A. Every gas appliance for use with liquefied petroleum gas equipped with a vent collar shall be properly vented to the outer air. The following requirements cover proper venting:

B. Draft Hood: A draft hood which meets the approval requirements of the AGA shall be made a part of the vent connections to the vertical chimney or vent, unless construction of the appliance serves the same purpose.

C. Damper: A manual damper or similar device shall never be installed in the vent pipe from the appliance. However, this is not to prevent the installation of a listed automatic vent damper device intended for use in the venting system when the appliance is in operation and to automatically open the venting system when the appliance is in operation and to automatically close off the venting system when the appliance is in standby or shutdown condition. The automatic vent damper device may be installed on an approved type appliance listed and equipped with a draft hood provided the installation is performed by qualified personnel in strict accordance with the manufacturers requirements and recommendations. All vent damper devices shall be of an approved type and shall be listed.

D. Size: All appliances required to be vented shall be vented into a vertical vent, flue, or chimney of a size not less than the area of the vent collar of the appliance and in no case less than seven (7) square inches in area.

E. Height: The vertical vent, flue, or chimney shall extend at least two (2) feet above the highest elevation of the building within ten (10) feet of the termination of the vertical vent, flue or chimney. This requirement may be altered by the Board when sufficient evidence indicates proper venting may be obtained otherwise.

F. Venting Material: In case venting material (not a chimney) is used for the vertical vent, the material used shall conform to the local building code. In addition, it shall be installed according to the local building code. In the absence of a local building code, the vent shall consist of approved fireproof material. All masonry chimneys constructed for the purpose of venting a gas appliance shall be lined with terr-cotta or comparable flue lining. Whenever a gas appliance is vented into an existing unlined masonry chimney, the chimney shall be clean. The horizontal vent connection in all cases shall enter the chimney at least one (1) foot above the bottom of the chimney. Means shall be provided for cleaning out the base of the chimney.

G. Horizontal vent connection: The horizontal vent connection shall be as short as practicable and shall not be longer than seventy-five (75) percent of the height of the vertical vent, flue, or chimney, and shall have an incline of one (1) inch per foot if possible, however in no case shall the incline be less than one-half ( ½ ) inch per foot of length. The horizontal vent connection, when in contact with the soil shall be insulated and protected against corrosion. The horizontal vent connection shall not project into the free area of the flue or chimney.

H. Holes: Both vertical vent and horizontal vent connections shall be clear and free from any stoppage and free from any holes that would restrict draft.

I. Area: When the appliance is connected to a chimney or vertical vent, flue, or chimney into which other appliances are connected, or when two or more appliances are connected to a single vertical vent, the vertical vent, flue, or chimney shall have a cross-sectional area of the largest vent collar, plus fifty (50) percent of the area of each additional appliance vent collar connected thereto.

J. Combustion air Fixed ventilation shall be provided to any confined space which encloses the appliance by means of a duct or grill arranged to supply combustion air unless adequate natural ventilation is provided. The duct or grill shall have a free area of not less than equal to one square inch per 1000 BTU input rating, having a minimum of not less than one hundred (100) square inches.

K. Where the design or use of a public building or residence renders it impractical to locate an automatically controlled appliance above the ground level, it may be installed in an attic or basement providing: