Are you looking for ways to heat your home stylishly, ecologically and cheaply? Then heating with wood is worth considering. A fireplace provides cozy warmth in winter and makes the house comfortable. There are now numerous different types of fuel such as logs, pellets and wood briquettes that are relatively easily available. The technology has also been greatly improved in recent years. When operated correctly, modern fireplaces produce heat with high efficiency and low C02 emissions. The systems in the living area not only look stylish, but also offer an impressive flame image thanks to large glass panes.
So that you can make the right purchase decision, you should be clear about your own wishes beforehand and know exactly which model would best cover your needs. By the way, you can also use various online help when making your selection, such as this interactive fireplace buying guide. However, so that you can correctly interpret the technical data and details of each stove model, we will give you some valuable information below.
Room size and heat output
The basis for effective wood heating is determining the required heat output in relation to the room to be heated. Power is measured in kilowatts (kW) and varies between 3 kW and 15 kW. For more precise determinations, in addition to the size of the room, several factors must also be taken into account, such as the insulation of the house, the number of windows, the location of the fireplace, etc. Especially in old buildings, where there is a lack of insulation or with large window areas, it doesn't hurt to add around 5 to the calculated wood output add up to 10 percent.
A rough estimate looks like this:
To achieve a comfortable room temperature of around 25 degrees (when the outside temperature is 0 degrees), you need an average of 1 kW of power for every 15 m³ of room volume.
Determine the length, width and height of the room and multiply the three values. If a room is 10 m long, 5 m wide and 2.5 m high, the total volume is 125 m³.
For average insulation, this value is divided by 15. So you need a stove with a rated heat output of 7 or 8 kW. The worse your room is insulated, the higher the kW number of the oven should actually be. In old buildings, the heating output determined in this case would be 11 to 12 kW. With good insulation, a heating output of 4 to 5 kW is sufficient.
| Insulation | Raumvolumen m³ | Desired temperature 25° / outside temperature 0° |
|---|---|---|
| Poor or no insulation (old buildings) | m³ ÷ 10 | Nominal heat output in kW |
| Average insulation (buildings built since 1975) | m³ ÷ 15 | Nominal heat output in kW |
| Good insulation (new buildings) | m³ ÷ 25 | Nominal heat output in kW |
Fuel and burning time
The fuels approved by the stove manufacturer are usually listed in the product description. In general, untreated wood, wood briquettes and lighting aids are permitted in Germany. Brown coal briquettes may only be used if the stove has been tested for coal fuel. Painted, coated wood or wood treated with wood preservatives is not permitted for wood stoves. You can find out more about the appropriate firewood and briquette qualityread this brochure from TFZ.
In principle, you can use all types of wood for heating. However, different types of wood have different calorific values. The heavier the type of wood, the higher the calorific value of the wood. If you heat with light wood, you will need to add firewood more often. By the way, you can buy a mix of light and heavy types of wood. The light wood can belight easilyand the hard type of wood is used for long-term heating.
If the stove has to burn with one fuel for more than 10 hours or overnight, pay attention to the term “continuous burning”. In addition to logs and wood briquettes, continuous burning stoves are primarily operated with coal and can heat a room independently over a longer period of time.
Modern technology brings with it better efficiency
The efficiency indicates how efficiently the fireplace works in full operation. High efficiency means cost-effective and ecologically sensible heating. Because significantly less fuel is used.
To protect the environment mustold fireplaces until the end of 2017be retrofitted with a special filter or shut down. This threatens ovens for generations, as stricter requirements for efficiency and pollutant emissions are also planned in the future. The Ecodesign Directive recommends a minimum efficiency of over 80% from 2022.
cladding material
Modern fireplaces are mainly made of steel or cast iron. However, cladding can improve heat retention and therefore energy efficiency. This means the room stays warmer for longer. The different claddings have different advantages and disadvantages. Soapstone and other natural stones, for example, are characterized by high thermal conductivity. They absorb a lot of heat quickly, but release it just as quickly. Ceramic tiles and sandstone have lower thermal conductivity and take longer to fully heat up, but release the energy over a correspondingly long period of time.
We know that choosing the right stove for your home is no easy task - but we hope that our guide has been of some help to you. The better informed you are as a customer, the lower the risk of experiencing unpleasant and possibly expensive surprises.
