Roof Curb Installation/Duct/Utility Connections - Modine Manufacturing Atherion ERM Installation And Service Manual

ROOF CURB INSTALLATION / DUCT / UTILITY CONNECTIONS
Roof Curb Installation
An optional roof curb is available to simplify site preparation
and raise the unit above roof water and snow level for
drainage. It can be installed in advance of the unit. The curb
is shipped knocked down with separate instructions for its
assembly, flashing, and sealing with the roof. The following are
some general guidelines for roof curb installed units:
1. The roof structure must be adequately designed to support
the live weight load of the unit and any other required
support structure. The roof curb should be supported at
points no greater than five feet apart. Additional truss
reinforcement should be provided, if necessary.
2. Roof curbs supplied by the factory are fabricated from 10
gauge galvanized steel and supplied knocked down for
assembly on the job site. The curb consists of two side
pieces, two end pieces, gasketing, four joiner angles, four
2x4 inch wood nailing strips, nuts, bolts, and washers.
3. Outside dimensions must be held when installing curb.
Top surface must be level and straight to insure weather-
tightness. If roof is pitched it will be necessary to construct
a sub-base on which to install the curb. All corners must
be square.
4. When installing roof curbs for both the MPR unit and the
ERM unit, spacing between curbs is critical to ensure the
units mate properly when installed. Refer to installation
instructions shipped with the roof curbs.
5. All dimensions are +1/8 inch.
6. Final electric connections must be made after unit is
installed to allow for tolerance in setting of unit on curb.
7. Maintain a 12-inch minimum height from top of roof deck
to top of curb.
8. Caulk butt joints after curb is assembled and installed on
roof structural members and roof flashing is added.
9. For improved sound attenuation, line the roof deck within
the curb area with 2" acoustic fiberglass.
Figure 4.1 - Typical Curb Details
Counterflashing
(By Others)
Roofing
Material
(By Others)
Insulation
(By Others)
Cant Strip
(By Others)
Roof Insulation
(By Others)
Roof
Truss
*Available as a factory supplied, field installed accessory.
4
Curb Gasketing*
or Caulk by Others
2 x 4 Wooden
Nailing Strip*
Curb*
2" Acoustic
Fiberglass
(By Others)
6" Inverted
Channel
Roof Deck
Both Sides
(By Others)
Duct Installation
The unit is designed to be close coupled to the MPR unit
through the factory installed transition duct. The inlet and
exhaust discharge openings are designed to be protected with
rainhoods. Refer to Figure 4.2.
Figure 4.2 - ERM Unit Inlet/Outlet Openings
Outside Air
Inlet Hood
Exhaust Air Economizer Bypass
Outlet Hood (Access Door Removed)
Utility Connections
Utility and control connections are made to the ERM unit
from the MPR unit, through the transition duct between the
units, once the two units are installed. This is detailed in the
"Electrical Connections" section.
ATH15-520.2
Transition Duct
to Main Unit