Helios LEWT Series, Инструкция по установке и эксплуатации, Страница: 5 / 8

Ground-to-Air Heat Exchanger LEWT Kit
1
MATERIALS AND APPLICATION
The undersoil collector duct is a coextruded compound duct made from poly­
ethylene.
The sanded wall penetration is made from polypropylene. The wall penetration
profile sealing rings for connection to the slatted hood are made from an SBR
elastomer. The undersoil collector duct is a flexible, externally corrugated and
internally smooth compound duct, in a coil with 2 x 25 metres (advantages: Low
air resistance, low contamination tendency, good cleaning properties).
The undersoil collector duct is designed specifically for underground installation.
These instructions apply for underground installation, based on DIN EN 50086­
2­4, part 2­4: “Particular requirements for conduit systems buried underground”.
STATIC ANALYSIS FOR THE UNDERSOIL COLLECTOR DUCT
Use of the Helios undersoil collector duct is permissible without static analyses
under the following conditions.
– Minimum cover of 1.20 m below traffic areas and for traffic loads SLW 60
according to DIN 1072;
– Maximum covering: 6.00 m. A deformation and stress analysis should be
carried out for higher coverings. Corresponding bedding conditions must be
observed;
– Type of bedding material/ filling material: Sand 0/4 mm;
– Bedding conditions: Embedding conditions B1 or B4 and covering conditions
A1 and A4 according to ATV A 127 section 6.2 and 5.2.
In case of deviation from the aforementioned conditions, a static analysis must be
carried out (e.g. ATV work sheet A 127 E, issue 1998).
ATTENTION: Pressing water must be prevented with appropriate construction
measures before installing the undersoil collector duct. It is also recommen-
ded that the connection points are sealed by the customer (e.g. cold shrink
tape) to prevent water penetration.
SUPPORT AND EMBEDDING
The support and embedding of the Helios undersoil collector duct is of the utmost
importance for permanent serviceability due to the coactive “underground duct”
system and the flexible duct construction. The support and embedding must
therefore be carried out carefully according to DIN EN 1610: 1997 (DIN 4033
successor standard) section 7 bedding type 1 with a lower bedding layer of at
least 10 cm or according to the static requirements.
The compression of the bedding material must be ensured with at least 95%
simple proctor density. In case of groundwater, it must be ensured that the filling
material cannot be displaced.
INSTALLATION
The ducts must be checked for transport damage before installation. The ducts
must be installed according to DIN EN 1610 section 8. The Helios undersoil col­
lector duct is longitudinally elastic. A carefully, evenly compacted lower layer at
the planned gradient is crucial for a perfect result. The ducts on this level must be
carefully aligned in height and lateral position.
INSTALLATION AND OPERATING INSTRUCTIONS
All the following provisions must be read carefully and observed in order to
ensure correct functioning and for safety purposes.
RECEIPT
Please check delivery immediately on receipt for damage, accuracy and comple­
teness. If damaged, please notify carrier immediately. ln case of delayed notifica­
tion, any possible claim may be void.
The ground­to­air heat exchanger
LEWT kit (Ref. no. 2977) consists of the fol­
lowing units:
LEWT-E+M Undersoil collector duct (coil with 25 running metres length)
incl. connecting sleeve (with profile sealing rings (4x) and end
caps (4x)), including sanded wall penetration (1x).
Ref. no. 2991
LEWT-S+F Automatic controller and duct form parts.
Ref. no. 2990
LEWT-A / Outside air intake with slatted hood and cone filter
VGP G03
class G3.
Ref. no. 2992
STORAGE
When storing for a prolonged time the following steps are to be taken to avoid
damaging influences for the electrical and metal parts: Protection by dry, air­ dust­
proof packing (plastic bags with drying agent and moisture indicators). The sto­
rage place must be water­proof, vibration­free and free of temperature variations.
Damages due to improper transportation, storage or commissioning are verifiable
and not covered by warranty.
AREA OF APPLICATION
The task of a ground­to­air heat exchanger is to pre­heat or cool the outside
air in a ventilation system for a building. The outside air is sucked in through the
underground duct system. In this respect, the ground serves as a source of heat
or cold. Depending on the weather (outside air temperature), the intake outside
air can be heated or cooled.
Winter operation: Outside air temperature
≤
5 °C
During the heating season and an outside air temperature below 5 °C, the air is
heated in the ground­to­air heat exchanger. The existing geothermal heat is used
for pre­heating and thus saves heat energy.
Summer operation: Outside air temperature ≥ 20 °C
During the summer months, the outside air is cooled down by the ground­to­air
heat exchanger due to the lower ground temperature, supplied to the building and
thus ensures a pleasant indoor climate.
Spring/autumn operation: Outside air temperature between 5 – 20 °C
During the transitional seasons, the outside temperature is subject to strong fluc­
tuations (sun during the day – very cool at night). The ground temperature remains
constant (cool in spring – still warm in autumn). Therefore, the supply air should
not pass through the ground­to­air heat exchanger at noon on a warm day in
spring (heating system still in operation). The air flowing in would be colder than
the solar­heated air temperature, which is not desirable. However, in case of coo­
ler night temperatures, heating by the ground­to­air heat exchanger is reasonable.
The opposite applies on days in autumn. The optimal operation is automatically
controlled by the LEWT­S+F kit (by means of bypass shutter, servo motor, dual
thermostat and control box).
LEWT-E+M Undersoil collector duct and wall penetration
LEWT-A/VGP G03
LEWT-E+M
LEWT-S+F