Part No. 4801-5120 Rev. 1-2020
Mega-Cool System
Page 40 of 48
Operation
Initial Start-up
When the pads are new, their slick surfaces will prevent the fast soaking that
will happen with older pads. For this reason, when new pads are used for the
first time, it is important to allow the Pump to run for one or two days
continuously. This will "soak-in" the pads, and allow faster start-up later. This
one to two days is called the "break-in" period.
At the end of the "break-in" period, inspect pads carefully. Any dry streaks will
indicate an inconsistent water distribution. If you find these dry streaks, you
will need to clean the spray line. To clean the spray line, follow the procedure
outlined on next page.
Normal Operation
Under normal conditions, the Pump should run constantly when air is being
drawn through the pads. If outside conditions are not warm enough to run the
system constantly, it may not be warm enough to run at all.
While the system is operating, look for signs of scale formation. Scale is a
concentration of solids that will "plate" onto the surface of the pads, if water
contains too many impurities. If scale is noticed, increase your bleed off rate.
If you allow the water level in the reservoir to get too high, the bottom of the
pads may stand in water. If the pads are submerged, they will become
waterlogged. When this happens, they will lose their rigidity, and begin to break
down at the bottom. This will greatly reduce pad life, and should be avoided.
Extending Pad Life
As you use the Mega-Cool system, you will notice the need for good
preventative maintenance. Algae growth, scale (hard crusty deposits), and dirt
accumulation are typical problems associated with poor maintenance.
Maintaining the Mega Cool is very simple. It takes a small amount of time and
effort. If you follow the guidelines below, your pad and gutters will last much
longer, and be much more effective.
Limit On-Off Cycling
Many users have initially seen greater cooling effects from evaporative cooling
systems when they run the system on a ten minute timer. Although this cooling
may have a great short term effect, the pad life is greatly shortened. For this
reason, you must choose for yourself which is more important.
When the system is started and stopped every ten minutes, the pads are wetted,
and dried outs six times per hour (Up to 144 times per day!). Each time the pads
dry, the minerals in the water remain on the pad, and limit the cooling
effectiveness.
Mega Cool pads have a recommended water flow rate for best performance. If
this flow rate is maintained, the water flowing down the pad will continuously
flush the pad clean. (As only a small percentage of the water will evaporate).
Dry the pads completely each night by turning off the In-Line Pump, and
drawing air through the pads with your fans.
Why Bleed-Off Water From The System?
If you have ever left a pot of coffee warming on the coffee maker, you know the
two principles at work in evaporative cooling systems. First, as the coffee sits
on the warming plate, the level of water in the pot goes down. Second, the
remaining coffee gets stronger as the water evaporates. In your cooling system,
these effects still apply. As water evaporates, no impurities are carried along.
This leaves all sorts of minerals, chemicals, and other impurities behind. The
concentration of impurities in the reservoir and system will quickly rise.
As the water is evaporated, the make-up water is added. Since this water still
contains impurities, make up water contributes to the problem. The only way to
reduce the concentration is by taking water from the system. Cumberland's
Mega Cool system is designed with an exhaust valve in the supply line just
before the pipe union on the discharge side of the In-Line Pump. This valve
should be throttled to allow just enough water to escape the system.
The amount of water you should bleed off depends on the water quality in your
area. If you have a large amount of impurities, you will need to allow more
water to escape. If you see scale beginning to form on the pads, you will need to
increase your bleed off rate. The best method for determining the bleed off rate
is to first find out how much evaporation is occurring. To calculate a rough
estimate of your evaporation, multiply the area of the pad by the air speed
through the pad, by the temperature drop from one side to the other. Then
divide the final number by 500,000.
