REHAU RAUGEO GROUND-SOURCE SOLUTIONS - Specifinder

REHAU RAUGEO GROUND-SOURCE SOLUTIONS
RENEWABLE SOURCE OF HEATING AND COOLING
www.rehau.co.uk
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INTRODUCTION
GROUND SOURCE ENERGY
Rising energy prices and decreasing fossil fuel reserves are causing
many specifi ers, clients and contractors to turn to renewable energy
sources to provide a building’s energy demands. Legislation is also
driving the market towards more energy-effi cient building solutions,
reducing the burden on our planet’s precious resources.
Introduction to Ground-Source Energy .............................................................. 03
RAUGEO PE-Xa Probes ............................................................................... 04
RAUGEO PE 100 Probes .............................................................................. 05
RAUGEO Helix Probes ................................................................................ 06
RAUGEO Horizontal Collectors ....................................................................... 07
RAUGEO Energy Piles ................................................................................ 08
RAUGEO Modular Manifolds .......................................................................... 09
RAUGEO Manifold Chambers ......................................................................... 10
REHAU AWADUKT Thermo ............................................................................ 12

INTRODUCTION TO GROUND-SOURCE ENERGY
RENEWABLE AND SUSTAINABLE ENERGY SOURCE
Ground-source energy is one of the most commonly
exploited renewable energy sources, relying on the
near constant temperature of the ground throughout
the year. A common misconception is that this
energy comes from the earth’s core (geothermal
energy) but the energy actually comes from the sun
(ground-source energy), think of the earth as a
huge solar collector. At a depth of around 1.5-2m,
the ground varies from between 7-12ºC throughout
the year and at around 20m deep, the ground
becomes a constant 10ºC.
Advantages of ground-source energy:
- Completely renewable energy source
- Save up to 75% of heating requirements
and 85% of cooling requirements
- Year round usage
- Hidden from view
- Reduces CO2 emissions
A ground-source heat pump (GSHP) is required to
extract this energy from the ground. By installing
a pipe network in the ground, heat can be
transferred from the ground into the heat pump,
which converts this heat into usable heat for the
space heating requirements. The typical Coeffi cient
of Performance (COP) of a GSHP is around 3-4,
this means for every unit of electricity the heat
pump uses, it creates 3-4 units of heating energy.
Ground-source is ideally linked up with underfl oor
heating due to the lower temperatures required
compared to radiator.
3

RAUGEO PE-Xa PROBES
MAXIMUM RELIABILITY FOR INSTALLATIONS
Example PE-Xa probe showing continuous circuit with no joint
Probe base of the RAUGEO probe PE-Xa
Borehole Installation Erlangen, Germany
4
Probes are the most effi cient method of
extracting ground-source energy, as the ground
temperature becomes more constant after
around 15-20m. Probes are typically installed in
boreholes between 70-100m deep, but in some
European countries, the trend is for deeper
boreholes of up to 200m or even deeper.
REHAU RAUGEO probes are all double-U probes
which means 2 fl ow and 2 return pipes. This is
a failsafe for any potential damage to the probes
but also provides around 10-15% better thermal
performance.
RAUGEO PE-Xa probes offer the highest reliability
and reassurance for the client. Using cross-linked
polyethylene (PE-Xa) provides the following advantages:
- High resistance to notches and grooves
- PE-Xa probe tip has no joint which means
no potential leakages
- Better bending radius (for coming out of
the borehole)
- Lower pressure losses due to smooth pipe
inner surface
- Probe tip protected by special fi breglass resin
RAUGEO probes come in
32mm and 40mm.

RAUGEO PE 100 PROBES
OPTIMISED 2ND GENERATION PROBE TIP
Modular weight system with new PE 100 probe
REHAU have launched the 2nd generation of PE
100 probes with a specially designed probe tip
which is more robust and compact. RAUGEO
PE 100 probes are all welded in the factory
(externally monitored) and manufactured to
SKZ test regulations (HR 3.26).
The new probe tip now includes vertical ribbing
and is arrowed for a safer installation. This ribbing
provides more secure mechanical protection for
the welded probe tip. This probe tip is also now only
80mm in diameter, meaning smaller boreholes can
be utilised.
Another benefi t of the PE 100 probe is the lower
pressure losses due to fl ow-enhancing bend.
Alongside the new PE 100 probes, the 2nd generation
of RAUGEO weights have been introduced:
- Modular weight system (in 12.5kg increments)
- For single-U and double-U probes
- Same weight can be used for PE-Xa and PE 100
- Fast and reliable mounting
New 2nd generation probe tip
Double-U probe tip
5

RAUGEO HELIX PROBES
COST-EFFECTIVE ALTERNATIVE TO PROBES
6
RAUGEO Helix probes are the ideal solution when
borehole installations are not cost-effective and
there is not enough space for horizontal collectors.
They can easily be used for new build projects but
also for refurbishments. The Helix PE-Xa probe is
delivered in a 1.2m high coil, which can be extended
to 3m in height on site.
The Helix probe provides the following benefi ts:
- Low installation costs due to max 5m
deep borehole
- Low storage and transportation costs
- High quality PE-Xa material for optimum
reliability
- Optimised regeneration due to special
PE foil membrane
- Ideal for limited space installations
The drilling requires no special equipment
(a standard Auger drill) and can be done by
a civil contractor. The backfi ll is just sand and
water which makes for rapid and cost-effective
installations of each Helix probe.

