Table of Contents
Advertisement
unit location
dANGeR
Appliances must not be installed where they may be
exposed to potentially explosive or flammable atmosphere.
CAUtIoN
Appliances are designed for outdoor installation only.
DO NOT LOCATE APPLIANCES INDOORS.
IMPoRtANt
To prevent premature heat exchanger failure, do not locate
ANY gas-fired appliances in areas where corrosive vapors (i.e.
chlorinated, halogenated or acid) are present in the atmosphere.
location recommendations
1.
When locating the packaged rooftop unit, Model MPR,
consider general space and cooling/heating requirements and
availability of gas and electrical supply.
2.
Be sure the structural support at the unit location site is
adequate to support the weight of the unit and any other
required support structure. For proper operation the unit
must be installed in a level horizontal position.
3.
All mechanical equipment generates some sound and
vibration that may require attenuation. Locating the
equipment away from the critical area is desirable within
ducting limitations. Frequently, units can be located above
utility areas, corridors, restrooms, and other non-critical
areas. Generally, a unit should be located within 15 feet of
a primary support beam. Smaller deflections mean lesser
vibration and noise transmission. For critical applications,
please consult with an acoustical attenuation expert.
4.
Do not install units in locations where the flue products
(if equipped with a gas fired heating option) can be drawn
into the adjacent building openings such as windows, fresh
air intakes, etc.
5.
Be sure that the minimum clearances to combustible
materials and recommended service clearances are
maintained. For units with the gas heating option, be sure
clearances are maintained to the combustion air inlet
louvers and power exhauster discharge cover. Units are
designed for installation on non-combustible surfaces with
the minimum clearances shown in Figure 5.1.
6.
On units that have fresh air openings, a method must be
provided to prevent water and debris from entering the unit
such as a rainhood, which is available as an accessory
from Modine. Where possible, install the unit so that the
inlet is not facing into the prevailing wind to prevent water
entrainment.
7.
The exhaust fan is not designed for high temperature
or smoke control exhaust applications. Exhaust air
temperature must not exceed 104°F. Operating the
exhaust fan above 104°F will result in failure of the
exhaust fan.
4
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 (Literature
#MCP15-590) 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 Modine 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 ensure 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.
All dimensions are +1/8 inch.
5.
When a roof curb is used in conjunction with factory
supplied discharge and/or return air connectors, the
ductwork can be fastened to the connectors prior to the
unit installation. The connectors will accept 90° flanged
ductwork (see Figure 7.1).
6.
Final electric and gas connections must be made after unit
is installed to allow for tolerance in setting of unit on curb.
For electrical power supply allow approximately eight feet
of wire, plus provisions for weathertight flexible conduit for
connection to unit, as required by local codes.
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 attentuation, line the roof deck within
the curb area with 2" acoustic fiberglass.
Figure 4.1 - Typical Curb Details
Roof
Trusses
MCP15-500.7
Curb Gasketing*
Counterflashing
(By Others)
Roofing Material
(By Others)
*Available as a factory
supplied, field installed
Insulation
accessory.
(By Others)
Cant Strip
(By Others)
Roof Insulation
(By Others)
6" Inverted Channel
(Both Sides)
(By Others)
2 x 4 Wooden
Nailing Strip*
Curb*
2" Acoustic
Fiberglass
(By Others)
Roof Deck
Hide quick links:
Advertisement
Table of Contents
Troubleshooting
Need help?
Do you have a question about the MPR and is the answer not in the manual?