// CODE SNIPPET
803.2 Multiple Appliance Vent Table 803.2(1) Through Table 803.2(9)
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Venting Table 803.2(1) through Table 803.2(9) shall not be used where obstructions are installed in the venting system. The installation of vents serving listed appliances with vent dampers shall be in accordance with the appliance manufacturer's instructions or in accordance with the following:
- The maximum capacity of the vent connector shall be determined using the NAT Max column.
- The maximum capacity of the vertical vent or chimney shall be determined using the FAN + NAT column when the second appliance is a fan-assisted appliance, or the NAT + NAT column when the second appliance is equipped with a draft hood.
- The minimum capacity shall be determined as if the appliance were a fan-assisted appliance, as follows:
- The minimum capacity of the vent connector shall be determined using the FAN Min column.
- The FAN + FAN column shall be used when the second appliance is a fan-assisted appliance, and the FAN + NAT column shall be used when the second appliance is equipped with a draft hood, to determine whether the vertical vent or chimney configuration is not permitted (NA). Where the vent configuration is NA, the vent configuration shall not be permitted and an alternative venting configuration shall be utilized. [NFPA 54:13.2.1]
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||||||||||
VENT CONNECTOR CAPACITY | ||||||||||||||||
TYPE B DOUBLE-WALL VENT AND CONNECTOR DIAMETER — D (inch) | ||||||||||||||||
3 | 4 | 5 | 6 | 7 | ||||||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | |||||
Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | 22 | 37 | 26 | 35 | 66 | 46 | 46 | 106 | 72 | 58 | 164 | 104 | 77 | 225 | 142 |
2 | 23 | 41 | 31 | 37 | 75 | 55 | 48 | 121 | 86 | 60 | 183 | 124 | 79 | 253 | 168 | |
3 | 24 | 44 | 35 | 38 | 81 | 62 | 49 | 132 | 96 | 62 | 199 | 139 | 82 | 275 | 189 | |
8 | 1 | 22 | 40 | 27 | 35 | 72 | 48 | 49 | 114 | 76 | 64 | 176 | 109 | 84 | 243 | 148 |
2 | 23 | 44 | 32 | 36 | 80 | 57 | 51 | 128 | 90 | 66 | 195 | 129 | 86 | 269 | 175 | |
3 | 24 | 47 | 36 | 37 | 87 | 64 | 53 | 139 | 101 | 67 | 210 | 145 | 88 | 290 | 198 | |
10 | 1 | 22 | 43 | 28 | 34 | 78 | 50 | 49 | 123 | 78 | 65 | 189 | 113 | 89 | 257 | 154 |
2 | 23 | 47 | 33 | 36 | 86 | 59 | 51 | 136 | 93 | 67 | 206 | 134 | 91 | 282 | 182 | |
3 | 24 | 50 | 37 | 37 | 92 | 67 | 52 | 146 | 104 | 69 | 220 | 150 | 94 | 303 | 205 | |
15 | 1 | 21 | 50 | 30 | 33 | 89 | 53 | 47 | 142 | 83 | 64 | 220 | 120 | 88 | 298 | 163 |
2 | 22 | 53 | 35 | 35 | 96 | 63 | 49 | 153 | 99 | 66 | 235 | 142 | 91 | 320 | 193 | |
3 | 24 | 55 | 40 | 36 | 102 | 71 | 51 | 163 | 111 | 68 | 248 | 160 | 93 | 339 | 218 | |
20 | 1 | 21 | 54 | 31 | 33 | 99 | 56 | 46 | 157 | 87 | 62 | 246 | 125 | 86 | 334 | 171 |
2 | 22 | 57 | 37 | 34 | 105 | 66 | 48 | 167 | 104 | 64 | 259 | 149 | 89 | 354 | 202 | |
3 | 23 | 60 | 42 | 35 | 110 | 74 | 50 | 176 | 116 | 66 | 271 | 168 | 91 | 371 | 228 | |
30 | 1 | 20 | 62 | 33 | 31 | 113 | 59 | 45 | 181 | 93 | 60 | 288 | 134 | 83 | 391 | 182 |
2 | 21 | 64 | 39 | 33 | 118 | 70 | 47 | 190 | 110 | 62 | 299 | 158 | 85 | 408 | 215 | |
3 | 22 | 66 | 44 | 34 | 123 | 79 | 48 | 198 | 124 | 64 | 309 | 178 | 88 | 423 | 242 | |
50 | 1 | 19 | 71 | 36 | 30 | 133 | 64 | 43 | 216 | 101 | 57 | 349 | 145 | 78 | 477 | 197 |
2 | 21 | 73 | 43 | 32 | 137 | 76 | 45 | 223 | 119 | 59 | 358 | 172 | 81 | 490 | 234 | |
3 | 22 | 75 | 48 | 33 | 141 | 86 | 46 | 229 | 134 | 61 | 366 | 194 | 83 | 502 | 263 | |
100 | 1 | 18 | 82 | 37 | 28 | 158 | 66 | 40 | 262 | 104 | 53 | 442 | 150 | 73 | 611 | 204 |
2 | 19 | 83 | 44 | 30 | 161 | 79 | 42 | 267 | 123 | 55 | 447 | 178 | 75 | 619 | 242 | |
3 | 20 | 84 | 50 | 31 | 163 | 89 | 44 | 272 | 138 | 57 | 452 | 200 | 78 | 627 | 272 |
COMMON VENT CAPACITY | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
TYPE B DOUBLE-WALL COMMON VENT DIAMETER — D (inch) | ||||||||||||
4 | 5 | 6 | 7 | |||||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | ||||||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | 92 | 81 | 65 | 140 | 116 | 103 | 204 | 161 | 147 | 309 | 248 | 200 |
8 | 101 | 90 | 73 | 155 | 129 | 114 | 224 | 178 | 163 | 339 | 275 | 223 |
10 | 110 | 97 | 79 | 169 | 141 | 124 | 243 | 194 | 178 | 367 | 299 | 242 |
15 | 125 | 112 | 91 | 195 | 164 | 144 | 283 | 228 | 206 | 427 | 352 | 280 |
20 | 136 | 123 | 102 | 215 | 183 | 160 | 314 | 255 | 229 | 475 | 394 | 310 |
30 | 152 | 138 | 118 | 244 | 210 | 185 | 361 | 297 | 266 | 547 | 459 | 360 |
50 | 167 | 153 | 134 | 279 | 244 | 214 | 421 | 353 | 310 | 641 | 547 | 423 |
100 | 175 | 163 | NA | 311 | 277 | NA | 489 | 421 | NA | 751 | 658 | 479 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | ||||||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | ||||||||||
VENT CONNECTOR CAPACITY | |||||||||||
TYPE B DOUBLE-WALL VENT AND CONNECTOR DIAMETER — D (inch) | |||||||||||
8 | 9 | 10 | |||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | |||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | ||||
