The same as warm, moist air usually escapes via your attic, likewise, warm air or smoke rises up and goes out through your chimney. This is often called the “stack effect”. The dispersion of pollutants more than a higher region can minimize their concentrations and aid compliance with regulatory boundaries. https://chimneyinspection13333.ziblogs.com/28158231/outdoor-fireplace-things-to-know-before-you-buy