This is called a “draught” and it forces air into the fireplace, this air feeds the flames as it rushes past the fire. The oil gets trapped into the oil collectors and the odor, smoke, steam, heat is thrown out of the kitchen through the duct. Aeg Black Chimney Hood Dve5971hg Kitchen Sale Kitchen Prices Wellness Design A filterless chimney works on motor suction power and has a different motor placement inside the chimney. How does a kitchen chimney work . The taller the chimney, the more draft it will produce at a given temperature difference. This fan pushes out the air into the duct, forcing it to travel higher up the column for ventilation. The table below shows how heat in the chimney and chimney height work together to produce draft. Knowing how a chimney works also helps people fix problems when something isn’t working right. Since the lower level fireplace is below the npp, it draws air into the basement through the chimney. It is made of aluminium. Kitche...