Min | Max | Max | Min | Max | Max | Min | Max | Max | |||
6 | 1 | 92 | 296 | 185 | 109 | 376 | 237 | 128 | 466 | 289 | |
2 | 95 | 333 | 220 | 112 | 424 | 282 | 131 | 526 | 345 | ||
3 | 97 | 363 | 248 | 114 | 463 | 317 | 134 | 575 | 386 | ||
8 | 1 | 100 | 320 | 194 | 118 | 408 | 248 | 138 | 507 | 303 | |
2 | 103 | 356 | 230 | 121 | 454 | 294 | 141 | 564 | 358 | ||
3 | 105 | 384 | 258 | 123 | 492 | 330 | 143 | 612 | 402 | ||
10 | 1 | 106 | 341 | 200 | 125 | 436 | 257 | 146 | 542 | 314 | |
2 | 109 | 374 | 238 | 128 | 479 | 305 | 149 | 596 | 372 | ||
3 | 111 | 402 | 268 | 131 | 515 | 342 | 152 | 642 | 417 | ||
15 | 1 | 110 | 389 | 214 | 134 | 493 | 273 | 162 | 609 | 333 | |
2 | 112 | 419 | 253 | 137 | 532 | 323 | 165 | 658 | 394 | ||
3 | 115 | 445 | 286 | 140 | 565 | 365 | 167 | 700 | 444 | ||
20 | 1 | 107 | 436 | 224 | 131 | 552 | 285 | 158 | 681 | 347 | |
2 | 110 | 463 | 265 | 134 | 587 | 339 | 161 | 725 | 414 | ||
3 | 113 | 486 | 300 | 137 | 618 | 383 | 164 | 764 | 466 | ||
30 | 1 | 103 | 512 | 238 | 125 | 649 | 305 | 151 | 802 | 372 | |
2 | 105 | 535 | 282 | 129 | 679 | 360 | 155 | 840 | 439 | ||
3 | 108 | 555 | 317 | 132 | 706 | 405 | 158 | 874 | 494 | ||
50 | 1 | 97 | 627 | 257 | 120 | 797 | 330 | 144 | 984 | 403 | |
2 | 100 | 645 | 306 | 123 | 820 | 392 | 148 | 1014 | 478 | ||
3 | 103 | 661 | 343 | 126 | 842 | 441 | 151 | 1043 | 538 | ||
100 | 1 | 91 | 810 | 266 | 112 | 1038 | 341 | 135 | 1285 | 417 | |
2 | 94 | 822 | 316 | 115 | 1054 | 405 | 139 | 1306 | 494 | ||
3 | 97 | 834 | 355 | 118 | 1069 | 455 | 142 | 1327 | 555 |
COMMON VENT CAPACITY | |||||||||
---|---|---|---|---|---|---|---|---|---|
TYPE B DOUBLE-WALL COMMON VENT DIAMETER — D (inch) | |||||||||
8 | 9 | 10 | |||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | 404 | 314 | 260 | 547 | 434 | 335 | 672 | 520 | 410 |
8 | 444 | 348 | 290 | 602 | 480 | 378 | 740 | 577 | 465 |
10 | 477 | 377 | 315 | 649 | 522 | 405 | 800 | 627 | 495 |
15 | 556 | 444 | 365 | 753 | 612 | 465 | 924 | 733 | 565 |
20 | 621 | 499 | 405 | 842 | 688 | 523 | 1035 | 826 | 640 |
30 | 720 | 585 | 470 | 979 | 808 | 605 | 1209 | 975 | 740 |
50 | 854 | 706 | 550 | 1164 | 977 | 705 | 1451 | 1188 | 860 |
100 | 1025 | 873 | 625 | 1408 | 1215 | 800 | 1784 | 1502 | 975 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
NUMBER OF APPLIANCES: | TWO OR MORE | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | ||||||||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | ||||||||||||
VENT CONNECTOR CAPACITY | |||||||||||||
TYPE B DOUBLE-WALL VENT AND CONNECTOR DIAMETER — D (inch) | |||||||||||||
12 | 14 | 16 | 18 | ||||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | |||||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | ||||
Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 2 | 174 | 764 | 496 | 223 | 1046 | 653 | 281 | 1371 | 853 | 346 | 1772 | 1080 |
4 | 180 | 897 | 616 | 230 | 1231 | 827 | 287 | 1617 | 1081 | 352 | 2069 | 1370 | |
6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
8 | 2 | 186 | 822 | 516 | 238 | 1126 | 696 | 298 | 1478 | 910 | 365 | 1920 | 1150 |
4 | 192 | 952 | 644 | 244 | 1307 | 884 | 305 | 1719 | 1150 | 372 | 2211 | 1460 | |
6 | 198 | 1050 | 772 | 252 | 1445 | 1072 | 313 | 1902 | 1390 | 380 | 2434 | 1770 | |
10 | 2 | 196 | 870 | 536 | 249 | 1195 | 730 | 311 | 1570 | 955 | 379 | 2049 | 1205 |
4 | 201 | 997 | 664 | 256 | 1371 | 924 | 318 | 1804 | 1205 | 387 | 2332 | 1535 | |
6 | 207 | 1095 | 792 | 263 | 1509 | 1118 | 325 | 1989 | 1455 | 395 | 2556 | 1865 | |
15 | 2 | 214 | 967 | 568 | 272 | 1334 | 790 | 336 | 1760 | 1030 | 408 | 2317 | 1305 |
4 | 221 | 1085 | 712 | 279 | 1499 | 1006 | 344 | 1978 | 1320 | 416 | 2579 | 1665 | |
6 | 228 | 1181 | 856 | 286 | 1632 | 1222 | 351 | 2157 | 1610 | 424 | 2796 | 2025 | |
20 | 2 | 223 | 1051 | 596 | 291 | 1443 | 840 | 357 | 1911 | 1095 | 430 | 2533 | 1385 |
4 | 230 | 1162 | 748 | 298 | 1597 | 1064 | 365 | 2116 | 1395 | 438 | 2778 | 1765 | |
6 | 237 | 1253 | 900 | 307 | 1726 | 1288 | 373 | 2287 | 1695 | 450 | 2984 | 2145 | |
30 | 2 | 216 | 1217 | 632 | 286 | 1664 | 910 | 367 | 2183 | 1190 | 461 | 2891 | 1540 |
4 | 223 | 1316 | 792 | 294 | 1802 | 1160 | 376 | 2366 | 1510 | 474 | 3110 | 1920 | |
6 | 231 | 1400 | 952 | 303 | 1920 | 1410 | 384 | 2524 | 1830 | 485 | 3299 | 2340 | |
50 | 2 | 206 | 1479 | 689 | 273 | 2023 | 1007 | 350 | 2659 | 1315 | 435 | 3548 | 1665 |
4 | 213 | 1561 | 860 | 281 | 2139 | 1291 | 359 | 2814 | 1685 | 447 | 3730 | 2135 | |
6 | 221 | 1631 | 1031 | 290 | 2242 | 1575 | 369 | 2951 | 2055 | 461 | 3893 | 2605 | |
100 | 2 | 192 | 1923 | 712 | 254 | 2644 | 1050 | 326 | 3490 | 1370 | 402 | 4707 | 1740 |
4 | 200 | 1984 | 888 | 263 | 2731 | 1346 | 336 | 3606 | 1760 | 414 | 4842 | 2220 | |
6 | 208 | 2035 | 1064 | 272 | 2811 | 1642 | 346 | 3714 | 2150 | 426 | 4968 | 2700 |
COMMON VENT CAPACITY | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
TYPE B DOUBLE-WALL COMMON VENT DIAMETER — D (inch) | ||||||||||||
12 | 14 | 16 | 18 | |||||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | ||||||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | 900 | 696 | 588 | 1284 | 990 | 815 | 1735 | 1336 | 1065 | 2253 | 1732 | 1345 |
