Hot water tank jackets are typically constructed from different insulating materials, including fiberglass and radiant foil. While a fiberglass jacket insulates the water tank by preventing the heat from escaping, a radiant foil jacket works by reflecting the heat back to the tank.
Approximately 20 percent of the average domestic use of electricity can be attributed to water heating. Conventional heaters work by heating the water and depositing it in a storage tank. Without a tank jacket, much of the heat is lost. By using a hot water heater jacket, an average household can save up to $4.00 per month in electricity.