Nortec GS Series - Manual (Page 44)

41 | GS Series Installation
Scale Management
General
The gas humidifier will periodically “blowdown” water from the tank to reduce the concentration of total
dissolved solids that accumulate during long term operation. Gas Humidifiers are shipped factory set with a
blowdown of 25%. This setting ensures that scale build-up will be minimized for all water conditions.
Once the water conditions are known, the blowdown rate can be adjusted by software (GSTC models) or by
using dip switches on the logic control board (GSP models).
Another effective means of controlling the amount of scale in the tank is with the use of the Full Tank
Blowdown (FTBD) built into the software. When this feature is activated, the drain pump will be energized to
drain the entire contents of the tank and then the tank will be refilled with fresh water, thus keeping the
amount of total dissolved solids to a minimum. The feature can be programmed in the software to occur
after a specific amount of operating time and can also be triggered by a signal sent to the humidifier from a
building management system.
Water Quality
Due to the wide range of water conditions found throughout North America it is important that the blowdown
is set according to the local water conditions. By water conditions we are referring to the hardness of the
water supplied to the humidifier. The hardness is measured in grains per gallon. It is also important to test
for silica content. Silicates may cause foaming and contribute to scale buildup in the humidifier tank and
float chamber.
Figure 30: Site Water Test Kit P/N 1507214
If you are unaware of the hardness or silica content of your water supply, there are many “do it yourself” kits
which can be purchased, or there are several companies that will perform the tests for a reasonable price.
You can even contact your municipality for your water condition or order the NORTEC water test kit.
NOTE: Water quality conditions resulting in component failures are not covered under NORTEC’s standard
warranty.
Silica Test: Measured in ppm (parts per million) Follow the directions with the kit. A high reading will
decrease the performance of your system. The recommended operating range for silica is 0 ppm to 14 ppm.
Note: A high silica content along with a high hardness content may increase the service intervals of the
system. Consult the factory if this condition exists at the site.