8 | 994 | 773 | 652 | 1423 | 1103 | 912 | 1927 | 1491 | 1190 | 2507 | 1936 | 1510 |
10 | 1076 | 841 | 712 | 1542 | 1200 | 995 | 2093 | 1625 | 1300 | 2727 | 2113 | 1645 |
15 | 1247 | 986 | 825 | 1794 | 1410 | 1158 | 2440 | 1910 | 1510 | 3184 | 2484 | 1910 |
20 | 1405 | 1116 | 916 | 2006 | 1588 | 1290 | 2722 | 2147 | 1690 | 3561 | 2798 | 2140 |
30 | 1658 | 1327 | 1025 | 2373 | 1892 | 1525 | 3220 | 2558 | 1990 | 4197 | 3326 | 2520 |
50 | 2024 | 1640 | 1280 | 2911 | 2347 | 1863 | 3964 | 3183 | 2430 | 5184 | 4149 | 3075 |
100 | 2569 | 2131 | 1670 | 3732 | 3076 | 2450 | 5125 | 4202 | 3200 | 6749 | 5509 | 4050 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||||
VENT CONNECTOR CAPACITY | ||||||||||
TYPE B DOUBLE-WALL VENT AND CONNECTOR DIAMETER — D (inch) | ||||||||||
20 | 22 | 24 | ||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | |||
Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
6 | NA | NA | NA | NA | NA | NA | NA | NA | NA | |
8 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 471 | 2737 | 1800 | 560 | 3319 | 2180 | 662 | 3957 | 2590 | |
6 | 478 | 3018 | 2180 | 568 | 3665 | 2640 | 669 | 4373 | 3130 | |
10 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 486 | 2887 | 1890 | 581 | 3502 | 2280 | 686 | 4175 | 2710 | |
6 | 494 | 3169 | 2290 | 589 | 3849 | 2760 | 694 | 4593 | 3270 | |
15 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 523 | 3197 | 2060 | 624 | 3881 | 2490 | 734 | 4631 | 2960 | |
6 | 533 | 3470 | 2510 | 634 | 4216 | 3030 | 743 | 5035 | 3600 | |
20 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 554 | 3447 | 2180 | 661 | 4190 | 2630 | 772 | 5005 | 3130 | |
6 | 567 | 3708 | 2650 | 671 | 4511 | 3190 | 785 | 5392 | 3790 | |
30 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 619 | 3840 | 2365 | 728 | 4861 | 2860 | 847 | 5606 | 3410 | |
6 | 632 | 4080 | 2875 | 741 | 4976 | 3480 | 860 | 5961 | 4150 | |
50 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 580 | 4601 | 2633 | 709 | 5569 | 3185 | 851 | 6633 | 3790 | |
6 | 594 | 4808 | 3208 | 724 | 5826 | 3885 | 867 | 6943 | 4620 | |
100 | 2 | NA | NA | NA | NA | NA | NA | NA | NA | NA |
4 | 523 | 5982 | 2750 | 639 | 7254 | 3330 | 769 | 8650 | 3950 | |
6 | 539 | 6143 | 3350 | 654 | 7453 | 4070 | 786 | 8892 | 4810 |
COMMON VENT CAPACITY | |||||||||
---|---|---|---|---|---|---|---|---|---|
TYPE B DOUBLE-WALL COMMON VENT DIAMETER — D (inch) | |||||||||
20 | 22 | 24 | |||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | 2838 | 2180 | 1660 | 3488 | 2677 | 1970 | 4206 | 3226 | 2390 |
8 | 3162 | 2439 | 1860 | 3890 | 2998 | 2200 | 4695 | 3616 | 2680 |
10 | 3444 | 2665 | 2030 | 4241 | 3278 | 2400 | 5123 | 3957 | 2920 |
15 | 4026 | 3133 | 2360 | 4971 | 3862 | 2790 | 6016 | 4670 | 3400 |
20 | 4548 | 3552 | 2640 | 5573 | 4352 | 3120 | 6749 | 5261 | 3800 |
30 | 5303 | 4193 | 3110 | 6539 | 5157 | 3680 | 7940 | 6247 | 4480 |
50 | 6567 | 5240 | 3800 | 8116 | 6458 | 4500 | 9837 | 7813 | 5475 |
100 | 8597 | 6986 | 5000 | 10 681 | 8648 | 5920 | 13 004 | 10 499 | 7200 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||||||||
APPLIANCE VENT CONNECTION: | SINGLE-WALL METAL CONNECTOR | |||||||||||||||
VENT CONNECTOR CAPACITY | ||||||||||||||||
SINGLE-WALL METAL VENT CONNECTOR DIAMETER — D (inch) | ||||||||||||||||
3 | 4 | 5 | 6 | 7 | ||||||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | |||||
Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | NA | NA | 26 | NA | NA | 46 | NA | NA | 71 | NA | NA | 102 | 207 | 223 | 140 |
2 | NA | NA | 31 | NA | NA | 55 | NA | NA | 85 | 168 | 182 | 123 | 215 | 251 | 167 | |
3 | NA | NA | 34 | NA | NA | 62 | 121 | 131 | 95 | 175 | 198 | 138 | 222 | 273 | 188 | |
8 | 1 | NA | NA | 27 | NA | NA | 48 | NA | NA | 75 | NA | NA | 106 | 226 | 240 | 145 |
2 | NA | NA | 32 | NA | NA | 57 | 125 | 126 | 89 | 184 | 193 | 127 | 234 | 266 | 173 | |
3 | NA | NA | 35 | NA | NA | 64 | 130 | 138 | 100 | 191 | 208 | 144 | 241 | 287 | 197 | |
10 | 1 | NA | NA | 28 | NA | NA | 50 | 119 | 121 | 77 | 182 | 186 | 110 | 240 | 253 | 150 |
2 | NA | NA | 33 | 84 | 85 | 59 | 124 | 134 | 91 | 189 | 203 | 132 | 248 | 278 | 183 | |
3 | NA | NA | 36 | 89 | 91 | 67 | 129 | 144 | 102 | 197 | 217 | 148 | 257 | 299 | 203 | |
15 | 1 | NA | NA | 29 | 79 | 87 | 52 | 116 | 138 | 81 | 177 | 214 | 116 | 238 | 291 | 158 |
2 | NA | NA | 34 | 83 | 94 | 62 | 121 | 150 | 97 | 185 | 230 | 138 | 246 | 314 | 189 | |
3 | NA | NA | 39 | 87 | 100 | 70 | 127 | 160 | 109 | 193 | 243 | 157 | 255 | 333 | 215 | |
20 | 1 | 49 | 56 | 30 | 78 | 97 | 54 | 115 | 152 | 84 | 175 | 238 | 120 | 233 | 325 | 165 |
2 | 52 | 59 | 36 | 82 | 103 | 64 | 120 | 163 | 101 | 182 | 252 | 144 | 243 | 346 | 197 | |
3 | 55 | 62 | 40 | 87 | 107 | 72 | 125 | 172 | 113 | 190 | 264 | 164 | 252 | 363 | 223 | |
30 | 1 | 47 | 60 | 31 | 77 | 110 | 57 | 112 | 175 | 89 | 169 | 278 | 129 | 226 | 380 | 175 |
2 | 51 | 62 | 37 | 81 | 115 | 67 | 117 | 185 | 106 | 177 | 290 | 152 | 236 | 397 | 208 | |
3 | 54 | 64 | 42 | 85 | 119 | 76 | 122 | 193 | 120 | 185 | 300 | 172 | 244 | 412 | 235 | |
