ICP 8MPT Installation Insrtuctions page 26

See Table 6 for required high-velocity filter sizes.
High Velocity Air Filter Sizes (max.
600
FPM)
Internal
Cabinet Filter External Filter Rack
Width in(mm)
in (mm)
Bottom Bottom Side+
151/2 14X25 14X25 14 X 25 (355.6 x 635)
(393.7) (355.6 x 635) (355.6 x 635) or 16 X 25 (508 x 635)*
191/8 16 X 25 * 16 X 25 16 X 25
(485.8) (406.4 x 635) * (406.4 x 635)* (406.4 x 635)*
223/4 20 X 25 20 X 25 16 X 25
(577.9)
(508
x 635)*
(508
x 635)*
(508
x 635)*
* Greater than 1600 CFM with a maximum of 2000 CFM requires both (left and right)
side return filter racks or for single return in an upflow application, must use filter rack
NAHA001TK. See Figure 23.
+ Side return air duct(s) is not permitted with horizontal or downflow furnace installa-
tion.
Use either filter type:
• Washable, high-velocity filters are based on a maximum air
flow rating of 600 FPM.
• Disposable, low velocity filters are based on a maximum air
flow of 300 FPM when used with with external filter grille.
REDUCED FURNACE LIFE HAZARD
Failure to follow caution instructions may result in
reduced furnace life.
Use of excessively dirty and/or restrictive air filters
may increase furnace operating
temperatures and shorten the life of the furnace.
Filters supplied with the furnace are rated at a
maximum of 600 fpm air velocity and sized for the
furnace's airflow rate. Replacement filters must be
of equivalent type, size, and rating except as
described below.
Disposable, low-velocity filters may be used to
replace washable, high-velocity filters, providing
they are sized for 300 FPM or less.
The furnaces with 1600 or less CFM rating are supplied
with a 16" x 25" (406 x 635mm) high-velocity filter and
rack. On these models the supplied filter may be installed
internally for bottom return or the supplied filter and rack
may be mounted externally for bottom return.
The furnaces with greater than 1600 CFM to 2000 CFM
may require that bottom return or both (left and right) side
returns are used or for single side return in upflow applica-
tion, must use filter rack NAHA001TK. Two side return fil-
ters and racks are required. Filter racks must be mounted
externally. (See Figure 23 and Figure 24.) If return air
must be on one side only, an optional 20" x 25" (508 x
635mm) filter standoff rack kit can be used. (See
Figure 23.) For bottom return, an internal filter can be used
or a filter rack kit can be mounted externally.
See Technical Manual, Circulation Air Blower Data for addi-
tional information.
NOTE: The 20" x 25" (508 x 635mm) standoff side filter rack
gives more filter area but does not provide more air. (See
Figure 23.) To achieve 2000 CFM 2 side returns may be required.
(See Figure 25.)
NOTE: Disposable, low-velocity filters may be replaced with
washable, high-velocity filters providing they meet the minimum
size areas for 300 FPM or less. Washable, high-velocity filters
can be replaced ONLY with same type and size filter.
ii _)}i i
Optional Duct Standoff-
NAHA001TK in(mm)
20 x 25 (508
Optional Filter Rack
(175)
Filter
_i i2o
_o8
18_2
(470) i
Filters Rack Installation
Side Return
Center the filter rack on the side panel, flush with the bottom edge
of the furnace. Mark the fastening holes. Drill the fastening holes
in the side panel and fasten the filter rack in place with sheet metal
screws. See Figure 24 & Figure 25.
iii i ii:: _
Filter
25-23-05-1
Filters Installed on Two Sides
UsingTwo
Filter Racks
\
Filter
Filter
25-23-05-3
44101 202301
Specifications are subject to change without notice
26