Rotex GSU 320, Operating Instructions Manual

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2 x Product description
10 BA ROTEX GSU - 09/2007
2.2 Brief description
The ROTEX GasSolarUnit is a completely pre-assembled gas condensation boiler, which is integrated in a hot water storage tank.
This integration ensures that there are no external surface and cooling losses. The heat is given completely to the storage tank
water and not to the surroundings. In addition, the excellent heat insulation of the plastic storage tank ensures minimum heat
losses. The very flat cylinder-shaped aluminium boiler body is recessed into the cover of the storage tank. The combustion
chamber is arranged centrally. The flue gas is directed in a spiral around the burner chamber and then taken away upwards.
The flue gas temperature always remains below 90 °C.
Solar utilisation
The hot water storage tank of ROTEX GSU can also be heated by solar energy. In the models GSU 520S and GSU 530S, the gas
condensing boilers are designed to maintain only the upper zone of the storage tank at the target temperature. In solar heating,
the entire storage tank can be heated up, depending on the heat offered by the sun. The stored heat is now used for hot water
generation as well as for the heating support. The high total storage capacity in the 500-litres tank even allows temporary tiding
over without sunshine.
In the models GSU 320 and GSU 535, the total storage tank is configured as zone for domestic water. It is possible to make
thermal use of solar energy for hot water preparation. The solar component is optimised in combination with an upstream
Solaris system (pre-heating stage).
Operating principle
The ROTEX GasSolarUnit is designed such that it can be operated independently of the ambient air. The combustion air is drawn
in through an installation shaft or a double-walled flue gas conduit from the burner directly from the open air. This method has
several advantages:
– The heating room needs no ventilation opening to the open air and therefore does not cool down.
– Lower energy consumption.
– Additional energy recovery in the flue gas line by combustion air pre-heating.
– Additional energy yield from a distinctive temperature layering system generated in all devices by the arrangement and flow
through the heat exchanger.
– Contamination from the environment around the burner is not sucked in. The heating room can therefore can also be used as
a work-room, laundry or for similar purposes.
– Possible to install as central roof unit and in garages.
The drinking water is heated indirectly in a stainless steel corrugated pipe heat exchanger by the pressureless storage tank water
from the hot water tank. This contains about 24 litres (19 litres in GSU 320) of hot drinking water at the temperature level of
the domestic water zone. If a higher quantity of hot water is tapped, this water is heated in the geyser principle.
The precipitating condensation is collected at the lowest point of the boiler body, directed to the storage tank through a plastic
tube and neutralised there. From there, it is directed through the safety overflow connection.
Safety management
The entire safety management of the ROTEX GasSolarUnit is entrusted to electronic control. This effects a safety switch-off in
the event of water shortage, gas shortage or undefined operating states. A corresponding fault message shows the expert all the
necessary information for troubleshooting.
Electronic control
A fully electronic digital control combined with the "intelligent" automatic firing unit of the burner controls all heating and hot
water functions fully automatically for the direct heating circuit, an optionally available mixed heating circuit as well as a storage
tank charging circuit. The continuously modulating control adjusts the heating output flexibly to the changing requirements.
All settings, displays and functions are made through the ROTEX Control THETA 23R or the ROTEX Control ALPHA 23R.
The display and the keyboard offer comfortable operations.
A digital room station (ROTEX THETA RS, 15 70 18 ) or a room controller set (THETA RFF, 15 40 70 ) are available
as option for greater convenience.
The room temperature control (ALPHA RTR-E, 17 51 26 ) is available as option for more convenience.
Condensing technology
The condensing technology makes optimum use of the energy contained in the heating gas. The flue gas is cooled down in the
boiler and in the flue gas system -- in the ambient air-independent method, such that the temperature is below the dew point. Part
of the water vapour generated on combustion of the gas thus condenses. The condensation heat is added to the heating, as
opposed to the case with low temperature boilers. This makes it possible to achieve efficiency levels higher than 100%.
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