STIEBEL ELTRON wpf 20 User Manual

10 | WPF 20/27/40/52/66 WWW.STIEBEL-ELTRON.COM
Mixing ratio
The brine concentration varies when using a ground collector or
a geothermal probe as a heat source.
The mixing ratio can be found in the table below.
Ethylene glycol Water
Geothermal probe 25% 75%
Geothermal collector 33% 67%
After filling the system with brine and prior to commissioning.
open the fill & drain valve until brine runs out of it. No water must
remain in the pipe run to the fill & drain valve.
10.3.3 Check the brine concentration:
f Determine the density of the ethylene glycol/water mixture,
e.g. with a hydrometer.
Using the actual density and temperature, you can check the actual
concentration in the diagram.
1,10
1,09
1,08
1,07
1,06
1,04
1,03
1,02
1,01
1,00
0,99
0,98
-20 0 20 40 60 80 100
50 Vol.-%
0
1,05
40
33
30
25
20
10
A
26�03�01�1914
X Temperature [°C]
Y Density [g/cm³]
A Frost protection [°C]
Note
The quoted details refer to ethylene glycol (see
"Specification").
10.3.4 Checking the flow rate (during heat pump
commissioning)
Check the flow and return temperatures of the heat source. For
this. determine the temperature differential by measuring the
temperature under the thermal insulation on both flow and return
pipes of the heat pump.
The diagram shows the temperature spread at the nominal flow
rate.
6
1
2
5
4
3
2
1
-5 0 5 10 15 20
84�03�01�0017
Y Temperature differential
X Source inlet temperature
1 Brine = heating flow 35 °C
2 Brine = heating flow 50 °C
!
Risk of damage!
At the WPM II. set parameter source in the commissioning
list to "Ethylene glycol". otherwise the frost stat would
stop the heat pump at temperatures below 7 °C. The
source inlet temperature can be checked on the display
of the WPM II under the Info Temp. system parameter.
10.4 Installation of the heat consumer system
The layout of the connection material on the heating side has to
be done according to the evaporator and condensator materials
(Technical Datas) to avoide corrosion.
Implement the heat consumer system (heating circuit) in
accordance with current technical rules. For safety equipment in
heating systems. consult the DIN EN 12828.
Ensure the correct connection of the heating flow and return.
Protect the heating water lines against frost and moisture (only
in case of external installation). Protect flow and return lines
in external installations with an adequate amount of thermal
insulation against frost and by routing them inside a conduit
against moisture
.
Maintain the required insulation thickness in accordance with the
Heating System Order [or local regulations].
The integral frost protection control (inside the heat pump). that
automatically starts the circulation pump in the heat pump circuit
at + 8 °C and thereby safeguards circulation in all water-bearing
components. offers additional frost protection. The heat pump is
started automatically no later than when the temperature inside
the buffer cylinder drops below + 5 °C.
Prior to connecting the heat pump. check the heating system for
leaks. flush it thoroughly. fill and carefully vent it.
INSTALLATION
INSTALLATION

STIEBEL ELTRON wpf 20 Specifications

General

Brand	STIEBEL ELTRON
Model	wpf 20
Category	Heat Pump
Language	English