Tanked Water Heaters: One of the most scrutinized and regulated appliances in the home or business
Over the years most appliances in homes, apartments, condominiums, and businesses have greatly improved in energy efficiency. Water heaters are no different and have become one of the most scrutinized and regulated appliances in the home. A decade ago the U.S. Department of Energy stated that the water heater represented around 25% of a home’s energy cost. Now, according to energy.gov, water heaters are still the second-largest energy expense in many homes, even though they’re down to about 18% of the average utility bill. [Read more at energy.gov/energysaver/tips-water-heating. – Ed]
The most common type of water heater provides a storage tank capable of holding anywhere between 20- and 80 gallons of water which is heated using electricity, natural gas or propane. The Energy Efficiency Standard Group, a division of the DOE, tests water heaters and determine their individual energy factor, which is a water heater’s overall energy efficiency based on the amount of hot water produced per unit of fuel consumed. Represented as a decimal like a baseball batting average, the higher the decimal number used to represent a unit’s EF, generally the more efficient the unit is.
Before the implementation of new National Energy Appliance Conservation Act standards last year, electric storage water heaters between 20- and 55 gallon capacity needed to post EFs between .90 and .93, according to information provided by Rheem at http://bit.ly/29ned7R. Today the standard is .95 EF. Electric storage water heaters of greater than 55 gallon capacity had to carry EF ratings between .81 and .88. Today, those same units must have EFs ranging from 1.92 to 1.98.
A gas storage water heater between 30- and 50 gallons capacity once needed to score an EF between .58 and .61 More than 55 gallon units required EFs ranging between .53 and .56. Today, the smaller gas units need to have EFs ranging from .60 to .63 and the larger gas units need EFs ranging between .53 and .56.
In addition, tanked units wishing to consider themselves “greener” alternatives can achieve elective Energy Star certification through the U.S. Environmental Agency’s program by complying with even more stringent energy factors. For example, electric heaters less than or equal to 55 gallon capacity need to post EFs greater than or equal to 2.0 for Energy Star certification, and gas heaters of the same capacity need EFs greater than or equal to .67 for Energy Star certification, and some of this type rack up numbers as high as .99 today.
Manufacturers have improved water heater efficiency to keep up with more stringent requirements in a few different ways:
1) A tank water heater works by storing water and maintaining it at a set temperature. Standby Loss occurs when there is no demand for hot water, so the water in the tank cools and calls for the heating element to cycle and bring it back up to temperature. This happens all day long and it’s one of the largest energy wasters associated with tank water heaters.
2) Adding electronic controls and microprocessors that constantly monitor and maintain consistent and accurate water temperatures have improved energy efficiency.
3) Many manufacturers have also combined heating methods by adding heat pumps and/or solar capabilities to tank water heaters. The hybrid water heater uses a heat pump to pulls the heat out of the air and uses that to heat the water.
4) Some manufacturers actually recommend that consumers use a water heater insulation jacket to improve efficiency. Consumers should always follow the manufacturer’s recommendations on this method, as if not done properly it could block vents.
Another side effect of 2015’s NAECA regs is the new standard has increased the size of most tank water heaters by at least two inches in diameter due to the additional insulation required to meet the standards. This can create some installation problems for places with limited space such as apartments and condos when the owner or tenant needs a new water heater. In addition, manufacturers are no longer manufacturing standard tank water heaters larger than 55 gallons and are replacing the larger ones with hybrid (heat pump) tank water heaters.
The DOE has determined that the new standards for residential water heaters, pool heaters, and direct heating equipment such as gas fireplaces will save consumers up to $10 billion and prevent the release of up to 164 million tons of carbon dioxide over 30 years.