Zehnder EASY 5.0
57
19.6. QUATTRO controller
The QUATTRO controller is a closed-loop air volume controller based on the CO
2
concentration at the return.
The speed of the supply and return air fans is adjusted individually and continuously
according to an adjustable law in order to maintain a CO
2
concentration measured on the
return air at an acceptable level for the comfort of the occupants while minimising the
energy consumption from ventilation.
The difference compared to the DIVA controller is that here the fan speed setpoint is controlled in a closed loop to
obtain an air volume setpoint. The QUATTRO controller allows greater precision because the air volume is known and
therefore better controlled. It does not depend on the state of clogging of the filters and the minimum volume of the unit
can be managed more precisely.
Factory settings are made to obtain a proportional variation of the fan speed or volume over the range 800 to 1000ppm
CO
2
while remaining within a speed (DIVA) or volume (QUATTRO) modulation range equivalent to the respective ECO
and MAC2 settings.
Z-MASTER-V1122-CSY-INM-Zehnder Easy5.0
Volume flow
Constant volume
flow HS
Constant volume flow LS
Pa
Air volume setpoint
Supply
Air volume setpoint
Return
CO2 se Fan offset
CO2 se Fan offset
Air flow value reflection
Air flow value reflection
Setpoint speed
Setpoint speed
+
+
-
-
PID
PID
TRPS
TRPR
Return air
Fresh air (outdoor)
Exhaust air
Supply air
VAS
VAR
CO2
PID
PID
