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ALIGNMENT
HOLE
(IN BASE
EDGEFLANGE
_
ALIGNMENT
HOLE SHOULD
LINE
UP WITH
ROOF
CURB
EDGE
FLANGE
C06276
Fig. 5 - Alignment
Hole
Details
UNIT DAMAGE AND PERSONAL
INJURY HAZARD
Failure
to follow
this warning
could
cause equipment
damage
and/or personal
injury.
For vertical supply and return units, tools or parts could
drop
into ductwork
and
cause
an injury.
Install
a
90-degree
turn in the return ductwork
between
the unit
and the conditioned
space. If a 90-degree
elbow cannot
be
installed,
then a grille
of sufficient
strength
and
density
should
be
installed
to prevent
objects
from
falling into the conditioned
space.
RETURN
SUPPLY
OPENING
OPENING
CURB
CURB
RETURN
SUPPLY
L
OPENING
ALIGNMENT
-_,.
_
HOLES FOR
CURB-BOTH
_.
jJ
SIDES
ROOF CURB
Fig. 6 - Alignment
Hole Location
C06277
Step 4 -- Field Fabricate
Ductwork
On
vertical
units,
secure
all ducts
to roof
curb
and building
structure.
Do
not
connect
ductwork
to
unit.
For
horizontal
applications,
field-supplied
flanges
should
be
attached
to
horizontal
discharge
openings
and
all ductwork
secured
to the
flanges.
Insulate
and weatherproof
all external
ductwork,
joints,
and roof openings
with counter
flashing
and mastic
in accordance
with applicable
codes.
Ducts
passing
through
an
unconditioned
space
must
be
insulated
and covered
with a vapor barrier.
If a plenum
return is used on a vertical
unit, the return should
be
ducted through
the roof deck to comply
with applicable
fire codes.
A minimum
clearance
is not required
around
ductwork.
Cabinet
return-air
static shall not exceed
-.35-in.
wg with econonfizer
or
.45-in.
wg without
econonfizer.
These
units
are designed
for
a minimum
continuous
return-air
temperature
in heating
of 50°F
(dry
bulb),
or an internfittent
operation
down to 45°F (dry bulb), such as when used with a night
set-back
thermostat.
To operate
at lower
return-air
temperatures,
a field-supplied
outdoor-air
temperature
control must be used to initiate both stages
of heat when the temperature
is below
45°F.
Indoor
comfort
may
be compronfised
when these
lower air temperatures
are used with
insufficient
heating
temperature
rise.
Step 5 -- Make Unit Duct Connections
Vertical Configuration
Unit is shipped
for thru-the-bottom
duct connections.
Ductwork
openings
are shown
in Fig. 1 and 4. Duct connections
for vertical
supply
and
return
configuration
are
shown
in
Fig.
7.
Field-fabricated
concentric
ductwork
may be connected
as shown
in Fig. 8. The unit is designed
to attach the ductwork
to the roof
curb. Do not attach duct directly
to the unit.
Units with electric
heat require
a I-in.
clearance
for the first 24 in.
of
ductwork.
Outlet
grilles
must
not
lie
directly
below
unit
discharge.
ECONOMIZER
<37
SEE
NOTE
I#[_
[_
AIR
OUT
NOTE: D onot drill inthis
area. Damage
to basepan
mayresultinwater leak.
C06378
Fig. 7 - Air Distribution
- Vertical
Supply
and Return
ECONOMIZER
SEE
<7>
\\
_\
1SEE
I \\\
\\\
,\
//qNOTE
\
X\
/
AIR OUT
AIR
IN
AIR OUT
NOTE: Do not drill in this area. Damage to basepan may result in water leak.
C06379
Fig. 8 - Air Distribution
- Concentric
Duct
NOTE:
A 90-degree
elbow
must
be provided
in the supply
ductwork
to comply
with
UL (Underwriters'
Laboratories)
codes
for use with electric heat.
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