Energy-Efficient Water Heating
The U.S. Department of Energy Energy-Efficiency and Renewable Energy website has an excellent guide to energy-efficient water heating. Since water heating can account for 14%–25% of the total energy consumed in your home, the following strategies can help reduce your energy usage and environmental impact:
- Reduce Hot Water Use
You can lower your water heating costs by using and wasting less hot water in your home. To conserve hot water, you can fix leaks, install low-flow fixtures, and purchase an energy-efficient dishwasher and clothes washer.
- Lower Your Water Heating Temperature for Energy Savings
You can reduce water heating costs simply by lowering the thermostat setting on your water heater. For each 10ºF reduction in water temperature, you can save between 3%–5% in heating costs. Some manufacturers set water heater thermostats at 140ºF, but most households only need them to be set at 120ºF. Water heated at 140ºF also poses the risk of scalding. However, if you have a dishwasher without a booster heater, it may require a water temperature within a range of 130ºF to 140ºF for optimum cleaning. Reducing your water temperature to 120ºF also slows mineral buildup and corrosion in your water heater and pipes, helping it to last longer and operate at maximum efficiency. - Insulate Your Water Heater Tank
If you are using a water heater tank instead of a tankless on-demand water heating system, it may benefit from additional insulation. Unless your water heater’s storage tank already has a high R-value of insulation (at least R-24), adding insulation to it can reduce standby heat losses by 25%–45%. This will save you around 4%–9% in water heating costs. If you don’t know your water heater tank’s R-value, touch it. A tank that’s warm to the touch needs additional insulation. Insulating your storage water heater tank is fairly simple and inexpensive, and it will pay for itself in about a year. You can find pre-cut jackets or blankets available from around $10–$20. Choose one with an insulating value of at least R-8. Some utilities sell them at low prices, offer rebates, and even install them at a low or no cost. - Insulate Hot Water Pipes
Insulating your hot water pipes reduces heat loss and can raise water temperature 2ºF–4ºF hotter than uninsulated pipes can deliver, allowing for a lower water temperature setting. You also won’t have to wait as long for hot water when you turn on a faucet or showerhead, which helps conserve water. Insulate all accessible hot water pipes, especially within 3 feet of the water heater. It’s also a good idea to insulate the cold water inlet pipes for the first 3 feet.
