All about pellet heating
In recent years, the wood pellet heating system has become increasingly popular. When someone plans to change the heating system, for example to switch from wood, coal or electricity to wood pellets, there are many unknowns ahead of them. Pellet quality, price, price with transport, boiler price… Advantages and disadvantages, pros and cons, there are many topics… We will try to alleviate the dilemmas when it comes to this investment.
What exactly pellet is? It is a firewood that is created by compressing wood mass such as sawdust and shavings. Depending on the manufacturer, i.e. the way in which the wood pulp is supplied, it can be beech, oak, pine or a mixture of different types of wood. The production process involves grinding, drying and pressing. When pressing under high pressure, the temperature of the wood rises and natural glues are released in the wood mass, so that no additional chemicals are used for bonding. This makes pellets an ecological fuel, which, in addition to protecting the natural environment, thanks to its cleanliness, also preserves the boiler or furnace where it burns. The pellet is produced in cylindrical granules with a diameter of 6 to 8 millimeters and a length of one to four centimeters. It is packed in nylon bags of 15 kilograms and on pallets, where there are 70 bags on each barn, which is approximately one ton.
Pellets can burn in boilers that are connected to the central heating system, and smaller spaces can be efficiently heated by pellet stoves that emit heat locally. A pellet stove is actually a replacement for a wood stove. The advantages are that there is no more input, splitting and stacking of wood. When the stove is supplied with pellets, it can work longer and it is not necessary to constantly maintain the fire.
Also, starting does not mean lighting a fire, but pressing a button. One of the advantages of a pellet stove compared to a wood stove is an incomparably higher degree of fuel efficiency. A wood stove is a relatively primitive device, in which the wood in the firebox burns inefficiently, and then a large percentage of the produced heat is lost by going through the chimney.
It is easy to be convinced of that if you touch hot drain pipe of the wood stove and the popular “Smederevac”. All that heat, unused, goes through the chimney into the air. Pellet stoves have a degree of utilization of more than 90 percent, which is incomparably better than about 70 percent of the efficiency of wood stoves. It also means that pellets as fuel will take up less space than wood, which is also an advantage for many. Pellet stoves produce less ash, so cleaning is less frequent and incomparably more comfortable. The disadvantages of pellet stoves are that they are noisier than wood stoves due to the fan system. Also, in case of power failure, the pellet stove stops heating, while the wood stove works without electricity. There is a possibility of connecting to a car battery, which is a good solution for areas with frequent power restrictions.
The boiler or burner?
Pellet boilers, unlike stoves, are used for heating buildings with several rooms, because they are connected to the central heating system. This solution is most interesting for households that already have a central heating system with a wood or coal boiler, because such a boiler is simply replaced by one that uses pellets. One of the options is to install a pellet burner on an existing solid fuel boiler.
This means that a special burner is installed on the door of the solid fuel boiler, which enables the pellet to burn in the existing boiler. This system provides all the advantages as a classic pellet boiler, which is a smaller amount of ash, the inclusion of “push-button”, longer autonomy of work without constant maintenance of fire. However, one detail disqualifies this solution, and that is the degree of utilization. When a pellet burner is installed on an existing boiler, which is probably already old, no one can guarantee the degree of utilization. It will certainly not be nearly as high as with a boiler designed only for pellets. Here the whole mathematics falls apart, because less investment in the burner, instead of into a new boiler, can be melted after a few years, depending on the square footage that is heated.
The first and basic cost is the purchase of a boiler. The boiler is selected depending on the area to be heated. Precise data on how many kilowatts are needed per square meter cannot be given, because it depends on many factors, such as the quality of construction, the quality of carpentry, insulation, etc.
The roughest orientation is that one hundred square meters of well-insulated space could be heated with about 8 kilowatts, while with an uninsulated house, that number can be around 11 kilowatts.
However, this should be taken as the roughest orientation when choosing a boiler. Of course, it should always be slightly higher than the obtained calculation, in order to ensure work without load even during the biggest winter minuses. Depending on the boiler manufacturer, the costs also vary. Some boilers have a built-in water pump, some do not, so it is necessary to buy it, or use the one in the existing heating system. There are already many combinations, so it is best to consult a master. With most boiler manufacturers, the procedure is as follows: when you buy a boiler from them, they deliver it to your home address. Then it is necessary for the master to install it, i.e. to connect it to the central heating system and the chimney. After that, authorized service technicians from the manufacturer where you bought the boiler come, check if it is connected properly and put it into operation. So, the master you plan to invite to have your boiler installed, it is best to ask which boiler would be best for your square footage and heating system. After buying the boiler, calculate that there will be more costs.
Depending on the system, many other elements (flue pipes, copper pipes, mixing valve, etc.) are needed to connect the boiler and put it into operation. Boiler sellers offer a standard kit, which is sold at a price of about 8,000 dinars, but it should not be bought. Depending on the position of the boiler, the distance of the chimney and numerous other elements, it is not possible to determine exactly how many water pipes, elbows or flue pipes are needed. This specification can be most precisely made by the master when the boiler arrives. Most important of all is that the master is experienced and perhaps more importantly, that he is honest.
And the cost of heating?
Heating costs also depend on many factors. It may sound overly optimistic, but a well-designed pellet heating system can be cheaper than wood heating. A wood-fired boiler, especially when the heating season is over, when dirt accumulates in the drainage channels, can consume a lot of wood. A house of 150 square meters can easily burn up to 20 meters of wood per season. For such an area, 4 to 5 tons of pellets should be enough. The prices of wood and pellets, as the year goes by, grow equally, but five tons of pellets generally is cheaper than 20 meters of wood. It is best to buy pellets in the spring. Then the pellet sellers have the lowest turnover, so the prices are the lowest. You only need to get into that rhythm once, because postponing a purchase means a much higher cost.
How to recognize quality pellets?
Like any product, pellets can be high quality and low quality. Depending on the type of pellet, also depend the operation of the boiler itself, its reliability, level of soiling and amount of ash. The first thing that is needed is for the seller to have a certificate, for something to be written on the bags, and then by “googling” you can get information about the quality. The first thing required is that the seller is certified, something to be written on the bags, and then by “googling” you can get information about the quality.
It is necessary to write the composition on the bag, i.e. what wood the pellet is made of, as well as numerous other specifications about the dimensions of the granules, the percentage of moisture… By buying pellets in an unlabeled bag, you are actually “buying a cat in a bag”. It also means that you have no one to complain to or report a complaint to. The seller of such pellets is probably the last address you can contact. There should be as little dust as possible in the bags (with quality pellets, there is practically none). The granules themselves must be smooth and smell like wood, not chemical ingredients. You can make a simple test with a few granules: those in a glass of water must sink and after a few minutes swell and practically disintegrate, and the water must remain clear. All this means that there are no unwanted ingredients and glues in the pellet, which can damage the combustion system in the boiler.