For testing certain wall assemblies, the 2012 International Building Code (IBC) requires National Fire Protection Association (NFPA) 285, Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-load-bearing Wall Assemblies Containing Combustible Components.
The first article in this two-part series lays the groundwork for this discussion on R-values and their use as a metric for thermal insulation performance. Now, in this second part, the author examines the real-world use of it as a gauge for ensuring insulation products function as intended.
What exactly is R-value? This question is not asked often enough in today’s environmentally conscious design/construction industry. However, an even better question may be, whether R-value is still a valid unit of measurement for the performance of insulation products.
The custodian at Asheboro Church of God (North Carolina) had a well-worn routine during summer months. Every Saturday, he would turn on the church’s air-conditioning (AC) at 3 p.m. to ensure the space was cool and comfortable for morning service the next day.
In an ideal world, a continuous layer of R-10 insulation could be installed over the entire surface of a building, resulting in an enclosure with an effective insulating value of R-10. However, such a structure would be both aesthetically unacceptable and impractical to build.