Data Sheet for Product

Page 2 of 13 Document No. 588-209
The ventilation PID calculates ventilation demand in occupied mode by measuring the space CO2
and comparing it to the configured CO2 setpoint. The ventilation demand is used by the flow
component to generate a primary air flow setpoint between 0 and the configured maximum cooling
flow.
If both the cooling and ventilation PIDs are generating demand values, then the component with the
larger setpoint value will drive the primary air flow PID. The primary air flow PID maintains the
measured air flow to the larger of these two setpoints by modulating the position of the primary air
damper.
The reheat coil is off.
Perimeter heat is off.
Heating
The heating PID maintains the measured space temperature at the occupied heating setpoint by
modulating perimeter heat, the reheat coil and the primary air flow setpoint. The setpoint varies
between the maximum heating flow and the minimum heating flow. Relative sequencing of
perimeter heat, the reheat coil, and the primary air flow is set according to site specific
requirements.
The ventilation PID calculates ventilation demand in occupied mode by measuring the space CO2
and comparing it to the configured CO2 setpoint. The ventilation demand is used by the flow
component to generate a primary air flow setpoint between 0 and the configured maximum cooling
flow.
If both the heating and ventilation PIDs are generating demand values, then the component with
the larger setpoint value will drive the primary air flow PID. The primary air flow PID maintains the
measured air flow to the larger of these two setpoints by modulating the position of the primary air
damper.
NOTE: Ventilation demand will only operate until the temperature falls a configurable number of
degrees below heating setpoint. If the temperature falls below this configured value, then the
ventilation loop will be disabled, causing the heating PID to be the sole input to the primary air flow
PID.
Unoccupied Mode
The Predator applies unoccupied settings for the space temperature setpoints and the primary air
flow minimum. The typical result is a wide operating band with no HVAC energy consumption, and
heating or cooling applied only at extreme conditions.
Cooling
The cooling PID maintains the measured space temperature at the unoccupied cooling setpoint by
modulating the primary air flow setpoint between the maximum cooling flow and the unoccupied
minimum flow.
The primary air flow PID maintains the measured air flow at the varying setpoint by modulating the
position of the primary air damper.
The reheat coil is off.
Perimeter heat is off.
Heating
The heating PID maintains the measured space temperature at the unoccupied heating setpoint.
Operation of each HVAC device, in response to heating demand is selectable in the unoccupied
mode. The behavior of primary air damper and reheat coil may be individually configured. They
may be forced on, locked out, modulated or cycled according to the required sequence.