23
Water system
Prior to water system start-up
and balancing, the chilled and
hot water systems should be
flushed to clean out dirt and
debris which may have collected
in the piping during construction.
All unit service valves should be
in the closed position during
this procedure to prevent debris
from entering metering devices
and coils. Strainers are
recommended to help protect
against debris entering units
during normal operation.
During system filling, air venting
from the unit is accomplished by
the use of the standard, manual
air vent or the optional automatic
air vent that is installed at the
top of each coil’s header. Manual
air vents are capped Schrader
valves. To vent the air from the
coil, unscrew the cap, turn the
cap over and insert the pointed
end of the cap into the vent to
depress the valve until all of the
air has been vented from the coil.
When water begins to escape
from the vent, release the valve
and replace the cap. Automatic
air vents may be unscrewed one
turn counterclockwise to speed
up the initial venting but should
be screwed in for automatic
venting during normal operation.
The air vents provided are not
intended to replace the main
system air vents and may not
release air trapped in other parts
of the system. Inspect the entire
system for potential air traps and
independently vent those areas
as required. In addition, some
systems may require repeated
venting over time to fully
eliminate air in the system.
Water treatment
Proper water treatment is
a specialized industry and
therefore it is recommended
to consult an expert in this
field to analyze the water for
compliance with the water
quality parameters listed below
and to specify the appropriate
water treatment program. The
expert may recommend rust
inhibitors, scaling preventative,
antimicrobial growth agents or
algae preventatives. Anti-freeze
solutions, glycols, may also be
used to lower the freezing point.
All Zehnder Rittling water coils are
constructed of copper tubes and
headers while multiple brass and
bronze alloys may be present in
the valve packages. It is the end
user’s responsibility to ensure
that any of the water delivery
components are compatible with
the treated water.
Failure to provide proper water
quality will void the fan coil unit’s
warranty.
Water content
Required
concentration
Sulphate
< 200 ppm
pH
7.0 – 8.5
Chlorides
< 200 ppm
Nitrate
< 100 ppm
Iron
< 4.5 mg/L
Ammonia
< 2.0 mg/L
Manganese
< 0.1 mg/L
Dissolved solids
< 1000 mg/L
Calcium carbonate
hardness
300 – 500 ppm
Calcium carbonate
alkalinity
300 – 500 ppm
Particulate quantity
< 10 ppm
Particulate size
800 micron max
Start-up
