System Example 6 - Viessmann VITOSOLIC 200 Installation And Service Instructions Manual

System example 6

DHW heating with freshwater module and central heating backup
with heating water buffer cylinder
Main components
■ Viessmann solar collectors
■ Freshwater module
■ Heating water buffer cylinder
Vitocell 140-E or Vitocell 160-E
■ Vitosolic 200
■ Solar-Divicon
■ Wall mounted oil/gas boiler or oil/gas
boiler
Function description
Freshwater module qP heats DHW
when hot water is drawn. The energy
supply to freshwater module qP is pro-
vided via heating water buffer cylin-
der rP. Buffer cylinder rP is heated by
the solar thermal system or, in the upper
area, by boiler 1.
The heated DHW is heated by freshwa-
ter module qP according to the instanta-
neous water heater principle. An internal
pump transports the heating water from
heating water buffer cylinder rP into the
freshwater module qP. This heats the
DHW in the heat exchanger of the fresh-
water module qP according to the coun-
tercurrent principle. This is regulated by
the internal control unit of the freshwater
module qP.
When utilising the freshwater module
with integral DHW circulation pump, the
three-way diverter valve qQ in conjunc-
tion with sensors qE and S4 qW of the
freshwater module can be regulated by
its control unit to provide an optimum
stratification of the return water into the
heating water buffer cylinder rP.
DHW heating with solar energy
Solar circuit pump R1 eE starts and
heating water buffer cylinder rP is
heated up if the temperature differential
between collector temperature sensor
S1 eQ and cylinder temperature sensor
S2 rQ is greater than the start tempera-
ture differential ΔTon.
Solar circuit pump R1 eE is stopped in
accordance with the following criteria:
■ Actual temperature dropping below
the stop temperature differential ΔToff
■ Exceeding the electronic temperature
limit of control unit eZ (max. 90 °C)
■ Reaching the temperature selected at
high limit safety cut-out rR (if installed)
Entire heating water buffer cylinder rP is
heated by the solar thermal system if the
insolation is adequate.
The upper part of heating water buffer
cylinder rP will only be reheated by
boiler 1 if the actual water temperature
falls below the set temperature selected
at boiler control unit 2.
DHW heating without solar energy
The upper area of heating water buffer
cylinder rP is heated by boiler 1. The
cylinder thermostat with cylinder temper-
ature sensor 3 of boiler control unit
2 regulates circulation pump for cylin-
der heating 4.
System examples
41