50 | 1 | 46 | 69 | 34 | 75 | 128 | 60 | 109 | 207 | 96 | 162 | 336 | 137 | 217 | 460 | 188 |
2 | 49 | 71 | 40 | 79 | 132 | 72 | 114 | 215 | 113 | 170 | 345 | 164 | 226 | 473 | 223 | |
3 | 52 | 72 | 45 | 83 | 136 | 82 | 119 | 221 | 123 | 178 | 353 | 186 | 235 | 486 | 252 | |
100 | 1 | 45 | 79 | 34 | 71 | 150 | 61 | 104 | 249 | 98 | 153 | 424 | 140 | 205 | 585 | 192 |
2 | 48 | 80 | 41 | 75 | 153 | 73 | 110 | 255 | 115 | 160 | 428 | 167 | 212 | 593 | 228 | |
3 | 51 | 81 | 46 | 79 | 157 | 85 | 114 | 260 | 129 | 168 | 433 | 190 | 222 | 603 | 256 |
COMMON VENT CAPACITY | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
TYPE B DOUBLE-WALL COMMON VENT DIAMETER — D (inch) | ||||||||||||
4 | 5 | 6 | 7 | |||||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | ||||||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | NA | 78 | 64 | NA | 113 | 99 | 200 | 158 | 144 | 304 | 244 | 196 |
8 | NA | 87 | 71 | NA | 126 | 111 | 218 | 173 | 159 | 331 | 269 | 218 |
10 | NA | 94 | 76 | 163 | 137 | 120 | 237 | 189 | 174 | 357 | 292 | 236 |
15 | 121 | 108 | 88 | 189 | 159 | 140 | 275 | 221 | 200 | 416 | 343 | 274 |
20 | 131 | 118 | 98 | 208 | 177 | 156 | 305 | 247 | 223 | 463 | 383 | 302 |
30 | 145 | 132 | 113 | 236 | 202 | 180 | 350 | 286 | 257 | 533 | 446 | 349 |
50 | 159 | 145 | 128 | 268 | 233 | 208 | 406 | 337 | 296 | 622 | 529 | 410 |
100 | 166 | 153 | NA | 297 | 263 | NA | 469 | 398 | NA | 726 | 633 | 464 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||
APPLIANCE VENT CONNECTION: | SINGLE-WALL METAL CONNECTOR | |||||||||
VENT CONNECTOR CAPACITY | ||||||||||
SINGLE-WALL METAL VENT CONNECTOR DIAMETER — D (inch) | ||||||||||
8 | 9 | 10 | ||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | |||
Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | 262 | 293 | 183 | 325 | 373 | 234 | 447 | 463 | 286 |
2 | 271 | 331 | 219 | 334 | 422 | 281 | 458 | 524 | 344 | |
3 | 279 | 361 | 247 | 344 | 462 | 316 | 468 | 574 | 385 | |
8 | 1 | 285 | 316 | 191 | 352 | 403 | 244 | 481 | 502 | 299 |
2 | 293 | 353 | 228 | 360 | 450 | 292 | 492 | 560 | 355 | |
3 | 302 | 381 | 256 | 370 | 489 | 328 | 501 | 609 | 400 | |
10 | 1 | 302 | 335 | 196 | 372 | 429 | 252 | 506 | 534 | 308 |
2 | 311 | 369 | 235 | 381 | 473 | 302 | 517 | 589 | 368 | |
3 | 320 | 398 | 265 | 391 | 511 | 339 | 528 | 637 | 413 | |
15 | 1 | 312 | 380 | 208 | 397 | 482 | 266 | 556 | 596 | 324 |
2 | 321 | 411 | 248 | 407 | 522 | 317 | 568 | 646 | 387 | |
3 | 331 | 438 | 281 | 418 | 557 | 360 | 579 | 690 | 437 | |
20 | 1 | 306 | 425 | 217 | 390 | 538 | 276 | 546 | 664 | 336 |
2 | 317 | 453 | 259 | 400 | 574 | 331 | 558 | 709 | 403 | |
3 | 326 | 476 | 294 | 412 | 607 | 375 | 570 | 750 | 457 | |
30 | 1 | 296 | 497 | 230 | 378 | 630 | 294 | 528 | 779 | 358 |
2 | 307 | 521 | 274 | 389 | 662 | 349 | 541 | 819 | 425 | |
3 | 316 | 542 | 309 | 400 | 690 | 394 | 555 | 855 | 482 | |
50 | 1 | 284 | 604 | 245 | 364 | 768 | 314 | 507 | 951 | 384 |
2 | 294 | 623 | 293 | 376 | 793 | 375 | 520 | 983 | 458 | |
3 | 304 | 640 | 331 | 387 | 816 | 423 | 535 | 1013 | 518 | |
100 | 1 | 269 | 774 | 249 | 345 | 993 | 321 | 476 | 1236 | 393 |
2 | 279 | 788 | 299 | 358 | 1011 | 383 | 490 | 1259 | 469 | |
3 | 289 | 801 | 339 | 368 | 1027 | 431 | 506 | 1280 | 527 |
COMMON VENT CAPACITY | |||||||||
---|---|---|---|---|---|---|---|---|---|
TYPE B DOUBLE-WALL COMMON VENT DIAMETER — D (inch) | |||||||||
8 | 9 | 10 | |||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | 398 | 310 | 257 | 541 | 429 | 332 | 665 | 515 | 407 |
8 | 436 | 342 | 285 | 592 | 473 | 373 | 730 | 569 | 460 |
10 | 467 | 369 | 309 | 638 | 512 | 398 | 787 | 617 | 487 |
15 | 544 | 434 | 357 | 738 | 599 | 456 | 905 | 718 | 553 |
20 | 606 | 487 | 395 | 824 | 673 | 512 | 1013 | 808 | 626 |
30 | 703 | 570 | 459 | 958 | 790 | 593 | 1183 | 952 | 723 |
50 | 833 | 686 | 535 | 1139 | 954 | 689 | 1418 | 1157 | 838 |
100 | 999 | 846 | 606 | 1378 | 1185 | 780 | 1741 | 1459 | 948 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||||||||||
VENT CONNECTOR CAPACITY | ||||||||||||||||
TYPE B DOUBLE-WALL VENT CONNECTOR DIAMETER — D (inch) | ||||||||||||||||
3 | 4 | 5 | 6 | 7 | ||||||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | |||||
Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | 24 | 33 | 21 | 39 | 62 | 40 | 52 | 106 | 67 | 65 | 194 | 101 | 87 | 274 | 141 |
2 | 26 | 43 | 28 | 41 | 79 | 52 | 53 | 133 | 85 | 67 | 230 | 124 | 89 | 324 | 173 | |
3 | 27 | 49 | 34 | 42 | 92 | 61 | 55 | 155 | 97 | 69 | 262 | 143 | 91 | 369 | 203 | |
8 | 1 | 24 | 39 | 22 | 39 | 72 | 41 | 55 | 117 | 69 | 71 | 213 | 105 | 94 | 304 | 148 |
2 | 26 | 47 | 29 | 40 | 87 | 53 | 57 | 140 | 86 | 73 | 246 | 127 | 97 | 350 | 179 | |
3 | 27 | 52 | 34 | 42 | 97 | 62 | 59 | 159 | 98 | 75 | 269 | 145 | 99 | 383 | 206 | |
10 | 1 | 24 | 42 | 22 | 38 | 80 | 42 | 55 | 130 | 71 | 74 | 232 | 108 | 101 | 324 | 153 |
2 | 26 | 50 | 29 | 40 | 93 | 54 | 57 | 153 | 87 | 76 | 261 | 129 | 103 | 366 | 184 | |
3 | 27 | 55 | 35 | 41 | 105 | 63 | 58 | 170 | 100 | 78 | 284 | 148 | 106 | 397 | 209 | |
