Ductwork Installation; Attaching Downflow Ductwork To; Roof Curb; Attaching Downflow Ductwork To Roof - Trane 4WCY4036B3 Installation And Operation Manual

Ductwork Installation

Attaching Downflow Ductwork to Roof

Curb
Supply and return air flanges are provided on the roof
curb for easy duct installation. All ductwork must be
run and attached to the curb before the unit is set into
place.
Attaching Downflow Ductwork to Roof

Frame

Follow these guidelines for ductwork construction:
Connections to the unit should be made with three (3)
inch canvas connectors to minimize noise and vibration
transmission.
Elbows with turning vanes or splitters are
recommended to minimize air noise and resistance.
The first elbow in the ductwork leaving the unit should
be no closer than two (2) feet from the unit, to minimize
noise and resistance.
To prevent leaking, do not attach the ductwork to the
bottom of the unit base. Refer to the bottom example in
the figure below.
Figure 5. Attaching Down Airflow Ductwork
AIR PROOF
THIS SEAM
FIELD DUCT
UNIT DUCT
FLANGE
FIELD
DUCT
UNIT DUCT
FLANGE
NOT RECOMMENDED
Attaching Horizontal Ductwork to Unit
All conditioned air ductwork should be insulated to
minimize heating and cooling duct losses. Use a
minimum of two (2) inches of insulation with a vapor
barrier. The outside ductwork must be weatherproofed
between the unit and the building.
When attaching ductwork to a horizontal unit, provide a
flexible watertight connection to prevent noise
18-BB34D1-19B-EN
UNIT BASE
UNIT DUCT
FLANGE
AIR PROOF
THIS SEAM
UNIT BASE
FIELD DUCT
AIR PROOF
THIS SEAM
UNIT BASE
UNIT DUCT FLANGE
UNIT BASE
WATERPROOF SEAM
WITH BUTYL OR
SILICONE
FIELD DUCT
transmission from the unit to the ducts. The flexible
connection m m u u s s t t be indoors and made out of heavy
canvas.
N N o o t t e e : : Do not draw the canvas taut between the solid
ducts.
Figure 6. Attaching Horizontal Airflow Ductwork

Condensate Drain Piping

A 3/4-inch female NPT condensate drain connection is
provided on the evaporator access panel end of the
unit. Provide a trap and fill it with water before starting
the unit to avoid air from being drawn through. Follow
local codes and standard piping practices when
running the drain line. Pitch the line downward away
from the unit. Avoid long horizontal runs. See
7, p. 15.
N N o o t t e e : : Do not use reducing fittings in the drain lines.
The condensate drain must be:
• Made of 3/4" pipe size
• Pitched 1/4" per foot to provide free drainage to
convenient drain system
• Trapped
• Must be connected to a closed drain system unless
the trap is properly vented
Figure 7. Typical Condensate Drain Piping
/ " PVC OR COPPER
3
4
TUBING AND FITTINGS
1-1/2" MIN.
1-1/2" MIN.

Air Filter Installation

The packaged unit requires an air filter. The unit does
not come with a factory installed filter rack in it,
however, two filter frame accessories are offered that
will allow the installation of a filter within the unit,
BAYFLTR101 & BAYFLTR201. Otherwise a field
supplied filter rack must be installed by the installer in
the return duct work. Refer to table for field supplied
filter racks.
U U n n i i t t I I n n s s t t a a l l l l a a t t i i o o n n
UNIT EXTERIOR
WEATHERPROOF
THIS SEAM
FIELD DUCT
UNIT EXTERIOR
WEATHERPROOF
THIS SEAM
FIELD DUCT
Figure
15