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Subject to technical amendments without notice | 83050700gUK – Translation of the original operating manual | ait-deutschland GmbH
11 Area of use and
heat source requirements
Taking into consideration the ambient conditions, limits
of use and the relevant regulations, every heat pump
can be used in new or existing heating systems.
“Technical data / scope of delivery” overview,
Water temperature / water quantity
The water in the extraction well of the heat source sys-
tem must have a minimum temperature of 7 °C all year
round and may not exceed a temperature of 25°C.
Depending on the heat output required or its cooling
capacity as a relevant variable for dimensioning the
heat source, a minimum water rate is required, which
must be provided by the heat source as a continuous
output. Before installing the water/water heat pump, a
pump test should/must be carried out for at least 12
hours with verification of a quasi-constantly lowered
water table (persistence) in order to provide informa-
tion about the quantity of water available. For efficient
operation of the well, during the initial start-up the
nominal flow rate must be adjusted on the heat source
side. Any appropriate components, which enable bal-
ancing are to be installed in the pipe network here.
The material of the components used must be chosen
according to the water quality. The necessary flow rate
(heat source water rate) must meet the heat pump's
requirements.
“Technical data/scope of supply” overview
Water quality
In Germany the well must be designed and built to DIN
4021 and VDI 4640 (in other countries according to the
corresponding regulations). Wells may only be drilled
and built by drilling companies with a permit in accord-
ance with DVGW W120. The water quality of the heat
source is defined as normal groundwater. Ensure that
the suction and return pipe always extends below the
water level by sufficient depth, to ensure that oxygen
is not added to the water (risk of iron oxide deposits).
Please discuss the problem of iron oxide deposits with
your well builder. During the planning the quality of the
groundwater should be checked in advance as well as
possible (e.g. by asking the competent water authority
or searching for data on existing adjacent wells) and
subsequently verified by water analysis in the built pro
-
duction well. The following table helps to assess the
water quality.
IMPORTANT
A water analysis and pump test must be car-
ried out before installing the water/water heat
pump.
NOTE
Water analyses are prepared by water test
laboratories. Initial information about possi-
ble use of groundwater is available from your
local water management authority. A pump
test provides information as to whether a suf-
ficient quantity / rate of water is available to
cover the requirements for the heating output
of your unit. The minimum groundwater flow
rate must at least be available as a continu-
ous output.
“Technical data/scope of supply” overview,
“Heat source flow rate” section
Evaluation of the water analysis
Water constituents - minimum requirement. The water
should be analysed in advance for the test values listed
below (table). An important criterion to be used for tak-
ing water samples is the DVGW Standard, Technical
Notices, Leaflet W 112 and use of the technical rules
listed in it (DIN, EN and ISO standards).
Designation
Limit
pH value
> 6,8
Iron level
< 0,2 mg / l
Manganese level
< 0,1 mg / l
Chloride level
< 300 mg / l
Free chlorine level
< 3 mg / l
Turbidity
keine
Technical freedom
from sand
< 0,1 ml sand per 10 l
pumped water
IMPORTANT
If a value does not conform to the value listed
in the table, a water/water heat pump may
not be used. Direct operation of the unit in
conjunction with surface water, wastewater,
industrial wastewater or mixtures of water
and alkali solutions, acids or chlorine is also
not allowed.
