The U.S. Department of Energy (DOE) has increased efficiency standards for tank and tankless water heaters. The new standards take effect on April 16, 2015.
Why This Matters
Water heating is the second largest consumer of energy in the typical home. Since water heaters are so common (in virtually all homes) and they’re typically used every day, even a small increase in water heater efficiency will save a huge amount of energy.
Our federal government often makes incremental increases in efficiency standards to realize a big improvement over time. This strategy helps avoid disrupting markets. Changes in standards are typically made with significant industry and public input. The changes are also typically made with significant notice so the industry has time to roll out new products before the standards take effect.
The “New” DOE Standards
The U.S. Department of Energy has regulated the efficiency of oil, gas and electric water heaters since 1990. The improvement in energy efficiency for water heaters that goes into effect on April 16, 2015 was released by the U.S. DOE in 2010 to give manufacturers a chance to develop and bring new products to market.
Most residential water heaters heat and store water in a tank that’s less than 55 gallons. For units that heat and store less than 55 gallons of water, new units should see an energy efficiency increase of about 4%.
The new energy efficiency standard will push water heaters with a tank size of 55 gallons or more into the next generation of technologies like heat pump and gas condensing water heaters. They should be able to deliver an energy savings between 25% to 50% when compared to older technologies.
Tankless technologies for heating water probably already meet the energy efficiency requirements that will go into effect on April 16, 2015. It’s worth asking your plumber to check any new water heater purchase against the most current requirements to be sure you’re not helping a supplier clear out its inventory of old equipment.
What This Means For Homeowners
The changes to meet the efficiency requirements for tank water heaters less than 55 gallons are simple. The increased efficiency is found with slightly more efficiency parts and more insulation of the storage tank. This requires a bit more space for the tank though you’ll probably find it’s an increase of just a few inches.
Homeowners will need to be particularly careful when purchasing a new water heater if you have need for 55 or more gallons of hot water. You can meet that need with a larger storage tank though the purchase price for the new technologies may be significantly higher than the older technology. That may create a temptation to install two small water heaters that use the older technology.
If you need a water heater with a tank that’s 55 gallons or more, you need to carefully compare your options. For example, does it make make sense to pay a higher purchase price for a water heater with lower fuel costs that you’ll pay every month or should you buy two smaller water heaters that don’t cost as much to purchase but they cost more to operate?
Your design team should be able to help you forecast your costs for the various design solutions. The costs will vary by use, energy costs and other issues though you can get enough information to make an informed decision.
Efficiency Is Erased by Bad Design (and Behavior)
The energy savings from the most efficient water heater can be erased by poor plumbing design. Water wasted through bad plumbing design is called structural waste. The hot water heating and distribution system should be structured so they have the shortest possible pipe runs from the water heater to the plumbing fixture. We also waste water through our behavior – behavioral waste.
The “house as a system” way of teaching the relationship between the building envelope, air sealing and heating + cooling has helped the construction industry design and build healthier, more comfortable and more efficient homes. The “house as a system” way of thinking doesn’t account for our heating and using of water.
Even though water heating is the second highest consumer of water in the home, it doesn’t get enough design attention. It’s worth consulting a qualified professional to design a system that will serve you well through the life of your home. Having a design will help you resist the salesperson who just wants to sell you what’s on his truck or in his warehouse – whether is a good solution for you or not.
Water heaters that comply with the increased DOE energy efficiency standards are already on the market. You shouldn’t have trouble finding options and information about the improved efficiencies from all major manufacturers.
Everything in your house is part of a system. Please work with your design team to be sure you’re making decisions by looking at the parts of your house in context. Understanding how the parts work as a system will help you make the best possible investment and enjoy a home that meets your needs.
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Image by Brian Cantoni used under creative commons license.