Technical data

i-KI(R) MTD
i-KI(R)_MTD_0031_201110_EN HFC 410A
7
SYSTEM PUMP OPERATION
When reaching the system water temperature set point, the com-
pressor stops and the system pump is activated periodically, so
as to minimise energy consumption and ensure correct measure-
ment of the water temperature. The pump on and off times can
be set using a parameter, according to the type of system.
In systems with fan coils, the time between one sniffing cycle
and the next should be reduced in order to avoid excessive
cooling of the water, in heating operation, and if and if the sys-
tem water content is equal to the minimum value shown in the
paragraph on “Minimum and maximum system water content”.
DOMESTIC HOT WATER PRODUCTION
The controller manages domestic hot water production using a
3-way valve installed outside of the unit, deviating the flow of
hot water to the DHW storage tank, which must be suitably
sized according to the type of usage.
Production is enabled when the water temperature inside the
DHW storage tank (probe BT8) is less than the DHW set point.
The production of domestic hot water is guaranteed in both
summer and winter, according to the operating limits shown in
this manual. If heat pump operation is expected outside of the
limits, consider using a supplementary source of heat, managed
directly by the controller.
An electric heater should be installed inside the DHW storage
tank to ensure the temperature does not fall below 10°C in the
event of extended periods of heat pump inactivity (standby).
LEGIONELLA PREVENTION FUNCTION
The Legionella prevention function ensures the elimination of
the Legionella bacteria that reside in domestic water storage
tanks. The temperature and duration of the Legionella preven-
tion cycles to eliminate bacteria are typically:
• 2 minutes > 70°C
• 4 minutes > 65°C
• 60 minutes > 60°C
The Legionella prevention cycles are managed directly by the
controller, enabling the heater in the domestic hot water storage
tank domestic, with the possibility to set the duration, tempera-
ture, day and time.
AUXILIARY RESOURCES
System operation can be distinguished as monovalent, all-elec-
tric or bivalent. The controller can activate the external source
to achieve one of the functions listed above.
Monovalent operation
For monovalent operation, the heat pump has to meet the entire
demand of the building. There may be excessive heating capac-
ity of the heat pump above all when the outside air temperature
is above zero, as well as high power consumption.
Make sure the home’s energy meter is correctly sized.
Solution suggested for new homes.
All-electric operation
In all-electric operation the heat pump is integrated with an
electric heater to meet the entire demand of the building.
The electric heater is activated below certain outside tempera-
tures so as to satisfy demand in the building that the heat pump
cannot manage on its own.
Considering the reduced number of hours of heat pump opera-
tion at low outside temperatures during the winter period, oper-
ation of the supplementary heater will also be reduced, and
consequently power consumption will be negligible.
Therefore the system’s seasonal energy efficiency remains
unchanged.
This solution is suggested for new homes and lower invest-
ments than monovalent heat pumps.
Bivalent operation
In the case of bivalent operation the heat pump meets the
needs of the building down to a certain outside temperature,
called the bivalence point.
Below the bivalence point the heat pump switches off and only
the auxiliary source (e.g. boiler) provides heat for the building.
This solution is ideal for traditional systems and renovations.
0
2
4
6
8
10
-15 -10 -5 0 5 10 15 20
Pt [kW]
Outside Air Temp. [°C]
Heat Capacity
P.d .C
Elec. Heater
Heat pump
Winter Load
0
2
4
6
8
10
-15 -10 -5 0 5 10 15 20
Pt [kW]
Outside Air Temp. [°C]
Heat Capacity
P.d .C
Boiler
Heat pump
Winter Load
0
2
4
6
8
10
12
14
-15 -10 -5 0 5 10 15 20
Pt [kW]
Outside Air Temp. [°C]
Heat pump
Heat Capacity
P.d.C
Winter Load