RAUGEO HORIZONTAL COLLECTORS
FOR LARGE INSTALLATION AREAS
For projects where using probes is not a viable
option, RAUGEO horizontal collectors are ideal
when there is a large area available. Collectors
are buried around 1.5m deep in the ground,
with a pipe spacing of 0.7m. RAUGEO collectors
are available in 20, 25, 32 and 40mm.
Using PE-Xa allows the pipe to be installed without
a sand bed, saving installation time and also costs.
This is due to excellent physical properties of PE-Xa
which provide resistance to puncture loads. PE-Xa
also has an excellent bending radius, allowing for
tight bends, perfect for small areas.
REHAU do not recommend the RAUGEO being
used for slinky systems. This is due to too
much energy being extracted from the ground, which
affects the long-term performance of the groundsource
heat pump. The German Ground-source
standards VDI (Institute for German Engineers) 4640
recommend at least 0.3m pipe spacing so slinky
systems do not conform.
RAUGEO PE 100 collectors are also available.
Please speak to your nearest REHAU sales offi ce
for further details.
Open cast laying for PE-Xa collect RAUGEO collect PE-Xa installation
PE-Xa collector pipe
The PE 100 collector pipe
PE 100 collectors must be
installed in a sand bed.
7

RAUGEO ENERGY PILES
EXPLOITING A BUILDINGS FOUNDATION
RAUGEO Installation Lu-Teco, Germany
8
Energy piles provide a cost-effective alternative to
probes if the building is already including foundation
piles as no extra drilling needs to be carried out.
Piles are typically between 10-20m deep, depending
on site conditions. Ground-source pipework can
simply be integrated into the pile with cable ties.
PE-Xa is ideal for energy piles to the bending radius
of PE-Xa which removes the need for a joint in the
pile, therefore eliminating any potential leakages.
Vertical zig-zag pipe laying U pattern pipe laying

RAUGEO MODULAR MANIFOLDS
MAXIMUM FLEXIBILITY FOR INSTALLATIONS
To meet the high market demands for groundsource
manifolds, REHAU have designed a
modular manifold solution to ensure maximum
fl exibility for installations. The manifold is made
of corrosion-resistant Polyoxymethylene (POM)
and aluminium.
Benefi ts:
- Quick on-site assembly
- From 2 to 12 circuits
- Individual control of circuits via adjustment
valves in fl ow and return lines
- Post-installation fi tting of extra circuits,
thermometers and pressure gauges
- Connections for PE-Xa and PE 100 possible
in 25, 32 and 40mm
Connecting unions
Base set
RAUGEO modular manifold Pre-defi ned sizes are available
9

RAUGEO MANIFOLD CHAMBERS
PRE-FITTED WITH MODULAR MANIFOLD

Due to the success of the
modular manifold, a bespoke
manifold chamber was designed
to complete the RAUGEO
ground-source range. The
chamber comes complete with
pre-integrated modular manifold,
ready for on-site rapid installation.
- Made of high-impact resistant
polypropylene with vertical and
horizontal ripping for maximum
static loads
- Lightweight (only 50-55kg)
- Pre-drilled holes for pipe
connections (no electrofusion
connections necessary)
- Manifold is horizontally installed
to allow for simple groundworks
below the manifold
The following options
are available:
- 3-5 circuit manifold
- Connections in 25, 32, 40
and 50mm
- With or without fl owmeters
- Water-tight or open version
(no base)

REHAU AWADUKT THERMO
GROUND-AIR HEAT EXCHANGER FOR CONTROLLED VENTILATION
12
Ground-source energy can be exploited in other
ways. REHAUs AWADUKT Thermo is simple and
effi cient renewable energy solution and has
proven extremely popular in both residential and
commercial applications. By drawing ventilation air
through an underground network of pipes 1.5m
deep, the air can be pre-cooled in summer and
pre-heating in winter.
When used in conjunction with a heat-recovery unit,
this signifi cantly reduces the heating and cooling
costs for a building. It can even eliminate the
need for air-conditioning in some circumstances.
Additional benefi ts include the reduced need for
natural ventilation (such as opening windows),
which improves security, noise levels and draughts.
Particularly in the winter, carbon dioxide can build
up very quickly in schools and offi ces but a groundair
heat exchanger provides a constant source of
fresh, fi ltered air.
Ground
Fresh air
fi lter box
+28˚ C
+10˚ C
Ground to air
heat exchanger
+16˚ C
The pipe is made of polypropylene and comes
complete with an integrated antimicrobial layer,
made of silver particles. This prevents microbial
growth on the inside of the pipe, which would
otherwise cause musty smells. The air inlet also
has a dust and pollen fi lter, further benefi t allergy
sufferers. The PP material is used for its excellent
thermal conductivity, to ensure the best heat
transfer between the ground and the air.
REHAU have bespoke design software for Awadukt
Thermo to calculate the expected energy savings of
the system. A COP of around 50 can be achieved
using AWADUKT Thermo, which, compared with a
COP of between 3-4 for a ground-source heat pump,
making it a very effi cient renewable energy solution.
Ground
Fresh air
fi lter box
-5˚ C
+10˚ C
Ground to air
heat exchanger
Operating principle of the ground air-heat exchanger in Summer Operating principle of the ground air-heat exchanger in Winter
+4˚ C

www.rehau.co.uk 827711EN/DAIR/01.09