When combining spaces on the same story for calculating combustion air intake, a minimum free area of 1 square inch per ________is used. (4 Points) 3,000 Btu/h 4,000 Btu/h 1,000 Btu/h 2,000 Btu/h 8.Which of the following is NOT an exception for requiring fuel gas supply pipe and fittings to bear the identification of the manufacturer? (4 Points) Where identification is provided on the product packaging or crating. Steel pipe fittings 2 inches and less in size. Where other approved documentation is provided. Steel pipe sections that are 3 feet or less in length. 9.Insulation shields for factory-built chimneys that pass through insulated assemblies shall be made of ________. (4 Points) 0.0187-inch steel Solid 2 x 6 fire retardant blocking .250" iron plate Ceramic plate