Boilers

Photo: 

THE PRODUCT:

Boilers heat water that is then used to heat a home using a hot water or steam distribution system. The technology used for steam boilers is the same as for hot-water boilers, except that circulating pumps are not used in steam boilers. Boiler capacities range greatly, but they tend to be higher than furnace capacities.

THE STANDARD:

Standards for residential boilers were included in the Energy Independence and Security Act (EISA) of 2007 and apply to gas-fired hot water boilers, gas-fired steam boilers, oil-fired hot water boilers, oil-fired steam boilers, and electric hot water boilers with an input of less than 300,000 Btu per hour manufactured after September 2012. The standards for each type of boiler include a requirement for annual fuel utilization efficiency (AFUE) and/or design requirements. AFUE refers to the rate at which fuel is converted to useful energy. The prescribed standards, which were included in the Furnace and Boiler Technical Amendment, published in the Federal Register on July 28, 2008, are as follows: 

DOE estimates that, over 30 years, the boiler standards will save 0.16 quads of energy, $1.2 billion at a 3% discount rate and 2.6 million metric tons of CO2.

The 2012 ASAP/ACEEE report, The Efficiency Boom, analyzed a standard level for natural gas boilers using condensing technology and advanced controls. Condensing technology is used to condense water out of flue gases to recoup heat to warm the home that would otherwise be vented up the chimney. The analysis indicates that approximately 20% savings can be achieved at this level. Estimated savings are 40 trillion Btu in 2035 alone and $1.4 billion in net present value savings for consumers. The next standard for natural gas boilers is expected in 2015.

KEY FACTS:

Space heating is the largest energy end-use in the U.S. residential sector, accounting for approximately 41% of total residential energy consumption. About 10% of U.S. households use boilers, a share which has been declining since 1987. Annual shipments are estimated at 230,000.