Installation, Operation & Maintenance Manual
IM-875
5
Rooftop/Curb Mounted
For a unit that discharges downward through a curb, locate the required opening for connecting ductwork. Cut through roof
deck for connection of duct to blower discharge. Allow adequate, at least one inch, clearance on all sides between ductwork and
decking material. Position the curb on the roof in relation to the roof penetration, as shown on the blueprint. Secure the curb to
the structural members. The curb may now be flashed into the roof. Rooftop, down discharge units are provided with a skirt that
is larger than the curb on all sides. This allows for roofing up to the top of the curb, if so desired.
The unit may now be lifted up onto the curb.
Note:
Units that discharge down through the curb with discharge dampers must have the roof opening cut large enough to allow
access to the damper motor and linkage from below the roof. The damper should be mounted and motor wired with pigtail provided
before the unit is set on the curb.
Note:
We recommend the connection of a short length of ductwork to the unit before setting on the curb to extend through the roof
if minimum (1") clearance is being used around the duct.
Pad Mounted
For a unit designed to mount on a pad or other support and discharge horizontally, vibration isolators are recommended. A
channel iron support adequate to carry the weight of the unit must be secured to the bottom of the unit, one at each end,
extending at least 3" past the sides of the unit. On AEH models, refer to your submittal or record drawing for size, quantity and
location of isolators. Anchor the vibration isolators to the pad. The unit may now be set down onto the isolators and bolted to
them.
Indoor/Suspended
For a unit designed to be suspended within the building, hanger rods and channel iron adequate to support the weight of the
unit will be required. On AEH models, refer to your submittal or record drawing for size, quantity and location of channel iron and
isolators. Attach the hanger rods to the building structure so they hang down to the channel extensions under the unit. Make
sure the rod location does not interfere with the removal of unit access panels. Provide one suspension type vibration isolator
in each hanger rod. The minimum combined ratings of the vibration isolators and suspension materials should equal the total
weight of the fully assembled unit. Move the unit to its installation location. Fully assemble the unit with all included components
(motorized discharge dampers, etc.). Raise the unit so that one hanger rod drops through holes in the channel extensions. Attach
two nuts to hanger rods and level unit, jamb the two nuts together to prevent loosening.
The unit is now ready for piping, wiring and connection to any required ductwork.
Ductwork
Ductwork must be sized and installed in accordance with applicable codes and standards. On units mounted outdoors, it is
recommended that all discharge and return air ducts be insulated to prevent condensation during the "Off" cycle in cold weather.
A fresh air intake hood with bird screen and/or filters can be supplied by Aerovent with the heater. Our intake hood or one of a
similar design is recommended.
On units mounted indoors through the roof intake ductwork, a suitable weather resistant intake hood must be installed.
Sheet metal standards should be adhered to to ensure uniform air delivery to the heater inlet. This aids in preventing moisture
entrainment. When using a through-the-wall intake duct, a properly sized intake louver should be used, having adequate moisture
baffling characteristics for the design air volume.
In lieu of an intake louver, a wall mounted intake hood with mesh screen may be used. This can be supplied by Aerovent. It is
recommended that all intake ductwork that is exposed to the heated space be insulated.
The requirements for discharge ductwork are usually considerably less than with a conventional system, as the pressurization
principle lends itself to effective air distribution. Generally, a "splash plate" or other method of distributing the air is all that is
necessary.