Test results and technical data
Tulikivi fireplaces burn cleanly and efficiently minimizing environmental pollution, while maximizing heat output from each piece of wood burned. Tulikivi emissions have been tested worldwide. Whether in Germany, United States, or in Sweden, the fireplaces have performed to the highest standards. The most precise tests have been conducted in Sweden, the pioneer in environmental protection. In the demanding Swedish environmental tests, Tulikivi fireplaces came through without a blemish. These tests were also confirmed at the State Research Center of Sweden and the technical University of Stockholm. The results allow Tulikivi fireplaces to be installed in densely populated areas throughout Sweden.
Germany has a great deal of legislation pertaining to fireplace safety, reliability, economy, efficiency, construction, and environmental impact. Also, each household chimney must be inspected once a year by a state-certified inspector. All fireplaces are subject to special energy conservation regulations (ENEG), and DIN norms regulate fireplace assembly. Despite this characteristic German thoroughness, Tulikivi fireplaces passed with ease. They even passed the tests of the distinguished Rosenheim Institute, which examine the safety, health, and environmental impact of materials used in home construction.
In the United States, the EPA has started to regulate fireplaces. Tulikivi is a leader in the development of emission standards with appropriate trade associations and leading testing institutions, such as the Hearth Products Association, Masonry Heater Association, Virginia Polytechnic Institute and Omni Environmental Laboratories.
Each Tulikivi fireplace model is subjected to a lengthy process of testing which is conducted in Tulikivi's laboratories. The key measurements in that testing include, carbon dioxide emissions, carbon monoxide, particle emissions, overall efficiency, combustion efficiency, flue draft pressure, flue gas temperatures, surface temperatures, internal temperature and heating performance. These burn tests and subsequent computer analysis have an important role in product development and serve as the guidelines for the final design of each fireplace.
The overall efficiency is a measurement of the total energy available in the fuel (firewood) less heat losses up the chimney, non-combusted gases, and any unburned fuel. The efficiency testing is done according to the German standard DIN 18891.
The efficiency curve (red line) illustrates the rapid ignition characteristic of the Tulikivi fireplaces and bakeovens. The combustion efficiency quickly rises to 80-85% (bakeoven models closer to the 88%).
The carbon monoxide content (blue line) indicates harmful emission levels. The lower the number, the cleaner the emissions. The CO levels in Tulikivi fireplaces are so small that they are barely detectable on this scale. In normal burning, the values are below 0.5%, although they may rise to a few percent during the ignition phase of the burn. These excellent results are made possible by the patented airflow system and combustion chamber design.
During the combustion cycle only 0.5-1% of the available energy remains unburned when the stove is properly operated. Between 1% to 10% of the wood's energy is lost as non-combusted flue gases. Initial losses are high at the start of ignition (green line). This loss drops sharply as the combustion temperatures in the firebox rise. At the end of the combustion cycle, heat absorption into the stone diminishes slightly as the stone is saturated with heat causing loss of non-combusted flue gases to again rise.
The principle behind the Tulikivi system is to burn a very hot, combustion-efficient fire and then utilize soapstone's heat retention and thermal conductivity to captured and store the heat before it escapes up the chimney.
Surface temperature of a Tulikivi fireplace
During one to two hours of burning, the soapstone in the fireplace soaks up the fire's heat and stores it. The surface temperature typically rises to approximately 65 degrees C. (150 degrees F.) and can rise to circa 100 degrees C (212 degrees F). After the fire is out and the damper closed, the fireplace slowly and gently radiates the stored heat over a twelve to twenty-four hour period, depending on the outdoor temperature.
Flue draft pressure
The flue draft pressure is the most important measurement indicating the reliability of a Tulikivi system. Efficient burning is impossible without a strong draft, which is largely dependent on an adequate chimney system. Fortunately, the contra-flow flue channels in the Tulikivi help to increase draft pressure, thereby aiding the combustion process. Pressure starts around 5 Pascals and quickly rises to 20 Pascals, which is a good level of draft. The curve drops off at the end of the fire when the damper is closed.
Flue gas temperatures in the chimney are also important in order to ensure good draft and to prevent moisture from condensing on the flue surfaces. A minimum of 250 F (125C) should be maintained. Although most solid-fuel chimneys in North America are rated for 2100 F (1150 C) temperatures, the Tulikivi will produce temperatures on average of 500 F (260C) as seen from the temperature curve. These temperatures are ideal and will keep the chimney clean, promoting longer chimney life.
Tulikivi fireplaces and the greenhouse effect
As people become more aware of their responsibility for the environment, Tulikivi owners can sleep with a clear conscience. Burning wood does not contribute to the greenhouse effect. As a renewable resource, a tree will absorb far greater amounts of carbon dioxide during its life cycle than it will give off when it is burned. Nature has created its own check and balance system. While there are other gases emitted from wood during burning, the overall impact on the environment is minimal. The chief threats to the environment come from nonrenewable resources such as coal, oil, and natural gas. These fossil fuels emit harmful levels of sulfur and carbon monoxide. Using a Tulikivi to heat your home is a responsible commitment to the environment and reduces the need for fossil fuels.