935SA: Installation, Start-up, Operating and Service Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
21
Table 9 – Filter Media Pressure Drop (Clean) Versus Airflow - In. W.C. (Pa)
If the filter size that you are looking for is not contained in
for a comparison of Pressure Drop (initial/clean resistance to airflow)
versus Face Velocity for a variety of filter media types.
The following equations relate Face Velocity (FPM), Filter Area and Airflow (CFM):
Filter Face Velocity = Airflow / Filter Area
Minimum Filter Area = Rated System Airflow / Maximum Filter Face Velocity
Table 7 – Air Filter Selection and Duct Sizing - In. (mm)
FURNACE CASING WIDTH
FILTER SIZE
FILTER TYPE
*
*. Recommended to maintain air filter face velocity. See Product Data for part number.
SIDE RETURN
BOTTOM RETURN
14-3/16 (360)
†
†. Not all families have these models.
16 x 25 x 3/4 (406 x 635 x 19)
14 x 25 x 3/4 (356 x 635 x 19)
Washable
17-1/2 (445)
16 x 25 x 3/4 (406 x 635 x 19)
16 x 25 x 3/4 (406 x 635 x 19)
Washable
21 (533)
16 x 25 x 3/4 (406 x 635 x 19)
20 x 25 x 3/4 (508 x 635 x 19)
Washable
24-1/2 (622){
16 x 25 x 3/4 (406 x 635 x 19)
24 x 25 x 3/4 (610 x 635 x 19)
Washable
Table 8 – Opening Dimensions - In. (mm)
FURNACE
CASING WIDTH
IN. (mm)
APPLICATION
PLENUM OPENING
FLOOR OPENING
A
B
C
D
14–3/16
(360)
*
*.
Not all families have these models.
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
12-11/16
(322)
21-5/8
(549)
13-5/16
(338)
22-1/4
(565)
17–1/2
(445)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
16
(406)
21-5/8
(549)
16-5/8
(422)
22-1/4
(565)
21
(533)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
19-1/2
(495)
21-5/8
(549)
20-1/8
(511)
22-1/4
(565)
24-1/2
(622)
Upflow Applications on Combustible or Noncombustible Flooring
(subbase not required)
23
(584)
21-1/8
(537)
23-5/8
(600)
22-1/4
(565)
16 x 25 Filter
(406 x 635 mm)
Factory-Accessory
Washable
Factory-Accessory
Media*
Representative After-Market Filter Media*
Fiberglass*
Pleated*
CFM
L/s
(1-in. / 2.5 cm)
(4-in. / 10 cm)
(1-in. / 2.5 cm)
(2-in. / 5 cm)
(1-in. / 2.5 cm)
(2-in. / 5 cm)
600
(283)
0.04
(10)
0.05
(13)
0.06
(15)
0.09
(22)
0.20
(51)
0.13
(34)
800
(378)
0.05
(13)
0.07
(18)
0.08
(21)
0.13
(32)
0.29
(72)
0.20
(49)
1000
(472)
0.06
(16)
0.11
(28)
0.11
(28)
0.17
(43)
-
-
0.27
(67)
1200
(566)
0.07
(18)
0.15
(37)
0.14
(36)
0.22
(56)
-
-
-
-
1400
(661)
0.08
(21)
0.19
(48)
0.18
(45)
0.28
(70)
-
-
-
-
1600
(755)
0.09
(23)
0.24
(60)
0.21
(54)
-
-
-
-
-
-
1800
(850)
0.10
(25)
-
-
0.26
(64)
-
-
-
-
-
-
20 x 25 Filter
(508 x 635 mm)
Factory-Accessory
Washable
Factory-Accessory
Media*
Representative After-Market Filter Media*
Fiberglass*
Pleated*
CFM
(L/s)
(1-in. / 2.5 cm)
(4-in. / 10 cm)
(1-in. / 2.5 cm)
(2-in. / 5 cm)
(1-in. / 2.5 cm)
(2-in. / 5 cm)
800
(378)
0.04
(11)
0.05
(12)
0.06
(16)
0.09
(24)
0.22
(55)
0.15
(37)
1000
(472)
0.05
(13)
0.07
(18)
0.08
(21)
0.13
(32)
0.29
(72)
0.20
(49)
1200
(566)
0.06
(15)
0.09
(22)
0.11
(27)
0.16
(41)
-
-
0.25
(63)
1400
(661)
0.07
(17)
0.12
(31)
0.13
(33)
0.20
(51)
-
-
0.31
(79)
1600
(755)
0.08
(19)
0.15
(38)
0.16
(40)
0.24
(61)
-
-
-
-
1800
(850)
0.08
(21)
0.18
(47)
0.18
(47)
0.29
(73)
-
-
-
-
2000
(944)
0.09
(23)
0.22
(56)
0.21
(54)
-
-
-
-
-
-
2200
(1038)
0.09
(24)
0.26
(66)
0.25
(62)
-
-
-
-
-
-
Table 10 – Filter Media Pressure Drop (Clean) Versus Face Velocity- In. W.C. (Pa)
Face Velocity
Factory-Accessory
Washable
Representative After-Market Filter Media
*
*. Representative estimates from filter manufacturer data sheets.
See manufacturers’ specifications for pressure drop versus airflow data for specific filter media.
Fiberglass
Pleated
FPM
(m/s)
(1-in. / 2.5 cm)
(1-in. / 2.5 cm)
(2-in. / 5 cm)
(1-in. / 2.5 cm)
(2-in. / 5 cm)
200
(1)
0.04
(10)
0.05
(13)
0.08
(20)
0.18
(47)
0.12
(31)
300
(1.5)
0.05
(14)
0.09
(22)
0.13
(34)
0.30
(75)
0.21
(52)
400
(2)
0.07
(17)
0.13
(32)
0.20
(50)
-
-
0.31
(78)
500
(2.5)
0.08
(21)
0.18
(44)
0.27
(69)
-
-
-
-
600
(3)
0.09
(23)
0.23
-
-
-
-
-
-
-
700
(3.6)
0.10
(26)
0.29
-
-
-
-
-
-
-