Thermal Performance Calculator provides an on-line, interactive
method for determining the whole-wall R-value for a variety of wall
systems and house plans. The Whole-Wall Thermal Performance Calculator
makes use of a database of results from detailed thermal analyses
performed by Jan Kosny (email@example.com) using the HEATING finite-difference
heat transfer computer program. Graphics of wall structural details
and building floor plans were developed by Gail Snodgrass.