16
Ductwork
connections
Flexible duct connections should
be used on all air handling
equipment to minimize vibration
transmissions. Insulation and
ductwork should be installed to
allow servicing of equipment.
It is recommended to have sight/
sound baffles installed on
dual, opposite side, discharge
units with the exception
of top discharge. It is also
recommended to have at
least one discharge grille with
damper to aid in air balancing.
Dual discharge units with top
discharge require a field supplied
and installed damper in the top
discharge duct.
Zehnder Rittling assumes no
responsibility for undesirable
system operation due to improper
design, equipment or component
selection, and/or installation of
base unit, ductwork, grilles and
other related components.
Special application
Operation of the unit with field-
fabricated outside air provision,
or operation in coastal areas
of high humidity may make it
necessary to add insulation
and/or a suitable vapor barrier
between the drywall material and
the air handling compartment.
Such recommendations will
be made by the factory upon
request.
All ductwork and or supply and
return grilles should be installed
in accordance with the project
plans and specifications. If not
included on the unit or furnished
from the factory, supply and
return grilles should be provided
as recommended in the product
catalog.
All units must be installed in
non-combustible and non-
hazardous areas.
Some models are designed
to be connected to ductwork
with a minimum amount of
external static pressure. These
units may be damaged by
operation without the proper
ductwork connected. Consult
the approved submittals and the
product catalog for unit external
static pressure limitations.
Units provided with outside
air should have some form of
low temperature protection to
prevent coil(s) from freezing.
This protection may be a low-
temperature thermostat to
close the outside air damper,
a preheat coil to temper the
outside air before it reaches
the unit, or any other protective
method.
It should be noted that none of
these methods will adequately
protect a coil in the event of
power failure. The safest method
of freeze protection is to use
glycol in the proper percent
solution for the coldest expected
air temperature.