Project: A. O. Smith NEXT Hybrid® High Efficiency Gas Water Heater replaces two conventional water heaters for whole home water heating solution
Location: St. Louis, Missouri
Product: A. O. Smith NEXT Hybrid® High Efficiency Gas Water Heater
• Provides the best of both worlds— performs like a tankless model but installs similar to a conventional water heater
• 90% thermal efficiency
• Eliminates sudden interruptions in hot water delivery (“cold water sandwiches”)
• Interactive controls with multiple lifestyle modes
• Designed for the way you use hot water
Since moving into their home 11 years ago, the Huber family of St. Louis, Mo., has had to adjust their lifestyle around their two older conventional water heaters. Installed long before the Hubers purchased the home, the two 50-gallon direct vent units could no longer support the Huber’s hot water usage. Showers, laundry and other appliances all had to be scheduled so as not to overpower the water heating system. This was especially problematic during the weekends and holidays, when the Hubers like to entertain.
When the first heater began to fail in 2009, the Hubers worked to further adjust their schedules around the reduced hot water supply. However, by December 2010, retired electrical engineer Paul Huber had had enough. He began looking into new water heating options.
“I was interested in tankless water heaters because of the money saved with on‑demand water heating as well as the savings in space,” said Huber. “But between the cold ground water here in St. Louis and the minimum flow requirements, we’d still have to make concessions for our water heater to perform properly.”
That’s when Huber called plumbing contractor Ben Bippen with Dippel Plumbing. Bippen recommended and installed A. O. Smith’s NEXT Hybrid® High Efficiency Gas Water Heater as a replacement for both of the older power-vent units. The only water heater of its kind, the NEXT Hybrid combines a tankless engine and small buffer tank, offering the best of both tankless and conventional tank-type water heating technologies.
The NEXT Hybrid water heater installs similarly to a conventional unit, but provides all the benefits of a tankless unit. For maximum energy efficiency, exhaust gasses from the tankless engine are used to transfer additional heat to the small buffer tank. This design allows the unit to operate at 90 percent thermal efficiency, surpassing both conventional tank models and tankless units, which operate at 78 and 82 percent thermal efficiency, respectively.
The small, built-in buffer tank is critical to the NEXT Hybrid water heater’s performance because it combats common tankless water heater issues such as sudden interruptions in hot water delivery (“cold water sandwiches”), minimum flow rates, and cold ground water temperatures.
“During winter in St. Louis, water comes into a house at around 40 degrees, which makes it hard for a tankless unit to perform correctly,” Bippen said. “The NEXT Hybrid is a great solution for this. You get higher efficiency and water heating performance. You don’t have to change your daily habits with a hybrid unit.”
To best accommodate the Huber’s large threelevel home with multiple bathrooms on each floor, Dippel Plumbing also installed a recirculating pump to ensure the quickest possible hot water delivery to each fixture.
“The recirculating system ensures that hot water is delivered to the tap immediately,” Bippen said. “The NEXT Hybrid’s buffer tank is essential to this design. In a large house, it could take a few minutes for hot water to reach the tap. However, the recirculating system allows hot water to continuously circulate through the house without activating the water heater. You couldn’t do that with a tankless unit.”
Dippel Plumbing installed the NEXT Hybrid water heater in December 2010, and Huber was immediately impressed by the new water heater. After a few weeks of monitoring the unit, he was able to easily adjust the NEXT Hybrid’s simple-to-use digital temperature controls to best suit his family’s needs. Huber was also pleased with the arrival of his energy bills after installing the NEXT Hybrid water heater.
“I couldn’t believe it,” Huber said. “Gas prices are higher than ever, but since we installed the NEXT Hybrid, my utility bills are lower than they’ve been in years.”
NEXT Hybrid® Unit Replaces Two Conventional Water Heaters (PDF)