504.3.20 Chimney and vent location.
FGC § 504.3.20
Tables 504.3(1), 504.3(2), 504.3(3), 504.3(4), and 504.3(5) shall be used only for chimneys and vents not exposed to the outdoors below the roof line. Tables 504.3(6a), 504.3(6b), 504.3(7a) and 504.3(7b) shall be used for clay-tile-lined exterior masonry chimneys, provided that all of the following conditions are met: 1. Vent connectors are Type B double wall.
2.Not less than one appliance is draft hood equipped.
3.The combined appliance input rating is less than the maximum capacity given by Table 504.3(6a) for NAT + NAT or Table 504.3(7a) for FAN + NAT.
4.The input rating of each space-heating appliance is greater than the minimum input rating given by Table 504.3(6b) for NAT + NAT or Table 504.3(7b) for FAN + NAT.
5.The vent connector sizing is in accordance with Table 504.3(3). Editor's note: For related unconsolidated provisions, see Appendix A at L.L. 2014/051.
