Gas heater is an appliance that is used for space heating in most homes in the cold regions of the world. These heaters work by heating the closed space in which they are present, such as a room, though there are also gas heaters designed for outdoor heating which use a different technology. The gas used in these heaters is mainly natural gas, which is abundantly available on earth and is also comparatively cheaper than other gases. However, there are also gas heaters that use propane and butane.
The gas heaters that are used for room heating work by the principle of convection. When they are turned on, the air in the space immediately next to the heater gets heated first. This hot air becomes lighter and rises up in the room. Cooler air replaces the hot air that has been removed. Now the heater will heat this air and it will also rise upward, being replaced by cooler air. In this fashion, the air keeps circulating around the heater till all the air in the room becomes hot.
Most gas heaters are equipped with a thermostat arrangement that can maintain a particular temperature. The thermostat is set to a temperature as desired by the user. The gas heater will then stop its heating system when this temperature is reached so that the room remains at that level of temperature. However, air is going to cool down soon. When that happens, the thermostat will sense the drop in temperature and will restart its system so that the heating begins to happen again. In that way, the room remains at a steady temperature set by the user.
Gas heaters that are used within rooms have an important requirement – ventilation. When gas burns, it gives out several dangerous fumes which must not be allowed to accumulate in the room. This is done by providing a venting system from which these fumes can be automatically removed as soon as they are formed. At the same time, air is needed for the combustion of the gases. As the gases get heated, it can lead to depletion of oxygen in the room. Hence it is very necessary to bring in fresh air from the outside. This is done through the same venting system that expels the gases.
There are various safety precautions to go along with room gas heaters. The most significant one is to check the ventilation system regularly and to be wary of any change in odor within the room when the gas heater is used. Children must be kept away from gas heaters and they should be educated on the consequences of mishandling or even touching the apparatus.
Gas heaters are also used for outdoor purposes, but they follow a different principle. This is quite understandable because these heaters cannot be expected to heat all the air in an outdoor environment. Here, a technology known as radiation heating is made use of. These gas heaters radiate heat to a particular range around them. Anything present in this area – people or objects – will be able to absorb this radiated heat. Thus, the heaters can warm people up in a nearby area. However, due to the technology that they make use of, radiation gas heaters are not as efficient as room gas heaters.
Today, gas heaters are rapidly being replaced by solar heaters. Gas heaters are not friendly to the environment because of the fumes they release and because of the gases they use, which leads to environmental depletion. Solar heaters are beneficial on both these counts and hence they are used in most homes today. Despite the initial setup costs, the long term benefits are luring people toward harnessing solar energy and replacing gas for their heating purposes.