Water heating is the third largest energy expense in your home. It typically accounts for about 16% of your utility bill. There are four ways to cut your water heating bills: use less hot water, turn down the thermostat on your water heater, insulate your water heater, or buy a new, more efficient water heater.
A family of four, each showering for 5 minutes a day, uses 700 gallons of water a week; this is enough for a 3-year supply of drinking water for one person. You can cut that amount in half simply by using low flow aerating showerheads and faucets.
Water Heating Tips
• Install aerating, low-flow faucets and showerheads.
• Repair leaky faucets promptly; a leaky faucet wastes gallons of water in a short period of time.
• Lower the thermostat on your water heater; water heaters sometimes come from the factory with high-temperature settings, but a setting of 120°F provides comfortable hot water for most uses.
• Take more showers than baths. Bathing uses the hottest water in the average household. You use 15–25 gallons of hot water for a bath, but less than 10 gallons during a 5-minute shower.
• Insulate your electric hot-water storage tank, but be careful not to cover the thermostat. Follow the manufacturer’s recommendations.
• Insulate your natural gas or oil hot water storage tank, but be careful not to cover the water heater’s top, bottom, thermostat, or burner compartment. Follow the manufacturer’s recommendations; when in doubt, get professional help.
• Insulate the first 6 feet of the hot and cold water pipes connected to the water heater.
• If you are in the market for a new dishwasher or clothes washer, consider buying an efficient, water-saving model to reduce hot water use.
• Install heat traps on the hot and cold pipes at the water heater to
prevent heat loss. Some new water heaters have built-in heat traps.
• Drain a quart of water from your water tank every 3 months to remove sediment that impedes heat transfer and lowers the efficiency of your heater. The type of water tank you have determines the steps to take, so follow the manufacturer’s advice.
• Although most water heaters last 10– 15 years, it’s best to start shopping for a new one if yours is more than 7 years old. Doing some research before your heater fails will enable you to select one that most appropriately meets your needs.
Long-Term Savings Tips
• Buy a new energy-efficient water heater. While it may cost more initially than a standard water heater, the energy savings will continue during the lifetime of the appliance. If your current water heater is electric, consider switching to a natural gas water heater if gas is available.
• Consider installing a drain water waste heat recovery system. A recent DOE study showed energy savings of 25% to about 30% for water heating using such a system.
• Consider demand or tankless water heaters. Researchers have found savings can be as much as 34% compared with a standard electric storage tank water heater.
If you heat water with electricity, have high electric rates, and have an unshaded, south-facing location (such as a roof) on your property, consider installing a solar water heater. The solar units are environmentally friendly and can now be installed on your roof to blend with the architecture of your house. More than 1.5 million homes and businesses in the
The United States have invested in solar water heating systems, and surveys indicate over 94% of these customers consider the systems a good investment. Solar water heating systems are also good for the environment. Solar water heaters avoid the harmful greenhouse gas emissions associated with electricity production. During a 20- year period, one solar water heater can avoid over 50 tons of carbon dioxide emissions. When shopping for a solar water heater, look for systems certified by the Solar Rating and Certification Corporation or the Florida Solar Energy Center.
Windows can be one of your home’s most attractive features. Windows provide views, daylighting, ventilation, and solar heating in the winter.
Unfortunately, they can also account for 10% to 25% of your heating bill. During the summer, sunny windows make your air conditioner work two to three times harder. If you live in the Sun Belt, look into new solar control spectrally selective windows, which can cut the cooling load by more than half.
If your home has single-pane windows, as almost half of U.S. homes do, consider replacing them. New double pane windows with high performance glass (e.g., lower or spectrally selective) are available on the market. In colder climates, select windows that are gas filled with low emissivity (Low-E) coatings on the glass to reduce heat loss. In warmer climates, select windows with spectrally selective coatings to reduce heat gain. If you are building a new home, you can offset some of the cost of installing more efficient windows because doing so allows you to buy smaller, less expensive heating and cooling equipment.
If you decide not to replace your windows, the simpler, less costly measures listed below can improve their performance.
Cold-Climate Window Tips
• You can use a heavy-duty, clear plastic sheet on a frame or tape clear plastic film to the inside of your window frames during the cold winter months. Remember, the plastic must be sealed tightly to the frame to help reduce infiltration.
• Install tight-fitting, insulating window shades on windows that feel drafty after weatherizing.
• Close your curtains and shades at night; open them during the day.
• Keep windows on the south side of your house clean to let in the winter sun.
• Install exterior or interior storm windows; storm windows can reduce heat loss through the windows by 25% to 50%. Storm windows should have to weatherstrip at all moveable joints; be made of strong, durable materials; and have interlocking or overlapping joints. Lowe
storm windows save even more energy.
• Repair and weatherize your current storm windows, if necessary.
Warm-Climate Window Tips
• Install white window shades, drapes, or blinds to reflect heat away from the house. • Close curtains on south- and west-facing windows during the day.
• Install awnings on south- and west-facing windows.
• Apply gun-control or other reflective films on south-facing windows to reduce solar gain.
Long-Term Savings Tip
• Installing new, high-performance windows will improve your home’s energy performance. While it may take many years for new windows to pay off in energy savings, the benefits of added comfort and improved aesthetics and functionality may make the investment worth it to you. Today, many new window technologies are available that are worth considering. Glazing materials (the glass part of the window) now come with a variety of selective coatings and other features; frames are available in aluminum, wood, vinyl, fiberglass, or combinations of these materials. Each type of glazing material and frame has advantages and disadvantages.