Windhager DuoWIN, Assembly Instructions Manual

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2. For the Installer
Boiler start-up relief for wood gasification boiler:
Basically, a boiler startup relief always has to be installed for the wood gasification boiler so that the circulation
pump(s) switch off at boiler temperatures below 62°C. This prevents condensation from forming in the boiler and
extends its service life. A similar boiler start-up relief is contained in the MESplus control system.
2.2.4 Circulation pump
Since 2013, new circulation pumps are required in Europe to fulfill minimum energy efficiency requirements.
Please refer to the Energy Efficiency Index (EEI).
2.2.5 Return temperature
Wood gasification boiler:
Return flow temperature is required for wood gasification boilers. It is essential that a return temperature of 61
°C be maintained during heating.
In order to achieve good temperature stratification in the heat accumulator or buffer tank, we recommend
regulating the boiler circuit. When using the SK RH 61 return hold-up group in connection with the stratified charge
function (MESplus function module WVF+), regulating the boiler circuit is no longer necessary.
Pellet boiler:
As standard, a return flow temperature increase is installed in the appliance, allowing the boiler to operate with
a return temperature down to a minimum of 20 °C. No external return flow temperature increase is required.
Exception: If the heat accumulator or is buffer loaded directly from the pellet boiler, it will be necessary to incre-
ase the return flow temperature externally to at least 45 °C.
Information!
With parallel operation of both boilers (PowerBoost function) the buffer has to be loaded directly
from the pellet boiler. In this case, the return flow temperature has to be increased to at least 45°C
(accessory SKRH 45P).
2.2.6 Accumulator tank
The installation of a buffer tank is required by the following standards / laws:
– EN 303-5
– 1st Federal Immission Control Ordinance (Germany)
– Art. 15a of the Small Combustion Devices Agreement (Austria)
– Air Protection Ordinance (Switzerland)
A correctly sized accumulator tank is essential for proper operation of a wood-fired heating system. The fuel must
always be selected and the heat load of the building calculated. Heating characteristics ( e.g., hot water prepara-
tion in summer) and the system configuration (ground and/or radiator heating circuits) should also be taken into
consideration.
Information!
Rooms that are not always heated (guest rooms, seldom used living areas, etc.) must be subtracted
from the calculated heat load (QH) for the accumulator tank configuration!
Recommended accumulator tank content: 2000 l
Note!
Refer to planning documents for how to calculate the minimum buffer tank volume.