Daikin UATYA-B, Operation Manual

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Service manual Daikin R32 Rooftops UATYA-B
ESIE21-02 – 2021.03
3.13.7 Free heating
If the external air temperature value is favourable, the heating demand in the room is fulfilled with air changing, either totally
or partially.
The unit configuration to manage the free heating function is the same as for free cooling.
The parameters concerned are shown in the table.
The values of the parameters are representative. In specific cases, different values can be set.
Parameter Value UM Description
DA1 1 - All dampers - Management mode
DA5 0 - External air - FC / FH - Enabling mode
DA6 1.0 °C
External air - FC / FH - Temperature-based control - Temperature diff. required for
enabling
DA7 1.0 kJ/kg External air - FC / FH - Enthalpy-based control - Enthalpy diff. required for enabling
DA10 2.0 °C External air - Winter FH - Offset for regulation
DA11 2.0 °C External air - Winter FH - Diff. For regulation
DA12 30 % External air - FC / FH - Min opening
DA13 100 % External air - FC / FH - Max opening
A graphical representation is shown below.
DA10 DA11
DA13
DA12
%
STH1
TeSdR °C
Fig. 27 Damper command in free heating mode
In addition to the parameters listed in the table, the abbreviations in the graph are:
- TeSdR = temperature sensed by probe in return line
- % = opening signal percentage for external/exhaust air.
If the external air temperature is higher than the temperature in the return line plus the value set in parameter “DA6”, the
unit is enabled for operation in free heating mode.
If operation in free heating mode is enabled and the reference air temperature for thermoregulation is lower than the
setpoint value in parameter “STH1” minus the offset value stored in parameter “DA10”, the controller increases the external
air percentage within the differential set in parameter “DA11”.
The setpoint ranges between the min. value stored in parameter “DA12” and the max. value in parameter “DA13”.
Damper opening may be limited with respect to the max. value set in parameter “DA13” as a result of problems with tempe
-
rature or pressure, as described in the chapter on limitations.
Thanks to the factory set parameters (“DA10” = -2; “DA11” = 2), the free cooling function keeps 100% exter -
nal air until the setpoint is achieved.
When the reference air temperature is higher than the setpoint value, the free heating function reduces the
opening of the outside air damper to the min. value.
3 Software functions