8
2.
For the installer
2.2.3 Heat accumulator (buffer)
The installation of a heat accumulator (buffer tank) is required by the following standards and laws:
– EN 303-5
– 1. BImSchV
– Art. 15a of the Small Combustion Devices Agreement (Austria)
– Air Protection Ordinance (Switzerland)
Having a correctly sized heat accumulator (buffer tank) is essential for correct operation of a wood-fired heating system.
The fuel must always be selected and the heat load of the building calculated. The type of heating (e.g. bringing the hot
water tank up to temperature in summer) and system design (underfloor and/or radiator heating circuits) should also
be taken into account.
CAUTION
Rooms that are not heated at times (guest rooms. living areas only used at weekends.
etc.) must be subtracted from the calculated heat load (QH) for the tank configuration!
Recommended heat accumulator volume (buffer tank volume)
Wood gasification boiler
Boiler model
Recommend heat accumulator volume
LogWIN
LWP 180T – 305T
2000 litres
LWP 360T / 365T
2500 litres
LWP 500T / 505T
3000 litres
Note!
To calculate the minimum heat accumulator volume (buffer tank volume). see the planning documents.
2.2.4 Heating circuits
Several heating circuits:
In-line regulating valves must be installed to permit better regulation of the system. In a building without insulation
(new building. not yet plastered) the calculated and actually required heating requirements often differ to a consider-
able extent.
Minimum heat consumption:
The smallest possible boiler power must be continuously dissipated from the boiler during operation. Suitable measures
to ensure minimum heat consumption should be maintained throughout the entire burning time. e.g.:
– Correctly dimensioned buffer tank. see Section 2.2.3
– Using the MES INFINITY control function in the buffer load functional module.
incl. no thermostatic valves
– Non-blockable heating circuit. e.g. never fully close manual mixing valve. incl. no thermostatic valves
Note!
If operating with a manual mixing valve or the control system. elevated room temperatures may sporadi-
cally occur.
Mixer valve:
A 3-way mixer valve is always necessary; in conjunction with outside temperature control. there must be a 3-way motor-
ised mixing valve and a buffer tank.
Underfloor heating:
Only possible with a buffer tank (with outside temperature control. motorised mixing valve).
Return flow temperature increase:
This is necessary in all systems with a heat accumulator and a buffer tank and in old systems with a large volume of
water (> 200 l). With the LogWIN. it is essential for the temperature of the return flow to be kept to at least 45 °C during
