95
MIXING BOX/INLET PLENUM/DISCHARGE PLENUM/
EXTERNAL BYPASS/RETURN FAN
Attach the ductwork to the box frame rails with sheet metal screws
as shown in Fig. 38. Ductwork should be flanged out as close to
the damper framed opening as possible. Screws with weatherproof
washers and a bead of silicone around the duct flange must be
used for outdoor applications. Do not remove the screws retaining
the damper frame; the damper will fall out.
MIXING BOX/INLET PLENUM/DISCHARGE PLENUM
(BOTTOM)
Refer to Fig. 39 for bottom opening ductwork connection.
15.00
X1 ± .25
X2 ±.25
SIDE VIEW
A
A / 3
E1
A / 3
E1
A / 3
E1
.50 TYP.
4 CORNERS
.25 DIA HOLES
TYP. 4 CORNERS
.50 TYP.
4 CORNERS
AIR
MEASUREMENT
DAMPER
.44 TYP.
4 SIDES
(TYP.)
PREMIUM
DAMPER
.219 ± .031 DIA. HOLES at 6" C-C
WITH RANDOM START POINT
B
B1 D1
B2 D2
FACE VIEW
(BLADES SHOWN OPEN)
a39-4306
SIZES 72-110
LEGEND
NOTE: A and B dimensions are actual to O.D. of damper frames not including flanges.
Fig. 37 —
AMS Damper Dimensions (cont)
39M
UNIT
SIZE
DIMENSIONS (in.)
AMS
LOW
LIMIT
(CFM)
AMS
HIGH
LIMIT
(CFM)
A
B
A/3
B1
B2
X1
X2
D1
D2
E1
72W
113.00
46.00
37.60
27.60
18.40
11.74
11.96
24.60
15.02
35.42
6,115
40,768
85W
132.00
46.00
44.00
27.60
18.40
11.74
11.96
24.60
15.02
41.71
7,208
48,052
96W
132.00
52.00
44.00
31.20
20.80
13.52
14.36
28.20
16.85
41.71
8,148
54,319
110W
150.00
52.00
50.00
31.20
20.80
13.52
14.36
28.20
16.85
47.72
9,174
61,159
AMS
—
Air Measuring Station
IMPORTANT: For all sizes with bottom full openings, attach
ductwork to inside of baserails.
