Heating and cooling of homes accounts for nearly 40% of the total energy use in many houses.

Electric oil, panel and fan heaters convert electricity in to heat at 1:1 ratio, 1 unit of electricity for 1 unit of heat. They are the least efficient form.

Air conditioners convert electricity into heat at around a 1:3 ratio meaning they use 1/3 of the energy to produce the same amount of heat as a oil, panel or fan heater.

There are far more energy efficient forms of keeping your home warm (or cool) though, consider: