The proper or optimum size of a chimney or stack can be calculated in about 5 or 10 min, using the chart (or equation) given in this monograph. This applies to simple systems; those with interconnections or manifolding may take a little longer, depending on complexity. Some basic operating knowledge of the appliance, building, and of chimney construction is essential, together with a bit of preliminary study and practice with some sample illustrative problems.

In spite of its speed, the result is truly a calculation rather than an estimate, because the major significant parameters (there are eight or so) can be considered and evaluated in the process. Further, the method lends itself to a study of the economics of forced or gravity draft, individual or manifolded systems, and many other common problems.

This monograph attempts to distill some 20-odd years of observation, experiment, test, analysis, and literature review in the field of flow in vents, chimneys, and appliances into a useful concentrate of design methodology.