NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.
Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.
An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
DEPAF: A Computer Model for Design and Performance Analysis of Furnaces
Published
Author(s)
J. Chi
Abstract
The report covers the development of a computer simulation program DEPAF (Design and Performance Analysis of Furnaces) for residential fossil-fuel-fired furnaces. DEPAF is based upon an analytical model which accounts for cyclic (on-and-off) operation of furnace burner and blower. Transmission of heat at on-cycle uses the theory of radiative and convective heat transfer; transmission of heat at Off-cycle uses the theories of turbulent and free convective heat transfer. Confidence in DEPAF was established by the use of available experimental data on a gas-fired forced-war-air furnace. While the theory of transient heat transfer in combustion is complex in nature, theoretical results based upon quasi-steady-state analysis are in excellent agreement with experiments. If the building heat loss is known, DEPAF can be used to calculate the annual performance and operating cost residential heating systems with furnaces. Examples are given to illustrate applications of DEPAF to examine quantitatively the effect of design and operating variables on annual performance and operating costs of residential forced-warm-air furnaces. It was found that considerable savings in fuel and operating costs can often be achieved by performing certain modifications to existing furnaces.
Chi, J.
(1977),
DEPAF: A Computer Model for Design and Performance Analysis of Furnaces, American Society of Mechanical Engineers, Salt Lake City, UT, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=910791
(Accessed October 28, 2025)