Wood heating is an environmentally friendly and economical heating method.

Log boilers are the most traditional form of heating – burning split pieces of hardwood or softwood. They can also burn briquettes, which are wood scraps compressed into uniform pieces. They have a higher energy content than logs. Log boilers are typically loaded manually and achieve high efficiency thanks to wood gasification technology. Requiring no special storage or conveyor system, wood gasification boilers are inexpensive compared to other heating systems. The technology itself has been proven for many years, confirming its reliability. Biomass heating systems burning logs are available in a wide range of power outputs and are suitable for both new and existing buildings.

Fuel storage advice: Logs are easy to store. However, to ensure efficient combustion, their moisture content must be below 20 percent. Therefore, it is recommended to store them for several years.

Pellet boilers are available in a variety of power ratings and can be installed in both new and existing buildings. They operate on fine pellets made from forestry or industrial wood waste, making them one of the most environmentally friendly fuels available. They also have a particularly high energy content and, thanks to their uniform shape, can be automatically fed into heat generators, eliminating the need to manually fill these heaters with biomass. Pellet heating systems are more expensive to purchase and install than other heating systems due to the need for fuel storage and a conveyor system. These are necessary to ensure the pellets burn efficiently and produce the maximum energy possible. There are five methods for storing and feeding pellets:

• Storage and feeding to the pellet boiler via a vacuum system
• Pellet hopper with feeding to pellet boiler via vacuum system
• Warehouse with pellet boiler feed via flexible screw conveyor
• Pellet hopper with feeding to pellet boiler via flexible screw conveyor
• Pellet box – flexible and compact storage for pellets
• You can find detailed information about this in the section Storage and supply of pellets .

Fuel purchasing tip: Ensure the pellets you use meet a standard brand quality, such as ENplus-A1 or EN ISO 17225-2 A1. Only 100% unprocessed wood residues are used in the production of wood pellets that meet ENplus and EN ISO 17225-2 standards.

With the exception of the conveyor system, wood chip boilers operate similarly to pellet boilers. The most important difference: They run on wood chips, not pellets. Wood chips consist of dried and crushed forest and industrial residues, as well as firewood. Because they are easier to produce, natural wood chips are less expensive than pellets. They do not have a fixed shape and have a slightly lower and less consistent energy content. They also require more storage space than other biomass fuels. Wood chip boilers can be used in both new and old buildings and are particularly suitable for regions where fuel can be produced inexpensively from forest residues.

A wood-fired combination boiler is a versatile biomass heating system. It can be manually loaded with logs or wood briquettes, or automatically operated with wood pellets or wood chips. These versatile wood-fired heaters are available in a variety of power ratings and are suitable for heating both new and existing buildings. Compared to heat generators that burn only one type of wood, the purchase cost of a combination log/wood-fired boiler is higher.

Wood heating is considered the oldest form of heat generation using biomass combustion. Wood has provided people with warmth for centuries. Over time, the technology has been repeatedly optimized and is therefore considered very mature. Furthermore, wood heating systems are extremely durable. For example, some wood boilers with a solid cast-iron grate can handle screws or nails driven into the wood without damaging it. They are designed for a long service life. Furthermore, modern biomass combustion systems are fully automated and equipped with control and safety devices for reliable, efficient, and safe operation.

Viessmann wood-burning boilers can operate efficiently in both single and dual modes. In addition to providing domestic hot water, these boilers can also provide pleasant warmth during the winter months. Properly sized, the boiler operates according to the needs of each application, preventing unnecessary heat loss. A built-in combustion controller also ensures efficient energy consumption while reducing emissions.

With rising fossil fuel prices and growing environmental awareness, clean energy production is becoming increasingly important. The German government, for example, has set a goal of increasing the share of renewable energy sources to 60 percent by 2050. One of the advantages of wood heating is that it can be combined with other systems, such as solar. Using both of these technologies not only helps users protect the environment but also significantly improve their energy self-sufficiency.

