Computer Codes Used in Building Envelope Research










A Three-Dimensional Dynamic Wall Modeling Code

EQV_WALL (Equivalent Wall) is a computer code under development at ORNL to aid in the modeling of dynamic thermal performance of complex wall systems with significant thermal mass. The EQV_WALL code is based on a theoretical concept developed by Kossecka and Kosny.

EQV_WALL is a specialized version of HEATING developed by K. W. Childs to characterize the dynamic thermal behavior of high-thermal-mass wall systems exhibiting two- or three-dimensional heat transfer. Given a geometric description of a wall system, EQV_WALL calculates the response factors, overall R-value, and capacitance of a wall. Then, EQV_WALL uses the responses factors to calculate the thermal structure factors for the wall. The thermal structure factors are characteristic of the distribution of thermal resistance and thermal mass throught the thickness of the wall.

The EQV_WALL program uses the overall R-value, overall capacitance, and thermal structure factors to define a one-dimensional, multi-layer equivalent wall that has the same thermal structure coefficients and, consequently, the same dynamic thermal behavior as the original two- or three-dimensional wall system. This one-dimensional, multilayer wall description is suitable for inputting into whole-building energy modeling codes such as DOE-2.

Building Envelope Research
Oak Ridge National Laboratory

For more information, contact the program manager for Building Envelope Research:

André O. Desjarlais
Oak Ridge National Laboratory
P. O. Box 2008, MS 6070
Oak Ridge, TN 37831-6070

E-mail Andre Desjarlais

Revised: May 26, 2004 by Juanita Denton