505309-UIM-D-0511

Johnson Controls Unitary Products 9

SECTION III: FILTERS

FILTER INSTALLATION

All applications require the use of a field installed filter. All filters and
mounting provision must be field supplied.
Filters must be installed external to the furnace cabinet. DO NOT
attempt to install filters inside the furnace.
1.Air velocity through throwaway type filters may not exceed 300 feet per min-
ute (91.4 m/min). All velocities over this require the use of high velocity fil-
ters.
2.Do not exceed 1800 CFM using a single side return and a 16x25 filter. For
CFM greater than 1800, you may use two side returns or one side and the
bottom or one side return with a transition to allow use of a 20x25 filter.

SIDE RETURN

Locate the “L” shaped corner locators. These indicate the size of the cut-
out to be made in the furnace side panel. Refer to Figure 14.
Install the side filter rack following the instructions provided with that
accessory. If a filter(s) is provided at another location in the return air
system, the ductwork may be directly attached to the furnace side
panel.
FIGURE 13: Dimensions

FRONT

33
A

LEFTSIDE

CombustionAir Inlet
CondensateDrain
(Downflow)
VentOutlet
Thermostat
Wiring
28.5”
GasPipe
Entry
Electrical
Entry
Condensate
Drain
Thermostat
Wiring

RIGHTSIDE

VentOutlet
CondensateDrain
(Downflow)
14”
1”
1.5”
23”
CombustionAir Inlet
GasPipe
Entry
Electrical
Entry
Condensate
Drain

OptionalReturn Air

Cutout(Either side)

29.5”
(ForCladded door add appoximately an additional .75”)
C

SUPPLYEND

.56”
.56”
20”
B
3”
23.8”
.56”
Combustion
AirInlet
Vent
Outlet

RETURNEND

B
24.25”
Table 3: Cabinet and Duct Dimensions
BTUH (kW)
Input Nominal
CFM (m3/min) Cabinet
Size
Cabinet Dimensions (Inches) Approximate
Operating Weights
A (in) A (cm) B (in) B (cm) C (in) C (cm) Lbs (kg)
60 (17.6) 1200 (34.0) B 17 1/2 44.4 16 3/8 41.6 13 1/4 33.7 122
80 (23.4) 1200 (34.0) B 17 1/2 44.4 16 3/8 41.6 14 3/4 37.5 126
80 (23.4) 1600 (45.3) C 21 53.3 19 7/8 50.5 16 1/2 41.9 136
100 (29.3) 1600 (45.3) C 21 53.3 19 7/8 50.5 18 1/4 46.4 142
100 (29.3) 2000 (56.6) C 21 53.3 19 7/8 50.5 18 1/4 46.4 145
120 (35.1) 2000 (56.6) D 24 1/2 62.2 23 3/8 59.4 21 3/4 55.2 156
Single side return above 1800 CFM is approved as long as the filter
velocity does not exceed filter manufacturer’s recommendation and a
transition is used to allow use on a 20x25 filter.
Table 4: Recommended Filter Sizes (High Velocity 600 FPM)
CFM (m³/min) Cabinet Size Side (in) Bottom (in)
1200 (34.0) B 16 x 25 16 x 25
1600 (45.3) C 16 x 25 20 x 25
2000 (56.6) C (2) 16 x 25 20 x 25
2000 (56.6) D (2) 16 x 25 22 x 25
NOTICE
FIGURE 14: Side Return Cutout Markings
Some accessories such as electronic air cleaners and pleated media
may require a larger side opening. Follow the instructions supplied
with that accessory for side opening requirements. Do not cut the
opening larger than the dimensions shown in Figure 13.

Frontof

Furnace

Corner

Markings

Sideof

Furnace