Pipe Connections; General; Pipe Connections, The Building's Distribution System; Pipe Connection, Collector Side - Nibe HPAC 28 Instrucciones De Instalación Y Mantenimiento

Pipe connections

General

Pipe installation must be carried out in accordance with
current norms and directives. The HPAC can only ope-
rate up to a return temperature of about 50°C and an
outgoing temperature of about 65°C from the heat
pump. Since the heat pump is not equipped with shut-
off valves, such valves must be fitted outside of the heat
pump to make future servicing easier.
The fluid in the building's distribution system is the same
as in the ground/rock collector, if no separating heat
exchanger is used.
Pipe connections, the building's distribution
system
The heat pump is connected to the HPAC and, where
applicable, hot water heating.
Pipe connections are made at the bottom and top of the
HPAC. All required safety devices, shut-off valves (instal-
led as close to the cooling module as possible), and par-
ticle filter (supplied with the heat pump) are to be fitted
in such a way that the HPAC is also protected.
When connecting to a system with thermostats on all
convectors, either a relief valve must be fitted, or else a
number of the thermostats must be removed to guaran-
tee sufficient flow.

Pipe connection, collector side

The length of the collector hose varies depending on the
rock/ ground conditions and on the distribution system.
When installing the collector hose ensure it rises con-
stantly towards the heat pump to avoid air pockets. If
this is not possible, install high points to vent the air.
The distribution system must be fitted with two pressure
expansionvessels.
All the system's pipes are to be condensation insulated
except the pipes to the hot water heater.
If the temperature of the brine system can fall below
0°C this must be protected against freezing through the
mixture of propylene glycol (NOTE! Not ethanol). The
mixing ratio should be approximately 25 % propylene
glycol and the remainder water. As a guideline for the
volume calculation, use 1 litre of ready mixed brine per
meter of collector hose, (for 40 x 2.4 PN 6.3 PEM hose).
The installation should be marked with the antifreeze
used.
Shut-off valves should be installed as close to the heat
pump as possible. Fit a particle filter to the incoming
pipe.
In the case of connection to an open groundwater
system, an intermediate frost-protected circuit must be
provided, because of the risk of dirt and freezing in the
evaporator. This requires an extra heat exchanger. Also,
the groundwater flow needs to be large enough for all
components.
NOTE!
This system solution means that the brine
will also circulate through the heating
system. Check that all component parts are
designed for the brine in question.

Pressure expansion vessel

The collector circuit should be fitted with a pressure ex-
pansion vessel (membrane type). If there is a level vessel
this should be replaced. The brine side should be pressu-
rised to at least 0.5 bar.
The pressure expansion vessel should be dimensioned as
set out in the diagram, to prevent operating disturbanc-
es. The pressure expansion vessel covers the temperatu-
re range from -10 °C to +20 °C at a pre-pressure of 0.5
bar and the safety valve's opening pressure 3 bar. The
brineside should normally be pressurised to between 1.0
and 1.5 bar.
Pressure expansion vessel
Tryckexpansionskärl
l
50
40
30
20
10
0
0 100 200

Condensation insulation

Pipes and other cold surfaces must be insulated with
diffusion-proof material to prevent condensation.
Where the system may be operated at low temperatu-
res, a convection fan with drip tray and drain connec-
tion is to be installed.
HPAC 28
Pipe connections
300 400 500 600 700 800 900 1000
GB
Brine
Köldbärar
volume
volym
l
23