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A masonry heater (or masonry stove, ceramic stove, tile stove) is a device for warming an interior space through radiant heating, by capturing the heat from periodic burning of fuel (usually wood), and then radiating the heat at a fairly constant temperature for a long period . The technology has existed in different forms, from back into the Neoglacial and Neolithic periods. Archeological digs have revealed excavations of ancient inhabitants utilizing hot smoke from fires in their subterranean dwellings, to radiate into the living spaces. These early forms have evolved into modern systems. Evidence found from 5,000 B.C. of massive blocks of masonry used to retain heat foreshadowed early forms of fire hearths that were used as multifunctional heating sources. Later evolutions came in the Roman ''hypocaust'', Austrian/German (''kachelofen'', baths) using the smoke and exhaust of a single fire. In Eastern and Northern Europe and North Asia, these kachelofens (or ''steinofens'') evolved in many different forms and names: for example the Russian Stove/Fireplace ((ロシア語:Русская печь)), the Finnish Stove (in Finnish: ''pystyuuni'' or ''kaakeliuuni'', "tile oven") and the Swedish Stove (in Swedish: ''kakelugn'', "tile stove" or "contra-flow stove") associated with Carl Johan Cronstedt. The Chinese developed the same principle into their Kang bed-stove. The masonry heater has gained renewed domestic popularity recently because of its heating efficiency. ASTM International calls a masonry heater "a vented heating system of predominantly masonry construction having a mass of at least 800 kg (1760 lbs), excluding the chimney and masonry heater base. In particular, a masonry heater is designed specifically to capture and store a substantial portion of the heat energy from a solid fuel fire in the mass of the masonry heater through internal heat exchange flue channels, enable a charge of solid fuel mixed with an adequate amount of air to burn rapidly and more completely at high temperatures in order to reduce emission of unburned hydrocarbons, and be constructed of sufficient mass and surface area such that under normal operating conditions, the external surface temperature of the masonry heater (except in the region immediately surrounding the fuel loading door(s)), does not exceed 110°C (230°F)."〔Masonry Heaters: Designing, Building, and Living with a Piece of the Sun'' by Ken Matesz (Chelsea Green Publishing Co., 2010), p. xv. ISBN 978-1-60358-213-1〕 == Characteristics == The stove is made of masonry such as brick (firebrick), soapstone, tile, stone, stucco, or a combination of materials, rather than steel or cast iron. It is freestanding, and usually requires special support to bear its weight. It consists of a firebox and heat-exchange channels or partitions that provide additional surface area. These absorb heat from the hot exhaust gases before the gases exit into the chimney. The fire in a masonry heater burns much hotter than in a metal stove. Very hot fires reduce emissions significantly. When not being fired, the connection from the masonry heater to the chimney sometimes has a damper to prevent heat from escaping up the chimney; the heat is then radiated from the masonry. Masonry takes longer to heat than metal; but once warm, the heater will radiate this heat over a much longer period of time and at a much lower temperature than a metal stove would use (the metal is hot only when there is a fire burning inside the stove and for a short time thereafter). A masonry heater is warmed by fires that burn for a short time; it is mostly the heat stored by the heater's mass that heats the living space. Both in Europe and in America seating and even beds are occasionally built adjoining the masonry stove; this is possible because the heater's exterior surfaces are cool enough to touch safely. This cycle of short firings and long periods of heat-release makes a masonry heater a much more convenient option for actually heating a house with wood, than a metal wood stove. Masonry stoves can release heat from anywhere up to 36 hours after the fire has gone out (the larger the thermal mass the more heat the appliance can retain). This means that a householder might typically light a fire in the evening on returning home. In a more modern masonry heater with a glass door,this means that they can enjoy the fire during the evening. But overnight and throughout the next day when the fire is no longer alight the heater will still be warming the house, ready for the cycle to start again next evening. Compare this to a metal stove which is either often too hot or too cold (unlit) and the requirement for the owner to be present to load with logs at regular intervals and the benefits should be clear. Heat stress is a major concern during the construction of masonry heaters. Differences in temperature inside the masonry core of the heater can result in differential expansion. A skilled heater mason knows how to provide for this stress when designing and constructing the heater, thereby preventing uneven expansion from causing cracking in the exterior. There are two general ways this concern is addressed. One is to incorporate a gap between the inner core of the heater and its outer "skin." The other is to build a more monolithic design with post-tension aspects to mechanically compensate for expansion and contraction. Both methods are used with success.〔Masonry Heaters: Designing, Building, and Living with a Piece of the Sun'' by Ken Matesz (Chelsea Green Publishing Co., 2010), p. 172. ISBN 978-1-60358-213-1〕 Masonry heaters take a long time (from 5 hours up to two days) to get up to the right temperature and so are not always practical for taking the chill off a single cool evening or morning. The speed with which a masonry heater achieves the right temperature is called its responsiveness. Responsiveness is determined by the specific thickness and characteristics of the materials used in its construction. Very responsive heaters warm up faster and are good for quicker adjustments to indoor temperature. Less responsive heaters take longer to warm, but they are well-suited for long periods of cold weather because they store heat so well and provide dependable, even heat all day and night.〔Masonry Heaters: Designing, Building, and Living with a Piece of the Sun'' by Ken Matesz (Chelsea Green Publishing Co., 2010), p. 131. ISBN 978-1-60358-213-1〕 Because the radiant heat is given off at a low level a masonry heater is not likely to overheat a home the way a metal stove might in warmer parts of the year like fall or spring. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「masonry heater」の詳細全文を読む スポンサード リンク
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