What is Central heating?
[[File:Pelletkessel in Wohnhaus.JPG|thumb|upright|Hot water central heating unit, using wood as fuel]] A '''central heating system''' heats a building from one main source of heat. There may also be [[ventilation]], and [[Air conditioner|air conditioning]] which can cool the building. A central heating system has a [[furnace]] or [[boiler]] that uses [[fuel]] or [[electricity]] to heat water or air. Heated air is pumped through through [[Duct|ducts]]. Steam or hot water is pumped to [[Radiator|radiators]]. The fuel may be [[coal]] or [[wood]], [[oil]], [[kerosene]], [[natural gas]], or electricity. Central heating gives better temperature control in a building.. Large buildings may be divided into smaller parts with their own temperature controls. Before the general use of central heating in most homes there would be a fire in one room and the whole family would be there in the evening. With central heating people can use the different parts of the house. In 1965 a British Gas advertisement said that central heating “turns bedrooms into playrooms”.<ref>{{Cite web|title=How central heating changed everything about our homes|url=https://www.ft.com/content/9632c12c-1153-4f0f-acef-cbfe4b63ec58|access-date=2024-03-22|website=www.ft.com}}</ref> == Overview == In much of the [[temperate climate]] zone, central heating started to be fitted since before the Second World War. Coal-fired steam or hot water systems were common. More recently [[fuel oil]] or gas has been used more. [[Electric heating|Electrical heating systems]] are generally more expensive. [[Heat pump|Heat pumps]] are now being installed as they are cheaper and produce less [[greenhouse gas]]. .<ref>{{cite web|title=energy.og – Electrical Resistance Heating|url=http://energy.gov/energysaver/articles/electric-resistance-heating|access-date=2015-01-15}}</ref> [[File:Generations of district heating systems EN.svg|thumb|The four different generations of [[district heating]] systems and their energy sources]] Some buildings have [[central s