Thursday, April 2, 2015
Beginning April 16 there will be significant changes to water heater energy factor (EF) requirements as a result of updates to the National Appliance Energy Conservation Act. The U.S. Department of Energy (DOE) published a final rule for amended standards for residential water heaters on April 16, 2010, which become effective April 16, 2015. The 2015 DOE energy efficiency mandates will require higher EF ratings on virtually all residential gas, electric, and oil-fired water heaters. According to DOE, the new manufacturing standards will save about 3.3 quads of energy (1 quad=1015 Btu) and realize about $63 billion in energy bill savings for products shipped from 2015 through 2044.
As explained by Ambler, Pa.-based water heater manufacturer Bradford White, EF indicates a water heater’s overall energy efficiency based on the amount of hot water produced per unit of fuel consumed over a typical day. The higher the EF, the more energy efficient the water heater. EF is measured in three ways: recovery efficiency, or how efficiently the heat from the energy source is transferred to the water; standby losses, the percentage of heat loss per hour from the stored water compared to the heat content of the water; and cycling losses, the loss of heat as the water circulates through a water heater tank and/or inlet and outlet pipes.
Under the new DOE rule, gas tank-storage models may require additional insulation, incorporate newer flue baffling technologies, and have an electronic ignition in lieu of a standing pilot, or any combination of these. One likely impact will be an increase in overall product size, especially in diameter, notes DOE. For gas-fired units over 55 gallons capacity, fully condensing combustion technology will likely be required, based on currently available technologies that are capable of meeting the new requirements. This will also mean that line voltage will have to be available, as well as a means for condensate disposal.
Electric water heaters will also likely require additional insulation, DOE reports, increasing the diameter and/or height of the unit. Additional insulation may also be required for piping and fittings such as drain and T&P (temperature and pressure) valves. Electric water heaters over 55 gallons capacity will likely utilize integrated heat pumps to meet the new EF requirements, based on currently available technology. Oil-fired heaters face similar challenges. Much like gas products, they will likely require additional insulation and/or completely new combustion systems.
As explained by Ambler, Pa.-based water heater manufacturer Bradford White, EF indicates a water heater’s overall energy efficiency based on the amount of hot water produced per unit of fuel consumed over a typical day. The higher the EF, the more energy efficient the water heater. EF is measured in three ways: recovery efficiency, or how efficiently the heat from the energy source is transferred to the water; standby losses, the percentage of heat loss per hour from the stored water compared to the heat content of the water; and cycling losses, the loss of heat as the water circulates through a water heater tank and/or inlet and outlet pipes.
Under the new DOE rule, gas tank-storage models may require additional insulation, incorporate newer flue baffling technologies, and have an electronic ignition in lieu of a standing pilot, or any combination of these. One likely impact will be an increase in overall product size, especially in diameter, notes DOE. For gas-fired units over 55 gallons capacity, fully condensing combustion technology will likely be required, based on currently available technologies that are capable of meeting the new requirements. This will also mean that line voltage will have to be available, as well as a means for condensate disposal.
Electric water heaters will also likely require additional insulation, DOE reports, increasing the diameter and/or height of the unit. Additional insulation may also be required for piping and fittings such as drain and T&P (temperature and pressure) valves. Electric water heaters over 55 gallons capacity will likely utilize integrated heat pumps to meet the new EF requirements, based on currently available technology. Oil-fired heaters face similar challenges. Much like gas products, they will likely require additional insulation and/or completely new combustion systems.
