ASHRAE Research Project 472 employed a modified version of the DOE-2.1C computer program to compute weighting factors for 200,640 parametric zones to support improved cooling load calculation procedures. Because DOE-2 is fundamentally an energy calculation program, it was necessary to verify its ability to predict zone dynamic response under conditions of peak cooling loads. Accordingly, a cross-check was carried out among DOE-2.1C and three other programs, namely TARP (National Bureau of Standards), CP52 (National Research Council, Canada), and ESP (ABACUS, University of Strathclyde). The steady-periodic responses of different zones to a sinusoidal heat gain with a 24-hour period were used as a basis of comparison. It was found that the programs predict cooling load amplitude within a discrepancy range of approximately ±10% of the heat gain amplitude and predict delay with a discrepancy range of ±0.6 hour. Also discussed in the paper is the implementation of several modifications to the DOE-2.1C program that were intended to make the weighting factors more appropriate for RP-472. These changes include those needed for installation on a supercomputer, as well as improvements to radiative transfer calculations and boundary conditions and special file output provisions. The use of the results obtained with the modified program are presented in companion papers (Sowell 1988a, 1988b).

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