Boiler Stack Height Above Roof

Read and follow all operating instructions supplied by the manufacturer.

Boiler stack height above roof. For example a stack placed 30 ft away from an air intake should be at least 10 ft higher than the center of the intake. National fire protection association nfpa standard 45 specifies a minimum stack height of 10 ft to protect rooftop work ers. Discharge the exhaust at a height that is above the re circulation region or bubble that forms over the roof. 2 feet minimum of 100 feet chimney height installation scenario outdoor wood furnace best burn practices 1 1.

If the chimney extends more than 5 feet above the roof it will require additional bracing. The height of the stack or chimney is determined by several factors including. Further guidance on gep stack height may be found in the us epa document guideline for determination of good engineering practice stack height technical support document for the stack height regulations revised june 1985 epa 450 4 80 023r. The height of the chimney above the roof surface measured at the up slope side of the chimney from the roof surface to the chimney top should be at least three feet the green line in our photo.

It is essential to understand what the vent category means in order to select correct venting materials and properly terminate the flue. This is a bit of an odd measurement and chimney clearance case because the chimney side is actually about 8 away from the roof edge. The primary purpose of a stack or chimney though is to exhaust the products of combustion at some elevation above the boiler which aids the environmental conditions in the immediate area around the boiler. Full scale stack heights 10 15 20 and 25 feet above roof full scale building heights 60 80 and 100 feet.

Back to our example over a run of 10 feet the roof would rise 40 inches. So take the top number of your roof pitch and multiply it by 10 then add 24 note example 1. Height of the nearest building or roof line. With the permission of the canadian standards association figure 1 is reproduced from ansi z212 13 2000 csa 4 9 2000 which is copyrighted by canadian standards association 178 rexdale blvd toronto on m9w 1r3 www csa ca.

Standard z9 5 recommends a minimum stack height of 10 ft above the adjacent roof line an exhaust velocity v e of 3000 fpm and a stack height extending one stack diameter above any architectural screen. Chimney height should be 2 feet above roof line. Reducing stack height. We suggest using a roof brace kit or a field fabricated assembly using a support bracket assembly as shown in figure 15.

Stack height should be 10 ft higher than any roof line or air intake located within 50 ft of the stack figure iii 3 8.