Halogen heaters are economical, because they work with energy-efficient halogen bulbs. These devices begin to heat very quickly. In addition to being efficient, they are also safe to have around children and pets, because their design prevents them from being too hot to the touch.
Other types of spaces heaters are also efficient. The design of a ceramic-element heater allows a relatively low temperature to provide a significant amount of heat. An oil-filled radiator, which does not need refueling, provides heat even after its switch is turned to the "off" position. For any heater, efficiency is enhanced when the correct size of the device is chosen for the space to be warmed.