H Pressure Drop Of The Solar Heating System - Viessmann Vitosol
100 Technical Manual

Pressure drop of the solar heating system
The total pressure drop of the solar
heating system consists of:
H Collector resistance values,
H Pipe resistance values,
H Individual resistance values of the
fittings and
H Resistance values of the heat exchanger
in the DHW cylinder.
For calculation of total pressure drop
H Collectors connected in series:
Total pressure drop = sum of the
individual pressure drops
H Collectors connected in parallel:
Total pressure drop = individual
pressure drop (assuming all individual
pressure drops are equal).
Pressure drop of solar heating system flow and return pipes (per metre pipe length)
(relative to water)
200
100
70
50
30
20
10
5
3
20 30 40
3 5 6 10
Flow rate in l/min
VITOSOL
3.2 Sizing pipe diameters and circulation pump
Hydraulically, the collectors can be
connected as follows:
Vitosol 100, type s/w 2.5
Up to 10 collectors can be joined to form
a single collector array.
Up to 2 collector arrays can be connected
in series.
For low flow operation, we recommend
alternate connection, see page 43 and 44.
Vitosol 200
2
Up to 6 m absorber surface area can be
connected to form one collector array.
This can give both a parallel and a series
circuit (pressure drops for different
combinations can be ascertained directly
from the flow diagram).
2
Max. 2 × 6 m absorber surface area for
series connection.
Vitosol 250
Up to six collectors can be electrically
connected to form a single collector array.
Vitosol 300
2
Up to 6 m absorber surface area can be
joined to form a single collector array.
This creates a series circuit (pressure
drops for different combinations can be
ascertained directly from the flow
diagram).
49