Radiator humidifiers are the most environmentally friendly humidifiers in existence! They do not use any electricity and they work just when you need them, in the heating season when radiators are on and the air is driest. Simply fill the container and hang them of a radiator. When they heat up, the water evaporates and is released into the air negating the dryness caused by the heat. These humidifiers are beneficial for your skin and respiratory system, as well as being great for the health of plants and protect furniture, they guard against drying out when you have your heating on.