Water heating is the second-highest home energy cost for most households in Wisconsin.

On-demand water heaters
(Also known as tankless or instantaneous water heaters.)

An on-demand water heater with an Energy Factor (EF) of 0.83 can save about 25% on natural gas costs for water heating compared to a tank-style heater with an EF of 0.61. For the average Wisconsin home, savings are about $40 to $70 per year.

Potential advantages of on-demand heaters:

• Save energy.
• Never run out of hot water (within flow limits).
• Should last longer.
• Free up floor space.
• Failed components can be replaced. When a tank leaks on a regular water heater, the whole water heater must be replaced.

Potential disadvantages of on-demand water heaters:

• Cost more to buy and install.
• Hot water often takes longer to arrive.
• Can't provide a slow trickle or a splash of hot water.
• May require bigger gas and water pipes or a larger gas meter.
• Many plumbers do not install them.

Information:

• Dept. of Energy - Demand water heaters
• MGE On-demand water heaters fact sheet [PDF - 104 KB]
• National Association of Home Builders Research Center

Equipment:

• Bosch AquaStar
• Eemax, Inc.
• Low Energy Systems Inc.
• Noritz
• Paloma
• Rheem/Ruud/Richmond
• Rinnai
• Seisco
• Takagi
• TanklessWater.com

Conventional water heaters
Most water heaters use natural gas or electricity to heat water stored in an insulated tank. Natural gas heaters generally heat water faster and cost approximately half as much to operate.

Water-heater efficiency is rated by an Energy Factor (EF). The higher an EF, the more efficient the heater.

Information:

• Focus on Energy "Cash-Back Rewards"
• Dept. of Energy:
  • Energy-efficient water heating
  • Selecting a new water heater
• MGE Water Heaters brochure [PDF - 400 KB]

Equipment:

• A. O. Smith water heaters
• American Water Heater
• Bock
• Bradford White
• GSW Water Heating
• Marathon electric water heaters
• Rheem and Ruud water heaters
• Richmond water heaters
• State water heaters
• Vaughn electric and solar storage water heaters

Solar water heaters
Water heating is the most cost-effective way to capture and use solar thermal energy in the Wisconsin climate. Unlike solar home heating systems, solar water heaters make use of the long days and direct sun of summer.

Cash-back rewards on the installation of qualifying solar water heating and other renewable energy systems are available from Wisconsin's Focus on Energy. For details, call 1-800-762-7077 or go to their Web site listed below.

Also, beginning in 2006, federal tax credits will be available for qualifying renewable energy systems.

Information:

• Focus on Energy
• Midwest Renewable Energy Association fact sheet
• Sustainable Building Sourcebook
• Dept. of Energy - Solar water heaters

Equipment:

• Real Goods solar equipment
• Solar water heating business guide
• Vaughn solar tanks and heat exchangers

Heat-pump water heaters

Information:

• National Association of Home Builders heat pumps
• Oak Ridge National Labs heat pumps

Equipment:

• AirTap water heater add-on
• E-Tech heat pump water heaters
• Quantum Energy Systems International heat pump water heaters
• WaterFurnace geothermal water heaters