COMPARISON OF THE PERIODIC-SOLUTION METHOD WITH TRNSYS AND SUNCODE FOR THERMAL BUILDING SIMULATION

Based on periodic solutions of the governing heat conduction equations in a single zone building, computer software ADMIT has been developed for thermal simulation of buildings. Standard computer software, name ly TRNSYS and SUNCODE, have also been used to simulate the same buildi ng under similar conditions. Simulations have been performed for three different climatic zones in India for light and heavy constructions u nder conditions of glazed/unglazed areas and ventilation rates. The re sults are presented in terms of the hourly variation of the room tempe rature. For insulated heavy construction, the results of different mod els are significantly different. This difference is due to the use of different approaches to solve the heat conduction equations. SUNCODE d epends on the RC network approach and underestimates the heat losses. TRNSYS uses the transfer function approach, which is sensitive to the initially assumed value of the room temperature. ADMIT represents a qu asi-steady-state periodic variation and is not suitable for transient variations. For insulated light buildings, the heat transfer mechanism s used in the mathematical models are not the governing factors. The m odels also differ in treating the penetration of solar radiation throu gh a glazed window and the subsequent heat-transfer mechanism. For a s outh window and air changes in an insulated building, the results obta ined by SUNCODE and ADMIT are in good agreement, but the results obtai ned by TRNSYS are considerably different. The reason for this needs de tailed analysis. Copyright (C) 1996 Elsevier Science Ltd.