how does central heating work ?
In simple terms, you have a single point in the house where heat is generated. Heat may be generated by boiling water (steam), hot water, burning oil or gas to heat air or compressing a refrigerant and absorbing the cold air (heat pump). The heat from this central heater is distributed throughout the house via steam pipes or water pipes to baseboard heat exchangers or air ducts for hot air systems. A thermostat tells the heating unit when to turn on or turn off base upon room temperature and the desired setting.
Central Heating has a single heat source or furnace and heat is distributed to structure by warmed air or steam from the single heat source or furnace. Non-Central Heating may have stoves or heat sources in several rooms to heat those rooms.
Central heating systems consist of basic parts like: Air Intake - central heating works by bringing in air, warming it up and blowing the warm air out into your house. Your system will have one intake duct that pulls air in, usually through a vent near the ceiling. Heater - The heater pumps cold air over a heating element. In electric heaters, this element is heated by running electrical current through it. In gas heaters, it's a gas-fed flame. Air comes in from the intake duct, flows over the element and then out through the ducts.
Central heating... How does it work? Just about every customer I visit seems to feel they don't fully understand exactly how their heating system works. This, I think, is due to the lack of an overall user instruction leaflet. There will be a boiler leaflet, a programmer leaflet, thermostat leaflets, but no overview of how they all work together as a system. Here's my attempt to explain it... An average, ordinary modern domestic heating system has the following major components. (The first five have controls that the user can set or adjust): Boiler Programmer Room thermostat Hot water cylinder thermostat Radiators Hot water cylinder Diverter valve pump And here's how they work together as a whole system... 1) The boiler has two separate functions. To heat your hot water tank and to heat your house. 3) Your programmer contains a clock and two time switches (channels) which turn the hot water and central heating services on and off at pre-selected times of day (or night). 4) Once the system is turned 'on' by the programmer, the boiler will be turned on and off by either the room thermostat and the hot water cylinder thermostat. Each thermostat will turn the boiler on when heat is needed, then turn it off again when it isn't. 5) The diverter valve is an electrically operated valve which switches the hot water flowing from the boiler to the radiators or hot water cylinder depending on which thermostat is calling for heat. If both are calling for heat at the same time the valve will assume a 'mid-position', sharing the flow between cylinder and radiators. The diverter valve is sometimes called a 'mid-position valve' for this reason.
