Heating stove
A heating stove is a stove with a hob (possibly also a baking compartment) which also feeds warm water into the central heating system via a water supply . If necessary, it can also generate hot domestic water . Heating stoves are tested according to their own technical standard.
advantages
Water-bearing heating stoves enable the entire house to be heated, as the energy they generate reaches the radiators in the rooms. In addition, they can cover the heat for the hot water supply for the shower and bath. The hob can be used to heat or keep food warm. Any existing baking compartment can also be used for baking. In conventional wood-burning stoves, the heat is only transported through the heated air in the fireplace room and possibly directly adjacent or above rooms, since heated air can only rise. Rooms below the fireplace room cannot be heated without installing additional devices.
Ovens in which cooking and baking are in the foreground and heating is only of secondary importance are called table stoves .
Use / use
Water-bearing heating stoves are connected to a water-bearing heating system in the house. They thus serve to heat the installation room and supply their “excess” energy as thermal heat to the heating network of the house. The heat thus reaches the radiators in the individual bedrooms and living rooms via the heating network and can also be used to supply the house with hot water.
Technical variants
There are two basic variants of heating stoves, the closed, pressurized systems and the open, pressureless systems.
Pressurized systems
In the closed, pressurized systems, the water flows from the heating system through two connections to the heating system into the heating stove in such a way that the heating water has direct contact with the walls that come into contact with the flame. The water of the heating system is always exchanged with the water of the heating stove or it is the same water. With these systems, a return temperature increase must be connected upstream of the heating stove to avoid corrosion from any condensation that may occur. The pressure in the heating network is also available in all areas of the heating stove.
Pressureless systems
The open, pressureless systems already have a permanently installed heat exchanger inside the heating stove. The water from the heating system does not come into contact with the walls that come into contact with the flame. These systems have two separate water areas, the water in the heat exchanger and the water in the heating stove. The water in the heat exchanger is not mixed with the water in the heating stove. When the heating stove is put into operation, the walls that come into contact with the flame first heat up and the water behind them is heated. The heat exchanger is now in this heated water and is also heated. The water in the heating system only flows through the heat exchanger when the water from the heating stove exceeds an adjustable temperature. This ensures that water that is too cold from the heating system does not reach the walls that come into contact with the flame and that no corrosion from condensation can occur. Furthermore, there is no need to install a return temperature increase in such systems . The systems are open and are therefore not under pressure, which increases safety, only the heat exchanger integrated in the heating stove, which is connected to the heating system, is subjected to the pressure that is specified in the heating system. This pressure is required to supply higher-lying radiators with hot water.
Classification in a European standard
The technical requirements that a water-bearing heating stove must meet in Europe are standardized in EN 12815 for Europe. This standard summarizes all safety-relevant requirements as well as the requirements for efficiency. Furthermore, the standard regulates which tests a technical testing institute must carry out so that a water-bearing heating stove can be sold in Europe. The manufacturer has to have the test according to the standard carried out by an accredited testing institute. Proof of compliance with the requirements specified in EN 12815 is provided by the manufacturer on the nameplate attached to the heating range.
environmental Protection
The requirements that environmental protection places on heating stoves are defined at two legal levels, the European and the national level. In addition to the safety and performance tests specified in EN 12815, the smoke gases are also examined. EN 12815 specifies the maximum permitted levels of carbon monoxide (CO) in Europe . The standard provides for a limitation of the CO content of 12,500 mg / m 3 with a reference oxygen content of 13 % by volume . According to EN 12815, this limitation can be further reduced by national laws and regulations. For Germany, the ordinance on small and medium-sized combustion plants of January 26, 2010 stipulates that the carbon monoxide (CO) content should not exceed 3,500 mg / m 3 (level 1) or 1,500 mg / m 3 ( Level 2) with a reference oxygen content of 13% by volume. Compared to other countries in Europe, this corresponds to a reduction to 28% or 12% of the limit value that is permitted in other European countries and thus represents a significant technical challenge for manufacturers of water-based heating stoves. Evidence of compliance with additional environmental protection requirements is provided by the manufacturer on the nameplate to be attached to the heating stove. Furthermore, national regulations in German-speaking countries stipulate that the efficiency specified in EN 12815 is increased from 60% to 75% and there is also a clear limitation of fine dust emissions.
