icomfort Touch
7−Day Programmable Communicating Thermostat
Page 9
Explanation of Humidification and Dehumidification Modes
HUMIDIFICATION modes
NOTE − Do not use Steam Humidifier in Precision mode hu-
midification.
BASIC & PRECISION
These modes allow user control of
RH between 15 and 45%. These conditions must be met for
either mode to operate:
humidification mode has been enabled, and
the unit is in HEAT mode, and
humidification demand exists (24V present at H), and
BASIC
mode also requires presence of heating demand
[Y for HP heat, or W for gas heat (W may be energized
with G de−energized)].
DEW POINT CONTROL
(Available only if outdoor sensor
is attached) Dew point adjustment mode will change the hu-
midification setpoint based on the outdoor temperature and a
user−defined dew point adjustment setting.
DEHUMIDIFICATION modes
NOTE −
Basic
and
Precision
dehumidification modes are
functions of the HVAC system with NO external dehumidifica-
tion devices installed. Humiditrol and Auxiliary Dehumidifiers
do not use these modes.
In
BASIC
mode, dehumidification occurs if these conditions
are met and signals are present at specific terminals:
dehumidification has been enabled on installer settings,
and
the unit is in COOL mode, and
dehumidification demand exists (RH above set point),
and
cooling demand exists (Y1 energized).
In
PRECISION
mode, dehumidification occurs if all BASIC
conditions are true, except cooling demand may or may not
be present. Maximum overcool from cooling setpoint is 2ºF.
HUMIDITROL or AUXILIARY DEHUMIDIFIER
mode re-
quires:
NOTE − Systems using icomfort
t
and a dehumidifier − De-
hum" jumper on furnace/air handler control does not need to
be cut.
outdoor sensor must be installed and set up
dehumidification has been enabled on installer settings,
and
the unit is in COOL mode, (or if in AUTO, at least one ther-
mostat cooling call made prior to the dehumidification de-
mand), and
a dehumidification demand exists (RH above set point),
and
outdoor temp. below 95°F; indoor temp. above 65°F, and
for
HUMIDITROL
, adjust Humiditrol comfort parameters
as follows:
MAX
adj. − Indoor temp > 2°F above heating setpoint
MID
adj. − Indoor temp >
HEAT SCOOL SETPOINT
2
MIN
adj. − Indoor temp > 2°F below cooling setpoint
Auxiliary Dehumidifier (stand alone dehumidifier)
When this option is selected, dehumidification will be allowed
under the following conditions,
if there is NO call for humi-
dification
:
In the absence of heating or cooling calls, or
Simultaneous with heating or cooling calls, or
Simultaneous with blower only calls
NOTE − Circulation fan speed must match auxiliary dehumidi-
fication unit CFM.
Auxiliary dehumidification is controlled by the thermostat de-
humidification demand. The thermostat sends the demand
and, if the blower is not operating, the thermostat initiates
blower operation. The blower demand (when required) pro-
vides a CFM override to control blower speed when the in-
door unit reports the indoor blower CFM speed. In such
cases, the value of the override is calculated as:
minimum CFM + (maximum CFM − minimum CFM)
2
If indoor blower CFM range is not reported and indoor blower
CFM speed is reported (one or the other must be reported),
the override is not used and is set to zero.
Activate: If RHmeasured is >= (RHse 2%)
Deactivate: If RHmeasured is <= (RHsetpoint − 2%)
