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8.
Planning the brine-earth heat
exchanger system
8.1 Planning requirements
When planning and configuring a ventilation
system with an EW brine-earth heat exchan-
ger, the condition of the ground and the
above ground and underground conditions
are decisive.
Condition of the ground
Important points for a geothermal power near
the surface with heat extraction are the:
●
The specific thermal capacity of the ground
●
The thermal conductivity of the ground
●
The density of the ground
●
The diffusion of water and water vapour
The following in-ground factors have to be
taken into account, for example:
●
Installations
●
Cable lines
●
Drains, etc.
The following factors relating to the
property have to be taken into account, for
example:
●
Property borders
●
Buildings
●
Vehicular access
●
Vegetation
The geological structure is of great
importance to laying work. The laying depth
and space and the possible specific
extraction rating of the ground collector
depend on this.
Since ground temperatures at a depth of 1 m
may reach freezing point and at a depth of 2
m the volume of heat supplied by the earth's
surface actually starts to decrease, the depth
of laying should be between 1.2 m and 1.5 m.
Temperatures at this depth fluctuate over the
year between 7 °C and 13 °C. This
temperature level can be used very
effectively for heating purposes in winter and
for cooling purposes in summer.
8.2 Specialist requirements of staff
●
The work involved in laying ducts, including
the hydraulic connection to the brine-earth
heat exchanger, should be undertaken and
supervised by trained and experienced
specialists.
●
The building firms tasked with the laying
work must have the competence required
to do the work and must be able to prove
this.
●
Competence is considered to have been
proven when the building company is in
possession of the corresponding
DVGW certification, in accordance with
DVGW GW301 and GW303 and/or
DVGW GW331.
●
Process sheet W400-2 and the following
rules of the employers' liability insurance
associations and/or safety at work
inspections and the general technical rules
applicable to building work of VOB Part C
in accordance with DIN 18300, DIN 18303
and DIN 18307 are to be taken into
account.
●
Particular attention should be paid to
compliance with EC Directive 92/57/EEC
and the Construction Site Ordinance.
