As practice shows, several factors influence the actual consumption of pellets for space heating. Consider the most important of them:
- Climate and ambient temperature;
- Heat loss of the room. This indicator is affected by the material used for the construction of the building and the method of weatherization of walls, ceiling and floor. Everything is simple here – the less heat loss, the lower the consumption of solid fuel;
- Solid fuel furnace design, its power and heat distribution system;
- The quality of the granules, their grade. The combustion rate, calorific value and ash content depend on this.
How much pellet is needed to heat a house of 100 m²?
As discussed above, the calculation of fuel consumption is a subjective concept. The main variable here is the heat loss of the room. In the construction of modern houses, regardless of material, they use high-quality thermal insulation. It is believed that the average value of heat loss is 70 W / kV.m. in an hour. We will also calculate the required amount of fuel pellets for well weatherproof houses (50 W / m² / hour), poorly weatherproof (100 W / m² / hour) and practically not weatherproof (150 W / m² / hour).
To begin with, we calculate the amount of heat for heating a house with an area of 100 m² per day according to the formula:
Q1 = S * 24 * 0.7 * 70, where:
Q1 – indoor heat consumption during the day, W;
S – area of the house, m². In our case, this indicator is 100 m²;
0.7 – coefficient of equipment operation, hour;
70 – average heat loss of the house, W / m² / hour.
Substituting the values in the formula, we get:
Q1 = 100 * 24 * 0.7 * 70 = 117600 W. or 117.6 kW.
Tab. 1. The required heat for heating of rooms of different quality of insulation
|Total heat loss, W / h||The required amount of heat for heating during the day, kW|
In order to find out the amount of pellets needed to heat the room during the day, you should use the formula
- V day = Q1 / Q2, where:
V– volume of solid fuel (pellets), kg;
Q1 – the required amount of heat per day, kW;
Q2 – calorie content, kW / kg (a certain amount of thermal energy obtained by burning 1 kilogram of wood pellets).
In our case, substituting the obtained values, we obtain:
- day = 117.6 / 4.659 = 25.24 kg.
Table 2. The daily need for fuel pellets for houses with varying degrees of heat loss
|Total heat loss, W / h||The volume of pellets for heating during the day, kW|
Knowing the daily consumption rate, you can determine the number of pellets for the entire heating season. Use the following formula
- Vseason = M days * d, where
d – the number of days of the heating season (usually no more than 180 days). If you use a solid fuel boiler for heating the cottages only on weekends, calculate the approximate number of days when heating will occur.
Substituting the values, we get
- Vseason = 180 * 25.24 = 4534 kg. or 4.534 tons.
Table 3. The volume of fuel pellets for the entire heating season, depending on the heat loss at home
|Total heat loss, W / h||The volume of pellets for heating during the heating season, kW|
As you can see, the required amount of fuel depends on the quality of the insulation of the house. This should be taken into account so that the use of wood pellets is worthwhile.