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DOK41 HOIAO C0DEN · FD 9912
11
Air-to-water heat pump 9 - 12 kW
English
The following points must be observed when filling the system:
Untreated filling water and make-up water must be of
drinking water quality
(colourless, clear, free of sediments)
Filling water and make-up water must be filtered (max.
pore size 5 µm).
Scale formation in domestic hot water heating systems cannot
be avoided, but in systems with flow temperatures below 60 °C,
the problem can be disregarded. With high-temperature heat
pumps and in particular with bivalent systems in the higher per-
formance range (heat pump + boiler combination), flow tem-
peratures of 60 °C and more can be achieved. The following
standard values should therefore be adhered to with regard to
the filling and make-up water according to VDI 2035, sheet 1:
The total hardness values can be found in the table.
Abb. 6.1:Guideline values for filling and make-up water in accordance with
VDI 2035
For systems with an above-average specific system volume of
50 l/kW, VDI 2035 recommends the use of fully demineralised
water and a pH stabiliser to minimise the risk of corrosion in the
heat pump and heating system.
!!
ATTENTION!
With fully demineralised water, it is important to ensure that
the minimum pH value of 7.5 (minimum permissible value for
copper) is complied with. Failure to comply with this value can
result in the heat pump being destroyed.
Minimum heating water flow rate
The minimum heating water flow rate through the heat pump
must be assured in all operating states of the heating system. If
the minimum heating water flow rate is not reached, the heat
pump is blocked.
The nominal flow rate is specified depending on the max. flow
temperature in the device information and must be taken into
account during planning. For return temperatures under 30 °C,
the flow must be designed for the nominal conditions.
The specified nominal flow rate (see “Device information”) must
be assured in all operating statuses. The installed flow rate
monitoring is used only for switching off the heat pump in the
event of an unusual and abrupt drop in the heating water flow
rate and not to monitor and safeguard the nominal flow rate.
Frost protection
A method of manual drainage should be provided for heat
pumps which are exposed to frost. The frost protection func-
tion of the heat pump manager is active whenever the heat
pump manager and the heat circulating pump are ready for op-
eration. The system must be drained if the heat pump is taken
out of service or in the event of a power failure. The heating cir-
cuit should be operated with a suitable frost protection if heat
pump systems are implemented in buildings where a power
failure can not be detected (holiday home).
6.4 Temperature sensor connection
The following temperature sensors are already installed or must
be installed additionally:
Outside temperature (R1) is (NTC-2)
Return temperature (R2) installed (NTC-10)
Demand sensor (R2.2) installed (NTC-10)
Flow rate monitoring with flow sensor (R3.1) installed
(PT1000)
Domestic hot water temperature (R3) installed (NTC-10)
6.4.1 Sensor characteristic curves
The temperature sensors to be connected to the heat pump
manager must correspond to the values specified in the table.
6.4.2 Mounting the outside temperature
sensor
The temperature sensor must be mounted in such a way that all
weather conditions are taken into consideration and the meas-
ured value is not falsified.
Mount on the external wall on the north or north-west side
where possible
Do not install in a "sheltered position" (e.g. in a wall niche or
under a balcony)
Not in the vicinity of windows, doors, exhaust air vents, ex-
ternal lighting or heat pumps
Not to be exposed to direct sunlight at any time of year
Total heat
output in
kW
Total
Alkaline earths
in mol/m³ and/
or mmol
Specific system volume
(VDI 2035) in l/kW
< 20
20 < 50
50
Total hardness in °dH
< 50
2.0
16.8
11.2
< 0.11
50 - 200
2.0
11.2
8.4
200 - 600
1.5
8.4
< 0.11
> 600
< 0.02
< 0.11
1
1. This value lies outside the permissible value for heat exchangers
in heat pumps.
Temperature in °C
-20
-15
-10
-5
0
5
10
NTC-2 in k
14.6
11.4
8.9
7.1
5.6
4.5
3.7
NTC-10 in k
67.7
53.4
42.3
33.9
27.3
22.1
18.0
PT 1000 in k
0.92
0.94
0.96
0.98
1.0
1.02
1.04
15
20
25
30
35
40
45
50
55
60
2.9
2.4
2.0
1.7
1.4
1.1
1.0
0.8
0.7
0.6
14.9
12.1
10.0
8.4
7.0
5.9
5.0
4.2
3.6
3.1
1.06
1.08
1.1
1.12
1.14
1.16
1.18
1.2
1.22
1.24
Dimensioning parameter sensor lead
Conductor material
Cu
Cable-length
50 m
Ambient temperature
35 °C
Laying system
B2 (DIN VDE 0298-4 /
IEC 60364-5-52)
External diameter
4-8 mm