Herrmidifier Herrmidicool Technical Guide - Manual (Page 10)

External Duct Plate Applications
If the duct is not high enough for proper turning of the
spray to prevent impingement, the atomizing heads may
sometimes be mounted to an "External Duct Adapter
Plate" which suspends the manifold and atomizing
heads outside the duct and thus may gain the necessary
distance for proper turning of the spray in the air stream.
General rules on placement of the Herrmidicool
system in air handlers:
The minimum distance between each of the heads is 3".
The minimum distance between the end heads and the
side of the duct or air handler is 12".
To determine the proper head spacing on the manifold,
subtract 24" from the duct width and divide the
difference by the number of heads minus one. If this is
less than 3", multiple manifolds must be used, or the
head capacity increased, to reduce the number of
heads.
If multiple manifolds are used, alternate and stagger the
location of the heads between successive manifolds to
provide and an interlocking spray pattern. (See Fig. 2)
If duct height is greater than (2 x Distance from top of
head to duct casing) (ref. Dim. A) the head manifold may
be centered in the duct with the heads alternately
spraying up and down. Otherwise, the head manifold
must be placed as low or as high as possible in the duct
with the heads spraying 90
0 to the airflow. The minimum
duct height for installation of atomizing head within the
duct is Dimension A + 12.
This technique has the added feature of increasing the
ease of maintaining the system. This is only possible
with the Herrmidicool atomizing heads because of their
high discharge velocity. This technique also permits the
use of the Herrmidicool system in ducts carrying
contaminated, corrosive or high temperature air.
If the duct height and head size do not allow for the
manifold to be mounted in the duct, the manifold may be
mounted externally be means of an external duct
adapter plate.
Warning: Before
obtaini ng access to
terminals, all supply
circuits must be
disconnected.
FIGURE 4
Placement of the Herrmidicool manifold in a return
plenum should be avoided as most air handler systems
involve some amount of exhaust. The atomizing head
manifolds should NEVER be placed in a lined duct, as
the droplets will impinge on the liner.
If the manifold is placed upstream of the cooling coil and
interlock to prevent the A/C system from operating
simultaneously is recommended. This takes full
advantage of the evaporative cooling provided by the
Herrmidicool system. If the manifold is placed down-
stream of the cooling coil, you should specify an
interlock to prevent the Herrmidicool from operating
when the A/C is on, which could cause condensation in
the duct.
HERRMIDICOOL Technical Manual