Viessmann VITOCAL 151-A Installation And Service Instructions Manual page 20

Installation sequence
Installing the outdoor unit
If the outdoor unit is to be installed on a flat roof, in
addition to the requirements for floor and wall installa-
tion, the following planning measures to be taken into
account include:
■ As the outdoor unit is located higher up when instal-
led on a flat roof, operating noise propagation is
more intense than when the unit is installed on the
ground. Roof surfaces are normally more reverber-
ant than areas on the ground.
To prevent noise nuisance, install the outdoor unit at
a sufficient distance from neighbouring buildings. If
required, provide suitable noise reduction measures.
Take into account sound reflection from the surfaces
of buildings when analysing sound propagation: See
technical guide.
■ Provide on-site wind protection measures if required,
e.g. screens, walls, etc.
■ Check to ensure that the installed height of the out-
door unit does not exceed the permissible building
height, e.g. as specified in outline planning restric-
tions.
■ Provide easy, year-round access to the outdoor unit
for service and maintenance. Provide sufficient main-
tenance areas.
Install suitable protection equipment, e.g. anchorage
points.
We recommend installing the heat pump on a steel-
■
reinforced concrete ceiling.
■ Installation on flat roofs with a low weight per unit
area (e.g. roofs made from timber rafters or trapezoi-
dal sheet metal) is not permissible.
■ With flat roof installation, considerable wind loads
may occur, depending on the relevant wind zone and
the height of the building. Have the substructure
designed according to DIN 1991-1-4 by a specialist
design engineer.
■ The higher roof and wind loads must be taken into
account in the structural calculations and the fixture
system of the outdoor unit.
Siting
■ In accordance with EN 378-3:2016, the outdoor unit
should only be installed in the open air.
■ The refrigerant circuit in the outdoor unit contains
easily flammable refrigerant in safety group A3
according to ANSI/ASHRAE Standard 34.
Therefore a safety zone is defined in the immediate
vicinity of the outdoor unit, in which special require-
ments apply: See chapter "Safety zone".
■ Observe the information regarding noise levels.
Sound emission regulations (TA-Lärm in Germany)
must be observed.
When siting the heat pump, always take into account
■
the distances to neighbouring properties in accord-
ance with local building regulations.
■ Do not install with the discharge side facing towards
the house wall or the main wind direction.
20
(cont.)
During defrosting, cool vapour escapes from the out-
■
door unit air discharge vents. This vapour discharge
must be taken into consideration during installation
(choosing the installation location, orientation of the
heat pump).
Provide wall outlets and protective conduits for the
■
hydraulic connection lines and electrical connecting
cables without moulded parts or changes of direc-
tion.
All wall outlets must be made gas-tight. This also
includes wall outlets that lie below ground level in
the safety zone.
Provide equipment for the protection of the outdoor
■
unit against mechanical damage e.g. Impact damage
from footballs.
■ Take environmental and weather influences into
account in the selection of the installation location,
e.g. flooding, wind, snow, ice damage, etc. Install
suitable protection equipment if required.
Siting in garages, multi-storey car parks and car
parking areas:
■ Prior to installation, it must be established for the
case in question whether the installation is permissi-
ble under local garage and parking area regulations
(German regulations GaStellV, GaStplVO, BetrVO).
Provide systems with refrigerants in safety group A3
■
with impact protection. This impact protection must
be designed so that a strike by a vehicle at the appli-
cable maximum speed does not result in damage to
the refrigerant circuit.
■ Mark the outdoor unit safety zone with prohibition
notices to identify ignition sources.
Siting in underground car parks is not permissible.
■
Siting in coastal areas: Distance < 1000 m
■ In coastal areas salt and sand particles in the air
increase the likelihood of corrosion:
Site the heat pump where it is protected from direct
onshore wind.
If required, provide a wind break on site. Observe the
■
minimum clearances to the heat pump: See the fol-
lowing chapter.
Weather influences
Observe wind loads when installing the unit on sites
■
exposed to the wind.
■ Fit the pipework exposed to the outdoor air outside
the support for floorstanding installation (accesso-
ries) with adequately thick thermal insulation in
accordance with the German Buildings Energy Act
(GEG): See the following table.
Pipework inter-
nal
≤
> 22 mm
λ
Min. thickness of thermal insu-
lation layer with
7
= 0.035 W/(m
λ
22 mm
Thermal conductivity
K)
·
40 mm
60 mm