Enviroment: Local

2015 DOE Changes


Rising Efficiency Standards Create Challenges. Rinnai Tankless Water Heaters Provide Solutions.

As part of the National Appliance Energy Conservation Act (NAECA), the U.S. Department of Energy (DOE) issued updated efficiency mandates in 2010 that take effect April 16, 2015. These new rules require higher Energy Factor (EF) ratings on most all residential gas, electric, oil and tankless gas water heaters.

To the DOE and its updated standards, Rinnai simply says, “Welcome. We’ve been waiting for you.”

Innovation That Exceeds Compliance

Thanks to a decades-long commitment to innovative design and engineering, Rinnai’s TANKLESS water heaters are steps ahead in delivering the ultimate in energy efficient performance. Since all of our units already meet the minimum DOE energy factor standards of .82, the changes will have no direct impact on our industry-leading family of TANKLESS water heaters.

Since Rinnai tankless units already meet the minimum DOE standards of .82, this change does not impact our current Rinnai product offering.

For gas-powered storage water heaters, complying with the sweeping efficiency changes creates numerous design, manufacturing and installation challenges.

For gas water heaters with storage tanks 30 to 50 gallons in size, for example, the increase in the minimum standards will trigger an increase in the insulation needed, resulting in a larger tank diameter. This can be as much as 2 inches or more in some cases. This will make equipment replacement problematic because the same size tank in gallons may not fit in the same location, especially in locations with narrow doorways, openings and narrow stairways to the attic.

The following grids show the changes in DOE minimum efficiency requirements

Gas Storage Water Heaters
Volume Current Federal Minimum Federal Minimum from 2015
114L (30gal) .61 .63
151L (40gal) .59 .62
190L (50gal) .58 .60
246L (65gal) .55 .75
284L (75gal) .53 .74
Gas Tankless Water Heaters
Current Federal Minimum 0.62
Federal Minimum from 2015 0.82

Tanks above 55 gallons will now need to be high efficiency condensing units requiring an electrical outlet to power the unit, different venting, as well as a means to drain the condensation. For contractors, these heavier, more complex tanks can double the manpower needed for installation jobs, as well as create a need for bigger service trucks and more storage space. These changes add up to an increased overall cost of storage tank water heaters including greatly increasing the manufacturing cost of storage tank water heaters coupled with potentially higher installation costs.

With the size and design of our compact products unchanged by the new regulations, Rinnai tankless water heaters can be installed in a wider variety of locations, including places where new, larger tanks won’t fit.

With saving energy on everyone’s list of top priorities, Rinnai’s engineers reasoned long ago that there was no sense in developing products driven by the goal to merely comply with energy regulations. What was needed instead was a proactive focus on creating advanced, high-performance appliances that exceeded the most demanding water heating needs of homeowners and businesses alike.

Performance Meets Efficiency

Rinnai’s emphasis on leading-edge engineering and smart technology has built a family of versatile, gas powered solutions that provide an endless supply of hot water and a steady flow of energy savings.

In fact, because they operate on an as-needed basis, Rinnai Tankless Water Heaters use up to 40%* less energy than traditional systems, which can significantly reduce utility costs and environmental impact. As a growing number of consumers are driven to look for energy efficient homes, Rinnai’s tankless units can increase home values by improving HERS and LEED ratings, the two nationally recognized programs that measure a home’s energy performance.

The Home Energy Rating System (HERS) Index is the industry standard by which a home's energy efficiency is measured. It’s also the nationally recognized system for inspecting and calculating a home's energy performance.

LEED, or Leadership in Energy & Environmental Design, is a green building certification program that recognizes best-in-class building strategies and practices. To receive LEED certification, building projects satisfy prerequisites and earn points to achieve different levels of certification. Prerequisites and credits differ for each rating system, and teams choose the best fit for their project.

When it comes to performance that complies with the new DOE energy efficiency standards, Rinnai has it covered. In fact, you might say we had a major head start.

*As based on the average cost to run an electric tank water heater per the DOE Average Energy Costs (www.doe.gov).


In response to the new DOE standards, ENERGY STAR® has raised their ratings as well. As of April 16, 2015, their gas tankless water heater energy factor minimum will increase to .90.

Energy Star Timeline

January 1, 2015

  • All new product submittals will need to meet Version 3.0 requirements to qualify for an Energy Star rating.
  • Products certified/listed prior to this date can be listed utilizing the ENERGY STAR Version 2.0 requirements and can continue to bear the ENERGY STAR logo until April 15, 2015.

