A gas heater is a

space heater A space heater is a device used to heat a single, small- to medium-sized area. This type of heater can be contrasted with central heating, which distributes heat to multiple areas. Types Dominant mode of heat transfer All space heaters t ...

used to heat a room or outdoor area by burning

natural gas Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium ...

liquefied petroleum gas Liquefied petroleum gas, also referred to as liquid petroleum gas (LPG or LP gas), is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, Butane, ''n''-butane and isobutane. It can also contain some ...

propane Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum ref ...

, or

butane Butane () is an alkane with the formula C4H10. Butane exists as two isomers, ''n''-butane with connectivity and iso-butane with the formula . Both isomers are highly flammable, colorless, easily liquefied gases that quickly vaporize at ro ...

. Indoor household gas heaters can be broadly categorized in one of two ways: ''

flue A flue is a duct, pipe, or opening in a chimney for conveying exhaust gases from a fireplace, furnace, water heater, boiler, or generator to the outdoors. Historically the term flue meant the chimney itself. In the United States, they a ...

d'' or ''non-flued,'' or ''vented'' and ''unvented''.

History

The first gas heater made use of the same principles as the

Bunsen burner A Bunsen burner, named after Robert Bunsen, is a kind of ambient air gas burner used as laboratory equipment; it produces a single open gas flame, and is used for heating, sterilization, and combustion. The gas can be natural gas (which is main ...

. Beginning in 1881, the burner's flame was used to heat a structure made of

asbestos Asbestos ( ) is a group of naturally occurring, Toxicity, toxic, carcinogenic and fibrous silicate minerals. There are six types, all of which are composed of long and thin fibrous Crystal habit, crystals, each fibre (particulate with length su ...

, a design

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

ed by Alice H.Parker, a England

engineer Engineers, as practitioners of engineering, are professionals who Invention, invent, design, build, maintain and test machines, complex systems, structures, gadgets and materials. They aim to fulfill functional objectives and requirements while ...

Function

The gas heater is able to warm up a whole room by first allowing the flame to heat the air locally, then it disperses throughout the air by

convection Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...

. Today the same principle applies with outdoor

patio heater A patio heater, also called a mushroom heater or umbrella heater, is a radiant heating appliance for generating thermal radiation for outdoor use. Types of heater A burner on top of a pole, it burns natural gas, liquefied petroleum gas (LPG), pro ...

s or "mushroom heaters" which act as giant Bunsen burners. Modern gas heaters have been further developed to include units that utilize

radiant heat Thermal radiation is electromagnetic radiation emitted by the thermal motion of particles in matter. All matter with a temperature greater than absolute zero emits thermal radiation. The emission of energy arises from a combination of electro ...

technology, rather than the principles of the Bunsen burner. This form of technology does not spread via convection, but rather, is absorbed by people and objects in its path. This form of heating is useful for

outdoor heating Outdoor heating is space heating that allows people to stay in substantially unenclosed spaces that would otherwise be too cold for comfort. To this end, various outdoor heating appliances are available, including gas patio heaters, quartz or cera ...

, where it is more economical than using a standard air heating system.

Flued heaters

Flued heaters are permanently installed wherever they are placed. The

, if properly installed with the correct overall height, size, and orientation should extract all of the heater emissions. A correctly operating flued gas heater is typically safe for use.

Non-flued heaters

Non-flued heaters – also known as unvented heaters, vent-free heaters, or flueless fires, may be either permanently installed or portable, and sometimes incorporate a

catalytic converter A catalytic converter part is an vehicle emissions control, exhaust emission control device which converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalysis, catalyzing a redox ...

. Non-flued heaters can be risky if appropriate safety procedures are not followed. There must be adequate ventilation, they must be kept clean, and they should always be switched off before sleeping. If operating correctly, the main emissions of a non-flued gas heater are

water vapour Water vapor, water vapour, or aqueous vapor is the gaseous phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Water vapor ...

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

, and

nitrogen dioxide Nitrogen dioxide is a chemical compound with the formula . One of several nitrogen oxides, nitrogen dioxide is a reddish-brown gas. It is a paramagnetic, bent molecule with C2v point group symmetry. Industrially, is an intermediate in the s ...

Operation

Home gas heating controls cycle using a mechanical or electronic

thermostat A thermostat is a regulating device component which senses the temperature of a physical system and performs actions so that the system's temperature is maintained near a desired setpoint. Thermostats are used in any device or system tha ...

. Gas flow is actuated with a valve. Ignition is by an electric filament or

pilot light image:Merker Durchlauferhitzer.jpg, Merker Tankless water heating, tankless gas-fired water heater from the 1930s, with pilot light clearly visible through the aperture in the front cover. The large opening allowed for the manual lighting of the ...

. Flames heat a

radiator A radiator is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

in the air duct but outside the flue,

or a fan may distribute the heat.

References

External links

* {{authority control Burners Heaters

Heater Heating, ventilation, and air conditioning (HVAC ) is the use of various technologies to control the temperature, humidity, and purity of the air in an enclosed space. Its goal is to provide thermal comfort and acceptable indoor air quality. ...

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