The contra-flow system is used to collect thermal energy from hot flue gases. When wood burns in the firebox high temperatures are reached quickly, forcing the burning flue gases into the upper combustion chamber below the top lid. The hot gases are then guided down and out into the side channels, where the heat is released into the exterior stones. At the same time, room air outside the fireplace walls warms and moves up the stone surface in a path opposite to the interior downflow. These two opposing air flows are known as contra-flow. Most of the generated heat is transferred evenly into the room in the form of comfortable radiant heat.
Firewood burns quickly and efficiently in the firebox and the solid mass of the Tulikivi rapidly stores the heat. A couple of loads of wood are sufficient to heat any room, and heat will be radiated up to 24 hours or more.
A Tulikivi masonry heater does not waste heat or wood like a normal stove or open fireplace, which have to be continually fed to keep the fire burning.
Tulikivi masonry heaters can be equipped with an outside air kit, e.g. in passive energy houses. An air duct guides combustion air from outside directly into the combustion chamber. Models of fireplace groups 1 and 2 require an additional adapter, whereas group 3 models can be connected without an adapter.
The Tulikivi bakeoven contains a little bit of the old and a lot of new. The basic structure of the oven respects the work of the old master craftsmen. Other manufacturers lack the heat technology developed and patented by Tulikivi, which represents a whole new way of thinking.
A Tulikivi bakeoven however only needs one flue connection instead of the two they used to have. Whether you burn wood in the firebox of the fireplace or in the bakeoven, the whole oven is sure to warm evenly from top to bottom.
Burning wood in the bakeoven ensures a long baking time and an even temperature
Tulikivi’s bakeovens also feature an ingenious structure. They work on a double combustion principle, making use of all the energy of the wood and lengthening the effective baking time. The wood is burned in the firebox of the bakeoven. Incombustible flue gases rise with the flames into the upper fire chamber. Thanks to the secondary air flowing through the ashbox and grate, these gases also burn into usable heat. Finally the coals are deposited through the rear section of the firebox onto the grate, where they burn quickly and generate additional heat. No separate flue is required.