As mentioned, beyond the economic aspects, there are also numerous environmental benefits when homeowners choose wood heating. Two notable advantages are independence from fossil fuels and the sustainability of the source.

Oil and gas prices are highly dependent on economic and political fluctuations and are difficult to predict. However, the overall trend is upward, not least because oil and gas are limited resources. Wood, on the other hand, is very economical and, as a local fuel, is not subject to sharp price fluctuations.

Indeed, fuel gas can be produced from renewable energy sources. However, this development is progressing slowly. Thus, independence from fluctuating fossil fuel prices is one of the many advantages of heating with wood.

Burning wood only releases as much CO₂ as the trees absorbed during their lifetime. Therefore, heating with wood is CO₂ neutral. Furthermore, the fuel typically comes from regional forests and does not need to be transported long distances. As wood heating has become increasingly popular in recent years, some companies have begun importing wood fuel from abroad. This cheap wood is sometimes of poor quality and burns poorly. Furthermore, it is not always possible to determine whether the fuel was obtained from illegal logging or from sustainable forests.

Therefore, it’s always important to pay attention to the origin of your firewood and, whenever possible, choose locally produced wood. Certificates such as EN Plus for pellets are a good guide when choosing wood fuel. Purchasing from local sellers ultimately reduces the environmental impact and supports the regional economy.

In addition to environmental and economic benefits, wood heating systems provide a highly reliable energy supply. Firstly, wood heating is the only renewable energy source capable of providing heat from -25 to +20 degrees Celsius, regardless of the weather. Furthermore, the raw wood grows locally, making wood heating system owners independent of global crises.

Viessmann wood-burning boilers are so easy to use that they can provide heat for virtually any detached house or apartment building. A key requirement is a dry storage area, as residual wood moisture is a critical factor influencing combustion quality. Modifications, such as chimney installations, are generally not required.

Viessmann wood-burning heating systems are also an excellent complement to oil and gas heating systems.

Logs are an ideal choice for those who can source their own fuel, such as from local forests. The wood must be properly seasoned, meaning it must be stored until it reaches the lowest possible residual moisture content. Pellets are made from sawdust and pressurized. Their low residual moisture content gives them a high net calorific value. Pellets are easier to transport and store. Feeding and dosing into a wood heating system is automated and convenient.

Since both types of wood fuel have their own strengths and weaknesses, this question cannot be answered definitively. It is important that the boiler is suitable for the building and best meets the heating needs of all residents. A heating contractor can usually provide detailed, customized advice.

A buffer tank captures heat generated by the boiler and stores it. This has two advantages: it ensures a continuous heat supply and prevents the need for frequent combustion restarts. This increases the boiler’s service life and ensures highly efficient fuel combustion. Use of a buffer tank may be a requirement for government subsidies.

The buffer tank takes up little space, but in most cases it ensures economical operation of the heating system.

Wood fuel, especially wood pellets, are now the standard fuel for most fuel retailers. Like fuel oil, they are “pumped” into storage, which is quick and easy. Many sawmills and wood processing companies also offer pellets. Logs can be purchased at competitive prices from foresters or farms that are affiliated with forestry enterprises.

When purchasing, look for high-quality products. They are somewhat more expensive, but typically have a higher energy content and better combustion properties. This pays off ultimately when burning. High-quality pellets can be identified by a DIN Plus or EN Plus certificate.

Many older buildings already have a boiler room. This can also be used for storing wood fuel. This makes wood heating an ideal choice for older buildings. However, wood can, of course, also be used to heat new buildings. In this case, the choice of system is crucial to ensure its efficiency. Simply click the “Request an Expert Consultation” button to receive a free, no-obligation consultation with a Viessmann wood heating system specialist.

There’s no best time to purchase a wood heating system. In practice, most homeowners take advantage of the warm summer months to install a new heating system. The reasons are obvious: central heating is practically unused in summer, and less hot water is needed. Having a good window of time before the next heating season allows for accurate planning.