A new report from Newport Partners, a building-industry research and development firm, reveals that tankless water heaters — long purchased for their systems’ energy and money saving capabilities and hot water supply volume — recently out-performed electric heat pump water heaters in five key areas.
Energy source, CO2 emissions, economics, hot water delivery rate, and installation requirements are significantly favorable for tankless units, powered by propane gas, across the Newport Partners study, even over tank-style water heaters meeting EnergyStar® qualifications.
While certain electric water heater models can garner high-efficiency ratings, the upstream electricity required to power them generates substantial CO2 emissions, the study noted. On average, the CO2 emissions for a propane-powered tankless unit are 39% lower than that of an electric water heater.
Those findings are in line with the reduced energy bills of Rinnai tankless water heaters who have observed up to a 40% drop in utility costs post-installation — a substantial savings when water heating is the second largest use of energy most homes after HVAC usage, according to the Department of Energy. In fact, traditional tank water heating can account constitute up to 25% of overall household consumption.
Furthermore, the study verifies that the Annual Cost of Ownership (ACO) — the unit cost spread over the system’s rated service life — surpasses the ACO for heat pump water heaters: in new construction, tankless is 18% lower; as a replacement, 13% lower. Those savings continue to flow like hot water over time. The service lifespan for Rinnai Tankless Water Heaters is about 20 years, about twice that of a traditional tank.
Notably, tankless systems delivered triple the hot water flow rate than tank heaters in the study, including higher efficiency models designed for EnergyStar® endorsement. One Rinnai unit can deliver 240 gallons per hour with no recovery time. That’s the capacity of 10 40-gallon electric water heaters.
The price tag for installing electric water heaters in new construction ran 34% higher than those for tankless, the study further revealed. In a replacement scenario, they are at least 18% more expensive to both purchase and install than tankless, with complicated installations costing $400 to $650 or more.
The flexible installation of tankless units, made possible by their compact design and functionality, allows for placement indoors or outdoors and for serving as either a central system or point-of-use supply. They can save 16 square feet of space taken up by electric water heaters, which also require 1,000 cubic feet of surrounding air space.
Moreover, electric water heaters must be installed in locations remaining 40 to 90-degrees F, eliminating potentially useful locations like garages in northern climates. The exhaustion of cool air by electric water heaters indoors can also affect home heating costs, an issue tankless units bypass with a dedicated intake and exhaust.
For more comparisons and to further explore the tankless world, visit www.rinnai.us/tankless-water-heater.