Building Energy Simulation Test (BESTEST) and Diagnostic Method

by R Judkoff and J Neymark
USA, National Renewable Energy Laboratory, NREL, DE94000280, NREL/TP-472-6231, 1995, 296 pp

Abstract

A cooperative project between IEA ECBCS Annex 21 and IEA SHC Task 12.
The BESTEST project developed a procedure to systematically test whole-building energy simulation programs and to diagnose the sources of predictive disagreement. Field trials of the method were conducted with "reference" programs representing the best state-of-the-art detailed simulation capability available in the United States and Europe. The method consists of a series of carefully specified test-case buildings that progress systematically from extremely simple to relatively realistic. Output values for the cases - annual loads, maximum and minimum temperatures, and peak loads, and some hourly data - are compared and used with diagnostic logic to determine the algorithms responsible for predictive differences. The more realistic cases, although geometrically simple, test the ability of the programs to model such combined effects as thermal mass, direct solar gain windows, window-shading devices, internally generated heat infiltration, sunspaces, earth coupling, and dead-band and setback thermostat control. The more simplified cases facilitate diagnosis by allowing the excitation of certain heat transfer mechanisms. The report contains three parts. Part I is a user's manual with instructions on applying the BESTEST procedure. Part II describes the development, field testing, and production of data for the procedure. Part III presents reference programs' output in tables and graphs. A diskette contains weather data, some utility programs for formatting output data, and all reference data in a common spreadsheet format.