Engineering And Application - Herrmidifier Herrtronic AD Owner's Manual

Engineering and Application

Herrtronic AD Series Steam Humidifiers can be applied
in a variety of applications. The simplest application
consists of an "AD" unit and an "RDU' (Room Distribu-
tion Unit). Steam is generated by the "AD" unit, trans-
ferred to the "RDU" unit, and distributed into the condi-
tioned space. As shown in Figure 1, the "RDU" unit can
be mounted on the "AD" unit or remote from the "AD"
unit. Steam input is either into the bottom or rear of the
"RDU" unit. In this application, only the "RDU" unit
need be in the conditioned space. One "RDU" unit is
NOTE
A separate condensate return line must be installed
during installation.
required for up to 125 lbs./hr. of humidification.
Alternatively, steam generated by an "AD" unit can be
discharged directly into the system ductwork. In this
application, steam distributor pipe(s) are preferably
installed in the system ductwork at least three (3) feet
down steam of the supply air blower. There should be no
obstructions within the first three feet down steam of the
humidifier as shown in Figure 2. If the blower operates
intermittently ("Auto"), an air-proving switch should be
provided to assure blower operation prior to humidifier
Herrtronic AD Series Installation, Operation and Service Manual
operation. Further, a high limit humidistat (located ten
feet downsteam of the humidifier steam distributor)
should be included for better system control.
The number of steam distributor pipes will be at least
equal to the number of steam outlets on the humidifier -
i.e., ADM & ADS (up to 65 lbs./hr.) =1, ADS (65 - 125
lbs./hr.) =2. A "Y" connector (EST - 255) is available to
convert one steam outlet into two steam distributor
inputs. Figures 5, 6, and 7 reflect the spacing required
within the duct.
NOTE
The steam distributor pipes are inherently sloped to
return the condensate to the humidifier.
The steam piping from the humidifier to the steam
distributor should have an 8% slope up to the steam
distributor. Steam hose may be used up to a maximum
of 20 feet between the unit and the steam distributor.
Beyond 20 feet, system capacity is reduced unless
insulated copper pipe (I 1/2" ID) is used. If there are any
low spots between the humidifier and the steam
distributor, a condensate separator (EST-250) should be
used (Figure 8). .