4.5System design5
75
VITOSOL
4.5 System design5
Dual mode DHW heating and central heating backup with combination cylinder or with a heating water
calorifier with relayering system, with Vitosolic200
DHW heating without solar energy
The top part of the cylinder is heated by
the boiler. The integrated instantaneous
water heater/standby reservoir is heated
by the surrounding hot water of the
calorifier.
The cylinder thermostat with cylinder
temperature sensor 6 of the boiler
control unit switches cylinder loading
pump 7
.
DHW loading with solar energy
Solar circuit pump 4 is switched ON, if a
temperature differential greater than
start−up temperature differential T
on
is
measured between collector temperature
sensor 2 and cylinder temperature
sensor 3.
Pump 4 is switched OFF when
H the actual temperature falls below
shutdown temperature differential T
off
H the electronic temperature limit (safety
shutdown at 90 ºC) set at the control
unit or that set at the high limit safety
cut−out (if required) is exceeded.
The entire combination cylinder will be
heated by the solar heating system, if the
solar radiation is sufficient for heating the
domestic hot water.
The top part of the combination cylinder
will only be reloaded by the boiler, if the
temperature of the water falls below the
temperature set at the boiler control unit.
If the solar irradiation is insufficient, the
DHW in the bottom part of the
combination cylinder will be pre−heated
by solar energy whilst the top part is
raised to the required temperature by the
boiler.
Central heating with solar energy
Three−way diverter valveqP is set to
"ABA", if the temperature differential
between temperature sensor8 and
heating circuit return temperature
sensor9 is greater than start−up
temperature differential T6
on
; the
heating return water will be routed to the
boiler via the combination cylinder.
If the temperature of the pre−heated
return water is insufficient, the boiler
re−heats the water to the necessary flow
temperature level. The diverter valve will
be set to AB−B, if the actual temperature
falls below shutdown temperature
differential T6
off
.
5822135 GB