246653-YTG-E-0108
90
Johnson Controls Unitary Products
shall be selected for a minimum service factor of 1.2 and
have fixed pitched sheaves.
AIR FILTERING SYSTEM
All filter holding frames shall be of heavy duty construction
designed for industrial applications. All filters shall be either
side accessible or front loading with access doors provided
on both sides of the filter section. All filter media shall be
Class II listed under UL Standard 900. Filter efficiencies shall
be rated in accordance with ASHRAE Standard 52-76 2"
Throwaway Filters with fiberglass media multiple shall be
standard
OPTIONAL
Two inch pleated, throwaway filters with 30% efficiency. Rigid
filters shall be high performance, expanded area, disposable
type filters. Rigid filter sections shall be preceded by a 2
throwaway prefilter assembly. Filter efficiency shall be 95%
(Option: 65%) based on ASHRAE Standard 52-76.
AIR INLET SYSTEM
General
Outside Air inlet openings shall be covered by a factory
installed rain hood permanently attached to the cabinet to
prevent windblown precipitation from entering the unit. The
rain hoods on the front and back of the unit shall be rotated
into the cabinet and secured for shipment so that upon instal-
lation they need only be rotated upwards and screwed into
place. The outside air hood shall contain a removable and
cleanable filter with an efficiency rating of 50% based on
ASHRAE 52- 76. All damper assemblies shall be of low leak
design. Damper blades shall be fabricated from a minimum of
16 gauge galvanized steel. Blade ends and edges shall be
covered with vinyl seals. Damper shafts shall be fabricated
from solid steel and mounted in the frame with bronze bear-
ings. On all units not equipped with an economizer, an option
shall be available for a manually adjustable outside air
damper shall be capable of admitting 0-25% outside air.
Economizer (Optional)
An economizer shall have outdoor air and return air dampers
(optional standard or low leak type) that are interlocked and
positioned by fully modulating, solid state damper actuators.
The actuators shall be spring loaded so that the outside air
damper will close when power to the unit is interrupted. The
operation of the economizer shall be fully integrated into the
cooling control system. The economizer shall be available for
control via a dry bulb sensor (Optional: single or dual
enthalpy sensors).
RELIEF SYSTEM (Optional)
All units with relief must have an economizer.
Barometric Relief (Optional)
Building air exhaust shall be accomplished through baromet-
ric relief dampers installed in the return air plenum. The
dampers will open relative to the building pressure. The
opening pressure shall be adjustable.
Exhaust Air Fans (Optional)
General - forward curved centrifugal fan(s) shall be installed
in the return air plenum for positive power exhaust. Fans shall
be on a common shaft, driven by a single motor. The fans,
motors and drives shall be of the same quality and design as
specified for the Supply Air Fan, except the fans shall be
Class I. Fans shall be capable of exhausting up to 100% of
the nominal CFM of the unit. Non-modulating Exhaust - Units
with non-modulating power exhaust shall have a barometric
relief damper to prevent outside air from entering in the off
cycle. The fans shall cycle on and off with building pressure.
Modulating Operation - The fans shall be capable of modulat-
ing the amount of air from 0% to 100% of nominal CFM. Mod-
ulation shall be through discharge dampers or variable
frequency motor speed modulation. Dampers or VFD shall be
controlled by static pressure in the conditioned space or
return air duct.
ENERGY RECOVERY VENTILATION (FIELD
INSTALLED OPTION)
General
The packaged rooftop unit shall have attached at the jobsite a
powered exhaust combined with an air intake through a rotat-
ing energy recovery wheel, which captures sensible and
latent heat from the exhaust air stream and returns it to the
incoming air stream. The energy recovery module will be con-
tained in a separate enclosure designed to attach to the end
of the Millennium packaged rooftop unit equipped with Sim-
plicity® Elite™ control.
The Energy Recovery Ventilation module will be capable of
exhausting up to 8,000 (13,000) CFM.
Control parameters for the ERV will be preset in the unit con-
trol.
HEATING SYSTEM (OPTIONAL)
Gas-fired Heating Section
One or more gas-fired heating modules shall be installed to
provide the heating requirements per the schedule shown on
the plans. The heat exchanger shall be of tubular design.
Tubes shall be 2-1/4" OD and constructed of minimum 20
gauge, G160 aluminized steel (1.6 mil aluminum silicone
alloy) for corrosion resistance (Optional: 409 Stainless Steel).
Flue baffles shall be made of 430 stainless steel. Each gas-
fired heat module shall have an induced draft combustion fan
with energy efficient intermittent pilot spark ignition and
redundant main gas valves with pressure regulator. Units with
standing pilot ignition shall not be acceptable. An induced
draft fan shall be provided to maintain a positive flow of air
