Arizona Laws 36-1623. Ventilation by vent or flue
A. Gas appliances designed for space heating or water heating installed or placed in tourist courts, camps, hotels and lodging houses after June 26, 1952 shall be connected to an effective vent or flue leading to the outside air not less in size than the vent collar on the appliance.
B. A vent or flue for any appliance except one having a forced draft or sealed combustion chamber shall extend one foot above the highest portion of the building if the vent or flue is located within fifteen feet horizontally from the highest point. A vent or flue extending above the roof line shall terminate in a cap with a vent capacity not less than that of the vent or flue. An appliance with a forced draft or sealed combustion chamber shall be vented in accordance with the manufacturer’s instructions.
C. Every vent, flue or chimney shall be a terra cotta patent chimney, or constructed of brick, fire clay or similar masonry product not less than one-half inch thick, or of approved pipe having a wall thickness which will give an insulating value equal to a terra cotta patent chimney or a masonry product and which will not disintegrate from the effects of gas fumes and other products of combustion.