April 16, 2015

  • Any product manufactured and labeled ENERGY STAR must be certified to the Version 3.0 requirements.
  • Any product manufactured prior to April 16, 2015 that bears the ES2.0 logo can still be sold until depletion.
Energy Star Changes Summarized

Both Rinnai’s Ultra Series RUC Model Tankless Water Heaters, with more venting options right on the unit, and Ultra Series RUR Model Tankless Water Heaters with thermal bypass technology for faster hot water will maintain ENERGY STAR® status.

Rinnai non-condensing unit – where do they fall in the energy efficiency race? Ironically, these units will no longer bear the ENERGY STAR® logo, yet they are frontrunners in the energy efficiency race. While ENERGY STAR® policy has been that within each category only the most efficient products will receive the ENERGY STAR® ratings, the superior overall performance of the gas tankless water heater category means that some top models won’t get the certification they deserve.

Think of it like three top Olympic athletes going head to head for a gold medal in a single event. Only one will win, but the two who finished behind him are no less great and could have taken the gold in another event. The fact is, even the non-ENERGY STAR® Rinnai units with the an energy factor rating of .82 are still significantly more efficient than the minimum qualifying storage tank that does bear an ENERGY STAR® logo!

Confusing? It doesn’t have to be. The important thing to remember when you’re trying to determine the most efficient water heater is this: “Every Rinnai Tankless Is Still More Efficient Than a Tank.” And that’s true whether they receive an ENERGY STAR® mark or not.

Rinnai And Title 24

Rinnai America Corporation ("RAC") prepared a summary of California Title 24, primarily based on the California Energy Commission’s 2013 Building Energy Efficiency Standards. The purpose of the document is to provide a general overview of the requirements of California Code of Regulations (CCR) Title 24. This document is offered for informational purposes only as a broad summary of information provided by California Energy Commission; it is not a legal document.

What is “Title 24”?

“Title 24” references numerous state regulations that govern the design and construction of buildings and facilities as well as energy conservation. Within Title 24, there are multiple sections, each of which reference specific requirements concerning the codes for Electrical, Mechanical, Plumbing, etc. To ensure proper compliance, you should refer directly to CEC Title 24 or contact a professional certified in this area.

Title 24 Compliance

Title 24 breaks down energy use in buildings into several categories: space heating, space cooling, water heating and lighting. Since usage is impacted by climate conditions in the different areas of the State, the calculations will vary by Zone. The 16 Zones are shown in the below map provided by T24-Reports.com.

Title 24 provides two methods for compliance:

(1) Prescriptive Method: Each individual component of the proposed building must meet a prescribed minimum energy requirement. Certain requirements define maximum levels, such as maximum number of windows allowed. While it is the simplest approach, it is also the least flexible for compliance and is typically only used in 5-10% of the applications.

(2) Performance Method: Also known as the “computer method,” requires a detailed total accounting of a building’s energy usage. The “budget” for the proposed house is compared to a standard that not only considers the type of energy that is used (electricity, gas, or propane), but also when it is used. Unlike the Prescriptive Method, the overall valuation can then be manipulated with “trade-offs”, upgrades or downgrades of conservation features. While this approach requires the most effort, it also provides the greatest flexibility and as such is typically used in 90-95% of the applications.

The 2013 edition of the California Code of Regulations’ Title 24 implemented on July 1, 2014 sets the stage for a shift to high efficiency water heating products, stipulating gas line, electrical, venting and condensate drain upgrades. These requirements ensure that about 70% of the investment necessary for tankless installations would already be met, making retrofit to Rinnai’s energy-efficient tankless water heaters much easier and the clear choice for new construction.

What’s more, Rinnai’s compact designs can be conveniently located closer to fixtures, reducing or eliminating the need for recirculation, improving water conservation, and saving additional project costs on equipment, materials and labor.

Read the Title 24 White Paper

Water Heating Solutions For A Changing World

Rinnai Tankless Water Heaters are the solutions that open up all the right opportunities in a world of rising energy efficiency standards and compliance requirements.

Contractors and distributors can count on us for the high efficiency products that help them continue to grow their businesses. Customers can trust us to provide the innovation and precision engineering that deliver maximum performance, energy savings and peace of mind every time they turn on their hot water.

As we aggressively invest in the talent and technology that sets new benchmarks in water heating excellence, we look forward to exceeding even the highest expectations with our absolute best.

Click here to learn more about Rinnai’s complete lineup of high-efficiency tankless water heaters.


DOE Presentation
24 Title White Paper
Title 24 Demand Recirculation
Eye on Energy