Legal regulations in Europe and Germany
According to the Construction Products Act, manufacturers of heating stoves are only allowed to sell them within the EU and Switzerland if they have had a test carried out in accordance with EN 12815 or if they have been recognized by a national institute, e.g. B. the German Institute for Building Technology (DIBt) in Berlin. For the operation of a water-bearing heating stove, the requirements laid down in the ordinance on small and medium-sized combustion systems must be met. These are: - Test according to EN 12815 - Operation only with the specified fuels (wood, pellets) - Proof of compliance with the emission values for CO and dust - Proof of compliance with the degree of efficiency . According to Section 2 of the Ordinance on Small and Medium Firing Systems, heating stoves are treated the same as single-room firing. Long-term transitional provisions apply to "old systems" that were built and operated before March 22, 2010, when the revised regulation on small and medium-sized combustion systems came into force.
Combustion technology
The heat contained in the fuel is released in the combustion chamber and absorbed by the heating stove. The heat can now be passed on to a hob and, if available, a baking compartment, as well as to the installation room and the house. A smaller part of the energy is still used for the chimney draft necessary for a natural draft fireplace. The heat for the installation room is provided in the form of radiant heat if the fire door has a fire-resistant glass pane. Furthermore, the heat is transferred to the installation room through the hob and the outer, heated side walls, which act like a radiator. Another amount of heat is released into the room from the stove pipe. The amount of heat that is given off from the stove pipe to the living room and a chimney that runs inside the house also has a benefit, but this amount of heat is not taken into account when determining the efficiency according to EN 12815. These amounts of heat are available as additional profit for the house.
Heat distribution
The heat generated in the heating stove is used throughout the house. The heat is distributed in the house in different ways, whereby the respective share of the heat quantity can be regulated. In this way, the heat can be given off directly from the heating stove to the installation room through thermal radiation. Furthermore, the water-bearing heating stove, because it is connected to the heating system of the house, can convey the hot water generated by it into the heating system by means of circulation pumps. The heating system then distributes the heat generated by the heating stove to the radiators and also to a hot water tank, so that the necessary hot water is provided for the shower and bathtub. Furthermore, in the heating stove z. B. in the evening at the fireplace generated heat is also stored in a buffer tank and so z. B. can only be used the following day. The heating technology can heat a house in solo operation or in conjunction with other heat generators. In solo mode, the heat from the stove is pumped into the heating system's pipe network by a circulation pump. The hot water generated in the heating stove is then fed to the radiators, the z. B. have control thermostats and ensure a comfortable living environment. If a heating stove is used in solo operation, an expansion tank must also be installed in the heating network in addition to the circulation pump and the radiators. In combination with an oil or gas heater, the water-bearing heating stove can largely replace this and thus significantly reduce oil and gas consumption. A solar system can also be operated in addition to the heating stove. The heating stove then supplies the required heat, especially in times of low solar radiation.
Manufacturer certificates
All legal evidence relevant for the list, such as B. via the test according to EN 12815, proof of compliance with environmental protection requirements, such as B. the ordinance on small and medium-sized combustion systems for the Federal Republic of Germany or other national regulations must be documented by the manufacturer on the nameplate. In Germany, the responsible district chimney sweep takes all data relevant for building acceptance from the nameplate.
history
Orders from Count Palatine Karl IV. From 1772 also served to prevent a fire in connection with domestic fireplaces. According to the simultaneous building regulations, no more wooden chimneys were allowed to be erected, no more wooden hoses were allowed to be installed, which had to lead the smoke from the fireplace to the fireplace , just as it was forbidden to lead stovepipes out of the window.
Web links
- Energy from the water-bearing stove - calculation tool for the energy content in different types of wood and comparison with heating oil and natural gas. A free web app for woodburning stove users developed for iPhone and Safari.
Individual evidence
- ↑ Text of the ordinance on small and medium-sized combustion systems
- ^ Franz-Josef Sehr : The fire extinguishing system in Obertiefenbach from earlier times . In: Yearbook for the Limburg-Weilburg district 1994 . The district committee of the Limburg-Weilburg district, Limburg-Weilburg 1993, p. 151-153 .