Ĭarved brick chimneys characteristic of late Gothic Tudor buildings, at Thornbury Castle, 1514 The down-slope piece is called an apron, the sides receive step flashing and a cricket is used to divert water around the upper side of the chimney underneath the flashing. On a pitched roof where a chimney penetrates a roof, flashing is used to seal up the joints. Such appliances are generally installed near an external wall, and a noncombustible wall thimble allows a vent pipe to run directly through the external wall. In fact, most modern high-efficiency heating appliances do not require a chimney. Today's central heating systems have made chimney placement less critical, and the use of non-structural gas vent pipe allows a flue gas conduit to be installed around obstructions and through walls. Construction Ī section of a large late Georgian four storey house, showing the advantage of using a mechanical sweeper over climbing boysĪs a result of the limited ability to handle transverse loads with brick, chimneys in houses were often built in a "stack", with a fireplace on each floor of the house sharing a single chimney, often with such a stack at the front and back of the house. Lead and silver deposits formed on the inside of these long chimneys, and periodically workers would be sent along the chimneys to scrape off these valuable deposits. In the north of England, long near-horizontal chimneys were built, often more than 3 km (2 mi) long, which typically terminated in a short vertical chimney in a remote location where the fumes would cause less harm. In the 18th and 19th centuries, the methods used to extract lead from its ore produced large amounts of toxic fumes. To control downdrafts, venting caps (often called chimney pots) with a variety of designs are sometimes placed on the top of chimneys. Later chimneys were constructed by placing the bricks around tile liners. Early chimneys were of simple brick construction. Since then chimneys have traditionally been built of brick or stone, both in small and large buildings. Industrial chimneys became common in the late 18th century.Ĭhimneys in ordinary dwellings were first built of wood and plaster or mud. Another step in the development of chimneys was the use of built in ovens which allowed the household to bake at home. Smoke hoods were an early method of collecting the smoke into a chimney (see image). However, they did not become common in houses until the 16th and 17th centuries. The earliest extant example of an English chimney is at the keep of Conisbrough Castle in Yorkshire, which dates from 1185 AD. However, domestic chimneys first appeared in large dwellings in northern Europe in the 12th century. Industrial chimney use dates to the Romans, who drew smoke from their bakeries with tubes embedded in the walls. Seagull sits on top of a hot gas cooling chimney at The World of Glass, St. The dispersion of pollutants over a greater area can reduce their concentrations and facilitate compliance with regulatory limits. Additionally, the dispersion of pollutants at higher altitudes can reduce their impact on the immediate surroundings. The height of a chimney influences its ability to transfer flue gases to the external environment via stack effect. The term smokestack (colloquially, stack) is also used when referring to locomotive chimneys or ship chimneys, and the term funnel can also be used. In the United States, the term smokestack industry refers to the environmental impacts of burning fossil fuels by industrial society including the electric industry during its earliest history. Chimneys are adjacent to large industrial refineries, fossil fuel combustion facilities or part of buildings, steam locomotives and ships. The space inside a chimney is called the flue. Chimneys are typically vertical, or as near as possible to vertical, to ensure that the gases flow smoothly, drawing air into the combustion in what is known as the stack, or chimney effect. A chimney remaining after the destruction of a 19th-century two-story house ( Mount Solon, Virginia).Ī chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, stove, furnace, incinerator or fireplace from human living areas.
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