In 2015, the US Department of Energy changed your next water heater purchase. So what is the NAECA and what will it mean for your next water heater?

The National Appliance Energy Conservation Act (NAECA) began in 1975 in an effort to create a national regulatory standard for the efficiency of common home appliances such as water heaters, clothes washers, clothes dryers, and refrigerators. The energy efficiency of appliances is measured in EF or Energy Factor. As an example, a water heater with an energy factor of .94 would indicate that 94% of the energy used by the water heater goes to making hot water. The higher the EF, the more energy efficient the appliance. In April of 2015, the Department of Energy updated minimum standards for EF ratings on virtually all gas, electric, propane, and oil fired water heaters. These new water heater efficiency standards could change your next water heater purchase.

Things to consider regarding the new water heater efficiency standards

For gas and electric water heaters smaller than 55 gallons, the change comes down to size. New NAECA-compliant water heaters will be better insulated and all that insulation will make them bigger. This could create some problems where existing water heater tanks are squeezed into small spaces.

This shows an older gas water heater with natural draft technology

If you are replacing your old 50-gallon water heater and it barely fits in its current location, you may need to install a 40-gallon model if it is going to fit in the same space.  This reduced size can be inconvenient and result in running out of hot water, but there are some workarounds.

Workaround for water heaters smaller than 55 gallons

One way to visualize the function of a tank-style water heater is that it stores BTU’s in the tank. (BTU’s are British Thermal Units and they are a standard measure of heat) So if your new 40-gallon water heater is too small and you don’t want to run out of hot water, you can raise the temperature of the tank and store more BTU’s. Simple right? Just turn up the thermostat. The problem with this is you will create a scald hazard that can

Honeywell Mixing Valve

be a serious safety hazard, especially for small children. To solve this problem, a plumber can add a mixing valve to the hot water supply. This mixing valve or tempering valve can be pre-set to a safe 120-degree F. water temperature by mixing cold water with the hot water. Now you have a smaller, more energy efficient water heater, storing more BTU’s and you have more hot water available that is safely protected by a mixing valve. This is technically also safer as the higher temperatures in the tank make it less likely for Legionella (the bacteria that causes Legionnaires’ disease) to develop in the tank. All is good in water heater land.

What about water heaters bigger than 55 gallons?

Where you want a water heater larger than 55 gallons, things start to get more complex. Electric water heaters greater than 55 gallons will be required to use heat pump technology to make them more energy efficient. In my opinion, this is a frustrating requirement as heat pump water heaters do not add efficiency if they are installed inside your house and you are in a heating climate – these need to use EXTERIOR air to create a more efficient water heater.

This is what the top of a heat pump water heater looks like

If you install a heat pump water heater in your garage, this is great and a more energy efficient installation. But if you put the same water heater in your conditioned basement, in the winter time, you will be paying to heat the air in your basement with your furnace and then the heat pump will use that heat to heat your water. There is no free lunch in this configuration, so the location of the heat pump water heater is paramount in its ability to deliver a more energy efficient water heater.

For gas water heaters greater than 55 gallons, you will need to employ direct vent technology – these types of water heaters bring in outside air for combustion through a special flue pipe, such as the water heater shown below. This required change in technology could add significant cost and hassle when replacing an old

This shows a gas water heater with direct vent technology. This type of water heater can meet in new NAECA even when greater than 55 gallons. Note the grey mixing valve on top.

80-gallon water heater. This type of change can also put water heater replacement well out of the hands of a homeowner project. Changing from, for example, a natural draft appliance to a direct vent appliance should be permitted in my state of Washington and it should be done by a qualified contractor. I have seen homeowner versions of this conversion that resulted in an unsafe installation.

Good News For Lovers of Tankless Water Heaters

For some reason, everybody seems to love the idea of a tankless water heater. Well, you can thank the 2015 NAECA for giving you an excuse to upgrade. These are expensive water heaters to buy and install but they meet the standards of the 2015 NAECA and when sized and installed correctly, they produce unlimited hot water.

The shows a tankless water heater. All of these types of water heaters are direct vent and meet the 2015 NAECA standards.

Gas pipe sizing, proper venting, and control of condensate are important considerations when installing tankless water heaters and you need to have natural gas or propane; electric tankless water heaters require such a large amount of electricity that they are impractical in most situations. For more information about the advantages and disadvantages of tankless water heaters see:

I hope this article helps at least get you thinking about some complexities you could face when water heater replacement comes around next time. Water heater replacement is a common part of home ownership and it is nice to be prepared for these eventualities.