Chimney height relative to the roof ridge

Already at the stage of designing the house is necessary to give due attention to the choice of the heating system and to calculate the height and the chimney section. From it depends not only on the timely removal of the exhaust gases, but also the efficiency of heating appliances fueled by solid fuel or gas.

What affects the height of the chimney

Link in the pipe required for the combustion of oxygen and fuel, created by the differential air temperature in the boiler and on the outside. The hot air rising upward, cools down, the pressure difference in the top and bottom of the chimney contributes to the formation of air movement and thrust.

If the chimney has a narrow section and a sufficient length, the exit velocity of the combustion products will also be high, i.e., strong pull will result in the overrun fuel, the heat of the heated air will not have time to be transmitted room. But too long pipe begins to occur slowing air flow and thrust weakens.

If a short chimney draft is insufficient time to output the exhaust gas and smoke through the chimney. Soot will settle on the inside wall of the chimney, the heating system will not work effectively, the risk of carbon monoxide poisoning appear and even a fire, which is very dangerous for the occupants of the house.

How to find the optimum height of the chimney on the roof

When calculating the height of the chimney, in the first place, it is necessary to turn to the rules developed by the SNIP 2.04.05-91 for optimal selection of the chimney height and stick to them.

They consist of a number of points:

** The optimum length of the entire vertical flue on the grate to the upper edge of the tip of the pipe should be not less than 5 meters. For homes built-up roof with a chimney may be installed at a constant length condition at normal draft.

** Above the flat roof chimney must extend no less than 50 cm. This also applies to the flat roof of a high parapets - the upper end of the tube must be higher fence 50 cm, at least.

** If chimney exits to the roof at a point less than the distance of 1.5 meters from the ridge edges horizontally, it must rise above the ridge 50 cm or more.

** At a distance of 1.5 to 3.0 meters from the chimney exit point to the ridge edge of the horizontal pipe headroom should be flush or slightly rise above the ridge.

** If the pipe is located closer to the edge of the roof and is further 3.0 meters from the ridge, its minimum height defined by a line drawn from the ridge toward the chimney 100 at an angle downward from horizon.

** If there are high buildings, the upper end of the chimney should be above the highest point of the roof of the building. In the case of too high buildings or trees used for calculation of the standard 450 to the horizontal line drawn from the highest point to the chimney. The height of the pipe should not be below this line.

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