The piping layout in the hotel kitchen should follow the principle of "shortest" and use fewer elbows, especially large-angle elbows. This kind of pipe arrangement method is different from the "neat horizontal and vertical" of air conditioning, aiming at ensuring the effect of oil fume exhaust and saving investment. The central position of the hood is preferred for the main outlet of the gas collector above the hood.
both the fresh air duct and the exhaust duct pass through the partition wall of the room with silencers. The exhaust duct in the kitchen should try to avoid too long horizontal duct, otherwise it will not be conducive to the rapid exhaust of flue gas and affect the exhaust effect. Usually, the farthest distance of the exhaust duct is less than 15m. The horizontal pipeline should have a slope of more than 2%, and the smoke exhaust hood should be installed in the slope direction, and the oil collection box should be set at the lower part of the pipeline. Measures should be taken to prevent backflow of mechanical or natural vertical exhaust pipes in the kitchen. The ends of horizontal pipes are connected by movable flanges, so as to clean up oil dirt.
In principle, it is not allowed to discharge the oil fume into the underground sewage or drainage shaft, and the effect is extremely poor, which is also impossible from the aspect of health and safety.
The main air inlet and smoke outlet of the kitchen should be set separately to prevent short circuit, and the air inlet should be more than 2m away from the outdoor natural ground. If the air inlet and the air outlet are on the same floor, facing the same direction and approaching, the air inlet must be lower than the air outlet. Exhaust air flow at different orientation positions shall not flow back to the air inlet. When the height of the building where the kitchen is located is less than or equal to 15m, the oil fume outlet should be higher than the roof [131], and in principle it should be more than 2m higher than the building [131]. When the height of the building is more than 15m, the height of the oil smoke outlet should be more than 15m[131]. The outdoor exhaust port of the exhaust pipe should be equipped with a finished product of pipe cap (pipe cover) which is less affected by outdoor wind pressure.