Up to 25% of the energy used in the average home is spent on heating water. Most homes have storage-type water heaters that suffer from standby heat losses. Storage type water heaters heat a tank of water and keep it hot until there is a demand for hot water for showers, dishwashing, laundry, or some other source. Standby heat loss is the heat lost from a water heater when there is no demand for hot water. The water in the hot water storage tank loses heat and the water has to cycle on to keep the water hot.
Standby heat loss can be reduced by up to 45% by adding insulation to the water heater. Insulation blankets specifically designed for water heaters are available at your local home improvement center. Depending on the age and R-value of your water heater and the cost of installation (if any), a water heater insulation blanket will usually pay for itself in A water heater insulation blanket can be safely installed by a homeowner on an electric water heater. Installation of water heater insulation blankets on natural gas or propane water heaters is more complicated and should be completed by a professional plumber who handles water heater repair and installation.
Water heater insulation blankets are most effective on water heaters with a low R-value (below R-24). If your water heater is warm to the touch, you should see some benefit from installing an insulation blanket. In addition, water heaters installed in unheated space such as a garage, basement, or crawlspace will benefit from an insulation blanket more than water heaters installed in heated spaces.
