Viessmann Collector Range - Viessmann Vitosol 100-FM Technical Manual

Principles
Together with Viessmann heating systems, solar thermal systems
create an optimum system solution for DHW and swimming pool
heating, central heating backup and other applications.

1.2 Viessmann collector range

Vitosol-FM with ThermProtect automatic temperature-dependent shutdown
Vitosol-FM flat-plate collectors feature a unique absorber coating.
This coating changes its optical properties subject to temperature. In
the standard temperature range of the solar thermal system, the col-
lectors have the same performance values as conventional solar col-
lectors. As soon as the solar cylinder has reached the required heat-
up condition, an excess of solar energy causes the collector temper-
ature to rise. If the collector temperature exceeds the switching tem-
perature of the absorber, the output automatically adapts to match
the reduced heat draw-off. Stagnation temperatures of max. 145 °C
are reached in the collector when the system is at a standstill. When
the collector temperature drops, output will increase again. In a solar
thermal system with switching flat-plate collectors, the formation of
steam can be safely prevented with simultaneous adjustment of the
system pressure. This helps to protect the system components
(pump, check valves, expansion vessel, etc.) and the heat transfer
medium. Reliability and service life are improved.
Vitosol 300-TM with automatic temperature-dependent shutdown
Vacuum tube collector with phase-change temperature-dependent
shutdown
The Vitosol 300-TM is a highly efficient vacuum tube collector based
on the heat pipe principle, with ThermProtect automatic temperature-
dependent shutdown. Solar energy causes the medium sealed
inside the heat pipe to evaporate. The resulting condensation in the
condenser dissipates heat to the solar circuit. The medium flows
back into the sunlit area of the vacuum tubes. At collector tempera-
tures of 120 °C and above, the medium is no longer able to con-
dense. Thanks to this phase-change blocking, heat transfer is inter-
rupted and the system is thus protected against excessively high
stagnation temperatures. This results in a maximum stagnation tem-
perature of 150 °C.
Vitosol 200-TM with ThermProtect automatic temperature-dependent shutdown
The Vitosol 200-TM series solar collector also has ThermProtect
phase-change temperature-dependent shutdown. The collector
operating principle and shutdown are identical to those of the Vitosol
300-TM. The higher 175 °C stagnation temperature involves control-
led evaporation of the heat transfer medium.
Vitosol-F
Solar thermal systems with Vitosol-F supply efficient, reliable renew-
able heat for DHW heating and central heating backup, or process
heat. During summertime, the available solar energy may exceed
heat demand. The solar system stagnates, which can have a nega-
tive impact on the service life of system components.
VITOSOL
This technical guide includes a summary of all technical documents
for the required components, as well as design and sizing informa-
tion especially for systems for detached houses. This technical guide
is a product-related addition to Viessmann's "Solar thermal systems"
technical guide. You can obtain a printed version of Viessmann's
"Solar thermal systems" technical guide from your Viessmann sales
consultant or download it from http://www.viessmann.de. On the
website, you will also find electronic aids regarding collector fixing
and maintaining the correct pressure in solar thermal systems.
For economic reasons, the same sizing rules used for conventional
flat-plate collectors apply to switching collectors. Due to the low end
temperatures, the collector area may be oversized to achieve higher
solar coverage.
The collector adjusts itself automatically to the reduced heat con-
sumption. If the collector temperature drops, output will increase
again. Simultaneous system pressure adjustment safely prevents
steam formation. The system components are protected.
For economic reasons, the same sizing rules used for conventional
collectors apply to switching collectors. Due to the low end tempera-
tures, the collector area may be oversized to achieve higher solar
coverage.
It is therefore important that the professional installer ensures sound
system sizing. Design the collector area and cylinder size according
to the energy requirement. Alternatively, equip collectors with Therm-
Protect.
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