Hoval RoofVent CON-9, Design Handbook

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1 General information
Hoval's DigiNet is a control system that was specially devel-
oped for decentralised indoor climate units. The system was
developed together with Sauter AG, a company which also
supplies the hardware components.
2 System setup
Hoval's DigiNet is divided into three hierarchical levels
connected by a novaNet system bus.
2.1 Operator level
This is where the user operates the system. Different opera-
tional options are available according to project-specific
requirements.
2.2 Zone level
Indoor climate units that operate under the same conditions
are summarised into control zones. Criteria for the creation of
a zone can be, for example, operating times, room tempera-
ture set values and so on. In the zone control panel, there is
a DigiZone controller for each control zone. It switches the
operating modes of the units according to the scheduler.
Different unit types can also be combined in a control zone. A
distinction is made between:
■ Main units (= fresh air units or supply air units)
■ Additional units (= recirculation units that are switched on
if there is a heat or cool demand).
A DigiEco controller is installed in the zone control panel for
additional units.
Control zones max. 10
Main units in each control zone max. 9
Additional units in each control zone max. 9
Table L1: Application limits of the Hoval DigiNet
Note
Special solutions are possible for larger projects.
2.3 Unit level
A DigiUnit controller is installed in each main unit (= fresh
air unit or supply air unit). This controls the unit individually
according to local conditions.
2.4 novaNet system bus
The individual Hoval DigiNet components are connected via
a novaNet system bus (analogously to the OSI layer model)
Data transfer takes place in an event-oriented manner, this
reduces data traffic and ensures short reaction times.
novaNet system bus
Cable type 1 pair of wires, drilled,
shielded
category 5 or above
Topology in series
Length Max. 1900 m
For longer bus lengths: Include a
repeater or divide the system into
several networks.
Communication Cross-communication with equal
priority (peer-to-peer / multiplier)
Loop resistance max. 300 Ω
Capacity max. 200 nF
Table L2: novaNet system bus specification
Example – bus cable
Type _______________________ G51
Dimension (n x n x mm²) _______ 1 x 2 x 0.8
Loop resistance at 20 °C _______ 37.5 Ω /km
Operating capacity ____________ 60 nF/km
Application __________________ Category 5e / class D
Features ___________________ drilled, halogen-free
Control systems
General information