Installation guide

Table7--ExteriorMasonryChimneyFan+ Nat Installations
with Type-B Double Wall Vent Connectors ©NFPA & AGA
Combined Appliance Maximum Input
Rating in Thousands of Btuh per Hour
VENT HEIGHT
FT. (M)
6 (1.8)
8 (2.4)
10 (3.0)
15 (4.5)
20 (6.0)
30 (9.1)
INTERNAL AREA OF CHIMNEY
SQ. IN. (SQ. MM)
12 19
(7741) (12258)
74 119
80 130
84 138
NR 152
NR NR
NR NR
28
(18064)
178
193
207
233
25O
NR
38
(24516)
257
279
299
334
368
404
Table 8--Minimum Allowable Input Rating of Space-Heat-
ing Appliance in Thousands of Btuh per Hour
INTERNAL AREA OF CHIMNEY
VENT HEIGHT SQ, IN. (SQ, MM)
FT. (M) 12 19 28 38
(7741) (12258) 18084) (24516)
Local 99% Winter Design Temperature: 17 to 25 degrees F
5 0 55 99 141
8 52 74 111 154
10 NR 90 125 169
15 NR NR 167 212
20 NR NR 212 258
30 NR NR NR 352
Local 99% Winter Design Temperature: 5 to 16 degrees F*
6 NR 78 121 166
8 NR 94 135 182
10 NR 111 149 198
15 NR NR 193 247
20 NR NR NR 293
30 NR NR NR 377
Local 99% Winter Design Temperature: -10 to 4 degrees F*
6 NR NR 145 196
8 NR NR 159 213
10 NR NR 175 231
15 NR NR NR 283
20 NR NR NR 333
30 NR NR NR NR
Local 99% Winter Design Temperature: -11 °F (16°C) or
lower
Not recommended for any vent configuration.
*The 99.6% heating db temperatures found in the 1997 or 2001 ASHRAE
Fundamentals Handbook, Climatic Design Information chapter, Table 1A
(United States) or the 2005 ASHRAE Fundamentals handbook, Climatic
Design Information chapter, and the CD-ROM included with the 2005
ASHRAE Fundamentals Handbook.
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