Carel k.Air, User Manual, Page: 80 / 192

80
Functions
k.air +030220981 rel. 1.2 - 01.12.2020
The fi lters generate an alarm signal only, visible from the alarm menu and the dedicated fi lter alarm digital output. Select the
fi lters installed on the unit on screen Ac16, select the channels used by the fi lters in the IO confi guration menu; for HEPA fi lters
confi gure the type of transducer and range,
On screen G001 an alarm delay can be entered to be applied individually to each fi lter alarm and, for HEPA fi lters, the alarm
threshold value can be set, determined by the pressure transducer reading across the fi lter.
R if D escription D ev Min Max UoM D ir Modbus BAC net
F ILTE RS
G001 Delay time for dirty fi lter by DIN 10 0 999999 s R/W HR1560 PIV3061
HEPA fi lter alarm threshold 100.0 -9999.0 9999.0 % R/W HR1562 AV3062
Tab. 9.aq
9.19 A ir quality control
Air quality control involves the use of the CO2 sensor, and works by increasing the supply of fresh air. Consequently, it can only
be enabled and implemented if there is at least one modulating actuator, either a damper or a fan. The possible combinations
are shown below:
Modulating actuator 1 Modulating actuator 2 C ontrol
Fresh air damper - The air quality control function increases the supply of fresh air
by further opening the fresh air damper, closing the recirculation
damper or acting on both together. All within the control limits set
for the dampers.
Mixing damper -
Modulating fresh air and
mixing dampers -
- Modulating fi xed-speed fan The air quality control function increases the supply of fresh air by
increasing fan speed, from the fi xed value to the maximum limit.
- Modulating fan with fl ow- rate or
static pressure control The air quality control function increases the supply of fresh air by
increasing the fan speed, due to an increase in the fl ow-rate set
point or static pressure set point, starting from the nominal set
point up to the maximum setting (specifi c parameter).
At least one modulating damper Modulating fan Compared to the previous settings, which are single- point, in this
case sequential PID control is enabled. This involves a fi rst stage,
which modulates the opening of the dampers, and a second
stage, which modulates the fan speed. In each of these stages, the
behaviour is the same as for single-point control, and therefore it is
possible to combine one or more modulating dampers with mo-
dulating fan control, without a diff erential pressure sensor or more
advanced functions, through cascade control of the air fl ow-rate.
Tab. 9.ar
R if D escription D ev Min Max UoM D ir Modbus BAC net
FANS
Ba03 Enable air quality regulation for fans FALSE 0 1 - R/W CS245 BV245
Enable air quality regulation for fresh air OR mixing damper FALSE 0 1 - R CS289 BV289
Air Quality - Fans PID parameters - Proportional gain 1.0 0.0 999.9 - R/W HR1492 AV2993
Air Quality - Fans PID parameters - Integral time 60 0 999 - R/W HR1493 PIV2994
Tab. 9.as
R if D escription D ev Min Max UoM D ir Modbus BAC net
DA M P E RS
Ca03 Enable air quality regulation for fresh air OR mixing damper FALSE 0 1 - R/W CS289 BV289
Air Quality - Dampers PID parameters - Proportional gain 1.0 0.0 999.9 - R/W HR1640 AV3135
Air Quality - Dampers PID parameters - Integral time 60 0 999 - R/W HR1641 PIV3136
Tab. 9.at
Note:
• Both air quality control and freecooling tend to increase the supply of fresh outside air. For this reason, when both are active,
the dampers are controlled based on the higher of the two requests.
• If the fl ow- rate or static pressure set point is set to the maximum allowable value, air quality control will no longer have any
eff ect on the fans, as there is no more margin for modulation.