Brick wall with smoke and ventilation ducts: a) view, b) cross-section.
Smoke pipes, exhaust and ventilation are usually performed in internal walls between heated rooms, to ensure a good draft of gases and air. If they are placed in external walls, they should be insulated, that the gases and air are not cooled down, because then there will be no proper sequence.
The condition of good draft is also the tightness of the walls of the conduits and the smoothness of the internal surfaces. Wires are usually made of square or rectangular cross-section, and less often circular. The circular cross-section is more favorable with regard to the draft of gases and air, but it is more difficult to do. Such a conduit is made of special ceramic hollow bricks.
The smallest cross-section of the conductor is 1/2 bricks x 1/2 bricks. The smallest diameter of a conductor with a circular cross-section is 15 cm. The most commonly used conductor cross-sections are 14 x 14 cm, 14×20 cm, 14×20 cm, 14×27 cm,. Wires with a cross-section of 14×14 cm is most often used as ventilation, while the combustion engine with dimensions of 14×20 cm or 14×27 cm.
Smoke pipes, exhaust and ventilation should be run vertically, To reduce the number of chimneys extending above the roof, these pipes are grouped together. In this case, the cable deviation from the vertical should not exceed 30 °. Smoke pipes begin in the basement, and in buildings without a basement above the floor, where they are equipped with a door. The ventilation channels have an inlet 30 cm below the ceiling of the room.
Walls with ducts should be made of solid ceramic bricks. Perforated bricks must not be used on these walls, ceramic hollow bricks as well as cement and lime-silicon bricks (silicate). Bricks are connected with full joints. Cut bricks (nines) should be laid with smooth surfaces facing the inside of the duct.
The inside of the pipes should not be plastered, while in the attic, they should be plastered from the outside (raped).
Each coal kitchen hearth should have a separate smoke pipe. The use of collective flue and smoke pipes with house sewers and individual exhaust fans in the rooms, in which there are inlets to exhaust gas ducts or collective gravity ventilation ducts with house drains, is forbidden.
The part of the chimney protruding above the roof is made of well-baked ceramic ceilings or stone resistant to weather conditions. The top of the chimney is covered with a "cap" placed on a piece of paper and provided with a drip.
Wooden parts of the building structure (maybe, poles) must be moved away from the internal walls of the smoke and exhaust pipes at a distance 25 cm.