An 1880s neo-renaissance kakelugn (tiled stove - a form of
antique storage heater!), Mullhyttan, Närke, Sweden, 2007.
Europe endured a notably cold period from 1500 to 1800, which has come to be known as ‘Europe’s little ice age’. In 1776, the then King of Sweden - Adolf Frederik commissioned Carl Johan Cronstedt to invent and design a stove with a more viable way of utilizing the national wood resources while still keeping citizens warm.
Carl began by noticing that much heat was lost through the typical house fire. All homes need a chimney when a fire is being utilised in a home to keep warm. However the chimney led to most of the heat being released into the outside air of the home. A standard fireplace loses 90% of heat from the fire, right up the chimney. This inspired Carl to create a flue that snakes through a masonry stove, up and down pipes, into chambers and eventually up and out. It was important to keep the hot gas within the stove longer and the pollution that would normally be spewed into the atmosphere to get burned. This caused an intense heat which slowly warms the bricks within the stove, gets retained in these bricks and then radiates into the room for long periods of time.
The design concept is known as kakelugn, and incorporates firing up once or twice a day for short periods. With this design a burn of two and a half hours could produce warmth in the room for up to 24 hours. Homes with these stoves emitted only a minor amount of smoke. It has also been measured that in the course of a year, a kakelugn regularly will burn the wood of one medium sized tree, and that tree would have absorbed the complete amount of CO2 in the previous years that is emitted by the stove, ensuring the design is carbon neutral.
The kakelugn burns extremely hot, at 1110-1200 C. Yet one can still safely touch it and feel warmth and not be burnt.
The difference between modern heaters and a kakelugn is simple. The modern heater uses convection heating, while the kakelugn utilizes or emits radiant heating. In convection heating, the air is heated and heat rises. As the air rises it carries dust, toxins and mites around the room. This is an aggravation for people with asthma and allergies. Particles may also be fried while on the surface of iron stoves and very hot radiators, which is known to produce carcinogenic gases. Radiant heat warms the surfaces that it comes into contact with;that means you are warmed, your sofa, your chairs and everything in your home, but not the air. It has been compared to working like the sun.
Tiled stoves can be aesthetically appealing, making them suitable as a focal point in homes or as part of the décor.
Carl was an Earl, architect, inventor and scientist and he would be remembered in history for having developed the tiled stove. The tiled stove would meet the king’s specifications and be environmentally beneficial. During the industrial revolution, more modern forms of heating would be developed and promoted which caused the tiled stove to be less in vogue.