Filter Racks - Boyertown Furnace RSM 500 Installation, Operation And Maintenance Manual

Table 3 Recommended Maximum Duct Velocities, Feet Per Minute (FPM)
Application
Apartments
Auditoriums
Banks
Hotel Rooms
Libraries
Meeting Rooms
Offices
Residences
Restaurants
Retail Stores
*When sound control is critical use branch duct velocities
CFM
600FPM
50
100
150
200
250
300
400
500
750
1000
1250
1500
1750
2000
Note: For Systems not over 100 feet equivalent length. Do not apply this table to duct systems
which exceed 100 equivalent feet in length. For longer systems refer to ACCA Manual D.
Incorrectly sized ducts can result in unsafe or uncomfortable operation.
Nominal Size
2
Area in.
FILTER RACK
An external filter rack has been provided for ease of installation. Square knock outs are located on
eihter side when using the furnace in a highboy configuration. The return can also be ducted into the
rear of the unit in the highboy configuration. Square knockouts are provided in the galvanized pan
when using in the horizontal configuration.
Main Ducts*
Supply
900
1200
2000
1500
2000
2000
2000
900
2000
2000
Table 4 Duct Area Required at Listed Flow Conditions
Area Area
Sq. In. Sq. In.
800FPM
12
24 18
36 27
48 36
60 45
72 54
96 72
120 90
180 135
240 180
300 225
360 270
420 315
480 360
Table 5 Round Duct Equivalent Area
4 5
12.5 19.6
Return
700
1000
1500
1300
1500
1500
1500
700
1500
1500
Area Area
Sq. In. Sq. In.
1000FPM 1200FPM
14
22
29
36
43
58
72
108
144
180
216
252
288
6 7
28.3 38.5 50.3
Branch Ducts
Supply
600
1000
1600
1200
1600
1600
1600
600
1600
1600
Area
Sq. In.
1600FPM
12
18 14
24 18
30 23
36 27
48 36
60 45
90 68
120 90
150 113
180 135
210 158
240 180
8 9 10
63.6 78.5
Return
600
800
1200
1000
1200
1200
1200
600
1200
1200
Area
Sq. In.
2000FPM
14
18
22
29
36
54
72
90
108
126
144
12
113.1
7