8
For the Installer
2.4 System
2.4.1 Area of use
For heating buildings acc. to EN 12831.
The boilers are designed and approved as heat generators for hot water heating systems with permissible flow
temperatures of up to 90 °C.
2.4.2 Standards
The following European standard should be followed: EN 12828, this specifies that the following should be fit-
ted:
a) A closed expansion tank.
b) A reliably functioning safety valve installed at the highest point of the boiler or at a non-closable line.
c) A thermometer, a pressure gauge.
d) An automatic device for dissipating heat which will prevent the maximum permitted operating temperature
from being exceeded. The built-in thermal safety device (heat exchanger) should always be used in conjunc-
tion with the thermal process safeguard. In addition, a gravity feed hot water tank with thermal process safe-
guard can also be used.
e) A low-water cut-off: A low-water cut-off is not required for systems providing up to 300 kW nominal thermal
output, if it can be assured that excess heating will not result from a lack of water in the system.
If the boiler is above the radiators, then a low-water cut-off must be installed.
2.4.3 Accumulator tank
Having a correctly sized accumulator 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. Heating characteristics (e.g. bringing
the hot water tank up to temperature in summer) and the system configuration (ground and/or radiator heating
circuits) should also be taken into consideration.
Tip:
Correct amount of fuel – i.e. boiler only ¼ – ½ full at the turn of the seasons.
With domestic water supply plants, a heat dissipation of the smallest possible boiler output must
be assured even if there is a power failure! Failure to comply with this requirement can result in a
thermal overload of the boiler components and invalidation of the warranty.
Rooms that are not heated at times (guest rooms, living areas only used at weekends, etc.) must be
subtracted from the calculated heat load (Q
H
) for the accumulator tank configuration!
LogWIN
LWP 180
LWP 250
Formula
symbol
Unit
Beech fully filled
Spruce fully
filled
Beech fully filled
Spruce fully
filled
Recommended accumulator tank content:
l
2000
2000
2000
2000
Heat load of the building acc. to EN 12831
Q
H
kW
13.0
17.4
13.0
17.4
13.0
25.0
13.0
25.0
Burning duration of the LogWIN at nominal thermal output
T
B
h
10.3
6.6
7.2
4.6
Nominal thermal output of the LogWIN
Q
N
kW
17.4
25.0
Minimum thermal output of the LogWIN
Q
min
kW
13.0
13.0
Correction factor
1)
f
1.019
1.029
1.029
1.046
1.047
1.156
1.074
1.246
Recommended accumulator tank content:
