There are two common methods of using oil as a heating fuel. In a standard central heating system, oil fired boilers can be used, especially in remote areas where gas is not available. Oil is stored in a tank, usually in close proximity to the boiler room. From here it is fed, sometimes by gravity but more often pumped, to the boiler house. Often the first thing it flows through in the boiler house is a safety valve. This normally takes the form of a plunger with a heavy counter-weight, suspended by a steel cord. The cord is interrupted by a thermal link which, in the event of a fire, would melt. The steel wire is therefore unable to keep the arm of the safety valve raised, the counter-weight dropping and forcing the plunger to close the valve. After the safety valve, the oil flows through a filter to collect any dirt or impurities which may block the jets. Finally, it flows through the jets in the form of a fine spray, into the combustion chamber where it is ignited. Controlled by a thermostat, it then heats a central heating system in the conventional way, although industrial and commercial systems are often multiple boiler systems.
Alternatively, individual oil heaters may be used. These operate on a similar principle to the oil boiler, but instead of heating water they are used to heat a chamber through which air passes. Cool air is taken in through a low level grille, heated and passed out through a grille at the top of the heater. The air can be either forced by using a motor driven fan, or alternatively allowed to circulate by natural convection.
The disadvantage with both of these methods is that the oil has an odour and is considered by many not to be a particularly clean system, gas often taking preference where available.
