Minnesota Administrative Rules
Agency 151 - Labor and Industry Department
Chapter 1346 - MINNESOTA MECHANICAL AND FUEL GAS CODES
MINNESOTA FUEL GAS COD
Part 1346.5304 - SECTION 304 (IFGC) COMBUSTION, VENTILATION AND DILUTION AIR
Current through Register Vol. 49, No. 13, September 23, 2024
Subpart 1. Section 304.1.
IFGC section 304.1 is amended to read as follows:
Exceptions:
Table 304.1
Combustion Air Requirements for Gas-Fired Appliances When the Combined Input is Up to and Including 400,000 Btu/hr
Total input of appliances1, thousands of Btu/hr (kW) |
Required free area of air-supply opening or duct, square inches (sq mm) |
Acceptable approximate round duct equivalent diameter2, inch (mm) |
25 (8) |
7 (4,500) |
3 (75) |
50 (15) |
7 (4,500) |
3 (75) |
75 (23) |
11 (7,000) |
4 (100) |
100 (30) |
14 (9,000) |
4 (100) |
125 (37) |
18 (12,000) |
5 (125) |
150 (45) |
22 (14,000) |
5 (125) |
175 (53) |
25 (16,000) |
6 (150) |
200 (60) |
29 (19,000) |
6 (150) |
225 (68) |
32 (21,000) |
6 (150) |
250 (75) |
36 (23,000) |
7 (175) |
275 (83) |
40 (26,000) |
7 (175) |
300 (90) |
43 (28,000) |
7 (175) |
325 (98) |
47 (30,000) |
8 (200) |
350 (105) |
50 (32,000) |
8 (200) |
375 (113) |
54 (35,000) |
8 (200) |
400 (120) |
58 (37,000) |
9 (225) |
1For total inputs falling between listed capacities, use next largest listed input.
2If flexible duct is used, increase the duct diameter by one inch.*
*Flexible duct shall be stretched with minimal sags.
Subp. 2. [Repealed, 34 SR 537]
Subp. 2a. Section 304.6.1. IFGC section 304.6.1, Two-permanent-openings method, is deleted in its entirety.
Subp. 3. Section 304.6.2.
IFGC section 304.6.2 is amended to read as follows:
Subp. 4. [Repealed, 34 SR 537]
Subp. 5. [Repealed, 34 SR 537]
Subp. 6. [Repealed, 34 SR 537]
Subp. 7. [Repealed, 34 SR 537]
Subp. 8. Section 304.11.
IFGC Section 304.11 is amended to read as follows:
Exception: Direct vent gas-fired appliances designed for installation in a solid fuel-burning fireplace where installed in accordance with the listing and the manufacturer's instructions.
Exception: Combination makeup air and combustion air systems may be approved by the building official where they are reasonably equivalent in terms of health, safety, and durability.
Subp. 9. [Repealed, 34 SR 537]
Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326B.101; 326B.106; 326B.13