New Water Heater Technology Developed by NIST Aims to Eliminate Bacteria and Enhance Safety
Researchers at the National Institute of Standards and Technology (NIST) have developed and patented a new water heater design intended to eliminate harmful bacteria, such as Legionella pneumophila, which causes Legionnaires’ disease. The innovative design allows water heater tanks to maintain temperatures of 160 degrees Fahrenheit, a level lethal to Legionella bacteria, while ensuring the water delivered to faucets is cooled to safe, non-scalding temperatures for human use. This is achieved through an unmixed heat exchanger, a technology commonly found in HVAC systems and refrigerators, which preheats incoming cold water using the heat from the outgoing hot water. This process not only kills pathogens but also improves energy efficiency by recapturing waste heat. Current water heaters often struggle to maintain sufficiently high temperatures to kill bacteria without posing a scalding risk, as Legionella can survive in warm water pipes even if the tank temperature is set to 120°F.
