22
12.4. MAINTENANCE OF THE EXTENSIBLE GUIDES
To work silently, as well as in a reliable and robust way, the doors are fastened to the extensible ball guides. By using the device continuously,
the lubricant of the guides tends to run out progressively in time making their sliding more difficult and noisy. For this reason, together
with each device a high temperature grease is supplied in order to make the lubrication of the guides possible for the user, in case it
becomes necessary (excessive noise or reduction of smoothness). After having completely lifted the door of the stack, using a syringe,
apply internally on the track on a visible point, as high as possible, two grease balls (corresponding to 0.5 ml of the graduated scale of the
syringe). Pay attention not to exceed the suggested quantity. Repeat the same operation on the other track and lift and lower the door many
times so that the grease distributes on all balls.
CAUTION: use exclusively the grease supplied by La NORDICA
.
13. CALCULATION OF THE THERMAL POWER
There is not an absolute rule for calculating the correct necessary power. This power is given according to the space to be heated, but it
depends also largely on the insulation. On an average, the calorific value necessary for a properly insulated room is
30 kcal/h per m
3
(for
an external temperature of 0°C).
Given that
1 kW corresponds to 860 kcal/h
, it is possible to adopt a value of
38 W/m
3
.
Let’s suppose one wishes to heat a room of 150 m
3
(10 x 6 x 2.5 m) in an insulated apartment. In this case, it is necessary to have 150 m
3
x 38 W/m
3
= 5700 W or 5,7 kW. As main heating, a 8 kW device is therefore sufficient.
Approximate combustion value
Required quantity in relation to 1 kg of dry
wood
Fuel
Unit
kcal/h
kW
Dry wood (15% humidity)
kg
3600
4.2
1,00
Wet wood (50% humidity)
kg
1850
2.2
1,95
Wood briquettes
kg
4000
5.0
0,84
Brown coal briquettes
kg
4800
5.6
0,75
Normal anthracite
kg
7700
8.9
0,47
Coke
kg
6780
7.9
0,53
Natural gas
m
3
7800
9.1
0,46
Naphtha
L
8500
9.9
0,42
Electricity
kW/h
860
1.0
4,19
