Sterling EV - Manual (Page 9)

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Bleed-Off
Bleed-Off is required to maintain the water quality of
the system. When water evaporates, minerals and
other impurities are left behind, impurities are scrubbed
from the air fl owing through the system, and make-up
water (even good quality make-up water) adds more
minerals and impurities. These form deposits on the
media during the evaporative process.Therefore, it is
important to bleed-off a small quantity of recirculating
water to keep the concentration of impurities under
control. The bleed-off rate required is dependent upon
the quality of the water used and the rate of evaporation.
As climate conditions change, the rate of evaporation
may increase, requiring an increase in the bleed-off rate.
It is recommended that the bleed-off rate be adjusted
for the maximum water evaporation. An indication of
insuffi cient bleed-off is a uniform build-up of minerals
on the entering air face of the media. If this condition is
observed, increase the rate of bleed-off until the mineral
deposits dissipate.
Adjusting the Bleed-Off
1. The bleed-off is attached to the PVC tee. This
bleed-off system will eliminate a small quantity of
water from recirculation, which will reduce scale
build-up. This water will drain through the attached
tube, and out through the overfl ow. Disposal of this
water should comply with local codes.
2. Adjust the bleed-off rate according to Table 4.
Table 4
Unit Size Seconds to Fill
Capacity 12 oz. Can
10/15 69 46
20/25/50 52 34
30/35/60/70 41 27
40/80 38 25
Adjusting the Water Level and Float Valve
Fill the tank as follows:
1. Turn the water supply on. Fill the tank to a depth of
approximately 3.25" (82.6mm). While fi lling the tank,
check for good pressure and fl ow from the fl oat
valve.
2. The fl oat valve should shut down the water supply
at the 3.25" (82.6mm) level. It may be necessary to
adjust the fl oat valve by bending the rod. The rod
level adjustment screw should be set in lower notch
on lever.
3. Check the tank and all connections for leaks.
NOTE: The overfl ow fi tting is set so that the water
will begin to fl ow at the 3.25" (82.6mm) depth. It is
important that the water level not be above the pump
basket screen!
Adjusting the Water Flow
Proper water flow over the media is important.
Insufficient water flow will result in increased
accumulation of minerals on the media. Excessive water
fl ow will result in deterioration of the media and moisture
carryover.
1. Using the ball valve handle, adjust the water fl ow so
that the media is damp from the top to the bottom. If
you can see water fl owing on the entering side, your
water level is too high. Adjust the valve so that the
media is just damp on the entering side. Repeated
drying of the media will cause rapid buildup of
mineral deposits in the media. Drying is due to
improper adjustment of the water fl ow valve, frequent
shut-down of the pump to control the evaporative
cooling/humidifi cation, or localized air velocities
across the surface of the media. The area where dry
spots occur will exhibit high mineral deposits. The
valve must be adjusted so that no dry spots appear
on entering or leaving side, and when adjusted
correctly, enough water will fl ow through the media to
wash out most of the airborne dirt and other debris.
2. Prior to start-up, it is recommended that the tank
be fi lled, and the pump turned on, allowing the
unit to run for approximately 10 minutes. Repeat
this procedure two times to help fl ush any dirt that
may have accumulated during shipping.