Nortec RH2+ - Manual (Page 39)

Operation| 36
How the Humidifier Works
The RH2 is an atmospheric steam generator that uses heat generated by electrical current
flowing between submerged electrodes to generate steam. The RH2 is designed for air
humidification via steam distributor or blower pack.
Steam Generation

Once the unit receives a demand signal and the safety loop between terminal 1 and 2 is
closed, the humidifier closes the contactor and measures the electrical current.

If the demand is lower than the actual output the inlet valve is kept closed and output is
reduced by letting the water level in the cylinder decrease by evaporation.

If demand is higher than the actual output, after a brief delay the fill valve is activated and
water flows into the fill cup. Water from the fill cup flows into the bottom of the cylinder
through a hose connected to the drain valve housing.

As soon as the water in the cylinder comes in contact with the energized electrodes, current
flows through the water. The resistance of the water to the electrical charge generates heat
and in turn steam. The electrical current (and steam output) increases as the level of water
increases, as more of the electrode becomes submerged. The unit continues to fill until the
current matches demand or the high water sensor detects a high water level.

The RH2 repeats the fill and boil down cycle repeatedly to match output to demand.

Over time minerals in the water will adhere to the cylinder electrodes. The humidifier will
automatically fill to a higher water level to maintain full capacity during the life of the
cylinder. Eventually because of scale formation it will no longer be possible for the
humidifier to reach its full capacity. The RH2 software monitors this condition and, when
detected, will stop operating and flash the yellow LED in a repeating sequence of 4 flashes.
Drains

As steam is produced minerals are left behind, increasing the conductivity of the water. The
RH2 patented auto adaptive cycle will monitor the water conductivity and perform drains to
maintain the water at optimal conductivity for peak performance.

The auto adaptive cycle ensures cylinder life is maximized. It does this by keeping the
tightest control and most efficient use of water during the entire cylinder life.
Steam Distribution
Steam generated by the humidifier may be introduced into the air in several different ways. The
most common method for adding the steam into the air is to mount a steam distributor tube in
a supply air duct as shown in Figure 29: Humidifier Schematic. For introducing steam directly
into a room humidifier, built-in or remote mounted blower packs may be used see Figure 30:
Remote Blower Pack on page 37.
Note: The cylinder is gravity fed from the fill cup. If backpressure from the steam line is
too high it will cause water to back up in the fill cup and flow down the overflow line to the
drain.