Heat bath in the stone oven
Comforting warmth for relaxation
Journal articles:
The healing warmth of the stone oven
Thermal comfort and well being
Books:
Comforting warmth for relaxation
Published in "Kachelofen & Kamine" issue 11/2009
Heat bath without heat stress
The orginal Finnish sauna with the stacked up stones is no hot air sauna against the current opinion. The heated stones deliver the warmth in the form of heat radiation and warm up steady bodies like person and wooden walls. The air humidity hardly fall below the 30% mark. By contrast the German sauna is a hot air bath, because the heater generates continuously hot air and the sauna bathing then is in a so-called hot air chamber. Just this hot air baths distinguish themselves by a very low air humidity, often up to 2-5% of aerial moist under the cover. Especially older people suffer from this dry air and prefer saunas with low air temperature and higher air humidity. Out of this biosaunas were developed, is present to mark that the biosaunas are visited in the town baths only by few. The stay duration in the German saunas is recommended till max. 15 minutes with three sauna ways. If the sweat bath is carried out longer, is to be counted on heat buildups and circulation worry. In the orginal Finnish sauna, however, there were not these short stays, because even growing mothers have brought
her children in the sauna to the world. Numerous medical studies have shown that heat is an appropriate remedy, rheumatism and back pain relief and healing. Nevertheless, the heat bath is salutary only if no thermal problems arise or when bathing them in the form of alternating baths with cold and warm-irritating to be used.
Warming of the human body by heat radiation.
According to couch position the human body from head to toe is heated from the stone surface. In the prone position the body at the front and the back is heated . Provided that the body directly comes with the stone surface to touch, a part of the heat will transfer by conduction. The low thermal conductivity prevents skin burns, hence, higher surface temperatures is still tollerable in contrast to metal. Nevertheless, at a stone surface temperature more than 55 degrees Celsius a wooden rust is to be recommended, so that no more direct contact with the hot stone surface comes about any more.
Thermal stimuli on the irradiated body side
Because only the stone surface delivers heat radiation, the body is illuminated only by the underside. The upper side of the body is convectively heated by the increased blood flow. The body thereby reacts with a raised sweat secretion which lead to a round warming of the body. To view the convective cooling and heat
Low warming of the aerial body
The heat radiation of the stone oven is barely absorbed by the aerial body. Hence, the propagation of the heat rays is like with the beams of light of a lamp. The further one from the ray body distant, the lower is the radiation intensity. Therefore, the air is permeable for the heat rays. Only water molecules in the air absorb warm rays and the way there planing above the hot stone surfaces warms up at the same time the air. Hence, the air temperature rises only slowly and unterproportionally. In spite of low air temperature the human body on the bench with radiation to heat. The low air temperature differences between the areas also less air movements, so that symtoms can occur no drafts Hence, this low air temperature impairs by no means the heat bath on the stone oven, however, it also offers by the supply of fresh air a rest of the breath apparatus. The mucous membranes of the respiratory tract are loaded, on this occasion, by no means by dry air.
Especially for being relaxing and sleeping the inhalation of fresh air is essential.
Mild and intensive heat bath
A mild heat radiation of the stone oven offers a prolonged heat bath which can serve both to relax the muscles as well as for relaxation and sleep. The body is in a thermal state, which does not cause overheating and influences at the same time the warm regularization affermative. The heat accumulation which appear during the bath lead always to heat stress which leads, in the end, to the cessation of the bath. The heat supply is balanced by extra moist heat, so this create no heat stress. The musculature of the body can slowly relax and recover, so that also the blood circulation rises and which disappear like bad circulations bit by bit again. An intensive heat bath is to be preferred when colds appear and a strong sweating, like a fever which initiates recovery. Then the surface temperature of the stone surface must be higher accordingly, so that an intensive transpiration is stimulated. As a result of the high temperature effects which causes a strong heat stimules a wooden rust must become puts under to avoid the direct contact with the hot stone surface. Nevertheless, the heat bath carried out with strong warm charms can be carried out only for shorter time because the body can sweat not infinitely and takes the vaporization cooling, in the end. Then
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the body stores too much warmth which can be led away then only in a rest or an air bath. Because the body also stores warmth, the organism for longer time can profit from it and bend forward thus the colds and infections.
Heating demand for a cozy stone surface
To heat the stone oven - dry wood is only suitable, which is a great heat, he testifies and gives them to the ceramic flues. The large thermal mass should store the heat for a long period, as well as deliver slowly. To heat the stone masses on 40-70 degrees Celsius , it requires always of the same wooden amount, independent of the air temperature. Nevertheless, the fire place should be so big that the cinder can properly occur and thereby
a little unburned gases, like carbon monoxide, originate. Further the fire must also receive enough oxygen on this warranty optimum combustion. If the stone oven is not used, the chill air gliding over it can let the surface temperature of the oven sink faster, so that then heating becomes necessary and then a bigger wooden amount burns must become. In the end, the quick loss of heat of the hot plate, which heats the air faster.
If one is resting on the bench and covers a blanket, will reduce the heat to the room so that the heat bath, so that the heat bath can be also taken for a longer time. In spite of low air temperature a very hot heat bath can be carried out with the advantage that the body can breathe this fresh and cool air without freezing.
Heating and storing the excess heat in the stone oven
To be able to heat the big storing masses, it requires a big fire space. Only one big fire can develop that heat which can also heat the stone oven. To store the heat a heat-resistant material such as fireclay with a low thermal conductivity and heat is high storage capacity is essential.. It will also contribute moisture to absorb namely humidity and make it again. The feel-good heat, however, arises mostly when the stones are hot, and no fire is burning in the combustion chamber. The hot stone surfaces guarantee a heat radiation without additional frictional streams and electromagnetic fields. Thus underfloor heatings and electric blankets are always the disadvantage that the charge carrier of the molecules are defeated in her orientation of an influencing. Hence, older people complain about the discomfort in electric blankets or about thick feet with underfloor heatings. Lying on the floor heating does not correspond by far to the couch on a heated stone oven. Hence, marble and other stone slabs are therfore they will not - as some believe heating technician - is likely to get a pleasant heat bath without heat stress.
Reinhold Holzner