DOE Issues Final Rule on Water Heater Test Procedure

July 1, 2014 By Karen Henry

Energy Manage hot water heaterThe US Department of Energy (DOE) issued a pre-publication Federal Register final rule regarding the test procedure for residential water heaters and certain commercial water heaters so that it better represents real-world conditions.

Under the final rule, a uniform descriptor will be established that can be applied to all residential water heaters and to certain commercial water heaters that have residential applications. The final rule also establishes a new equipment class of commercial water heaters and corresponding definition for “residential-duty commercial water heater.” DOE will require water heaters that are classified as “residential-duty commercial” to be tested using the procedure outlined in the final rule.

DOE has also established the use of multiple draw patterns for testing water heaters, with certain draw patterns prescribed based on equipment capacity. The water heater draw pattern has been updated to be more reflective of real-world use, and the outlet water temperature requirement has been modified to better reflect conditions encountered in typical field installations.

While the new procedure addresses a number of longstanding testing issues in order to better replicate real-world usage and to more accurately measure energy consumption across various technologies, according to an American Council for an Energy-Efficient Economy (ACEEE) blog post, the DOE missed an opportunity to ensure that the electric heat pump water heater (HPWH) performs as expected in cold temperatures.

The HPWH offers large energy-savings opportunities, ACEEE said. A 2012 ACEEE/Appliance Standard Awareness Project study estimates that savings from potential HPWH standards could reach more than 400 billion kWh in cumulative electricity through 2035. Individually, EPA estimates that units save $250 a year in electricity bills when compared to standard electric-storage water heaters and that the higher purchase price can be recouped in about three years.

Leave a reply