Herrmidifier Herrmidicool Technical Guide - Manual (Page 6)

SECTION II DESIGNING A HERRMIDICOOL SYSTEM
Such things as airflow patterns, velocities, proximity to
coils and filters, cleanliness requirements, mineral
content of the feed water and the size and shape of air
handlers must be taken into account when designing a
Herrmidicool system. Because of the relative complexity
of all these factors, we recommend that you work closely
with your Herrmidifier representative in the planning
stages of any Herrmidicool project. He can review your
requirements; size the system and provide a quotation
with recommendations.
Determining Humidification Load
After you have performed the humidity load calculation,
(see Load Calculator Guide) you should then determine
if the desired psychrometric end result is possible. The
evaporative cooling effect of atomized water will lower
the system air temperature reducing its ability to hold
moisture. You must be sure that your air handling
system can handle the moisture you wish to introduce.
To determine this, use the Psychrometric Chart on page
3 by locating first the point directly on scale A that
corresponds to the dry bulb temperature of the air being
humidified. Then follow the diagonal line left to its
intersection with 85% RH on the parabolic relative
humidity scale. Now follow the horizontal line right from
this point until it intersects with the vertical line from
The optimum location for the Herrmidicool manifold is in
the air handler itself, upstream of the cooling coil with
four or more rows. The cooling coil insures a velocity of
less than 600 FPM with a large cross sectional surface
area and provides a natural mist eliminator and drain.
scale A representing the dry bulb temperature of the
area to be humidified and read the resulting relative
humidity. If it is lower than what you desire, you will not
be able to put that much moisture in your air handling
system without some reheating of the air prior to the
Herrmidicool system.
Selecting Herrmidicool Location Within Air Handler
System
Critical measurements are the distance from the heads
to the duct surface and the straight duct run required for
total evaporation. The second measurement is critical
only if the system is not installed prior to a cooling coil,
mist eliminator or evaporative media (Consult Factory if
this describes your application). Since the heads are
usually installed with the discharge at 90 degrees to the
air flow, the distance from the heads to the duct surface
is also important as any live mist that hits a surface will
impinge on that surface and coalesce, eventually
running. For that reason, it is important also to see that
no sensors, seams, cross bars or other obstructions are
in the path of the atomized spray, with the exception of a
cooling coil, mist eliminator or evaporative media.
The recommended distance from the heads to the top of
the duct is shown on Chart II and is based on the air
velocity in the duct or air handler.
Chart II
In this type of installation, the size of the heads used is
not so important and can be chosen based on availability
of installation space for the equipment and distribution
patterns. (See Fig. 6)
HERRMIDICOOL Technical Manual