Broadly speaking, heaters can be divided into two main categories - fixed and non-fixed.
Non-fixed or portable heaters can be picked up and moved around, and are mainly powered by electricity, although there are also portable fires fuelled by bottled gas.
Fixed heaters, such as fireplaces, wall fans and wood-burning stoves, can be powered by mains gas, LPG, electricity and solid fuels such as biomass and coal.
While there are a variety of electric heater options, the main kinds of portable electric heater are:
None of these is much more energy-efficient than the others. However, halogen heaters heat up and cool down more quickly, and fan heaters are also relatively quick to heat up and cool down, with the added advantage that they blow the heat to where it is needed. Halogen heaters also tend to use up the smallest amount of space, followed by fan heaters.
If children or other vulnerable people are around, you should take extra care with portable heaters. An oil-filled radiator may be unsuitable because of the high temperatures they can reach, which could harm anyone touching them.
There should be plenty of space around individual heating devices, especially fan heaters, as they need to draw in air, and halogen heaters that have an oscillating movement.
Standalone electrical heating devices will usually be less wasteful if they have thermostatic controls - in other words, if they have the capability of switching themselves off once a particular temperature has been reached. If a device doesn't have such a facility, a separate plug-in thermostat can be purchased.
Electric heaters come in a huge variety of designs and types and this is reflected in their price ranges. The following will provide a very broad idea of what you should expect to spend.
Prices for halogen heaters typically range from £15 to £150, depending on size and effectiveness. Fan heaters exist in a wide range of different shapes and sizes and can range from just £10 to over £600. Convector heaters usually cost between £20 and £400, whereas oil-filled radiators can cost between £15 and £400.
In terms of energy consumption, given that portable electric heating devices use electricity, they're generally not as cost-effective as central heating systems running on gas or oil.
Bottled gas heaters have wheels and are semi-portable - they're bulky, so getting them up and down stairs can be a challenge! Another disadvantage is that the bottles of gas become empty and have to be refilled or exchanged, whereas electricity is generally continuously available.
The fumes given off by bottled gas fires mean that you'll need to have a window open for ventilation which makes them even less efficient and expensive.
You can get fixed heaters for most different heating fuels, but in general the running costs are still higher than central heating systems.
For heat from electricity, you can get wall panel heaters, which work by convection and are often used to supplement storage heaters.
You can also get electric wall fan heaters. These are generally used in bathrooms and are fixed at head height or higher, blowing heat downwards.
When it comes to gas fires, the following options are available:
Fires with a balanced flue are more efficient, because there's no need for ventilation.
Modern gas wall heaters are also available with balanced flues, which means they're almost as efficient as modern central heating boilers. They don't act as the focal point of a room like a fire would, making them a better option for halls, stairwells and kitchens where there is an outside wall close by.
Solid fuels have been given a boost thanks to the popularity of wood-burning stoves.
There are also fires and burners for solid fuels like coal. Coal has a much higher energy density than wood - i.e. more heat can be delivered from a particular volume of fuel - and some stoves and fires are capable of burning both kinds of fuel.
If you live in a smoke control area - also known as smokeless zone - certain solid fuels can only be burnt on 'exempt appliances'.
Many stoves that burn wood and coal-based solid fuels have this exempt classification, because they're generally enclosed and glass-fronted. Such appliances also burn the fuel more efficiently and completely.
It's all well and good generating heat but what's the point unless you can keep it inside to warm your home?
While your heaters may need ventilation as discussed, it's also vital that you make sure your home is insulated and draught-proofed sufficiently to retain the heat you generate.
The first step towards keeping your home warm is loft insulation. Even if you already have some loft insulation in place it's worth checking whether you have the recommended level installed. Insulation installed in the 1970s or 1980s is likely to be insufficient; you can read our dedicated guide to loft insulation for more.
Your home may also be suitable for wall insulation. Homes built after 1930 are likely to have cavity walls, meaning and inner and an outer wall. While some newer homes will already have insulation between the inner and the outer walls, many will not. While the process is expensive, it can save you up to £225 a year, according to the Energy Savings Trust. You can read more in our wall insulation guide.