15 | 1 | 24 | 48 | 23 | 38 | 93 | 44 | 54 | 154 | 74 | 72 | 277 | 114 | 100 | 384 | 164 |
2 | 25 | 55 | 31 | 39 | 105 | 55 | 56 | 174 | 89 | 74 | 299 | 134 | 103 | 419 | 192 | |
3 | 26 | 59 | 35 | 41 | 115 | 64 | 57 | 189 | 102 | 76 | 319 | 153 | 105 | 448 | 215 | |
20 | 1 | 24 | 52 | 24 | 37 | 102 | 46 | 53 | 172 | 77 | 71 | 313 | 119 | 98 | 437 | 173 |
2 | 25 | 58 | 31 | 39 | 114 | 56 | 55 | 190 | 91 | 73 | 335 | 138 | 101 | 467 | 199 | |
3 | 26 | 63 | 35 | 40 | 123 | 65 | 57 | 204 | 104 | 75 | 353 | 157 | 104 | 493 | 222 | |
30 | 1 | 24 | 54 | 25 | 37 | 111 | 48 | 52 | 192 | 82 | 69 | 357 | 127 | 96 | 504 | 187 |
2 | 25 | 60 | 32 | 38 | 122 | 58 | 54 | 208 | 95 | 72 | 376 | 145 | 99 | 531 | 209 | |
3 | 26 | 64 | 36 | 40 | 131 | 66 | 56 | 221 | 107 | 74 | 392 | 163 | 101 | 554 | 233 | |
50 | 1 | 23 | 51 | 25 | 36 | 116 | 51 | 51 | 209 | 89 | 67 | 405 | 143 | 92 | 582 | 213 |
2 | 24 | 59 | 32 | 37 | 127 | 61 | 53 | 225 | 102 | 70 | 421 | 161 | 95 | 604 | 235 | |
3 | 26 | 64 | 36 | 39 | 135 | 69 | 55 | 237 | 115 | 72 | 435 | 180 | 98 | 624 | 260 | |
100 | 1 | 23 | 46 | 24 | 35 | 108 | 50 | 49 | 208 | 92 | 65 | 428 | 155 | 88 | 640 | 237 |
2 | 24 | 53 | 31 | 37 | 120 | 60 | 51 | 224 | 105 | 67 | 444 | 174 | 92 | 660 | 260 | |
3 | 25 | 59 | 35 | 38 | 130 | 68 | 53 | 237 | 118 | 69 | 458 | 193 | 94 | 679 | 285 |
COMMON VENT CAPACITY | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches) | |||||||||||||||
12 | 19 | 28 | 38 | 50 | |||||||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | NA | 74 | 25 | NA | 119 | 46 | NA | 178 | 71 | NA | 257 | 103 | NA | 351 | 143 |
8 | NA | 80 | 28 | NA | 130 | 53 | NA | 193 | 82 | NA | 279 | 119 | NA | 384 | 163 |
10 | NA | 84 | 31 | NA | 138 | 56 | NA | 207 | 90 | NA | 299 | 131 | NA | 409 | 177 |
15 | NA | NA | 36 | NA | 152 | 67 | NA | 233 | 106 | NA | 334 | 152 | 523 | 467 | 212 |
20 | NA | NA | 41 | NA | NA | 75 | NA | 250 | 122 | NA | 368 | 172 | 565 | 508 | 243 |
30 | NA | NA | NA | NA | NA | NA | NA | 270 | 137 | NA | 404 | 198 | 615 | 564 | 278 |
50 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 620 | 328 |
100 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 348 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||||
VENT CONNECTOR CAPACITY | ||||||||||
TYPE B DOUBLE-WALL VENT CONNECTOR DIAMETER — D (inch) | ||||||||||
8 | 9 | 10 | ||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | |||
Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | 104 | 370 | 201 | 124 | 479 | 253 | 145 | 599 | 319 |
2 | 107 | 436 | 232 | 127 | 562 | 300 | 148 | 694 | 378 | |
3 | 109 | 491 | 270 | 129 | 633 | 349 | 151 | 795 | 439 | |
8 | 1 | 113 | 414 | 210 | 134 | 539 | 267 | 156 | 682 | 335 |
2 | 116 | 473 | 240 | 137 | 615 | 311 | 160 | 776 | 394 | |
3 | 119 | 517 | 276 | 139 | 672 | 358 | 163 | 848 | 452 | |
10 | 1 | 120 | 444 | 216 | 142 | 582 | 277 | 165 | 739 | 348 |
2 | 123 | 498 | 247 | 145 | 652 | 321 | 168 | 825 | 407 | |
3 | 126 | 540 | 281 | 147 | 705 | 366 | 171 | 893 | 463 | |
15 | 1 | 125 | 511 | 229 | 153 | 658 | 297 | 184 | 824 | 375 |
2 | 128 | 558 | 260 | 156 | 718 | 339 | 187 | 900 | 432 | |
3 | 131 | 597 | 292 | 159 | 760 | 382 | 190 | 960 | 486 | |
20 | 1 | 123 | 584 | 239 | 150 | 752 | 312 | 180 | 943 | 397 |
2 | 126 | 625 | 270 | 153 | 805 | 354 | 184 | 1011 | 452 | |
3 | 129 | 661 | 301 | 156 | 851 | 396 | 187 | 1067 | 505 | |
30 | 1 | 119 | 680 | 255 | 145 | 883 | 337 | 175 | 1115 | 432 |
2 | 122 | 715 | 287 | 149 | 928 | 378 | 179 | 1171 | 484 | |
3 | 125 | 746 | 317 | 152 | 968 | 418 | 182 | 1220 | 535 | |
50 | 1 | 115 | 798 | 294 | 140 | 1049 | 392 | 168 | 1334 | 506 |
2 | 118 | 827 | 326 | 143 | 1085 | 433 | 172 | 1379 | 558 | |
3 | 121 | 854 | 357 | 147 | 1118 | 474 | 176 | 1421 | 611 | |
100 | 1 | 109 | 907 | 334 | 134 | 1222 | 454 | 161 | 1589 | 596 |
2 | 113 | 933 | 368 | 138 | 1253 | 497 | 165 | 1626 | 651 | |
3 | 116 | 956 | 399 | 141 | 1282 | 540 | 169 | 1661 | 705 |
COMMON VENT CAPACITY | |||||||||
---|---|---|---|---|---|---|---|---|---|
MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches) | |||||||||
63 | 78 | 113 | |||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | NA | 458 | 188 | NA | 582 | 246 | 1041 | 853 | NA |
8 | NA | 501 | 218 | 724 | 636 | 278 | 1144 | 937 | 408 |
10 | 606 | 538 | 236 | 776 | 686 | 302 | 1226 | 1010 | 454 |
15 | 682 | 611 | 283 | 874 | 781 | 365 | 1374 | 1156 | 546 |
20 | 742 | 668 | 325 | 955 | 858 | 419 | 1513 | 1286 | 648 |
30 | 816 | 747 | 381 | 1062 | 969 | 496 | 1702 | 1473 | 749 |
50 | 879 | 831 | 461 | 1165 | 1089 | 606 | 1905 | 1692 | 922 |
100 | NA | NA | 499 | NA | NA | 669 | 2053 | 1921 | 1058 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||||||||
APPLIANCE VENT CONNECTION: | SINGLE-WALL METAL CONNECTOR | |||||||||||||||
VENT CONNECTOR CAPACITY | ||||||||||||||||
SINGLE-WALL METAL VENT CONNECTOR DIAMETER — D (inch) | ||||||||||||||||
3 | 4 | 5 | 6 | 7 | ||||||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | FAN | NAT | |||||
Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | NA | NA | 21 | NA | NA | 39 | NA | NA | 66 | 179 | 191 | 100 | 231 | 271 | 140 |
