Water Heaters Key Terms

Knowing key terms can help you choose the right water heater

By Deborah Barr

Water heaters last a long time, so most of us don't have much experience with purchasing one. When it's time to choose a new water heater for your business, take your time. There's a lot to consider and you will have to live with your choice for years to come. Be sure to read and compare the manufacturers' information. Pay special attention to the various ratings and, of course, to the warranty.

First hour rating (FHR)

The first hour rating is how much hot water the heater produces within one hour. Many people assume that a large water heater storage tank equates with always having plenty of hot water. That's not necessarily so. Having enough hot water for the times when demand is highest depends on how quickly a tank can replenish hot water as it is drawn out.
Try: To learn more about the first hour rating visit the U.S. Department of Energy.

Energy factor (EF)

Every water heater comes with an energy factor (EF) rating. The higher the EF number, the more efficient the water heater. Keep in mind that a high EF rating does not mean the water heater will have the lowest annual operating cost. To determine that cost, you must factor in the first hour rating, the size of the tank and your fuel source.
Try: For more information about the energy factor rating, visit Bradford White.

Standby heat loss

Storage water heaters lose energy even when you are not running hot water. This is called standby heat loss. To minimize this, choose an insulated tank with a thermal resistance (R-value)of R-12 to R-25. To minimize standby heat loss in older models, wrap the tank in a water heater blanket and insulate your hot water pipes. To completely avoid the problem of standby heat loss, choose a tankless water heater.
Try: For more information about minimizing standby heat loss in older water heaters, visit Lower-My-EnergyBill.com.

Nitrous oxide (NOx) emissions

Water heaters emit NOx--reactive gases that contain varying amounts of nitrogen and oxygen. According the Environmental Protection Agency (EPA), NOx is a pollutant that contributes to global warming, acid rain and respiratory problems. If you live in Southern California or Texas, a water heater's nitrous oxide emissions rating is required to be very low.
Try: To learn more about NOx, go to Metal Finishing.

Sediment

Over time, the minerals in water collect at the bottom of a water heater tank and form sediment. Sediment eventually slows a water heater's ability to heat water. Proper water heater maintenance includes either periodically draining the tank to remove the sediment or dissolving sediment with a chemical. Since sediment build up can affect the life of your water heater, look for a 12-year warranty, which typically includes a more robust heating element.
Try: To learn more about how to control sediment visit Water Heater Rescue.

Hybrids

Hybrid water heaters are the newest water heating technology. Hybrids can be powered by electricity or gas. They use far less energy and emit very low NOx.
Try: To preview General Electric's hybrid electric water heater go to Consumer Report.org's blog. To learn more about hybrid technology visit Grand Hall.