York YPAL 060 User Manual

Page of 168
44
JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
Installation
DUCT SYSTEM
Duct Connection Guidelines
All intake and discharge air duct connection to the 
unit may be made directly to the unit. These air duct 
con nec tions  should  be  on  fl exible material and should 
be installed so they are suffi ciently loose. Duct runs 
and transitions must be made carefully to hold friction 
loss to a min i 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  equiv a lent  outlet  di am e ters. 
Never dead head the dis charge into the fl at sur face of 
a plenum.
Refer to Table 2-17 and 2-18 for available supply and 
return duct connection confi guration.
TABLE 2-17 –  SUPPLY AIR DUCT CONNECTION 
CONFIGURATIONS
UNIT CONFIGURATION
SUPPLY AIR
BOTTOM
LEFT
RIGHT
50-61 TONS
COOLING ONLY
COOL/GAS HEAT 375-750 
MBH
N/A
COOL/GAS HEAT 1125 MBH
N/A
N/A
TABLE 2-18 –  RETURN AIR DUCT CONNECTION 
CONFIGURATIONS
UNIT CONFIGURATION
SUPPLY AIR
BOTTOM
LEFT
RIGHT
50-61 TONS
NO EXHAUST
BAROMETRIC RELIEF 
DAMPER
N/A
POWERED EXHAUST FAN
N/A
RETURN FAN
N/A
N/A
Installation of elbows, discharge 
damp er and oth er abrupt fl ow  area 
changes installed di rect ly at the fan 
outlet will cause system losses. These 
losses must be taken into account 
dur ing  the  de sign phase and must be 
add ed to any fi eld mea sure ments.
SOUND AND VIBRATION TRANS MIS SION
All roof mounted air handling units generate some 
sound and vibration, which may or may not require 
some special treatment of the air con di tioned  space.  The 
noise gen er at ed 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 effi ciency of the fan. 
In ap pli ca tions where sound and vibration transmissions 
may be ob jec tion able,  good  acoustical  engineering 
prac tic es must be incorporated in the system design.
The eco
2
 unit is designed for lower sound levels than 
competitive units by using fl exible fan connections, 
fan spring isolators, double-wall construction, multiple 
fan options, and lower speed and horsepower fans. For 
VAV applications, VFDs are used instead of inlet guide 
vanes. Additional sound attenuation can be obtained 
using compressor sound blankets and fi eld-supplied 
sound attenuators when necessary.
Even with these equipment design features, the 
acoustical characteristics of the entire installation must 
never be overlooked. Additional steps for the acoustical 
characteristics of a rooftop installation should be 
addressed during the design phase of a project to avoid 
costly alterations after the installation of the equipment. 
During the design phase of a project, the designing 
engineer should consider, at a minimum, the impact of 
the equipment location, rooftop installation, building 
structure, and duct work. 
BOTTOM
FRONT
LEFT
RIGHT
FRONT
Discharge
Return
LD08045
NOTE:
This diagram is provided as a visual reference of the eco
2
 discharge & return air openings & locations for all sizes. Please refer to Fig 2-4 for exact 
size & location of panels and openings.