2 | NA | NA | 28 | NA | NA | 52 | NA | NA | 84 | 186 | 227 | 123 | 239 | 321 | 172 | |
3 | NA | NA | 34 | NA | NA | 61 | 134 | 153 | 97 | 193 | 258 | 142 | 247 | 365 | 202 | |
8 | 1 | NA | NA | 21 | NA | NA | 40 | NA | NA | 68 | 195 | 208 | 103 | 250 | 298 | 146 |
2 | NA | NA | 28 | NA | NA | 52 | 137 | 139 | 85 | 202 | 240 | 125 | 258 | 343 | 177 | |
3 | NA | NA | 34 | NA | NA | 62 | 143 | 156 | 98 | 210 | 264 | 145 | 266 | 376 | 205 | |
10 | 1 | NA | NA | 22 | NA | NA | 41 | 130 | 151 | 70 | 202 | 225 | 106 | 267 | 316 | 151 |
2 | NA | NA | 29 | NA | NA | 53 | 136 | 150 | 86 | 210 | 255 | 128 | 276 | 358 | 181 | |
3 | NA | NA | 34 | 97 | 102 | 62 | 143 | 166 | 99 | 217 | 277 | 147 | 284 | 389 | 207 | |
15 | 1 | NA | NA | 23 | NA | NA | 43 | 129 | 151 | 73 | 199 | 271 | 112 | 268 | 376 | 161 |
2 | NA | NA | 30 | 92 | 103 | 54 | 135 | 170 | 88 | 207 | 295 | 132 | 277 | 411 | 189 | |
3 | NA | NA | 34 | 96 | 112 | 63 | 141 | 185 | 101 | 215 | 315 | 151 | 286 | 439 | 213 | |
20 | 1 | NA | NA | 23 | 87 | 99 | 45 | 128 | 167 | 76 | 197 | 303 | 117 | 265 | 425 | 169 |
2 | NA | NA | 30 | 91 | 111 | 55 | 134 | 185 | 90 | 205 | 325 | 136 | 274 | 455 | 195 | |
3 | NA | NA | 35 | 96 | 119 | 64 | 140 | 199 | 103 | 213 | 343 | 154 | 282 | 481 | 219 | |
30 | 1 | NA | NA | 24 | 86 | 108 | 47 | 126 | 187 | 80 | 193 | 347 | 124 | 259 | 492 | 183 |
2 | NA | NA | 31 | 91 | 119 | 57 | 132 | 203 | 93 | 201 | 366 | 142 | 269 | 518 | 205 | |
3 | NA | NA | 35 | 95 | 127 | 65 | 138 | 216 | 105 | 209 | 381 | 160 | 277 | 540 | 229 | |
50 | 1 | NA | NA | 24 | 85 | 113 | 50 | 124 | 204 | 87 | 188 | 392 | 139 | 252 | 567 | 208 |
2 | NA | NA | 31 | 89 | 123 | 60 | 130 | 218 | 100 | 196 | 408 | 158 | 262 | 588 | 230 | |
3 | NA | NA | 35 | 94 | 131 | 68 | 136 | 231 | 112 | 205 | 422 | 176 | 271 | 607 | 255 | |
100 | 1 | NA | NA | 23 | 84 | 104 | 49 | 122 | 200 | 89 | 182 | 410 | 151 | 243 | 617 | 232 |
2 | NA | NA | 30 | 88 | 115 | 59 | 127 | 215 | 102 | 190 | 425 | 169 | 253 | 636 | 254 | |
3 | NA | NA | 34 | 93 | 124 | 67 | 133 | 228 | 115 | 199 | 438 | 188 | 262 | 654 | 279 |
COMMON VENT CAPACITY | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches) | |||||||||||||||
12 | 19 | 28 | 38 | 50 | |||||||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | NA | NA | 25 | NA | 118 | 45 | NA | 176 | 71 | NA | 255 | 102 | NA | 348 | 142 |
8 | NA | NA | 28 | NA | 128 | 52 | NA | 190 | 81 | NA | 276 | 118 | NA | 380 | 162 |
10 | NA | NA | 31 | NA | 136 | 56 | NA | 205 | 89 | NA | 295 | 129 | NA | 405 | 175 |
15 | NA | NA | 36 | NA | NA | 66 | NA | 230 | 105 | NA | 335 | 150 | NA | 400 | 210 |
20 | NA | NA | NA | NA | NA | 74 | NA | 247 | 120 | NA | 362 | 170 | NA | 503 | 240 |
30 | NA | NA | NA | NA | NA | NA | NA | NA | 135 | NA | 398 | 195 | NA | 558 | 275 |
50 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | 612 | 325 |
100 | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA | NA |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | CATEGORY I | |||||||||
APPLIANCE VENT CONNECTION: | SINGLE-WALL METAL CONNECTOR | |||||||||
VENT CONNECTOR CAPACITY | ||||||||||
SINGLE-WALL METAL VENT CONNECTOR DIAMETER — D (inch) | ||||||||||
8 | 9 | 10 | ||||||||
APPLIANCE INPUT RATING LIMITS IN THOUSANDS OF BTU PER HOUR | ||||||||||
VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
FAN | NAT | FAN | NAT | FAN | NAT | |||
Min | Max | Max | Min | Max | Max | Min | Max | Max | ||
6 | 1 | 292 | 366 | 200 | 362 | 474 | 252 | 499 | 594 | 316 |
2 | 301 | 432 | 231 | 373 | 557 | 299 | 509 | 696 | 376 | |
3 | 309 | 491 | 269 | 381 | 634 | 348 | 519 | 793 | 437 | |
8 | 1 | 313 | 407 | 207 | 387 | 530 | 263 | 529 | 672 | 331 |
2 | 323 | 465 | 238 | 397 | 607 | 309 | 540 | 766 | 391 | |
3 | 332 | 509 | 274 | 407 | 663 | 356 | 551 | 838 | 450 | |
10 | 1 | 333 | 434 | 213 | 410 | 571 | 273 | 558 | 727 | 343 |
2 | 343 | 489 | 244 | 420 | 640 | 317 | 569 | 813 | 403 | |
3 | 352 | 530 | 279 | 430 | 694 | 363 | 580 | 880 | 459 | |
15 | 1 | 349 | 502 | 225 | 445 | 646 | 291 | 623 | 808 | 366 |
2 | 359 | 548 | 256 | 456 | 706 | 334 | 634 | 884 | 424 | |
3 | 368 | 586 | 289 | 466 | 755 | 378 | 646 | 945 | 479 | |
20 | 1 | 345 | 569 | 235 | 439 | 734 | 306 | 614 | 921 | 387 |
2 | 355 | 610 | 266 | 450 | 787 | 348 | 627 | 986 | 443 | |
3 | 365 | 644 | 298 | 461 | 831 | 391 | 639 | 1042 | 496 | |
30 | 1 | 338 | 665 | 250 | 430 | 864 | 330 | 600 | 1089 | 421 |
2 | 348 | 699 | 282 | 442 | 908 | 372 | 613 | 1145 | 473 | |
3 | 358 | 729 | 312 | 452 | 946 | 412 | 626 | 1193 | 524 | |
50 | 1 | 328 | 778 | 287 | 417 | 1022 | 383 | 582 | 1302 | 492 |
2 | 339 | 806 | 320 | 429 | 1058 | 425 | 596 | 1346 | 545 | |
3 | 349 | 831 | 351 | 440 | 1090 | 466 | 610 | 1386 | 597 | |
100 | 1 | 315 | 875 | 328 | 402 | 1181 | 444 | 560 | 1537 | 580 |
2 | 326 | 899 | 361 | 415 | 1210 | 488 | 575 | 1570 | 634 | |
3 | 337 | 921 | 392 | 427 | 1238 | 529 | 589 | 1604 | 687 |
COMMON VENT CAPACITY | |||||||||
---|---|---|---|---|---|---|---|---|---|
MINIMUM INTERNAL AREA OF MASONRY CHIMNEY FLUE (square inches) | |||||||||
