Greenheck Fan HEAT RECOVERY UNIT WITH EVAPORATIVE COOLING HRE-20 - Manual (Page 15)

15
Symptom Solution
Leaving Air Entering Air
45 °
15 °
Insufficient water
volume or recirculation
pump not operating
Irregular water
distribution on cooling
media
Scale and mineral
deposit formation on
face of media
Excessive water
discharge into drain
Water Carry-Over
Poor performance
after cooling pad
replacement
Inadequate cooling
A . Check water level in base pan . The
level should be at 1 inch .
B . Check the pump filter at the inlet .
Clean the filter if clogged or dirty .
C . If pump is not operating, check
wiring for loose connections and
proper voltage .
D . Clogged or worn out pump .
E . Clogged header .
F . Water flow adjustment device
Water distribution header, orifices or media partially blocked or plugged .
Remove evaporative cooler from unit .
Disassemble and clean distribution header, orifices and media .
A . Increase bleed rate .
B . Increase water flow rate . Media is self-cleaning with flow rate of
1 1 /
2
to 2
gpm per square foot of media top area . Generally this flow rate prevents
dissolved solvents from collecting on the media . To prevent further
trouble, flush and clean the system more frequently .
C . Check water flow across the face of the media . Irregular water distribution
must be corrected (see above)
D . If this condition persists, chemicals may need to be added . Water pH
should be maintained between 6 and 8 .
A . Irregular water distribution on face of media (see above) .
B . Average face velocity exceeds 550 fpm . Decrease fan rpm and airflow .
C . Localized face velocities exceeding 550 fpm . Air filters or media face area
is partially blocked . Clean or replace air filters and media .
D . Check the overflow for blockage .
A . Irregular water distribution over face of media (see above) .
B . Check for uniform airflow .
C . Check outside wet-bulb temperature . High wet-bulb temperatures can
decrease performance .
D . Check water flow rate over media . Flow rate should be 1 1 /
2
to 2 gpm per
square foot of media top area .
A . Check the water bleed off rate and make sure that it is not excessive .
B . Check water level in base pan . The level should be at 1 inch .
Pad installed backwards . To get the
performance from the cooling pads,
they must be installed properly . The
pads are manufactured with 15/45
degree flute angles . The pads must
always be installed with the steeper
flute angle sloping down toward the
entering air side . See figure on right .
TROUBLESHOOTING FOR EVAPORATIVE MODULE
C
Header
Detail