Installation and Operation Manual -
WHDEHUM-90P
7
return path to the dehumidifier to improve overall
airflow from other far apart rooms. CAUTION: Be
sure that grills and/or diffusers do not excessively
restrict airflow.
Supply Ducting for Whole-House Separate Room
For the supply output ducting (output air from the
dehumidifier), the total duct length should be less
than 10 feet total to reduce the back pressure on
the dehumidifier blower. CAUTION: Be sure that
grills and/or diffusers do not excessively restrict
airflow.
Ducting for Whole-House HVAC Configuration
For whole-house HVAC duct connections, please
reference Figures 2A and 2B on page 4. In both of
these configurations, the dehumidifier is placed in
the return path of the HVAC system.
For Figure 2A, the dehumidifier sources its return air
connection from the HVAC return connection, and
then the source air connection from the dehumidifier
is fed back to the HVAC return air duct a few feet
downstream. For whole-house HVAC, this is the
most common, most effective, and easiest ducting
implementation to use. It is best because it is
dehumidifying the air ahead of the air conditioning
coil system to eliminate the wettest air first ahead of
the HVAC coils. This enhances the overall cooling
system efficiency. Also, by inputting air from the
HVAC return duct and returning the conditioned
air to the same HVAC return duct, there is not an
additional air pressure differential to overcome. In
this configuration, keep the length of the dehumidifier
return and source ducting at a minimum.
For the second whole-house HVAC configuration,
please reference Figure 2B on page 4. The
difference from Figure 2A is that the dehumidifier
return path is independent from the HVAC return
path. In this configuration, the dehumidifier has its
own completely independent and dedicated ducting
and return air grill. This configuration is ideal when
there is a need to dry a specific conditioned or
unconditioned area. An example would be to feed
the separate room from the main living area, which
would maximize the airflow from there, proving a
living area that likely is more dry than the other living
areas.
Discussed and illustrated here will be the basic
control scenario for three classes of dehumidifier
control:
1.
Standalone unit dehumidification
2.
Whole-house separated dehumidification
3.
Whole-house using high integration consolidated
thermostat and humidistat
SUD Configurations
No extra control wiring is required for SUD
configurations, as the dehumidifier in this mode
operates completely standalone, sampling humidity
from the local air - and then using the settings made
by the user interface to either switch-on or switch-
off. Please reference the Operation section for
details on how to configure and use the dehumidifier
in standalone configurations.
Whole-House Separated Room Configurations
This type can be controlled with the addition of a
single humidistat located in the living area that is
to be served by the dehumidifier. See Figure 4 on
page 8 to guide specific hook-ups. For external
control, the dehumidifiers are connected to the
control systems with the 6-position terminal strip as
illustrated.
Terminals A3 and A4 need to be powered to switch
the dehumidifier on, typically connecting A4 to the
control voltage common signal (C) and switching
the 24VAC control hot signal (R) through a set of
normally open contacts typically integrated into
the separate humidistat. When the humidity rises
above the set-point, the humidistat contacts close,
which then connects the dehumidifier pin A3 to
24VAC and switches the dehumidifier ON.
To implement a required interlock with the HVAC
fan control, interconnect dehumidifier terminal strip
connections A3 to A2 as illustrated below. Then,
connect the dehumidifier terminal strip A1 back to
the HVAC “green” connection, which typically turns
the HVAC fan ON.
Also in the illustration below, please note the
functionality associated with dehumidifier connections
A5 and A6. A5 and A6 can be used to interlock
the dehumidifier to the condensate drain system.
Wiring