63 | 78 | 113 | |||||||
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||||
VENT HEIGHT H (feet) |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
FAN +FAN |
FAN +NAT |
NAT +NAT |
6 | NA | 455 | 187 | NA | 579 | 245 | NA | 846 | NA |
8 | NA | 497 | 217 | NA | 633 | 277 | 1136 | 928 | 405 |
10 | NA | 532 | 234 | 771 | 680 | 300 | 1216 | 1000 | 450 |
15 | 677 | 602 | 280 | 866 | 772 | 360 | 1359 | 1139 | 540 |
20 | 765 | 661 | 321 | 947 | 849 | 415 | 1495 | 1264 | 640 |
30 | 808 | 739 | 377 | 1052 | 957 | 490 | 1682 | 1447 | 740 |
50 | NA | 821 | 456 | 1152 | 1076 | 600 | 1879 | 1672 | 910 |
100 | NA | NA | 494 | NA | NA | 663 | 2006 | 1885 | 1046 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | ||||||
---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | DRAFT HOOD-EQUIPMENT | ||||||
APPLIANCE VENT CONNECTION: | DIRECT TO PIPE OR VENT | ||||||
VENT CONNECTOR CAPACITY | |||||||
VENT CONNECTOR DIAMETER — D (inch) | |||||||
TOTAL VENT HEIGHT H (feet) |
CONNECTOR RISE R (feet) |
3 | 4 | 5 | 6 | 7 | 8 |
APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||
1 | 21 | 40 | 68 | 102 | 146 | 205 | |
6—8 | 2 | 28 | 53 | 86 | 124 | 178 | 235 |
3 | 34 | 61 | 98 | 147 | 204 | 275 | |
1 | 23 | 44 | 77 | 117 | 179 | 240 | |
15 | 2 | 30 | 56 | 92 | 134 | 194 | 265 |
3 | 35 | 64 | 102 | 155 | 216 | 298 | |
30 and up |
1 | 25 | 49 | 84 | 129 | 190 | 270 |
2 | 31 | 58 | 97 | 145 | 211 | 295 | |
3 | 36 | 68 | 107 | 164 | 232 | 321 |
COMMON VENT CAPACITY | |||||||
---|---|---|---|---|---|---|---|
COMMON VENT DIAMETER — D (inch) | |||||||
TOTAL VENT HEIGHT H (feet) |
4 | 5 | 6 | 7 | 8 | 10 | 12 |
COMBINED APPLIANCE INPUT RATING IN THOUSANDS OF BTU PER HOUR | |||||||
6 | 48 | 78 | 111 | 155 | 205 | 320 | NA |
8 | 55 | 89 | 128 | 175 | 234 | 365 | 505 |
10 | 59 | 95 | 136 | 190 | 250 | 395 | 560 |
15 | 71 | 115 | 168 | 228 | 305 | 480 | 690 |
20 | 80 | 129 | 186 | 260 | 340 | 550 | 790 |
30 | NA | 147 | 215 | 300 | 400 | 650 | 940 |
50 | NA | NA | NA | 360 | 490 | 810 | 1190 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||
---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | NAT + NAT | |||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||
COMBINED APPLIANCE MAXIMUM INPUT RATING IN THOUSANDS OF BTU PER HOUR | ||||||||
VENT HEIGHT H (feet) |
INTERNAL AREA OF CHIMNEY (square inches) | |||||||
12 | 19 | 28 | 38 | 50 | 63 | 78 | 113 | |
6 | 25 | 46 | 71 | 103 | 143 | 188 | 246 | NA |
8 | 28 | 53 | 82 | 119 | 163 | 218 | 278 | 408 |
10 | 31 | 56 | 90 | 131 | 177 | 236 | 302 | 454 |
15 | NA | 67 | 106 | 152 | 212 | 283 | 365 | 546 |
20 | NA | NA | NA | NA | NA | 325 | 419 | 648 |
30 | NA | NA | NA | NA | NA | NA | 496 | 749 |
50 | NA | NA | NA | NA | NA | NA | NA | 922 |
100 | NA | NA | NA | NA | NA | NA | NA | NA |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||
---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | NAT + NAT | |||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||
MINIMUM ALLOWABLE INPUT RATING OF SPACE-HEATING APPLIANCE IN THOUSANDS OF BTU PER HOUR | ||||||||
VENT HEIGHT H (feet) |
INTERNAL AREA OF CHIMNEY (square inches) | |||||||
12 | 19 | 28 | 38 | 50 | 63 | 78 | 113 | |
Local 99% winter design temperature: 37°F or greater | ||||||||
6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | NA |
8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
15 | NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
20 | NA | NA | NA | NA | NA | 184 | 0 | 0 |
30 | NA | NA | NA | NA | NA | 393 | 334 | 0 |
50 | NA | NA | NA | NA | NA | NA | NA | 579 |
100 | NA | NA | NA | NA | NA | NA | NA | NA |
Local 99% winter design temperature: 27°F to 36°F | ||||||||
6 | 0 | 0 | 68 | NA | NA | 180 | 212 | NA |
8 | 0 | 0 | 82 | NA | NA | 187 | 214 | 263 |
10 | 0 | 51 | NA | NA | NA | 201 | 225 | 265 |
15 | NA | NA | NA | NA | NA | 253 | 274 | 305 |
20 | NA | NA | NA | NA | NA | 307 | 330 | 362 |
30 | NA | NA | NA | NA | NA | NA | 445 | 485 |
50 | NA | NA | NA | NA | NA | NA | NA | 763 |
100 | NA | NA | NA | NA | NA | NA | NA | NA |
Local 99% winter design temperature: 17°F to 26°F | ||||||||
6 | NA | NA | NA | NA | NA | NA | NA | NA |
8 | NA | NA | NA | NA | NA | NA | 264 | 352 |
10 | NA | NA | NA | NA | NA | NA | 278 | 358 |
15 | NA | NA | NA | NA | NA | NA | 331 | 398 |
20 | NA | NA | NA | NA | NA | NA | 387 | 457 |
30 | NA | NA | NA | NA | NA | NA | NA | 581 |
50 | NA | NA | NA | NA | NA | NA | NA | 862 |
100 | NA | NA | NA | NA | NA | NA | NA | NA |
Local 99% winter design temperature: 5°F to 16°F | ||||||||
6 | NA | NA | NA | NA | NA | NA | NA | NA |
8 | NA | NA | NA | NA | NA | NA | NA | NA |
10 | NA | NA | NA | NA | NA | NA | NA | 430 |
15 | NA | NA | NA | NA | NA | NA | NA | 485 |
20 | NA | NA | NA | NA | NA | NA | NA | 547 |
30 | NA | NA | NA | NA | NA | NA | NA | 682 |
50 | NA | NA | NA | NA | NA | NA | NA | NA |
100 | NA | NA | NA | NA | NA | NA | NA | NA |
Local 99% winter design temperature: 4°F or lower Not recommended for any vent configurations |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2, °C = (°F—32)/1.8
Notes:
