System Designs - Viessmann Vitosol
100 Technical Manual

4 System designs

4 System designs
For our climatic zone: Dual systems
In our climatic zone, solar radiation is
insufficient to cover the entire
requirement for domestic hot water or
swimming pool heating, as well as central
heating, by means of solar energy.
How to implement the installation
Over the following pages, we have
described methods of operation and used
design suggestions to illustrate various
installation ideas involving different
equipment specifications. A summary is
provided which lists essential control
equipment.
The temperatures stated are guide values;
other values may be set to meet
particular requirements.
The circulation pumps referred to in these
examples (standard delivery with
Solar−Divicon) are AC pumps.
DHW cylinder backup by the boiler is
suppressed by the Vitosolic 100 or 200,
when the anticipated heat requirement
for DHW heating is expected to be
covered by the solar heating system.
To improve the start−up characteristics of
the system or for systems with several
collector arrays, we recommend
operation with a bypass circuit.
60
Therefore, a solar heating system for
DHW or swimming pool heating and/or
central heating should always be
combined with another heat generator.
Additional function for DHW heating:
According to DVGW W 551/W 552, in
larger systems with a cylinder capacity
above 400 litres, the whole water contents
must be maintained at 60 ºC. The
pre−heating stages above 400 litres must
be heated to 60 ºC once every day.
To meet this requirement, we recommend
that the system is heated up, preferably
late afternoon, to ensure that the lower
part of the cylinder or the pre−heating
stage is cold again following the expected
hot water consumption (in the evening
and the following morning) and can,
therefore, be heated up again by solar
energy.
If operation with bypass pump and
additional function is required, activate
the latter via the time switch of
Vitosolic 200.
In dual systems, for example, an oil or
gas fired boiler supplies the additional
heat required.
¨
Safety instructions
With temperatures higher than
60 ºC, limit the DHW temperature
60 ºC by installing a mixing device,
e.g. a thermostatic mixing valve
(DHW cylinder accessory). The
mixing equipment does not
prevent the risk of scalding at the
tap.
The installation of a mixer tap is
required.
Abbreviations used in the examples
KW Cold water
WW Hot water
RL Return
VL Flow
VITOSOL