- In-built ventilation, gas and smoke flues permanently combined with the construction or being standalone construction should:
- Have cross-section measurements and height, as well as be led in a way providing necessary draught and flow capacity,
- Meet requirements specified in Polish norms regarding technical requirements for chimney flues and chimney designs.
- Flues should be tight.
- It is forbidden to use:
- common gas and smoke gravity flues,
- common gravity ventilation flues,
- individual induced draught fans in rooms where gas flues exits are placed.
- In buildings located in II and III areas of wind load specified in Polish Norms, chimney pots should be used if required. They help to avoid draught reverse. The requirements don’t refer to fire boxes and chambers with mechanical activation of gas discharge.
- Chimney shafts separated from the building can’t be loaded with ceilings or counted in calculations as parts of the building construction.
- Flues exits should be available for cleaning and control.
- Gas and smoke flues should be equipped with soot or inspection holes with tight doors. In case of wet exhausts system of discharging condensate is also necessary.
- Chimneys in external wall of the building and outside the building need thermal insulation. Non-insolated parts of chimneys can be placed only in internal walls of heated buildings.
- Chimney flues should be led above roof to the height protecting from draught disturbance. The requirement is fulfilled when flues exits are led above roof in accordance with the Polish Norm for brick chimneys:
- for flat roofs of slope angle not higher than 12° flues exits should be at least 0,6m higher than ridge or roof edge (sunk),
- for pitched roofs of slope angle higher than 12° and roofing:
I. easily inflammable flues exits should be at least 0,6m higher than ridge.
II. uninflammable or flash resistant flues exits should be at least 0,30 m higher than roof surface and at least 1,0 m away from it (measured horizontally).
c. for chimneys located next to building’s parts that can disturb proper work of the flues their exits should be:
- above an area derived at a 12 ° angle down from the level of the highest obstacle for chimneys located from 3 to 10 m from this obstacle (refers to pitched roofs),
- at least at the level of upper edge of an obstacle for chimneys located from 1,5 m to 3,0 m from the obstacle,
- at least 0,3 m higher than the upper edge of an obstacle for chimneys located up to 1,5 m from the obstacle.