WOOD BURNING BOILER COOKER ALTEA 110 SICURO TOP
11
EN - Rev. 1.2
appliance is directly affected by the type of wood used, on average a well-seasoned wood has a calorific value of 3200
kcal/kg.
Calorific value of wood in relation to humidity:
CALORIFIC VALUE
of the wood means the amount of heat yielded during combustion, referring to the unit quantity of
the material burned.
The calorific value of a wood species depends on the presence of
lignin
(6000 Kcal/kg) or
cellulose
(4000 Kcal/kg) as
well as the abundance of
resin
(8500 Kcal/kg).
The calorific value per unit of weight ( = absolute) is highest in Conifers.
-
Absolute calorific value of conifers: 4700 Kcal/kg
-
Absolute calorific value of broad-leaved species: 4350 Kcal/kg.
On the other hand the
SPECIFIC WEIGHT
of the “broad
-
leaved species” is greater; therefore with equ
al volumes
introduced into the appliance, both the weight and amount of heat available for combustion are greater; in practice the
relative calorific value is higher (referring to a unit of volume).
For example:
the calorific value of the white fir is practically the same as that of the oak, but the oak has a specific
weight that is twice that of the fir. Therefore half the volume of oak must be introduced into the appliance in order to have
the same "heat" obtained from the fir.
*Calorific value
(Kcal/Kg)
**Specific weight
(Kg/m3)
WHITE FIR
4650
440
RED FIR
4857
450
MAPLE
4607
740
BIRCH
4968
650
BLACK ELM
4640
820
CHESTNUT
4599
580
TURKISH OAK
4648
900
CYPRESS
5920
620
BEECH
4617
750
ASH
5350
720
HOLM OAK
/
960
LARCH
4050
660
EUROPEAN ALDER
4700
530
FLOWERING ASH
/
760
PLANE TREE
/
690
CYPRESS POPLAR
4130
500
FALSE ACACIA
4500
790
DOWNY OAK
4631
880
* theoretical absolute value.
** wood seasoned in the air; residual humidity 12-15 %.
% of humidity
Calorific value kcal/kg
15%
3490
20%
3250
25%
3010
30%
2780
35%
2450
40%
2300
