36
VAPORSTREAM INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Dispersion:
Important:
Failure to follow the recommendations in this
section can result in excessive back pressure on
the humidifi er. This will result in unacceptable
humidifi cation system performance such as
leaking gaskets, blown water seals, erratic
water level control, and spitting condensate
from dispersion tubes.
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INSTALLATION
WARNING
Hot surface and steam hazard
Dispersion tube, steam hose, tubing,
or hard pipe can contain steam, and
surfaces can be hot. Discharged steam
is not visible. Contact with hot surfaces
or air into which steam has been
discharged can cause severe personal
injury.
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DriSteem humidifi ers operate with several types of dispersion assemblies for
open spaces and for ducts and air handling units.
Dispersion assemblies in ducts and air handling units must be positioned where
the water vapor being discharged is carried off with the airstream and is
absorbed before it can cause condensation or dripping.
• Non-wetting distance is the dimension downstream from the leaving
side of the steam dispersion assembly to the point where wetting will
not occur, although wisps of steam may be present. This distance was
calculated during humidifi cation system design and is dependent on
several application parameters. To determine your dispersion assembly’s
non-wetting distance, consult your system’s design engineer or project
documentation. Non-wetting distance can also be calculated using
DriSteem’s Dri-calc sizing and selection software, available at www.
dristeem.com. Note that your current design conditions may vary from
conditions used for system design.
• In general, the dispersion assembly is best placed where the air can absorb
the moisture being added without causing con den sa tion at or after the unit.
This normally will be after the heating coil or where the air tem per a ture is
highest.
• Place the dispersion assembly such that absorption will occur
– before the intake of a high effi ciency fi lter, because the fi lter can remove
the visible moisture and become waterlogged;
– before coming in contact with any metal surface;
– before
fi re or smoke detection devices;
– before a split in the duct; otherwise, the dispersion assembly can direct
more moisture into one duct than the other.
• When draining dispersion condensate to an open drain, provide a 1"
(25 mm) air gap between the condensate drain piping and the drain.
Locate the gap only in spaces with adequate temperature and air movement
to absorb fl ash steam; otherwise, condensation may form on nearby
surfaces.
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Selecting the dispersion assembly location
