at both ends of a cavity have R -value reductions approaching 50% for E in the reflective range. These examples provide a glimpse of a new dimension in the evaluation of reflective assemblies to be used in buildings.