Ground-to-Air Heat Exchanger LEWT Kit
2
LEWT-A / VGP G03 Outside air intake duct with filter
In this respect, it must be ensured that the duct is supported over the entire
length. The embedment (duct trench bottom to at least 30 cm above soffit) should
be carefully filled in layers with a lightweight compactor. The static requirements
for the degree of compaction must be observed and checked if necessary.
The wall penetration should be centrally embedded (even excess on both sides)
into the brickwork. Deformation during installation is not permitted. The installation
and laying must only be carried out by an authorised specialist.
The installation process is as follows:
– Check alignment, height position and gradient to condensation outlet (siphon).
– Establish duct connection in building and for the outside air intake.
– The total duct length should be at least 40 m. The flexible Helios underso
il collector duct can already be installed in the existing construction pit. The
distance between the ducting and the building should be at least 1 m.
IMPORTANT: In order to avoid damage, the undersoil col-
lector duct must be installed in frost-free temperatures.
The installation depth of the undersoil collector duct should be at least 1.2 m. The
efficiency increases with larger installation depths.
The distance from duct to duct should be larger than > 1 m – the minimum bending
radius is 50 cm. Thus, the pressure loss in the undersoil collector duct is kept low.
There must be a gradient of at least 2% in the undersoil collector duct to the con
densation outlet (siphon) for the resulting condensation.
If the building has no basement or if entry takes place above the installed undersoil
collector duct, there must be a condensation outlet (siphon) at the deepest point.
Furthermore, a floor structure must be created in the inspection shaft, which ensures
the swift infiltration of the resulting condensation as well as the rainwater in the shaft.
A sufficient distance between the siphon outlet and shaft floor must be ensured for
hygiene reasons and waterlogging. In case of installation in groundwater areas, the
use of a waterproof shaft with a condensate drain pump is recommended. In order
to create watertight connections, a profile sealing ring must be placed on the third
wave trough before the end of the duct. The wall penetration and the connecting
sleeves have two internal locking cams, which engage in the second wave trough
of the duct.
The sliding surfaces must be carefully cleaned (with a damp cloth) before connecting
the duct and wall penetration. All sliding surfaces – internal sleeves and visible parts
of the sealing ring – must be sufficiently covered with a commercial lubricant. The
spigot must then be inserted in the wall penetration without coming into contact
with the filling material and pushed in from the other end of the duct with a swift
movement.
Allow the Helios undersoil collector duct to protrude at least 20 cm (better 0.5 to
1.0 m) above ground for the connection of the outside air intake. Protruding ducting
must be shortened when installing the slatted head.
RECOMMENDATION: Cold shrink tape or Denso tape should be used by the
customer to seal the connection points!
SHIPPING AND STORAGE
The Helios undersoil collector duct and the wall penetration consist of PEHD and
PPC and they are protected against UV radiation and heat. Outdoor storage for
longer than 6 months is not permissible.
Profile sealing rings should not be stored outside due to potential damage from
UV radiation.
Ducts and form parts must be transported so that they are not damaged during
shipping. Do not throw or tip the Helios undersoil collector duct and the wall
penetration from the lorry loading surface.
WATERTIGHTNESS
The Helios undersoil collector duct and the wall penetration are classified accor
ding to the IP protection class 67 when using profile sealing rings.
CLEANING
The undersoil collector duct should be cleaned at regular intervals for hygiene
reasons.
AREA OF APPLICATION
The supply air is taken in via the outside air intake duct with cone filter class G3.
The outside air intake duct is made from stainless steel (surface class III C). A
cone filter class G3 is integrated in the outside air intake duct, which prevents the
intrusion of small animals, insects and contaminants.
APPLICATION LIMITS STAINLESS STEEL
Stainless steel 1.4301 can easily discolour due to air pollution!
Regular cleaning reduces the risk of discolouration. When used in cities and
industrial areas with heavy air pollution, this stainless steel is at risk of corrosion
to a certain extent. This stainless steel is not suitable in environments with heavy
air pollution and near the coast with a high salt concentration in the air without an
additional protective coating (acrylic clear coat).
INSTALLATION
The internal diameter of the outsideair intake duct is designed with a profile sea
ling ring for the insertion of the Helios undersoil collector duct. In order to anchor
the outsideair intake duct in dry construction, a concrete base and bordering
plate (onsite) can be positioned below the duct flange and screwed to the flange
using the 4 holes provided. The undersoil collector duct (with a profile sealing ring)
should be inserted approx. 10 cm high up to the grille in the undersoil duct. The
slatted hood and the outsideair intake fit into each other. The slatted hood can
be removed from the intake duct by hand without using tools; e.g. when changing
the cone air filter.
PRESSURE LOSS
Depending on the intensity of the polluted air, the filter surface clogs up more
or less quickly. Air filters create flow resistance, which increases with increased
pollution and reduces the volume flow (fan performance) accordingly. The pres
sure loss in the “pure condition” depending on the volume flow can be seen in
the diagram above. This value for the contaminated condition must be taken into
account for the fan design with a corresponding increase.
CLEANING
Remove the cone filter after removing the slatted hood (without tools). Loosen the
mounting ring on the filter and remove the cone filter cap. Clean the filter through
gentle tapping or washing in soapy water. Then reinstall the filter cap and insert
the cone filter in the intake duct.
Reattach the slatted hood on the intake duct; ensure an airtight fit in the process.
In case of cone filter alteration phenomena, which may occur after repeated clea
ning, replace the cone filter
ACCESSORIES replacement air filter (cone filter cap)
ELF-LEWT-A / VGP G03
VE = 3 pcs G3
Ref. no. 2975
LEWT-S+F Controller and duct form parts
The LEWT-S+F contains:
1 x bypass shutter NW 200 with servomotor 230 V
1 x crosspiece with cleaning opening and condensate collector
1 x siphon
1 x RAG Rainwater drainage grille for direct extraction
1 x 2 stage thermostat
1 x control box with doublethrow switch
AREA OF APPLICATION
Serves to control the supply of outside air via the undersoil collector duct or for
direct outside air intake in case of corresponding weather conditions. During the
transitional seasons of spring and autumn, it can happen that the air brought in
from outside is cooled in the undersoil collector duct, but there is still a heating
requirement for the building. In order to prevent this, the bypass shutter is control
led depending on the outside temperature using a thermostat. The temperature
range for the direct intake can be set individually on the thermostat. However, if
cooling or preheating is required, another mode of operation can be selected (see
SS798) using a manual switch.
INSTALLATION
The crosspiece is connected at the wall penetration to the undersoil collector duct
(in case of larger distances between the wall and ducting, a sliding sleeve must be
used with seals between the wall penetration and crosspiece). The end cap with
the siphon connection must be connected to the lower outlet. The siphon must
be inserted in the connector and connected to the sewage system with a hose.
The bypass shutter must be mounted in an upright position over the crosspiece.
A suction opening is provided at a minimum height of 1 m above ground (diameter
20 cm) for direct extraction.
The ducting to the suction opening (spiral duct and form pieces) must be arranged
by the customer.
In order to prevent contamination and the penetration of rainwater in the outside
air duct, the rainwater drainage grille RAG must be mounted on the facade before
the suction opening.
