Dehumidification Accessory Installed; Smart Zoning System; Heating / Cooling Changeover; Cooling Operation - Lennox S40 User Manual

Table 3. Humidity Control Modes of Operations
Setting
Mode
Dew point adjustment mode will change the humidification set
point based on the outdoor temperature and a user-defined dew
point adjustment setting.
NOTE: Dew Point - Adjustment requires an outdoor
temperature sensor and is automatically controlled by
the outside temperature.
dew point
−15%
Lennox Variable capacity outdoor units.
1

Dehumidification Accessory Installed

When either an Auxiliary Dehumidifier or Humiditrol equipment is installed
the settings available are Off and Dehumidify. When Dehumidify is selected
a Dehumidification Set-Point adjustment tool is available and allows
adjustments between 50% to 60%.

Smart Zoning System

NOTE: Lennox Zoning Control only work with Lennox communicating systems.
IMPORTANT
The Lennox Smart Room Sensor is not compatible with systems using the
Lennox Smart Zoning System (iHarmony) installed.
For user setting options, go to Menu > Settings > Zoning Control. By default
Zoning is ON on the Zoning Control screen. If you wish to place the system
into central mode then turn this setting OFF. You can also rename each zone
from this screen.

Heating / Cooling Changeover

The following is an example of how the zoning system operates during a
heating / cooling changeover.
Description
on
0%
15%
When the system is satisfying a call from zone 1 for heating and receives a call
for cooling from zone 2, the following will occur:
• The system will continue to fulfill the demand from zone 1 until satisfied, or a
maximum time of 20 minutes has occurred.
• If after 20 minutes the system is still operating based on satisfying the heating
demand from zone 1, the system will terminate that demand.
• The system will then shut system down for five (5) minutes. This will allow for
system temperatures and operating pressures to stabilize.
• After a five 5 minute delay the system will begin operations to satisfy the
cooling demand from zone 2.
The system will continue to operate in this manner each time it receives a zone
call that is opposite of the current mode of operation (heating or cooling).
When a zone thermostat makes a demand for cooling, the zone damper opens
and the cooling equipment begins operating.
Cooling demand is terminated when:
1. All zone demands for cooling are terminated.
2. The demand has exceeded the Heat • Cool changeover time limit (20
minutes) while a heat demand exists.
When cooling demand is terminated, a five minute minimum off time delay is
initiated.
Second stage cooling is energized when the discharge air temperature is 7°F
higher than the set point of the cooling staging temperature settings.
When a zone thermostat makes a demand for heating, the zone damper opens
and heating equipment begins operating. Heating demand is terminated when:
1. All zone demands for heating are terminated.
2. The demand has exceeded the Heat • Cool changeover time limit (20
minutes) while a cooling demand exists.
When heating demand is terminated, a five minute minimum off-time delay is
initiated.
Second-stage heating is energized if the discharge air temperature is lower
than the set point of the heating staging temperature set point.
28

Cooling Operation

Heating Operation