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83053503iUK – Translation into English of the original German operating manual – Subject to change without notice. www.novelan.com
DAMAGE THAT CAN OCCUR IN CASE OF NON
COMPLIANCE
- Malfunctions and the failure of components (e.g.
pumps, valves)
- Internal and external leaks (e.g. from heat exchangers)
- Cross-section reduction and blockaging of components
(e.g. heat exchanger, pipes, pumps)
- Material fatigue
- Gas bubbles and gas cushion formation (cavitation)
- Negative eect on heat transfer (formation of coatings,
deposits) and associated noises (e.g. boiling noises,
ow noises)
LIMESCALE THE ENERGY KILLER
Filling with untreated drinking water inevitably
leads to the precipitation of all calcium as scale. The
consequence: limescale deposits form on the heat
transfer surfaces of the heating. The eciency falls and
the energy costs rise. A rule of thumb is that 1 millimetre
of limescale deposit causes an energy loss of 10%. In
extreme cases it can even cause damage to the heat
exchangers.
WATER SOFTENING TO VDI 2035 PART I
If the water is softened before the heating is lled,
in accordance with the VDI 2035 guidelines, no scale
can form. This eectively and permanently prevents
limescale deposits and the resulting negative eects on
the entire heating system.
CORROSION AN UNDERESTIMATED PROBLEM
VDI 2035, Part II, deals with the problem of corrosion.
Softening the heating water can prove to be insucient.
The pH value can signicantly exceed the limit of 10. pH
values higher than 11 can set in, which even damage
rubber seals. The VDI 2035, Part 1 guidelines are fullled,
however, VDI 2035, Part 2 suggests a pH value between
8.2 and maximum 10.
If aluminium materials are used, which is the case in
many modern heating systems, a pH value of 8.5 must
not be exceeded, because otherwise there is a threat
of corrosion – and aluminium is attacked without the
presence of oxygen. Therefore, apart from softening
the heating ll and additional water, the heating water
should also be appropriately conditioned. This is the
only way to comply with the VDI 2035 requirements and
the recommendations and installation instructions of
the heat pump manufacturer.
Rinsing, lling and bleeding the
system
See “Operating instructions hydraulic module”
or “Compact Station Dual”.
CAUTION.
The system must be absolutely free from air be-
fore commissioning.
WATER QUALITY OF THE FILL AND ADDITIONAL
WATER IN HOT WATER HEATING SYSTEMS
ACCORDING TO VDI 2035 PART I AND II
Use of modern, energy-ecient heat pump systems
is becoming increasingly widespread. Their ingenious
technology enables these systems to achieve very good
eciencies. The decreasing space available for heat
generators has led to the development of compact
units with increasingly smaller cross-sections and high
capacities. This means the complexity of the systems and
the material diversity are also increasing, which plays an
important role especially in their corrosion behaviour.
The heating water not only aects the eciency of the
system, but also the life of the heat generator and the
heating components of a system.
The guide values of VDI 2035 Part I and Part II must
therefore be complied with as minimum requirements
for proper operation of the systems. Our practical
experience has shown that the safest and most trouble-
free running of the systems is achieved with so-called
low-salt operation.
VDI 2035 Part I gives important information and
recommendations regarding scaling and its prevention
in heating and domestic hot water heating systems.
VDI 2035 Part II primarily deals with the requirements for
reducing heating water corrosion in hot water heating
systems.
PRINCIPLES OF PART I AND PART II
The occurrence of scaling and corrosion damage in hot
water heating systems is low, if
- proper planning and commissioning is carried out
- the system is closed in corrosion terms
- adequately dimensioned pressurising is integrated
-
the guide values for the heating water are complied with
- and regular servicing and maintenance are carried out.
A system log should be kept, in which the relevant
planning data is entered (VDI 2035).