water heater energy fact sheet The water heater in your home works year-around. This can account for as much as 25% of the utility bill, second only to the cost of winter heat in northern climates. However, since 25 years ago, the efficiency of water heaters has improved by 30%. The accepted lifetime of a unit is 13 years. These facts should be among those to consider as to whether to replace the water heater in your household w/ a new high efficiency model. Energy-wise purchasing can be accomplished w/ a little forethought. Planning before an emergency can save time & be more comfortable.   fuel choice Water heaters can use fuel such as natural gas, propane, electricity, or oil & then store the heated water in a tank. A solar model & a heat pump are also systems in use today. A point-of-use style w/out a tank is available but only the common style w/ the storage tank will be discussed here. Gas water heaters cost about half as much as electric models to operate. However, off-peak rates are available from electric utilities, which would reduce this difference in operating cost. Keeping the temperature of the water constant in the tank day & night is what costs the most w/ a conventional model. Setting the heater at 125°F will be sufficient for most uses, especially w/ elderly or children in your home. Safety is an issue here as water that is too hot can cause burns & waste money.   size, EF & FHR The yellow EnergyGuide label offers valuable information about the cost of operating the heater during the year. Factors to consider in determining the right heater for your needs for the future decade are the EF (energy factor - number of cycles that can be completed w/ one kilowatt-hour of electricity), the FHR (First Hour Rating - amount of hot water a unit can produce in an hour), size & fuel type. Usually, the quicker the water heats, as determined by the FHR, the smaller the required storage capacity of the tank. Determining the size of the heater in your home can go beyond just matching the size of the one being replaced. The number of showers or baths in a row w/ or w/out shampooing or shaving, the number of loads of clothes to be washed, dishwashing & cooking all contribute to how fast the hot water is drained from the tank & the need to recover quickly. This is to what the EF & FHR refer. For traditional sizes, the EF varies from .6 & up for natural gas & propane heaters while electric heaters are over .9. However, gas heaters have a higher FHR & cost much less over time to operate. A 30-gallon sized tank would suffice for 2 people. A 40-gallon tank would likely suffice for a small family & larger tanks (60 gallons plus) are available for special situations including families w/ several teenagers. Many new or remodeled homes have a Jacuzzi or spa installed in the master bathroom & may have a separate heating unit. This also requires sufficient warm water at an additional cost of using it. A knowledgeable dealer or contractor will be able to help determine the proper size necessary for your needs.   other factors Location of the water heater in your house is important to the efficiency & cost of operation too. Minimizing the length of piping to the kitchen, bathrooms & laundry reduces lost heat as water flows. An unheated basement or garage is not a good place for the heater either. Heat traps should be installed on both water lines attached to the tank if not already included w/in the unit. This also will reduce heat loss when water is not flowing. Many gas units are vented directly to the outside & eliminate the use of a flue pipe to the chimney, or are also power vented w/ a blower on the top to help exhaust the unit. New gas water heaters will have electronic ignition to eliminate the wasted energy of a pilot light on old models. Thicker than standard insulation, built-in around the tank, will initially cost more but will save money during its use.