Daikin ALTHERMA HT Service Manual page 104

Field Setting
[3] Weather dependent set point
First
code
3
When weather dependent operation is active, the leaving water temperature is determined
automatically depending on the outdoor temperature: colder outdoor temperatures will result in
warmer water and vice versa. The unit has a floating set point. Activating this operation will
result in a lower power consumption than use with a manually fixed leaving water set point.
During weather dependent operation, the user has the possibility to shift up or down the target
water temperature by a maximum of 5°C. This "Shift value" is the temperature difference
between the temperature set point calculated by the controller and the real set point. E.g. a
positive shift value means that the real temperature set point will be higher than the calculated
set point.
It is advised to use the weather dependent set point because it adjusts the water temperature to
the actual needs for space heating. It will prevent the unit from switching too much between
thermo ON operation and thermo OFF operation when using the remote controller room
thermostat or external room thermostat.
During this operation, instead of showing the water temperature set point, the controller shows
Note :
the shift value which can be set by the user.
Lo_Ti
Hi_Ti
 [3-00] Low ambient temperature (Lo_A): low outdoor temperature.
 [3-01] High ambient temperature (Hi_A): high outdoor temperature.
 [3-02] Set point at low ambient temperature (Lo_Ti): the target outgoing water temperature
 [3-03] Set point at high ambient temperature (Hi_Ti): the target outgoing water temperature
If by mistake the value of [3-03] is set higher than the value of [3-02], the value of [3-03] will
Note :
always be used.
92
Second
code Setting name
Weather dependent set point
00 Low ambient temperature (Lo_A)
01 High ambient temperature (Hi_A)
02 Set point at low ambient temperature (Lo_Ti)
03 Set point at high ambient temperature (Hi_Ti)
T
t
Lo_A
Target water temperature
T
t
Ambient (outdoor) temperature
T
A
= Shift value
when the outdoor temperature equals or drops below the low ambient temperature (Lo_A).
Note that the Lo_Ti value should be higher than Hi_Ti, as for colder outdoor temperatures
(i.e. Lo_A) warmer water is required.
when the outdoor temperature equals or rises above the high ambient temperature (Hi_A).
Note that the Hi_Ti value should be lower than Lo_Ti, as for warmer outdoor temperatures
(i.e. Hi_A) less warm water suffices.
+ 05
00 Shift value
– 05
Hi_A T
A
Default
value Range Step
–10 –20~5 1
15 10~20 1
70 25~80 1
45 25~80 1
Test Operation
ESIE09-08B
Unit
°C
°C
°C
°C