An ideal solid fuel does not exist. The use of wood, coal and various compressed waste gives its pros and cons, including financial ones. The homeowner's task is to choose the most profitable option. To clarify this issue, our expert Vitaliy Dashko experimentally burned different types of fuel in real conditions. The goal is to compare what is best for heating a private house - fuel briquettes or firewood. We offer you to get acquainted with the results and the video process.
Why compare cheap firewood with expensive briquettes
For residents of regions rich in forests where woodworking enterprises are located, such a comparison is not relevant. Firewood and sawdust in those parts are inexpensive or get free. But we decided to compare them with briquettes for the following reasons:
- In the southern and desert regions there are practically no forests. Hence the higher price of firewood purchased by the owners of country houses and cottages.
- In these areas, it is beneficial to press any type of combustible mass - coal dust, agricultural waste and peat. Thanks to the development of such industries, the cost of briquettes is reduced and they become an alternative to firewood.
- It is more comfortable to heat molded products than raw wood, which our experiment will show.
The last reason is the conflicting reviews of homeowners about different fuels on thematic forums. A user who is not versed in this matter is unlikely to be able to navigate what types of briquettes are best used for a stove, fireplace or boiler. We will present the conclusions and expert opinion on this matter.
Experiment conditions and progress
The object of verification is a one-story private house of 150 m² with an individual heating system from a solid fuel boiler. Walls 300 mm thick are made of white silicate brick, inside - an air gap. There is no insulation of external fencing, windows are standard metal-plastic.
The remaining experimental conditions are as follows:
- The heating system is closed, two-pipe. It is divided into 2 branches - radiators and warm floors. The initial water temperature is 43 ° C.
- The average daily ambient temperature is 4–5 ° С. The building is cold, warms up for the first time in the heating season.
- The heat source is a solid fuel steel boiler of long burning DIZ-24 (24 kW), equipped with a turbocharger and an automatic control unit to maintain the set temperature.
- The scheme uses a buffer capacity of small capacity (150 liters).
Note. Before the experiment, the boiler and coolant were heated to 43 ° C by burning small logs.
Task: load 3 varieties of fuel one by one into the furnace and check the burning duration of each bookmark with a constant heating mode. The load is the same — 10 kg, the automation is set to maintain a water temperature of 50 ° C.
Purpose: determine what burns out faster - firewood or briquettes, how significant the difference will come out. The secondary goal is to compare the process of burning three types of fuel:
- dry firewood of shed storage;
- round briquettes from sunflower husk;
- briquetted peat.
For reference. The species of wood used is small elm (otherwise it is birch), the stack density of freshly cut logs with a humidity of 50% is 600 kg / m³.
The approximate density of pressed husks is 1800 kg / m³, peat briquettes - 2200 kg / m³. These data are reference and do not play a big role in the experiment, since the fuel was laid in the same amount - 10 kg. Let's start by burning wood.
The result of burning wood
During the inspection, the log blocks were cut into 4 logs and loaded into the furnace, where there were a few hot coals. The controller started the fan and firewood flared up for 1 minute. A total of 10 kg of wood was enough for 1.5 hours of boiler operation, after which the temperature of the coolant began to decline.
What points are worth noting:
- dry firewood gives little smoke and burn very evenly;
- the temperature jump after turning off the fan does not exceed 3 degrees (up to 53 ° C);
- a small residue of ash.
The process of burning dry wood is fairly predictable. If you fill the entire chamber of the heat generator of this model (112 liters) with such fuel, 1 bookmark will last at least 8 hours. Raw (freshly chopped) firewood decay faster: they give off less heat and therefore are more subjected to blowing with a fan.
Sunflower husk briquettes
Since pressed husk contains a fraction of vegetable oil, combustion has several features:
- Immediately after laying 10 kg of cylindrical "sausages", a sharp jump in temperature in the firebox is observed.
- While oil fumes are burning, the pipe is actively smoking. At this stage, it is not recommended to open the loading door - a powerful flame from a sharp supply of oxygen can scorch the face.
- After automatic shutdown of the boost, the coolant temperature rises another 6-7 degrees (up to 57 ° C), then drops to normal.
- While the bulk of the sunflower briquettes does not burn out, the fan is turned on only for purging, which is enough to maintain the water temperature.
