This National Standard of Canada apply to Factory-Built Type A Chimneys, which do not require field fabrication. They are for use with gas and liquid fuel-fired residential appliances and building heating equipment, where the appliance or equipment flue-gas temperatures do not exceed 540 °C. They are intended for installation inside or outside of buildings to provide an essentially vertical conduit or passageway for conveying flue gases to the outer air from the above-described class of appliances.