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1.2 Cylinder Life
1.2.1 Basics of the Steam Cylinder
The Steam Cylinder is the engine of the humidifier. As the water is evaporated inside the cylinder, minerals are left behind.
Much of these minerals are removed through the cylinder drain, however, some are deposited on the walls of the cylinder and
the cylinder electrodes. When a lower section of the electrodes develops 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 E8
Cylinder Expired error code. There are several factors that influence cylinder life.
1.2.2 Water
Water characteristics (mineral percentage and types) influence cylinder life and can vary greatly from place to place. Most
water conditions result in flaky 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. Use only cold water since the supply water is used to temper the hot drain water. Water quality affects the operation
of this unit, so the 5500 Steam Humidifier should be supplied with water that is untreated, drinkable, not softened, and not
demineralized. The water converted into steam is automatically replaced through an electric fill valve.
1.2.3 Water Filtration
Typically, additional filtration of the incoming water supply is not necessary. If 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 about 5 microns or less (micron is a size measurement) with 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 an increase in cylinder life will be accompanied by the need to replace filter elements with each cylinder change.
1.2.4 Humidity Load and Cylinder Life
Humidity load demands affect 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 thus extending cylinder life.
Installations that require constant operation at full capacity will reduce cylinder life. The water level in the cylinder is, on
average, much higher and the electrodes become completely insulated more quickly.
The importance of providing adequate humidifier capacity should not be underestimated.
1.2.5 Maximum Production
Another factor affecting cylinder life is the maximum production setting. A higher production
rate will result in a shorter cylinder life (See Figure 1.c.).
1.2.6 Structures Under Construction
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. 5500 Steam humidifiers may be operated while construction is underway,
but reduced cylinder life is to be expected. Good practice dictates that the steam cylinder also be replaced once the
project is complete.
1.3 Calculating Humidity Load
1.3.1 Steps to Estimate Humidity Load
Humidity Load Calculation (GPD)
Total Square Footage
x Average Ceiling Height
x Factor (From Table 1.b.)
x 1.05 for each Fireplace
x 2.88 convert to gallons/day
= Gallons per Day
