Radiator Labs solves uncomfortable temperatures and wasted energy in steam-heated buildings. It has developed a product that eliminates the waste implicit in steam-heated buildings. The system, called the Cozy, is a wireless, low-cost, and easily installed retrofit that drops on top of radiators to control indoor temperatures in buildings with radiator heat. In individual installations, the system can eliminate overheating and vastly improve comfort. By retrofitting whole buildings, the Cozy redistributes steam flow to heat up colder rooms faster, saving up to 40% in heating costs and yielding a potential cumulative annual savings of $7 billion over the 120 million residential and commercial radiators in the United States.