system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are some industrial chimneys so high, like what's the difference if it's 150 or 300 meters?
gpt
The chimney is there to generate draft. As hot air rises up through the chimney it will leave a void behind where fresh air is pushed into. The taller the chimney the more hot air is contained within it and the more draft it creates. So having a tall chimney means there will be a lot more draft which may be needed for bigger furnaces.