Installation; Direction Of Airflow; Duct Installation And Airflow Distribution - Modine Manufacturing IFS Installation And Service Manual

INSTALLATION

Direction of Airflow

Select proper direction of airflow. For models in which the 10th
digit of the model number is an "L" for Low Temperature Rise,
the airflow direction is fully reversible without modification to the
duct furnace. See Airflow Reversal Note.
If the unit is provided with an air distribution baffle (models in
which the 10th digit of the model number is an "H" for High
Temperature Rise), the air baffle must face the air inlet direction
as shown in Figure 4.1. If it is necessary to reverse the airflow
direction, remove the four screws securing the air distribution
baffle, reverse the air distribution baffle to the air inlet side and
replace the screws. See Airflow Reversal Note.
Figure 4.1 - Air Distribution Baffle Location
Airflow Reversal Note: If factory installed discharge air options
(thermostat, freeze protection, etc.) were provided, these
options would have to be relocated to the discharge air side of
the duct furnace.
Duct Installation (refer to Figure 4.2)
1. The furnace is designed to accept straight ductwork.
All connections between the ductwork and the furnace
MUST be airtight to prevent air leakage. Seams with
cracks in ductwork should be caulked and/or taped and
be of permanent type.
2. Provide removable access panels on both the upstream
and downstream sides of the ductwork. These openings
should be large enough to view smoke or reflect light inside
the casing to indicate leaks in the heat exchanger and to
Figure 4.3 - Typical Duct & Airflow Installation
A
Turning
Vanes
3" Min.
SIDE
3" Max.
A
B
12"
Min.
D
B
SIDE
A
Baffle
G
SIDE
No Air
4 4
Baffle location
shown on entering
air side of duct
furnace.
Turning
Vanes
12"
Min.
Air
Baffle
Turning
Vanes
3" Max.
24"
Min.
check for hot spots on heat exchangers due to poor air
distribution or lack of sufficient air (CFM).
Figure 4.2 - Duct Connections
Straight
Ductwork
Airflow Distribution
IMPORTANT
To prevent premature heat exchanger failure, observe heat
exchanger tubes by looking at the heat exchanger through
field installed access openings in connecting ductwork. If
the tubes become red while blower and duct furnace are in
operation, additional baffles must be inserted between blower
and duct furnace to assure uniform air flow across the heat
exchanger.
1. Provide uniform air distribution over the heat exchanger.
Use turning vanes where required (see Figure 4.3) to obtain
uniform air distribution. Avoid installing as in "G", "H" & "J" of
Figure 4.3.
2. A bottom, horizontal discharge type blower should be
installed at least 12" from the furnace (See "A", Figure 4.3).
3. A top, horizontal discharge type blower should be installed
at least 24" from the furnace (See "B", Figure 4.3). Provide
air baffle at top of duct to deflect air down to the bottom of
heat exchanger.
3" Max.
B
Air
3" Min.
Baffle
B
12"
Min.
SIDE
A
Baffle
24"
Min.
E
Turning
12"
Min.
Vanes
3" Max.
B
SIDE
A
3" Min.
Turning
Vanes
15° Max.
Baffle
H
SIDE
No Air
AIR 5-593.9
Mounting Holes
Access
Panel
C
12"
B
Min.
TOP
A
15° Max.
Dimensions "B" should never be less than / of "A".
1
2
F
Turning
12"
Vanes
Min.
TOP
Turning
15° Max.
Vanes
J
TOP
No Air