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- For the Grand Central Records albums, see Central Heating (Grand Central album) and Central Heating 2.
Central heating is standard method of providing warmth to the interior of a building. When combined with other systems in order to control the building climate the whole system may be referred to as HVAC (Heating, Ventilation and Air Conditioning).
Central heating differs from local heating in that the heat generation occurs in one place, which is not necessarily a "central" geometric point. The most common heat source is through combustion of fossil fuel in a furnace or boiler. The resultant heat is then distributed typically by forced air through ductwork, by water circulating through pipes or by steam fed through pipes. However, of increasing use, the heat source may be solar powered, in which case the distribution system is normally hydraulic.
In the UK and much of northern Europe and urban portions of Russia, where air conditioning in homes is rarely warranted due to its temperate climate, central heating is installed in most new housing. It is normally gas fired or, where gas is not readily available (as In Ireland), oil fired systems are used. In the western and southern United States natural gas fired central forced air systems are most common; these systems and central boiler systems are both in use in the far northern regions of the USA. Steam heating systems may be fired by coal, oil or gas and are used in the USA, Russia and Europe primarily for larger buildings. Far less energy efficient and less common are electrical heating systems.
History
Central heating systems were used in northern Roman cities circa 100AD. Air heated by furnaces was led through empty spaces under the floors and out of pipes in the walls - this system being termed a hypocaust. The Cistercian monks revived central heating using river diversions combined with indoor wood fired furnaces. An excellent example from the year 1202 of such an application is the well preserved Real Monasterio de Nuestra Senora de Rueda on the Ebro River in the Aragon region of Spain.
By the beginning of the 1700s Russian engineers were designing hydrological based systems for central heating. The best extant example is the Summer Palace of Peter the Great in St. Petersberg. Slightly later in the year 1716, water was first used in Sweden to distribute heat in buildings. This system was used by Martin Triewald, a Swedish engineer, on a greenhouse at Newcastle upon Tyne. Bonnemain, a French architect, made its first industrial use on a Cooperative, at Château du Pêcq, near Paris.
Water heating
The common components of a central heating system using water circulation are:
- Gas supply lines (sometimes including a propane tank) or oil tank and supply lines
- Boiler - heats water in a closed water system
- Pump - circulates the water in the closed system
- Radiators - wall mounted panels through which the heated water passes in order to release heat into rooms
It is also common in the United Kingdom and other parts of Europe to combine the needs of room heating with hot water heating and storage. These systems are less common in the USA. In this case, the heated water in a sealed system is allowed to flow through a heat exchanger in a hot water tank or hot water cylinder where water from the normal water supply is heated by it before being fed to hot water outlets in the house. These outlets could be hot water taps or appliances such as a washing machine or dishwasher.
Sealed water circulating system
A sealed system is a form of central heating in which the water used for heating is normally independent of the building's normal water supply. A pressure vessel contains compressed gas which is separated from the sealed system water by a diaphragm. This allows for normal variations of pressure in the system. A safety valve allows water to escape from the system when pressure is too high, and a valve can be opened to replenish water from the normal water supply if the pressure drops too low. Sealed systems are an alternative to open vent systems, in which steam is allowed escape the system, and thence replaced from the building's water supply via a feed and expansion tank.
Criticism of central heating
From an energy efficiency standpoint considerable heat is lost or wasted if only a single room needs heating, since distribution losses and (in the case of forced air systems particularly) some unoccupied rooms are heated without need. In such buildings where isolated heating is demanded, one may wish to consider non-central systems such as individual room heaters, fireplaces or other devices.
Central heating is not popular with everyone. Slighty tongue-in-cheek, Amy Clampitt wrote a poem called the Disadvantages of Central Heating."
See also
External links
- House.co.uk Central Heating - British Gas central heating systems and advice.
- Advice On Central Heating - Advice On Central Heating From Corgi Engineers.
- HVAC Directory.
- Advice On Boilers - Specific Advice On Boilers.
Zentralheizung | شوفاژ | セントラルヒーティング | Centrale verwarming | Centralvärme
"Central heating"