York CURBPAK CP23 - SOUND AND VIBRATION TRANSMISSION

FORM 100.10-NOM2
17
YORK INTERNATIONAL
FIG. 12 – STANDARD TIE-DOWN W/SNUBBER FOR
UNIT SIZES CP65 - 305
FIG. 14 – DOWN DISCHARGE DUCT CONNECTIONS
FIG. 15 – RECOMMENDED DISCHARGE DUCT
ARRANGEMENT WHEN TURNS ARE
REQUIRED
must be made carefully to hold friction loss to a mini-
mum. Avoid short turns, and duct elbows should con-
tain splitters or turning vanes.
Duct work connected to the fan discharge should run in
a straight line for at least two equivalent outlet diam-
eters and should be reduced in cross sectional area (See
Figure 15). A duct turn should NOT be in the same
direction as the fan rotation. Never deadhead the
discharge into the flat surface of a plenum.
Installation of elbows, discharge
damper and other abrupt flow area
changes installed directly at the fan
outlet will cause system losses. These
losses must be taken into account dur-
ing the design phase and must be
added to any field measurements.
On curb mounted units with a down discharge, duct
connections are contained within the roof curb. (See
Figure 14 for dimensions.)
SOUND AND VIBRATION TRANSMISSION
All roof mounted air handling units generate some sound
and vibration, that may or may not require some special
treatment of the air conditioned space. The noise gen-
erated by the air handling unit is dependent on the speed
of the fan, the amount of air the fan is moving, the fan
type and the static efficiency of the fan. In applications
where sound and vibration transmissions may be objec-
tionable, good acoustical engineering practices must be
incorporated in the system design.
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FIG. 13 – SEISMIC SNUBBER FOR UNIT SIZES
CP350 - 1030
5
4
I
SO
LAT
O
R RAI
L
3
D
O
N
O
T REM
O
V
E
S
TANDARD
GUSS
E
T
/
TIE-D
O
W
N
1
REM
O
V
E
3
B
O
LT
S
2
D
O
N
O
T REM
O
V
E
S
N
U
BBER B
O
L
T
(
ADJUST SNUBBE
R
TO BE FREE FLOATING
)
D
O
N
O
T REM
O
V
E
S
N
U
BBER
G
R
O
MME
T
WELDED
S
N
U
BBER N
UT
BL
O
WER RAI
L
I
SO
LAT
O
R RAI
L
S
TANDARD
S
PRIN
G
I
SO
LAT
OR
4
5
7
I
SO
LAT
O
R HA
T
(
N
O
T U
S
ED IN
C
P860 & 1030
)
6
GUSS
ET TIE-D
O
W
N
(
WELDED
)
3
2
1
REM
O
VE B
O
LT
S
AN
D
ANY
S
PA
C
ER
S
F
OU
ND
BETWEEN
GUSS
ET AND
BL
O
WER RAI
L
S
N
U
BBER
GUSS
E
T
(
WELDED
)
D
O
N
O
T REM
O
V
E
S
N
U
BBER B
O
L
T
(
ADJUST SNUBBER TO BE
FREE FLOATING
)
D
O
N
O
T REM
O
V
E
SNUBBER GROMMET
(
RUBBER
)
SNUBBER NUT
(
WELDED
)
SNUBBER JAMB NUT
(
LOCK
AFTER AD
JUS
TMENT F
O
R FREE
FLOATING BLOWER BASE
)
N
O
TE
:
AD
JUS
T
S
N
U
BBER T
O
BE FREE FL
O
ATIN
G
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LD06500
2