Halogen heaters are usually reserved for a small area and are used only occasionally. Halogen heaters with a high watt, however, can be efficient because of the way they produce heat. Contrary to popular belief, they tend to be fairly efficient when used in a small area- and they also don’t release carbon monoxide emissions. They produce radiant heat, which can be suitable for a small patio area. That said, while halogen heaters don’t use tons of electricity, they are comparatively expensive to run, especially as the weather cools.