York BQ 036 Technical Manual page 14

Roof curbs are designed to fit inside the base rails of the
unit and include both a wood nailing strip and duct
hanger supports.
• POWER EXHAUST - Our single input economizer
options are available with power exhaust. Whenever the
outdoor air intake dampers are opened for free cooling,
the exhaust fan will be energized to prevent the condi-
tioned space from being over-pressurized during econo-
mizer operation.
The power exhaust option can only be used on bot-
tom duct configurations.
• BAROMETRIC RELIEF DAMPER - This damper acces-
sory can be used to relieve internal building air pressure
on units with an economizer without power exhaust. This
accessory includes a rain hood, a bird screen and a fully
assembled damper. With bottom duct connections, the
damper should be mounted over the opening in the
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return air panel. With horizontal ductwork, the accessory
should be mounted on the return air duct.
• ENTHALPY ACCESSORY CONTROL KIT - This kit
contains the required components to convert a single
enthalpy economizer to dual enthalpy.
• BURGLAR BARS - Mount in the supply and return
openings to prevent entry into the duct work.
• CO SENSOR - Senses CO
2
overrides the economizer when levels rise above the
present limits.
• COIL GUARD - Customers can purchase a coil guard kit
to protect the condenser coil from damage. This is not a
hail guard kit.
• HAIL GUARD - Hail guard is available to protect the unit
from hail damage. This is a sloped hood that fits above
the coil.
036-21508-005-A-0305
levels and automatically
2
Unitary Products Group