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

General

Pipe installation must be carried out in accordance
with current norms and directives. The HPAC can only
operate up to a return temperature of about 50°C and
an outgoing temperature of about 60°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
(installed as close to the cooling module as possible),
and particle 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
guarantee sufficient flow.

Pipe connection, collector side

The length of the collector hose varies depending on
the rock/ground conditions and on the distribution sys-
tem.
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 pres-
sure 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 mix-
ture of propylene glycol (NOTE! Not ethanol). The mix-
ing 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 sys-
tem, 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.

Pipe connections

HPAC 28
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
expansion vessel (membrane type). If there is a level
vessel this should be replaced. The brine side should
be pressurised to at least 0.5 bar.
The pressure expansion vessel should be dimen-
sioned as set out in the diagram, to prevent operating
disturbances. The pressure expansion vessel covers
the temperature 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
0 100 200 300 400

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 tempera-
tures, a convection fan with drip tray and drain con-
nection is to be installed.
GB
21
Brine
Köldbärar
volume
volym
l
500 600 700 800 900 1000