Energy.gov

More than 14 million housing units, or 10 percent of the national housing stock, is heated by steam and hot water. Steam heating, which represents the majority of this market, is particularly inefficient, and is characterized by a central source of steam generation with a convective distribution system via a network of pipes and radiators.

There is no way to control heat transfer through this network, so building managers configure boiler systems to treat a building as a single zone keeping the coldest apartment above a minimum statutory temperature. This results in overheating of the other spaces in the building due to differences in exposure, level of insulation, distribution system heating, and radiator size. Regulation of individual apartment temperatures is usually accomplished by venting the excess heat through open windows. The New York State Energy Research & Development Authority estimates that 15 to 30 percent of the heat is wasted by overheating of steam buildings.

Radiator Labs developed a mechanism that allows heating systems to control heat transfer at each radiator. The Radiator Labs design utilizes an insulating radiator enclosure and control system that allows heat transfer to be turned on and off. The enclosure traps warm air inside the enclosure, and the control system can meter this heat into the room through a fan that forces air through the system.

Based on NYSERDA estimates for waste-heat in conjunction with a preliminary pilot installation, the Radiator Labs system will save approximately 20 percent of a steam-heated building’s energy costs when installed at all radiators on the property. The successful limitation of heat transfer will conserve energy in the central heating system, decreasing the boiler burn duration, and resulting in lower energy consumption.  This represents an achievable savings of more than 2 percent of all energy used to heat residential structures in the United States, a potential savings of over $4 billion per year.