OPERATING AND INSTALLATION INSTRUCTIONS LG 250 A
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Brine geothermal energy with optional
cooling function (factory setting)
Basic system components are illustrated in the “Brine Geothermal Energy with Optional Cooling Function”
pictorial schematic.
Geothermal exchangers must be carefully
planned and implemented taking into
account their energy efficiency and air
hygiene. The relevant guidelines and
standards must be observed. In particular,
amongst other things, ease of cleaning
and a suitable filter concept must be
ensured.
Support of a geothermal heat exchanger
with a changeover flap must be
specifically activated in the ventilation
unit. This is performed using PC software.
Geothermal heat exchanger winter
mode
The geothermal heat exchanger is
connected via the changeover flap
when the outdoor air temperature falls
below the geothermal heat exchanger's
parametered winter threshold value. In
this instance, the outdoor air is aspirated
into the geothermal exchanger and hence
preheated. If the outdoor temperature
(optional T5 sensor required) falls below
the geothermal heat exchanger's winter
parameter, the K1 relay switches on the
geothermal heat exchanger.
Geothermal heat exchanger summer
mode
In summer, the geothermal heat
exchanger is connected when the outdoor
temperature exceeds the geothermal
heat exchanger’s parametered summer
threshold value. In this case, the outdoor
air is drawn in via the geothermal heat
exchanger and is thus pre-cooled. If the
outdoor temperature (optional T5 sensor
required) exceeds the geothermal heat
exchanger's summer parameter, the K1
relay switches on the geothermal heat
exchanger.
Ventilation unit with
heat recovery
Outdoor air
Exhaust air
Supply air
Extract air
Brine
register
Brine pipe in
soil environment
Control system
power unit
Voltage
supply
Temperature
sensor ODA
Pump (on / off)
Safety module
(pressure equalisation, overpressure valve,
ventilator, manometer, shut-off valve,
filling and drainage valve)
Preliminary outdoor
air filter
Brine geothermal systems extract energy
from the earth in winter via a brine
pipe. The system may also be used for
cooling in summer. The heat or cold is
transferred indirectly into the supply air
via an external air register in the air duct
system.
In contrast to other frost protection
strategies such as an electric preheating
batteries, the advantage of geothermal
brine systems is their low operating
power. Their advantages compared to
the air duct geothermal heat exchanger
comprise hygienic aspects, simple laying
and good controllability. Indirect pre-
heating via a circulatory system with
frost-protected heat carrier, for instance,
should preferably be used in ground
containing hazardous substances (e.g.
radon contamination).
The manufacturer's guidelines for
implementation must be observed. The
brine heater battery must be protected
against contamination by an air filter
