There are two main lines in the Gastro: solid fuel oven/stove chimneys (N1–D–G) and a fan-assisted oily smoke exhaust (P1–W–O). These two systems cannot be combined in the same shaft; separate collectors, washing nozzles, siphon drainage, and sealing are required. In pizzerias, kebab/rotisserie restaurants, and pastry shops, spark arrestors, cleaning covers, and regular soot/grease cleaning are essential for operational safety and hygiene. Double-walled exterior walls and 316L are preferred; details are determined according to the appliance declaration and local regulations.