Greenheck Fan HRE-20 - Manual (Page 7)

1. After the energy recovery unit is set in place, run
the overflow and drain lines to the exterior fittings
on the evaporative cooler (drain & overflow
connections at unit are
3 ⁄
4
-inch female pipe thread).
The supply line can be attached at the
downstream side of the evaporative cooler. A
manual shut off valve should be mounted in the
supply line near the unit for servicing purposes.
Also, a trap should be installed in the drain line to
prevent sewer gas from being drawn into the unit
(see Figure 8).
2. The cooler will be prewired by the factory.
3. Check to make sure that the pump filter is around
the pump inlet.
4. Turn the water on and allow the pan to fill up with
water. The float should be adjusted to provide 2
inches of water depth in the sump.
5. Saturate the media without any airflow through the
unit. A jumper wire is required on the terminal strip
to provide power to the evaporative cooler pump
(see the wiring diagram for the proper location).
This saturation process will break-in the media and
minimize the odors associated with the media. The
media’s break-in period should be no less than 20
minutes. When the process is complete, remove
the jumper wires in the control center.
Note: Evaporative media may foam for a short
period following the initial start-up. Leave
the bleed-off valve fully open until the
foaming stops.
6. After the media break-in period, the water flow
rate over the media needs to be checked. The
pumps should provide enough water to saturate
the media in 1-3 minutes. If adequate flow rate is
not achieved, consult with the factory.
7. The water bleed-off rate will now need to be
adjusted. This measurement is 3 to 6 percent of
the media flow rate. The recommended flow rate is
1
1 ⁄
2
to 2 GPM per
square foot of
media pad top area
(see table at right).
After the unit has
been installed and
running for two
weeks the unit should be checked for mineral
deposits. If there are deposits, the bleed-off rate
needs to be increased. Some areas of the country
have water with greater amounts of dissolved
minerals requiring a higher bleed-off rate.
8. Verify that both airflow and system static pressure
are in agreement with the specifications. If these
conditions are met, check for water carry over
from the discharge side of the media. If carry over
is observed, check the distribution header for
holes or tears and the
water standoff tube for
blockage.
9. After all final
adjustments are made,
remove the jumper
wires and replace all
access panels. The
unit is now ready for
operation.
It is important to mount the heat recovery unit level to
ensure proper operation and water drainage. Piping
should be of adequate size to provide sufficient
supply of water to meet the maximum demand of the
evaporative coolers.
Evap Module Start-Up
Evaporative Cooling Modules
7
Roof Curb
Roof Line
Drain
Line
Trap
Overflow
Drain Line
Manual
Shutoff
Valve
Evaporative
Cooling
Media
Manual Shutoff Valve
Supply Line
Sump
Side of HRE Unit
Indirect Evaporative Cooler
(Exhaust/Scavenger Airstream)
Direct Evaporative Cooler
(Outdoor/Supply Airstream)
FIGURE 8
Unit Size Media Pad Top Area
HRE-20 1.5 ft 2
HRE-45 2 ft 2
HRE-55 2.5 ft 2
HRE-90 3.3 ft 2