1 See Figure 803.1.2(6) for a map showing local 99 percent winter design temperatures in the United States.
2 NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||
---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | FAN + NAT | |||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||
COMBINED APPLIANCE MAXIMUM INPUT RATING IN THOUSANDS OF BTU PER HOUR | ||||||||
VENT HEIGHT H (feet) |
INTERNAL AREA OF CHIMNEY (square inches) | |||||||
12 | 19 | 28 | 38 | 50 | 63 | 78 | 113 | |
6 | 74 | 119 | 178 | 257 | 351 | 458 | 582 | 853 |
8 | 80 | 130 | 193 | 279 | 384 | 501 | 636 | 937 |
10 | 84 | 138 | 207 | 299 | 409 | 538 | 686 | 1010 |
15 | NA | 152 | 233 | 334 | 467 | 611 | 781 | 1156 |
20 | NA | NA | 250 | 368 | 508 | 668 | 858 | 1286 |
30 | NA | NA | NA | 404 | 564 | 747 | 969 | 1473 |
50 | NA | NA | NA | NA | NA | 831 | 1089 | 1692 |
100 | NA | NA | NA | NA | NA | NA | NA | 1921 |
For SI units: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2
* NA: Not applicable.
NUMBER OF APPLIANCES: | TWO OR MORE | |||||||
---|---|---|---|---|---|---|---|---|
APPLIANCE TYPE: | FAN + NAT | |||||||
APPLIANCE VENT CONNECTION: | TYPE B DOUBLE-WALL CONNECTOR | |||||||
MINIMUM ALLOWABLE INPUT RATING OF SPACE-HEATING APPLIANCE IN THOUSANDS OF BTU PER HOUR | ||||||||
VENT HEIGHT H (feet) |
INTERNAL AREA OF CHIMNEY (square inches) | |||||||
12 | 19 | 28 | 38 | 50 | 63 | 78 | 113 | |
Local 99% winter design temperature: 37°F or greater | ||||||||
6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
10 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
15 | NA | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
20 | NA | NA | 123 | 190 | 249 | 184 | 0 | 0 |
30 | NA | NA | NA | 334 | 398 | 393 | 334 | 0 |
50 | NA | NA | NA | NA | NA | 714 | 707 | 579 |
100 | NA | NA | NA | NA | NA | NA | NA | 1600 |
Local 99% winter design temperature: 27°F to 36°F | ||||||||
6 | 0 | 0 | 68 | 116 | 156 | 180 | 212 | 266 |
8 | 0 | 0 | 82 | 127 | 167 | 187 | 214 | 263 |
10 | 0 | 51 | 97 | 141 | 183 | 201 | 225 | 265 |
15 | NA | 111 | 142 | 183 | 233 | 253 | 274 | 305 |
20 | NA | NA | 187 | 230 | 284 | 307 | 330 | 362 |
30 | NA | NA | NA | 330 | 319 | 419 | 445 | 485 |
50 | NA | NA | NA | NA | NA | 672 | 705 | 763 |
100 | NA | NA | NA | NA | NA | NA | NA | 1554 |
Local 99% winter design temperature: 17°F to 26°F | ||||||||
6 | 0 | 55 | 99 | 141 | 182 | 215 | 259 | 349 |
8 | 52 | 74 | 111 | 154 | 197 | 226 | 264 | 352 |
10 | NA | 90 | 125 | 169 | 214 | 245 | 278 | 358 |
15 | NA | NA | 167 | 212 | 263 | 296 | 331 | 398 |
20 | NA | NA | 212 | 258 | 316 | 352 | 387 | 457 |
30 | NA | NA | NA | 362 | 429 | 470 | 507 | 581 |
50 | NA | NA | NA | NA | NA | 723 | 766 | 862 |
100 | NA | NA | NA | NA | NA | NA | NA | 1669 |
Local 99% winter design temperature: 5°F to 16°F | ||||||||
6 | NA | 78 | 121 | 166 | 214 | 252 | 301 | 416 |
8 | NA | 94 | 135 | 182 | 230 | 269 | 312 | 423 |
10 | NA | 111 | 149 | 198 | 250 | 289 | 331 | 430 |
15 | NA | NA | 193 | 247 | 305 | 346 | 393 | 485 |
20 | NA | NA | NA | 293 | 360 | 408 | 450 | 547 |
30 | NA | NA | NA | 377 | 450 | 531 | 580 | 682 |
50 | NA | NA | NA | NA | NA | 797 | 853 | 972 |
100 | NA | NA | NA | NA | NA | NA | NA | 1833 |
Local 99% winter design temperature: —10°F to 4°F | ||||||||
6 | NA | NA | 145 | 196 | 249 | 296 | 349 | 484 |
8 | NA | NA | 159 | 213 | 269 | 320 | 371 | 494 |
10 | NA | NA | 175 | 231 | 292 | 339 | 397 | 513 |
15 | NA | NA | NA | 283 | 351 | 404 | 457 | 586 |
20 | NA | NA | NA | 333 | 408 | 468 | 528 | 650 |
30 | NA | NA | NA | NA | NA | 603 | 667 | 805 |
50 | NA | NA | NA | NA | NA | NA | 955 | 1003 |
100 | NA | NA | NA | NA | NA | NA | NA | NA |
Local 99% winter design temperature: —11°F or lower Not recommended for any vent configurations |
For SI units: 1 inch = 25.4 mm, I foot = 304.8 mm, 1000 British thermal units per hour = 0.293 kW, 1 square inch = 0.000645 m2, °C = (°F—32)/1.8
Notes:
1 See Figure 803.1.2(6) for a map showing local 99 percent winter design temperatures in the United States.
2 NA: Not applicable.
Related Code Sections
803.2 Chimneys and Vents, Multiple Appliance Vent Table 803.2(1) Through Table 803.2(9)
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Uniform Mechanical Code 2018 of Nevada > 8 Chimneys and Vents > 803.0 Sizing of Category I Venting Systems > 803.2 Multiple Appliance Vent Table 803.2(1) Through Table 803.2(9)
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Where a table permits more than one diameter of pipe to be used for a connector or vent, all the permitted sizes shall be permitted to be used. [NFPA ...
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803.2.21 Chimneys and Vents, Vent Connector Sizing
Vent connectors shall not be increased more than two sizes greater than the listed appliance categorized vent diameter, flue collar diameter ...
Uniform Mechanical Code 2018 of Nevada > 8 Chimneys and Vents > 803.0 Sizing of Category I Venting Systems > 803.2 Multiple Appliance Vent Table 803.2(1) Through Table 803.2(9) > 803.2.21 Vent Connector Sizing
803.2.4 Chimneys and Vents, Vent Offset
, and the horizontal length of the common vent offset shall not exceed 18 inches per inch (18 mm/mm) of common vent diameter ( D ). Where multiple offsets occur ...
Uniform Mechanical Code 2018 of Nevada > 8 Chimneys and Vents > 803.0 Sizing of Category I Venting Systems > 803.2 Multiple Appliance Vent Table 803.2(1) Through Table 803.2(9) > 803.2.4 Vent Offset
803.2.1 Chimneys and Vents, Vent Connector Maximum Length
The maximum vent connector horizontal length shall be 18 inches per inch (18 mm/mm) of connector diameter as shown in Table 803.2.1, or as permitted ...
Uniform Mechanical Code 2018 of Nevada > 8 Chimneys and Vents > 803.0 Sizing of Category I Venting Systems > 803.2 Multiple Appliance Vent Table 803.2(1) Through Table 803.2(9) > 803.2.1 Vent Connector Maximum Length