Direct Gas Make-Up Air
7
1. Install Curb and/or Equipment/Leg Support(s)
Position curb and/or equipment/leg support(s) on
the roof (reference the unit submittal for placement
in relation to the unit). Verify that unit supports are
level; shim if necessary. Attach curb to roof and flash
into place using appropriate methods. Attach the
equipment/leg support(s) to the roof, remove metal
cover, flash to wooden nailer, and reinstall cover.
Metal Cover
Equipment
Support
Roof Curb
Curb and Equipment Support
Leg Supports
Unit Profile and Leg Support
2. Install Ductwork
Follow good duct practices for all ductwork. Install
ductwork in accordance with SMACNA and AMCA
guidelines, NFPA 96 and local codes. Reference
Installation, Duct Sizes
section in this Installation,
Operation, and Maintenance Manual for proper duct
sizes.
The use of a duct adapter is recommended on a
downblast (DB) arrangement to align the ductwork with
the supply unit. The duct adapter is only a guide and is
not to be used as a support for the ductwork.
3. Apply Sealant
Apply an appropriate sealant around the perimeter of
the curb and duct to isolate fan vibration and prevent
water penetration.
Supply Air Ductwork
(Arrangement DB only)
Sealant
Ductwork
Installation
Outdoor Unit Mounting
Complete Rooftop Installation
5. Assemble and Attach Shipped Loose
Modules
Using sheet metal screws, assemble optional shipped
loose modules. Fasten the cover seams and vertical
panels on each module securely.
Some weatherhoods may ship disassembled. Detailed
assembly instructions ship with the weatherhood.
If an optional evaporative cooling module is included,
reference
Installation, Optional Component Mounting,
Evaporative Cooling Module
section in this Installation,
Operation and Maintenance Manual for more
information.
The installer is responsible for ensuring that the unit
fastening methods are sufficient to account for the
weight and size of these additional modules.
6. Seal Seam(s)
Using an appropriate sealant, seal the seam(s) between
each shipped loose module and the weatherhood.
4. Install Unit
Use a crane and a set of spreader bars hooked to the
factory lifting lugs to lift and position the unit on the
curb/equipment support(s). The use of all lifting lugs and
a set of spreader bars is mandatory when lifting the unit.
Fasten the unit to the curb/equipment support(s) using
appropriate methods. The installer is responsible for
determining appropriate support and fastening methods
to ensure compliance with all applicable codes.
Setting Unit
Standard Curb
