19
Table 5 -- Air Delivery -- CFM (With Filter)* (CONT)
FURNACE
SIZE
RETURN---AIR
INLET
SPEED
EXTERNAL STATIC PRESSURE (IN. W.C.)
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
135---16 /
048135
Bottom or
Side(s)
High
Med---High
Med---Low
Low
2090
1790
1545
1325
2010
1755
1525
1320
1930
1705
1500
1295
1835
1640
1450
1265
1710
1550
1380
1210
1590
1465
1315
1150
1470
1360
1215
995
1335
1210
1005
865
1025
945
855
745
835
785
670
540
135---22 /
066135
Bottom Only
High
Med---High
Med---Low
Low
2485
2195
1880
1640
2400
2150
1850
1635
2310
2090
1820
1615
2215
2000
1780
1585
2110
1920
1715
1530
2000
1825
1635
1465
1880
1720
1540
1370
1725
1565
1415
1255
1535
1405
1290
1150
1355
1255
1160
1040
Bottom, Sides or
1 Side & Bottom
High
Med---High
--- ---
2180
--- ---
2145
2385
2060
2305
2010
2195
1945
2085
1865
1960
1765
1825
1660
1670
1515
1465
1325
1Side Only
High
Med---High
--- ---
2135
--- ---
2085
2245
2035
2155
1975
2055
1895
1940
1795
1825
1685
1695
1565
1555
1445
1385
1265
155---20 /
060155
Bottom Only
High
Med---High
Med---Low
Low
2465
2115
1800
1570
2430
2105
1790
1565
2375
2075
1770
1550
2305
2030
1735
1525
2230
1980
1695
1495
2110
1910
1640
1445
2000
1830
1570
1370
1865
1725
1465
1270
1725
1590
1345
1175
1545
1425
1225
1070
Both Sides Or 1
Side & Bottom
High
Med---High
--- ---
2155
--- ---
2135
2375
2095
2285
2040
2200
1975
2105
1895
1995
1790
1870
1685
1730
1550
1570
1400
1Side Only
High
Med---High
--- ---
2140
--- ---
2095
2260
2040
2180
1975
2085
1890
1975
1810
1865
1705
1740
1595
1605
1480
1455
1325
*A filter is required for each return---air inlet. Airflow performance included 3/4---in. (19 mm) washable filter media such as contained in factory---authorized
accessory filter rack. To determine airflow performance without this filter, assume an additional 0.1 In. W.C. available external static pressure.
--- --- Indicates unstable operating conditions.
Table 6 – Maximum Capacity of Pipe
NOMINAL IRON PIPE
SIZE
IN. (MM)
INTERNAL
DIA.
IN. (MM)
LENGTH OF PIPE --- FT (M)
10 (3.0)
20 (6.0)
30 (9.1)
40 (12.1)
50 (15.2)
1/2 (12.7)
0.622 (158)
175
120
97
82
73
3/4 (19.0)
0.824 (20.9)
360
250
200
170
151
1( 25.4)
1.049 (26.6)
680
465
375
320
285
1-1/4 (31.8)
1.380 (35.0)
1400
950
770
660
580
1-1/2 (38.1)
1.610 (40.9)
2100
1460
1180
990
900
* Cubic ft. of natural gas per hr for gas pressures of 0.5 psig (14---In. W.C.) or less and a pressure drop of 0.5---In. W.C. (based on a 0.60 specific gravity gas).
Ref: Table 6 and NFPA/54 ANSI Z223.1---2009.
58D
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