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4 DESCRIPTION OF THE APPLIANCE
4.1
Characteristics
Murelle Revolution 25
is an innovative Ccass A++ wall-mounted
boiler designed by
Sime
SOLELY for space heating and producing
domestic hot water.
The appliance is made up of a latest-generation sealed
condensing gas boiler and a heat pump.
Murelle Revolution 25
can ONLY operate if it is connected to
the outdoor probe supplied with the appliance; if the outdoor
probe is NOT connected, Murelle Revolution 25 will NOT work.
The wall the appliance is mounted to must be able to support its
weight, and preferably be an outside wall, to simplify installing
the air inlet and outlet pipes.
Murelle Revolution 25
can produce water for a heating system
to a temperature of up to 75°C.
To obtain maximum performance
from
Murelle Revolution 25
, the delivery temperature
MUST NOT
exceed
65°C
and the return temperature must not be above of
45°C
.
The main design choices made by
Sime
for
Murelle Revolution
25
boilers are:
– use of a sealed boiler with a total pre-mix microflame burner
combined with a steel heat exchanger body and a rapid heat
exchanger for DHW
– use of a modulating circulation pump
– use of a heat pump (HP), which is supported by the boiler to
produce heat, and can operate separately or together with the
boiler, according to the temperature detected by the outdoor
probe
– a Main control panel (remote) which serves both as an
air thermostat and as a command and control device, a
microprocessor, with bus protocol to manage the
Murelle
Revolution 25
and related system
– use of a main evaporator with a patented smoke evaporator
in series and a plate heat exchanger to transmit the heat to
the water in the system. This allows the heat pump to operate
with an average COP of 4.
– the option of being connected to air thermostats or chrono-
thermostats for the zone.
The command board also has an internal connection where an
expansion which can control the external relays can be inserted.
Murelle Revolution 25
also has the following functions:
– the anti-freeze function which is activated automatically if
the temperature of the water inside the boiler falls below the
value set under “PAR 10” and if the outdoor temperature falls
below the value set under “PAR 11”
– the anti-blocking function of the pump and diverter valve, this
activates automatically every 24 hours if no request for heat
has been made
– the chimney sweep function lasts 15 minutes and makes the
job of the qualified technician easier when measuring the
parameters and combustion efficiency
– domestic hot water comfort function which allows the time
necessary for the hot water to become available to be reduced
and ensures that the temperature is stable
– screen display of the operating and self-diagnostic
parameters with error code display when the fault occurs.
This makes repair interventions easier and allows appliance
operation to be restored correctly.
4.2
Operation summary
4.2.1
Heating
When there is a heating request from the main control panel
(MCP) or from an air thermostat for the zone (ATz), where there
are no alarms and where the outdoor temperature is at least
-7°C, the heat pump is activated (HP).
After a set period of time, calculated using an algorithm
according to the current outdoor temperature, the gas boiler
also starts up to help heat the water in the system and respond
to the current request for heat.
When the system water temperature reaches the required value,
also calculated using a specific algorithm for the gas boiler, the
boiler stops and ONLY the heat pump continues to operate, until
the heating request has been satisfied; after which, the heat
pump also stops.
m
CAUTION
If, when there is a heating request, the outdoor
temperature is
below -7°C (e.g. - 10°C)
, only the gas
boiler is activated and the heat pump remains inactive.
4.2.2
Domestic Hot Water (DHW)
When there is a request for DHW, providing there is no heating
request from the air thermostats, the diverter valve prepares to
direct the flow of water towards the plate heat exchanger and
the boiler starts up to respond to the request.
Should there be a request for heat at the same time, the heat
pump stops and the boiler operates as described above. Once
the DHW request has been satisfied, standard heating operation
resumes.
