Nearly all electric heaters work by converting electricity directly to heat. Although nearly 100 per cent of the electricity is converted into heat, the electricity itself comes from power plants, which are fairly inefficient. Because of this, using electricity for heat is more expensive and less efficient than other methods such as gas. Nonetheless, there are some electric heaters that use less energy than others, either because of their small size or a novel heating method. By using the most efficient heaters available, turning down the heat a bit and winterising your home, you can save both energy and money this winter.
Although some heat pumps are expensive to install, they are much cheaper to operate than other forms of electric heaters. Rather than producing heat from electricity, heat pumps actually pump heat from the ground or the air. Working like an air conditioner in reverse, a heat pump moves a fluid through several chambers. Inside the house, the fluid is compressed, causing it to release heat into the air. Outside, it is allowed to expand, cooling and drawing heat out of the ground or the air. According to the U.S. Department of Energy, heat pumps can cut electricity costs by as much as 40 per cent.
Two common types of electrical convective heaters are available -- baseboard heaters and portable heaters. Although both work in the same way, baseboard heaters are installed in the room, while portable heaters are freestanding and can be moved from room to room. Both of these heaters work by converting electricity to heat. Although they work in basically the same way as a central heating system, they are more efficient for two principal reasons. The main reason is that they only heat a single room and not the whole house, greatly cutting down on the amount of waste heat that is generated. Secondly, because a central electric heater relies on ducts to transmit heated air through the house, some of the heat is lost in transit. With convection heaters, however, all or nearly all of the heat goes straight into the room.
Radiative heaters also turn electricity into heat, but that heat is disseminated in a different way. The central part of a radiative heater is an insulated quartz crystal with an electric element inside. Behind this is a reflector shaped to direct the energy in a particular direction. The element gets so hot that it begins to generate a lot of infrared radiation. This energy is directed out into the air and flows through it without heating it. When it hits an object such as a person or a couch, however, some of the infrared energy turns into heat. Some of the infrared will also bounce back off the object and strike something else, eventually turning into heat anyway.
In a well-winterised room, there's no reason to use an infrared heater; however, in some situations this is the most efficient type of electric heater to use. In a draughty or poorly insulated area such as a garage, an infrared heater can be used to heat just the people in a particular part of the room. Rather than using a lot of electricity to produce enough heat to keep the draughty room warm, the radiative heater uses a more modest amount of electricity to produce enough infrared heat to keep a few people or a small area of the room warm.