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Subject to change without notice | 83050700fUK – Translation into English of the original German operating manual | ait-deutschland GmbH
If this is required, install a shielded network cable
(category 6, with RJ-45 connector) through the
unit when installing the connections and run it
through the front panel of the unit, parallel to
the existing control cable of the heating and heat
pump controller.
After completing all electrical installation work,
close the switchbox inside the unit…
Screw on the front panel of the unit, if no further
installation work inside the unit is to be carried out
immediately.
Flushing and filling the system
IMPORTANT
The system must be absolutely free from air
before commissioning.
WATER QUALITY OF THE FILL AND MAKE-UP WATER IN
WATER HEATING SYSTEMS ACCORDING TO VDI 2035
PART I AND II
Use of modern, energy-efficient heat pump systems
is becoming increasingly widespread. Their ingenious
technology enables these systems to achieve very good
efficiencies. The decreasing space available for heat gen-
erators has led to the development of compact units
with increasingly smaller cross-sections and high capaci-
ties. 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 affects the efficiency 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 expe-
rience has shown that the safest, most reliable and fault-
free running is achieved with so-called low-salt operation.
VDI 2035 Part I provides 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 heat-
ing 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, design 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 plan-
ning & design data is entered (VDI 2035).
DAMAGE THAT CAN OCCUR IN CASE OF FAILURE TO
COMPLY WITH THE ABOVE
-
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 compo-
nents (e.g. heat exchanger, pipes, pumps)
- Material fatigue
- Gas bubbles and gas cushion formation (cavitation)
- Negative effect on heat transfer (formation of coat-
ings, deposits) and associated noises (e.g. boiling
noises, flow 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 efficiency falls and the energy costs rise.
A rule of thumb is that 1 millimetre of limescale deposit
causes an efficiency 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 in accordance with the VDI 2035
guidelines before it is used to fill the heating system, no
scale can form. This effectively and permanently prevents
limescale deposits and the resulting negative effects on
the entire heating system.
