CIAT FLOWAY ACCESS User Manual

3.9 - Free Cooling
Free cooling is used to cool the building when the outdoor temperature is lower than that inside the building. This operating mode
is used when the following conditions are met:
• Function activated in P150 parameters (only if control takes place on the return air or room temperature).
• Cooling requirement: the PID outlet must be greater than 0%
• The di󰀨erence between the regulated temperature (measured return or room) and the fresh air must be su󰀩cient: fresh air
temperature < regulated temperature – P206 (3°C factory value).
• The fresh air temperature is above the "free cooling temperature low limit" (P207)
When operating in free cooling mode, the supply air temperature is not controlled, and the recovery unit and coil are shut down. It is
important to congure a fresh air temperature low limit which is su󰀩ciently high to ensure no discomfort is caused.
150 Free cooling control
206 Free cooling and night cooling operating di󰀨erential compared to the controlled temperature
207 Temperature low limit for free cooling and night cooling
3.10 - Night cooling
The regulated temperature must be the return or room air value. The fans control must be based on ow rate. Night cooling is used
to cool the building using the colder night air
In this case, when night cooling is active, the ventilation ow rate setpoint is the "night cooling" ow rate (P212 and P213)
Several conditions must be met to activate night cooling:
• The function must be activated by the parameter P151
• The controller is located in a "night cooling" time slot or it is forced via the CMS.
• Cooling requirement: the regulated temperature must be greater than the night cooling temperature setpoint P210.
• There must be su󰀩cient di󰀨erence between the regulated temperature and the fresh air: fresh air temperature < regulated
temperature – P206 (3°C factory value).
• The fresh air temperature is above the "night cooling temperature low limit" (P207)
Periodic restarts: if one of the conditions for activation of night cooling is not veried (fresh air temperature, night cooling di󰀨erence,
or cooling requirement), the unit stops.
The fans will be restarted at the night cooling ow rate for 5 minutes each hour, and night cooling will be reactivated if all the
conditions are veried. Otherwise, the AHU will stop again. Furthermore, if the fresh air temperature is 3°C below P207 (Temperature
low limit for free cooling and night cooling) for more than 5 seconds, the restart must be stopped (to prevent the frost protection
fault triggering).
151 Night cooling control
206 Free cooling and night cooling operating di󰀨erential compared to the controlled temperature
207 Temperature low limit for free cooling and night cooling
210 Control setpoint in night cooling mode
212 Air intake fan ow rate setpoint in night cooling mode
213 Air extraction fan ow rate setpoint in night cooling mode
3.11 - CO
2
air quality
If there is a CO
2
sensor in the exhaust air ow and the FMAs are ow rate set, it is possible to activate the air quality function
(P152). This function calculates an IAQ (Indoor Air Quality) (P382) requirement thanks to a proportional controller (P217) so that
the CO
2
concentration setpoint (P216) can be monitored.
100 %
0 %
Air quality setpoint P216
Air quality proportional band
P217
IAQ requirement
Air quality
P331
3 - FEATURES
EN-21 FLOWAY ACCESS

CIAT FLOWAY ACCESS Specifications

General

Brand	CIAT
Model	FLOWAY ACCESS
Category	Air Handlers
Language	English