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Reco-Boxx ZXR / ZXA / Flat – Operation and maintenance instructions
[03/
2022 ]
Frost protection
Frost protection plate heat exchangers (PX)
In environments where the extract air can occasionally
be humid, the defrosting function can be activated to
protect the heat exchanger from frosting. There are
four strategies: down control of the supply air volume,
modulating by-pass control, modulation of capacity
of a preheating coil, differential pressure measure-
ment (cold climate option). If non of these measures
are effective, the air handling unit can be stopped by
limting the minimal supply air temperature. When the
Frost protection cycle is active, it will be indicated on
the HMI. The configurable temperatures are outdoor
temperatures.
Setting
Settings range
Factory setting
T° Low
1...3 °C
+1,0 °C
T° High
1...5 °C
+5,0 °C
Stop supply
airflow
No
Yes
Yes
Frost protection heating and cooling coils
The water coils are always protected against freezing
by an anti-frost temperature sensor. This sensor is
monted on the surface of the water coil. When the an-
ti-frost protection temperature of the hydraulic coil de-
tects a tempeature lower than 4°C (default), the pump
contact is closed and the 3 way valve is opened 100%
during 15 minutes. If the unit is running, the alarm is
activated immediately. For a water preheating coil, the
frost alarm is delayed by 2 minutes. If frost protection
conditions occur when the air handling unit is OFF, the
alarm is delayed by 5 minutes.
Setting
Settings range Factory setting
Internal heating coil
-10...+10 °C
+4,0 °C
External heating coil
-10...+10 °C
+4,0 °C
External cooling coil
-10...+10 °C
+4,0 °C
Internal preheating coil -10...+10 °C
+4,0 °C
Freecooling
The bypass on the Reco-Boxx product range, can be
configured for freecooling. The main parameters to
activate the free cooling function are the outside tem-
perature (T1) and the extract (room) air temperature
(T2). When there is maximal freecooling possibility the
bypass will be 100% open. The 100% opened bypass
can activate the configurable freecooling airflow.
Setting
Settings range Factory setting
Outdoor T°
0...27 °C
0,0 °C
Extract/Room T°
6...28 °C
22,0 °C
Supply airflow
(l/s, m³/h)
Extract airflow
(l/s, m³/h)
Bypass control
Frost protection
Freecooling
Frost protection &
free cooling
Freecooling
