1. Develop a three-dimensional, finite-difference HEATING model of the wall system.
2. Conduct a dynamic hot-box test. The main reason for using a dynamic hot box test in the procedure is not to directly estimate the R-value or the response factors, but to calibrate the computer model to enable further analysis. So, it is not necessary to create any specific complicated ramp on either side, but only a dynamic change (or changes) from one steady-state condition to another. Therefore, even poorly equipped testing facilities can make use of this procedure since a powerful chiller to accurately control the temperature ramp is not necessary.
3. Run the HEATING computer program with the same temperature transient used in the dynamic hot-box test, and compare results to measurements from Step 2.
4. When the test generated data are reproduced by the computer model with sufficient accuracy, the EQV_WALL computer code will be run. This program generates a simplified, multi-layer "EQUIVALENT WALL" that has the same dynamic thermal behavior as the actual complex wall. This task will generate a list of thermophysical properties for each uniform layer (R-value, thermal capacitance and thickness).
5. Run a whole-building simulation program such as DOE-2 with the "equivalent wall" and standard code-compliant wood-frame wall on a standard building in six U.S. Climates. The mass effect will be determined by comparing the annual energy consumption from the standard house using the "equivalent wall" to that resulting from the identical house with a wood-frame walls.
6. Prepare a report containing (a) a set of uniform-layer thermophysical properties for use in whole building simulation and (b) code-compliance tables: Council of American Building Officials (CABO) MEC thermal transmittance of the components of the opaque wall area and customized whole-wall thermal conductance, U_w.

Tables for this specific wall system will be derived using the hot-box-validated measurements described above. The same procedure will be used to develop the generic tables found in the MEC for all thermal mass walls with more than 6.0 Btu/ft²/F (123 kJ/m²/C) of wall thermal capacitance (CABO 1995). The existing MEC lists these generic U_w tables as Table No. 502.1.2a Required U_w (with insulation placed on the exterior of the wall mass), 2b (with insulation placed on the interior of the wall mass); and 2c (with integral insulation and mass mixed) (CABO 1995). The Energy Policy Act of 1992 suggests all states consider the adoption of this code. This customized table can be used to show code officials' compliance with the prescriptive U_w requirements in the MEC that are based on wood-frame constructions. Finally, a figure compliant with ASHRAE Standard 90.2, customized to replace the applicable figure in the prescriptive portion of this code will be developed.

References:

1. Christian, J. E., "Thermal Mass Credits Relating to Building Envelope Energy Standards," American Society of Heating and Refrigerating and Air-Conditioning Engineers, Transactions 1991, Vol. 97, Pt. 2.
2. C.A.B.O. - Model Energy Code, Council of American Building Officials, Falls Church, Virginia, 1995 Edition.
3. Jan Kosny, Elisabeth Kossecka, Jeffrey Christian, Andre Desjarlais, and Lance Berrenberg "Performance Check Between Whole Building Thermal Performance Criteria and Exterior Wall Measured Clear Wall R-value, Thermal Bridging, Thermal Mass, and Airthightness," American Society of Heating and Refrigerating and Air-Conditioning Engineers, Transactions 1998, V 104 Pt.2.