Why do you need to add a chimney to the coal stove to make way for it to burn more brightly?

You have seen boiling water and cooking in your life. You will find that no hot air is upward. This is because the specific gravity of hot air is small and lighter than the same air, so it rises. Similarly, the hot air balloon rises. When the stove is lit, add a chimney to it. The air in the chimney is heated up, the bottom of the chimney is supplemented with air (containing oxygen), and the coal is oxidized and burned violently. In this way, the circulating furnace will burn quickly, and the chimney is 3-5 times faster than no chimney.