Viessmann VITOLADENS 300-W Technical Manual page 56

Design information
Boiler circuit
The circulation pump in the Vitoladens must be able to supply the
required water volume against the (mostly low) pressure drop of the
boiler circuit; the pressure drop of the low loss header is negligible.
Subject to the water volume circulating in the generator circuit, the
respective residual head may be determined for the sizing of the inter-
nal pipe diameters using the pump diagram; alternatively the variable
speed pump can be adjusted accordingly.
Heating circuit
The central heating pumps to be installed on site must be able to
deliver the water volume in the heating circuits against their pressure
drop; size the pumps accordingly.
Principle of operation
T1
V primary
V secondary
T2
V Heating water volume in the boiler circuit (approx. 10 -
primary
30 % less than V
V Heating water volume heating circuit
secondary
T Flow temperature boiler circuit
1
5
T Return temperature boiler circuit
2
T Heating circuit flow temperature
3
T Heating circuit return temperature
4
Q Amount of heat supplied by the boiler
primary
Q Amount of heat transferred by the heating circuit
secondary
V < V
primary secondary
T > T
1 3
≃ T
T
2
4
Q = Q
primary secondary
Note
Suitable thermometers in the flow and return of the low loss header
make adjustments easier.
Low loss header in conjunction with Divicon
For further information, see page 31.
Low loss header
– R ¾
– R 1
– R 1¼
Divicon heating circuit distributor
– R ¾
– R 1
– R 1¼
VIESMANN
56
(cont.)
T3
T4
)
secondary
Max. flow rate
3
in m /h
4.5
4.5
7.5
1.0
1.5
2.5
599
120 120
A
B
C
HV
HR
HR Heating return
HV Heating flow
790
120 180 120 180 120
HV
HR Heating return
HV Heating flow
Low loss header from the Vitoset range
See "Vitoset" pricelist
VITOLADENS 300-W/VITOLADENS 333-F
HR