20
ENGLISH RAIS - Manual for RAIS RIVA
The following table shows the calorific value of different types of wood, which have been
stored for 2 years, and which have a residual moisture of 15-17%.
Wood
Kg dry wood pr. m
3
compared to beech/oak
Hornbeam
640
110%
Beech and oak
580
100%
Ash
570
98%
Maple
540
93%
Birch
510
88%
Mountain pine
480
83%
Fir
390
67%
Poplar
380
65%
1 kg of wood yields the same heat energy irrespective of wood type. 1 kg beech merely
takes up less space than 1 kg of fir.
Drying and storage
Drying wood takes time: proper air drying takes approx. 2 years.
Here are some tips:
Store the wood sawn, split and stacked in an airy, sunny place, which is protected against
rain (the south side of the house is particularly suitable).
Store the firewood stacks at a hand’s breadth apart, as this ensures that the air flowing
through takes the moisture with it. Avoid covering the firewood stacks with plastic, as
this prevents the moisture from escaping. It is a good idea to bring the firewood into the
house 2-3 days before you need it.