Viessmann Vitocal 222-G User Manual page 199

Vitocal 300-A/350-A
7.2 Vitocal 300-A, one heating circuit/cooling circuit without mixer and DHW heating
ID: 4605092_1304_05
Application range
Detached house with uniform utilisation patterns, underfloor heating
system and cooling demand. Size the DHW cylinder in accordance
with current standards and requirements.
Main components
■ Vitocal 300-A, type AWCI or AWO, with Vitotronic 200, type WO1B
■ One heating circuit without mixer
■ DHW cylinder Vitocell 100-V, type CVW 390 litres
Requirements
The minimum flow rate of the heat pump must be safeguarded by sec-
ondary pump 6 and overflow valve oW. The heating line and overflow
valve must be matched up.
Note
In type AWCI, circulation pump for cylinder heating 5 is replaced by
an internal and fully wired 3-way diverter valve.
Central heating by heat pump
Heat pump 1 starts if the actual temperature captured by the return
temperature sensor in heat pump 1 is lower than the set temperature
selected at control unit 2.
Heat pump 1 supplies the heating circuit with heat. Control unit 2
of heat pump 1 regulates the heating water flow temperature and
thereby the heating circuit. Secondary pump 6 delivers the heating
water either to DHW cylinder eP or to heating circuit oP.
The flow rate within the heating circuit is regulated by opening and
closing the valves at the underfloor heating system distributor.
Heat pump 1 and secondary pump 6 are switched off once the
actual return temperature at the return temperature sensor exceeds
the temperature set at control unit 2.
Required parameter settings
ID: 4605092_1304_05
Parameter
7000
7
71FE
7100
7101
7103
2003
VIESMANN
204
(cont.)
Value Function
2 With heating circuit A1/HC1, DHW cylinder (delivered condition)
1 Enable active cooling
3 Active cooling
1 Cooling via heating circuit A1/HC1
180 Min. flow temperature, cooling
1 Vitotrol 200A remote control activated for heating circuit A1/HC1
DHW heating by heat pump
In the delivered condition, DHW heating by heat pump 1 is given
priority over the heating circuit and takes precedence at night.
The heat demand is issued via cylinder temperature sensor eQ and
control unit 2, which controls circulation pump for cylinder heating
5 in conjunction with secondary pump 6. The control unit raises the
flow temperature to the value required for DHW heating.
DHW reheating can be provided by an electric booster heater (e.g.
immersion heater inside the DHW cylinder or instantaneous heating
water heater 4 in the flow). The control unit switches 3-way diverter
valve/pump 5 to the heating circuit when the actual temperature at
cylinder temperature sensor eQ exceeds the set value selected at the
control unit.
Instantaneous heating water heater (accessories)
The flow temperature can be raised with instantaneous heating water
heater 4 (accessories). This serves to cover peak loads, e.g. when
drying buildings or screed, or in mono energetic systems.
Central cooling by heat pump active cooling
The fan starts as soon as outside temperature 3 or room temperature
iZ/oQ exceeds the set room temperature by the hysteresis selected
at the control unit.
The heat pump supplies heating circuit oP with cold water.
Control unit 2 regulates the cold water flow temperature and thereby
the cooling function of the heating circuit in line with the selected cool-
ing parameters.
The set flow temperature at flow temperature sensor oE of the heating
circuit in cooling mode is assured and monitored accordingly by control
unit 2.
Possible condensate that may form as a result of changing ambient
conditions is captured by contact humidistat iE and active central
cooling is switched off via the heat pump.
Note
All lines where the cold water temperature can fall below the dew point
should be insulated so that they are vapour diffusion-proof.
In cooling mode, safeguard the minimum flow rate in the secondary
circuit. Open valves on the heating circuit distributor fully and perma-
nently or install an overflow valve.
System examples