Specifications
13
ModPac II, 9/09-15
Figure 3. Fresh Air Hood Damper
2.5 Fresh Air Hood
The fresh air hood is located on the inside, behind the slots on the bottom front panel. To ac-
cess the hood, remove the screws that hold the front panel. The air ow can be adjusted from no
(0%) fresh air to approximately 15% of rated air ow of fresh air, in 5% increments. The hood
is shipped from the factory in the closed position (no fresh air). To provide fresh air, remove the
two screws on either side of the hood and reposition as desired..
Table 2. Maximum Static Pressure
Basic Model Maximum Total Static Minimum Filter Area
24 .40 2.25 sq. ft.
30/36 .40 3.00 sq. ft.
42/48/60 .50 3.90 sq. ft.
system must be engineered to insure sufcient air ow through the unit to prevent over-heating
of the heater element. This includes proper supply duct sizing, sufcient quantity of supply regis-
ters, adequate return and lter area. Duct work must be of correct material and must be properly
insulated. Duct must be constructed of galvanized steel with a minimum thickness of .019" for
the rst three feet. Duct work must be rmly attached, secured and sealed to prevent air leakage.
Do not use duct liner on inside of supply duct within four feet of the unit.
Galvanized metal duct extensions should be used to simplify connections to duct work and grilles.
Use fabric boots to prevent the transmission of vibration through the duct system. The fabric
must be U.L. rated (UL-181) to a minimum of 197°F.