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1. Heat capacity terminates (if active), a 90 second post heat timer begins.
2. Supply fan speed slows to minimum speed, a 3 minute minimum speed timer begins.
3. VAV Box Relay de-energizes.
4. When the 90 second post heat and 3 minute minimum speed timer expire, modulating air flow
control is enabled, operating mode transitions, and capacity control enables.
Space Temperature Control
Space Temperature control units will also accept a Maximum Heat command via Heat Cool Mode
Request. On this command the Symbio™ 700 will transition to a heat mode while operating the supply
fan at 100% capacity. Heat Cool Mode Status will report Maximum Heat to indicate the mode is active.
Morning Warm-up
Morning Warm-up is an optional feature when heat is configured and can be Enabled or Disabled.
Morning Warm-up is a mode often used during building unoccupied periods and optimal start
applications to rapidly increase the space temperature, as efficiently as possible, before building
occupancy. The outdoor air damper minimum position setpoint will be overridden to 0%, ventilation air is
not provided during Morning Warm-up
For Morning Warm-up to initiate on a transition from Unoccupied to Occupied, Space temperature
control units must be in Heat, Max Heat, Emergency Heat or Auto. Discharge air control units can also
initiate Morning Warm Up on an Off to Occupied transition.
For all equipment types: On a transition from Unoccupied to Occupied or Occupied-Standby, and with a
valid space temperature 1.5° F below the Morning Warm-up Setpoint, morning warm-up operation
initiates. Heat Cool Mode Status reports Maximum Heat if the heat type requires full airflow and VAV
Box Relay binary output will energize (see Maximum Heat for details). Otherwise, heat types that allow
modulating airflow will report Morning Warm Up via Heat Cool Mode Status.
VVDA
The Symbio™ 700 operates in a discharge air control mode delivering heating capacity per Discharge
Air Heating Setpoint Active; this provides flexibility when 100% heat capacity in not desired. Variable air
volume discharge air control units will operate the supply fan per Duct Static Pressure Setpoint if the
installed heat type allows; otherwise, the supply fan operates in a full airflow mode and Maximum Heat
is reported via Heat Cool Mode Status. When 60 minutes expires or when space temperature equals or
exceeds the Morning Warmup Setpoint, Morning Warm Up mode will terminate.
Morning Warm-up mode can also be commanded via Heat Cool Mode Request from a building
automation system or external control. In this case, the unit remains in Morning Warm-up mode
indefinitely until the commanded mode is removed or changed. When the space temperature exceeds
the Morning Warm-up Setpoint, heating capacity is disabled but the supply fan operation continues to
circulate air until the Morning Warm-up command is removed. Heat capacity will re-enable if space
temperature falls 1.5°F below Morning Warm-up Setpoint.
Space Temperature Control
The Symbio™ 700 operates in a space temperature control mode controlling heating capacity to
manage space temperature at the Morning Warm-up Setpoint. The supply fan operates at maximum
speed.
When 60 minutes expire or when space temperature equals or exceeds the Morning Warm-up Setpoint,
Morning Warm-up mode will terminate.
Morning Warm-up mode can also be commanded via Heat Cool Mode Request from a building
automation system or external control. The Symbio 700 controller will continuously control space
temperature to the morning warm-up setpoint until the mode is released or changed.
Pre-Cool
Pre-Cool is a mode often used during building unoccupied periods and optimal start applications to
rapidly decrease the space temperature, as efficiently as possible, before building occupancy. Pre-Cool
Heat Cool Modes
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