Iharmony® Zoning Operations; Feature); Heating / Cooling Changeover; Damper Operation - Lennox iComfort E30 User Manual

iHarmony Zoning Operations (S30 Only Feature)
®
This section is applicable only to iComfort S30 controlled systems that have
the iHarmony zoning system installed. Works only with Lennox communicating
systems.
For user setting options available from home the home screen, go to menu
> settings > iHarmony zoning. For additional information, go to "iHarmony
Zoning (S30 Only Feature)" on page 15.

Heating / Cooling Changeover

The following is an example of how the system operates during a heating /
cooling changeover.
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:
• Then 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 satisfied the
cooling demand from zone 2.
The system will continue to operate in this matter each time it receives a zone
call that is opposite of the current mode of operation (heating or cooling).

Damper Operation

Cooling Operation Conventional Heat • Cool and Heat Pump Systems
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.
Heating Operation Conventional Heat • Cool and Heat Pump Systems
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.

Dual-Fuel Operation

NOTE: Only Lennox communicating heat pump outdoor units may be used
with a dual-fuel system.
When both a gas furnace and a heat pump are present on the system, the
thermostat uses the balance points to determine which source to use for
heating.
When the outdoor temperature is above the low balance point, the heat pump
is always attempted first before using the gas furnace.
In order to use the gas furnace as a primary heating source (not defrost
tempering) when the outdoor temperature is between the high and low balance
points, the following conditions must occur:
• Heat pump must be used for a minimum of 30 minutes.
• Temperature in the zone not increase by more than 0.5°F.
• Heat pump has not gone into defrost in the 30 minute period.
If any single-zone satisfies the specified conditions, the heat pump will stop
and the gas furnace is used to satisfy all heat calls for the next duration of the
parameter heat pump lockout time. After the heat pump lock out has expired,
the heat pump is again used as the primary heat source on the next call after
the equipment has stopped.

Emergency Heat Operation - Heat Pump Systems

When the Lennox communicating thermostat emergency heat is enabled the
unit will satisfy all heating demand with either gas or electric backup heat.
When the Emergency Heat setting is OFF, the heat pump is used to satisfy
heating demands.

Home Screen Zone Navigation

This will be displayed when the system is configured for zoning or more than
one iComfort thermostat is installed in the home. The iHarmony system can
supports zones 2 through 4. Zone 1 is the actual thermostat itself. By default,
the zones are labeled Zone 1, Zone 2, Zone 3 and Zone 4. There are also four
dots underneath the name that indicates which zone is active on the HOME
screen. Additional dots may be present if a second system is present. The
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