Know which type of water heater suits your home
Water heaters use about 20 percent of the energy on your utility bill so it pays to pay attention to how you use hot water and what type of water heater to buy when you need one.
There are several types of water heaters to choose from, plus different fuel types they use: electricity, gas, propane, fuel oil, geothermal, solar. The U.S. Department of Energy has detailed descriptions of choices at http://s.coop/2atk6. Also be sure to use a professional technician to install any heater you buy.
Following are key points about your choices:
Storage electric-resistance heater — This is the most common type of heater. It heats and stores 20 to 80 gallons of water in an insulated tank where the water is constantly maintained at the thermostat’s setting, ideally 120 degrees. Energy can be wasted even when a hot water tap isn’t running, which is most of the time. This is called standby heat loss. Some storage water heaters have heavily insulated tanks, which can significantly reduce standby losses, according to DOE. Look for tanks with a thermal resistance of R-12 to R-25.
Solar heaters — These heaters preheat water through thermal collectors before it reaches a conventional water heater. They are costly on the front end but may qualify for federal tax credits. The fuel, of course, is free but keep in mind the sun doesn’t always shine or shine long enough. Conventional storage water heaters usually provide backup.
The two types of types of solar heaters are active, with circulating pumps and controls, and passive without, and therefore less expensive. For details, go to http://s.coop/2atk7.
Heat pump water heaters — They cost more upfront, but in moderate climates like Missouri’s, can save up to 50 percent on your water heating bill. Whereas most homeowners use heat pumps to efficiently heat and cool their homes, they also can be used to heat water, either as stand-alone systems or as combination water heating and space conditioning systems.
Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to three times more energy efficient than conventional electric resistance water heaters.
There are both air-source heat pump varieties and geothermal heat pump varieties. The latter requires a desuperheater, which is a small auxiliary heat exchanger that uses superheated gases from the heat pump’s compressor to heat water. Both varieties need locations in the 40 to 90 degree range with at least 1,000 cubic feet of air space around the water heater. For details, go to http://s.coop/2atk8.