Insulating a Water Heater

Image Gallery When does a green home project make financial sense? In “Green Sense for the Home: Rating the Real Payoff From 50 Green Home Projects,” green architecture guru Eric Corey Freed and business expert Kevin Daum team up to give you straight talk on the value of going green at home — what’s worth paying for and what’s not, where to find all of the rebates and credits out there, and what kind of savings you’ll see — so you’ll know when to spend. Projects include weatherizing windows, harvesting rainwater, using a clothesline, installing a green roof, a many more. COVER: THE TAUNTON PRESS

The following is an excerpt from Green Sense for the Home by Eric Corey Freed and Kevin Daum (The Taunton Press, 2010). 

If your home is like most, hot water is produced in a hot water heater. This large tank usually sits in a garage, closet or basement and slowly heats up a vat of water. Think of it as a 60-gallon thermos with a built-in heater. If the stored water drops below a certain temperature, the heater automatically heats it back up again, so you always have hot water ready to go at any moment. Providing this endless supply requires energy — and lots of it. Nearly 20 percent of all of the energy used in the home goes just to the water heater, making it the second-largest energy user in homes after heating and cooling.

Whether your hot water heater runs on gas (a fossil fuel) or on electricity (created by burning fossil fuels), it contributes to global warming and to our ongoing energy crisis. By reducing the temperature of the heater — with a timer, thermostat or simply by turning it down — you can reduce its energy consumption. And just as you insulate the walls of your home to hold in heated or cooled air, insulating your hot water heater is equally important. The time it takes to install water heater insulation will be well worth the payback in energy savings.

What will this project do for your home? 

Insulating a water heater tank reduces the heat losses or standby losses from keeping the water sitting around waiting for you to turn on the hot water faucet by 25 percent to 45 percent. This translates to as much as a 9 percent savings in total energy usage.

If you have an electric water heater, you can save an additional 5 percent to 12 percent of your energy usage by installing a timer that turns the heater off at night or while you’re at work and don’t need hot water. Plus, a well-insulated water heater means there will be less chance of your running out of hot water during a shower, as the heat remains in the tank.

What will this project do for the Earth? 

In the United States alone, water heating is responsible for 122 billion kilowatt-hours (kwh) of energy used annually. If everyone insulated their hot water heaters, nearly 11 billion kwh of that energy would be saved — enough to power 1 million homes for a year.