5
System description auroSTEP plus 0020077748_FT1
2.2 Cylinder
unit
The auroSTEP plus solar energy system is used for solar
assisted hot water generation. Most of the components
of the compact solar energy system are integrated into
the domestic hot water cylinder unit. The system has a
built-in controller for post heating according to demand
using Vaillant boilers.
The Vaillant VIH SN 350i cylinder units are indirectly
heated solar cylinders supported by solar energy for
supplying hot water.
The cylinders and the pipe coils are enamelled on the
DHW side to ensure long service lives. Each tank has a
magnesium protection anode as a means of corrosion
protection. These protection anodes should be serviced
annually to ensure lasting corrosion protection. The
CFC-free EPS insulation provides the best thermal insu-
lation.
The indirectly heated solar cylinders operate in a closed
system, i. e. the water has no contact with the atmos-
phere. The hot water is pressed out of the cylinder by
the inflowing cold water if a hot water valve is opened.
The solar heat exchanger is located in the lower, cold
area. The relatively low water temperatures in the bot-
tom area ensure optimum heat transfer from the solar
circuit to the storage water even if there is only a low
level of solar radiation.
In the VIH SN 350/3 iP, additional post-heating takes
place when necessary in a second, separate heating cir-
cuit.
Furthermore, an electric heating element (accessory)
can be fitted in the VIH SN 350/3 MiP and VIH SN 350/3
iP solar cylinders to assist the post-heating, so that no
post-heating by means of the boiler is required in sum-
mer operation.
Apart from solar heating, post-heating of the hot water
is effected by means of the boiler or circulating water
heater or by the electric heating element in the upper,
warmer area of the cylinder. The pre-heated volume for
the post-heating is approx. 95 l.
The solar cylinder is equipped with a circulation pump
for optimum adjustment to the required circulating vol-
ume and the pump output.
The regulation of the nominal flow rate is effected by
means of the controller and does not need to be set
manually.
2.3 Construction
and
function
The Vaillant auroSTEP plus solar energy system is a
thermal solar energy system for generating hot water.
When the system is at a standstill, the solar fluid runs
from the collectors and the lines back into the solar cyl-
inder. In this way, damage to the system from frost or
overheating is prevented. The use of a water/glycol mix-
ture as the solar fluid ensures additional frost protec-
tion.
4
2
11
13
9
8
5
6
10
12
16
15
17
A
B
C
14
1
3
18
7
Fig. 2.2 Main components of the auroSTEP system with VIH
SN 350i cylinder (diagram showing principle of opera-
tion without connection accessories)
Key
1
Solar flow pipe
2 Cold water pipe
3 Control
system
4 Boiler
5 Hot water pipe
6 Upper cylinder sensor
7 Heating
heat
exchanger
8 Solar heat exchanger
9 Lower cylinder sensor
10 Built-in solar piping
11 Safety
valve
12 Lower filling and drainage tap
13 Collector pump 1
14 Upper filling and drainage tap
15 Collector pump 2
16 Solar return pipe
17 Flat collectors
18 Collector sensor
System description 2
Summary of Contents for 0010007381
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