- When the oil vapor finally burns out, the amount of smoke from the pipe decreases markedly.
- The remainder of the ash is negligible.
For reference. The purge mode lasts 10 seconds and turns on at intervals of 5 minutes. The goal is to free the boiler chamber from smoke.
The duration of burning a portion of agricultural briquettes was 2 hours 10 minutes, which is 40 minutes longer than firewood. Nuance: you need to learn how to use fuel correctly - at the initial stage, "sausages" emit a large amount of heat. By the way, in boilers with a mechanical draft regulator (without turbocharging), the effect of primary heating is less pronounced.
Pressed Peat Burning
In appearance, peat briquettes resemble coal, but differ in square shape. Equally successful products get their hands dirty, so loading is best done with gloves on. The characteristic moments of combustion are as follows:
- under the influence of boost, peat is well ignited and gives a stable powerful flame;
- when the set temperature of the coolant reaches 50 ° C, the fan stops, the heating "jumps" to 53–54 ° C;
- peat briquettes smoke more than dry wood;
- the amount of ash remaining is approximately 5-10%.
Note. Peat contains a certain fraction of loam, turning into ash. The magnitude of this fraction depends on the fuel manufacturer.
The duration of operation of a solid fuel boiler on peat briquettes is phenomenal - at least 3 hours, which is twice the burning of a similar amount of firewood. An unpleasant nuance is ash and black dust sticking to your hands.
The cheaper it is to heat your home
The price of fuel for heating a private house is of great importance, but it is pointless to consider it in isolation from heat transfer. We will calculate the cost of heating taking into account both parameters.
In the area where our expert lives, they ask for the following prices for proven types of fuel:
- Freshly cut firewood - 20 oz. e. for 1 m³. Tie the price to the mass: $ 20 per 600 kg or 33 y. for 1 ton.
- Briquette from pressed sunflower husks - 57 dollars per ton.
- Peat briquette - 84 y. e. / 1 t.
It is easy to calculate that 10 kg of wood will cost 33 cents, the rest of the fuel - 57 and 84 cents, respectively. Then 1 hour of heating on wooden logs costs 33 / 1.5 = 22 cents (remember, the wood burned for an hour and a half).
Similarly, determine the hourly rate for burning briquettes:
- pressed husk: 57 / 2.17 (2 hours 10 minutes) = 26 cents;
- briquetted peat: 84/3 = 28 cents.
Interesting result, right? In our case, heating a completely cold building costs 5.28 oz. per day on wood, 6.24 dollars on pressed husks and 6.72 at. - on peat bricks.
An important nuance. The prices of solid fuels in your region are likely to differ, and other heating equipment is installed in the boiler room. But the ratio and calculation principle remains unchanged. Apply this technique and consider what is more profitable - firewood or briquettes in your particular case.
Notice, we took the cost of raw wood (and it will decay sooner) and divided by the time of the full burning of dry wood. That is, the difference between traditional fuel and briquettes is minimized. We offer to track the progress of the experiment on video and listen to the expert opinion on this matter:
Reflection Information and Recommendations
We do not persuade anyone to abandon wood heating in favor of briquettes. The purpose of the publication is to convey useful information, help homeowners save money and find comfort. What conclusions can be drawn from the comparison:
- The attractiveness of firewood is a low price. The main thing is that they do not turn out to be too raw.
- In the previous section, the cost of firewood delivered in the form of logs is indicated. The latter need to be cut into logs and chopped into logs. If there is no chain saw in the household, you will have to pay extra for sawing.
- Due to the low density, the log blocks occupy more space than briquettes.
- Pressed waste burns much longer than wood and gives off more heat. The number of visits to the boiler room will decrease.
An important nuance. High-calorie fuel briquettes are a danger to homemade stoves. When the firebox is fully loaded and the chimney is open, the steel body of the furnace is often deformed by the effect of a high combustion temperature.
Pressed products are not perfect. The fuel from agricultural waste contains vegetable oil that settles on the walls of the chimney in the form of soot, and peat leaves ash. To find the best solution and clearly choose the briquettes for the stove, boiler or fireplace, select part of the day off and conduct a similar experiment with a variety of fuels. Combine bricks with firewood, observe the results and count the money - this is the right way to economical heating.