Specifications

IM 1059-1 / Page 7 of 36
Flexible
Connector
Flexible
Connector
Flexible Connector
Note 2
Note 2
Note 2
Note 1
Note 1
Note 1
Fan Rotation
(See Note 3)
Transformation Duct
Flexible Connector
Main Duct
Branch Duct
Trunk Duct
Distribution
Diffuser
Note 2
Figure 8: Suggested Supply Ducting per ASHRAE and SMACNA Publications
Fan Rotation
(See Note 3)
Fan Rotation
(See Note 3)
Fan Rotation
(See Note 3)
For minimum noise transmission, the metal duct material
shouldbeinternallylinedwithacousticbrousinsulation.
The ductwork should be laid out so that there is no line of
sight between the conditioner discharge and the distribution
diffusers.
Return air ducts can be brought in adjacent to the return
air of the conditioner. Typically, the equipment room becomes
the common return air plenum.
Do not insert sheetmetal screws directly into the unit cabi-
net for connection of supply or return air ductwork, especially
return air ductwork which can hit the drain pan or the air coil.
Ventilation Air
Outside air may be required for ventilation. The tempera-
ture of the ventilation air must be controlled so that mixture
of outside air and return air entering the conditioner does not
exceed conditioner application limits. It is also general prac-
tice to close off the ventilation air system during unoccupied
periods (night setback).
The ventilation air system is generally a separate building
subsystem with distribution ductwork. Simple introduction of
the outside air into each return air plenum chamber reason-
ably close to the conditioner air inlet is not only adequate, but
recommended. Do not duct outside air directly to the condi-
tionerinlet.Providesufcientdistanceforthoroughmixingof
outside and return air (see Operating Limits on page 12).
Notes:
1. Transformations to supply duct have maximum
slope of 1" to 7".
2. Square elbows with double thickness vanes
may be substituted.
3. Do not install ducts so that the air ow is
counter to fan rotation. If necessary, turn fan
deck assembly and motor.
4. Transformations and units shall be adequately
supported so no weight is on the exible
connection.