This paper presents a method for modeling the performance of sheet metal air-cooled chimneys used for factory-built wood stoves and fireplaces. This method has been used to design new state-of-the-art chimney systems, as well as predict the performance of special variations of standard chimney designs. The computer model described in this paper was developed and run on a 64k microcomputer. The model was programmed in BASIC language. The specific type of chimney described in this paper is an air-cooled chimney that utilizes the heat from the flue gas to cause buoyancy-driven airflow. The method of analysis presented here uses finite difference techniques to solve both heat transfer and buoyancy-driven flow equations. Although the system is three-dimensional, symmetry allows the use of classical heat transfer and pressure drop data for both developing and fully developed flow.

Units: I-P