YORK INTERNATIONAL
34
FORM 100.50-NOM1 (604)
Installation
ROOF CURB INSTALLATION
General Information
When ordered, the roof curb is shipped knocked-down
in a separate container and needs to be
Þ
eld assembled
and in stalled. Re fer to In stal la tion Man u al that is
shipped with the roof curb for spe ci
Þ
c in struc tions.
On full perimeter roof curb the opening in the roof
should not extend under the condenser section of the
curb. The condenser section of the roof curb is not in-
sulated and could result in condensation build up under
the condenser section as well as higher than normal
sound levels in the conditioned space.
The roof curb drawings contained in the York literature
are not intended as construction documents for the
Þ
eld
fabrication of a roof curb. York will not be responsible
for the unit
Þ
t up, leak integrity, or sound level with
Þ
eld fabricated roof curbs.
Wood or Fiber Cant Strips, Roofi ng
Felts, Roofi ng Ma te ri al, Caulking and
Curb-To-Roof Fas ten ers are to be fi eld
supplied.
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
ß
exible material and should be
installed so they are suf
Þ
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
ß
at sur face of
a plenum.
Static Pressure Control Plastic Tubing
(Pneumatic Tubing)
Duct static transducers (all VAV units) and any unit with
an op tion al building pressure control trans duc er, require
pneumatic tubing to be
Þ
eld supplied and in stalled.
The
“High” side
of the respective trans duc er must be routed
to the location in the building or duct work where a con-
stant pressure is de sired. Both the duct static transducer
(VAV only) and optional building pressure transducer
are mounted behind the left hand damper door. All wir-
ing from the trans duc ers is factory installed.
Duct Static Transducer
Plastic tubing (3/16" ID) must be run from the high
pres sure tap of the trans duc er to a static pres sure tap
(
Þ
eld supplied) in the supply duct, located at a point
where constant pres sure is de sired. This is normally
2/3rds of the way down the duct.
Building Pressure Transducer
Plastic tubing (3/16" ID) must be run from the high
pres sure tap of the building static pressure transducer
to a static pres sure tap (
Þ
eld supplied), located in the
con di tioned space or return air duct at a point where
con stant pressure is desired.
Static Pressure Probe Installation
On units with duct static transducers (VAV units) and
any unit with an optional building pressure, a factory
supplied Static Pressure Probe must be
Þ
eld installed at
the top of the rear corner post on the unit - see Fig. 10.
The factory supplied atmospheric pressure probe and
associated mounting hardware are shipped inside the
unit control panel. The hard ware consists of a mount-
ing bracket and a short section of pneu mat ic tubing.
The pneu mat ic tubing must be fi eld in stalled from a
factory pressure tap (next to the mount ing lo ca tion
for the static pres sure probe) to the at mo spher ic
pressure probe (see Installation Instructions, Form
100.50-N1)
If the unit is equipped with both a building pressure
trans duc er and a duct static trans duc er, a “tee” will
be factory installed, and both the duct static pres sure
transducer and building pres sure will be connected to
the “tee” - both building stat ic pres sure trans duc er and
duct static trans duc er will use the same fac to ry sup plied
at mo spher ic pres sure probe.
The “low” side connection of the
duct static or build ing pres sure trans-
duc ers are shipped with the pneu mat ic
tubing factory in stalled and rout ed, to
the external factory pressure tap.