2 cylinder life, 3 calculating humidity load – GeneralAire DS35 Elite Steam User Manual

Page 7

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1.2 Cylinder Life

1.2.1 Basics of the Steam Cylinder

1.2.2 Water

1.2.3 Water Filtration

1.2.6 Structures Under Construction

The Steam Cylinder is the engine of the humidifier. As the humidifier operates and water is evaporated and minerals are left

behind. Much of these minerals are removed through the cylinder drain. Some are deposited on the walls of the cylinder and

the cylinder electrodes. When a lower section of the electrodes develop a thick coating, the water level is raised to expose

clean electrode surface. Eventually minerals cover the electrodes’ entire length with a thick coating and little electrical current

can pass between them resulting in poor steam output. The humidifier can sense the low amperage and will display the E6

Cylinder Exhausted error code. There are several factors that influence cylinder life.

Characteristics of water influence cylinder life and can vary greatly from place to place. Total mineral content of the water is

important. Equally important is what minerals are present in the water. Most water conditions result in flakey scale that

eventually fills the bottom of the cylinder until it can no longer function. Water with high silica content can result in a thin

glass-like coating on the electrodes that is highly insulating resulting in shorter cylinder life. Only cold water is to be used

Typically additional filtration of the incoming water supply is not necessary. If, however, mineral content is known to reduce

cylinder life excessively or if cylinder life proves insufficient then water filtration can be added. In most cases the addition of a

two element water filter can improve cylinder life. The filter should contain an activated carbon element and a particulate filter

element rated for 5 microns or less. Micron is a size measurement. The filter system should have a flow rate of at least

2 gpm. The activated carbon will absorb much of the mineral content while the particulate filter will catch any granular material

or

sediment. It is important to remember that the increase in cylinder life will be accompanied by the need to replace filter

elements

with each cylinder change.

Humidity load demands have an effect on cylinder life. Normal installations where humidity capacity is properly sized require

only intermittent periods where full humidifier capacity is required. This allows the water level in the cylinder to be increased

only as electrode segments become insulated. This tends to maximize cylinder life.

Extraordinary installations that require constant operation at full capacity reduce cylinder life. The water level in the cylinder is, on

average, much higher, and the electrodes become completely insulated more quickly. Installations like this may result in

cylinder life of less than 1000 hours.

The importance of providing adequate humidifier capacity should not be underestimated.

In high end construction projects, humidification is often required while the structure is being finished. Humidification is

necessary to protect and stabilize wood floors, trim and decoration. Humidification load, however, in an unfinished structure may

be five to eight times higher than when finished. Elite Steam humidifiers may be operated while construction is underway but,

reduced cylinder life is to be expected and budgeted for. Good practice dictates that the steam cylinders also be replaced once

the project is complete.

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Steam Elite +03U221903 REV 2.1

1.2.4 Humidity Load and Cylinder Life

1.2.5 Maximum Production

1.3 Calculating Humidity Load

1.3.1 Steps to Determine Humidity Load

Total Square Footage

x Average Ceiling Height

x Factor From Table 1.2

x 1.05 for each Fireplace

Humidity Load in lbs./hour

x 2.88 convert to gallons/day

Gallons per Day Humidity Load

Table 1.2 Pounds of Moisture / Hour / Cubic Foot *

*Based on .5 air changes per hour.

Indoor Air Temp

Indoor RH%

35% 40% 45% 50%

F

68 0.00015 0.00018 0.00021 0.00024

70 0.00017 0.00020 0.00023 0.00026

72 0.00019 0.00022 0.00025 0.00028

Another factor affecting cylinder life is the maximum production setting. A higher

production rate will result in a shorter cylinder life. For this reason DS-35 and RS-35

units are preset from the factory at 70%. Further reductions in Maximum Production

will extend cylinder life. See Figure 1.c.

100%

20%

Cylinder

Life

Maximum Production

Figure.1.c

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