La Nordica Norma S Idro D.S.A пергамент [27/64] Maintenance on the water system

NORMA-S IDRO DSA / STEEL / CLASSIC

7197130s - IT-EN-DE-FR 27

13.9. MAINTENANCE ON THE WATER SYSTEM

Excessive incrustation deposits on the inner walls of the hearth considerably reduce the efciency of heat exchange; therefore, remove

these deposits using a steel brush whenever necessary. Never use corrosive substances that can damage the thermo-replace and

the boiler.

With the system switched off, once a year carry out the following checks:

• Check the operation and efciency of the blowdown and safety valves. If they are defective, contact your authorised installer. IT IS

STRICTLY FORBIDDEN TO REMOVE OR TAMPER WITH THE SAFETY DEVICES.

• Check the thermal insulation of the lling pipe and the safety pipe.

• Make sure that the system is lled and under pressure, checking the water level in the expansion tank; also check that it is working

properly and check the efciency of the safety pipe.

14. 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 caloric value necessary for a properly insulated room is 30 kcal/h per m

(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

Let’s suppose one wishes to heat a room of 150 m

(10 x 6 x 2.5 m) in an insulated apartment. In this case, it is necessary to have 150 m

x 38 W/m

= 5700 W or 5,7 kW. As main heating, a 8 kW device is therefore sufcient.

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

7800 9.1 0,46

Naphtha L 8500 9.9 0,42

Electricity kW/h 860 1.0 4,19