The cross-sectional areas of flues shall be designed and proportioned to meet the conditions of temperatures, within and without the flue, thickness of masonry, exposure, shape and material of flue and other influences. For solid or liquid fuels the areas shall be not less than seventy square inches for warm-air, hot-water and low-pressure steam heating appliances; not less than forty square inches for ordinary stoves, ranges and room heaters; not less than twenty-eight square inches for small special stoves and heaters; not less than seventy square inches for fireplaces, but at least one-twelfth of the fireplace opening when over twenty-two feet in height, and one-tenth of the fireplace opening when less than twenty-two feet in height.
For a determination of the necessary sizes of flues for given conditions, the “Guide” of the American Society of Heating and Ventilating Engineers may be followed.
(Ord. 42-1981. Passed 2-23-81.)