Bay Area Sets NOx Emissions Standards for Gas Water Heaters & Furnaces, Effectively Ending Sales Starting in 2027

Big news for clean air last week. The Bay Area Air Quality Management District (BAAQMD) adopted amendments requiring the elimination of nitrogen oxide (NOx) emissions from new water heaters by 2027 and new furnaces by 2029.

We’ve been hearing about the indoor pollution from gas stoves this year. Gas water heaters and furnaces also have pollution and air quality problems. To start, they account for 96% of gas burned in homes.

Source: PSE Healthy Energy

The pollution from gas furnaces and water heaters is vented to the outside so it doesn’t necessarily affect indoor air quality, but it does create significant outdoor pollution in the form NOx. RMI estimates that NOx emissions from gas appliances are more than twice the emissions of gas power plants. NOx is one of two components of summer ozone, or smog, and is a precursor to fine particle formation, which leads to premature mortality of ~100,000 Americans each year.

The new Bay Area emissions standards will be one of the first in the nation to phase out existing gas and fossil fuel water heaters. In a short few years, homes in the region will no longer be able to install gas combusting appliances. Organizations like the Regulatory Assistance Project have also created draft rules that can help jurisdictions phase out NOx emissions based in part on the BAAQMD standards and starting with water heaters. These rules follow and build on the all-electric new construction mandates which started with Berkeley in 2019 and quickly spread to other cities and states (which now number over 100 including the nation’s two largest cities, New York and Los Angeles). The nonprofit New Buildings Institute (where I’m lucky enough to work), helped write building codes which were adopted in 2022 in Washington State that mandate heat pumps for space and water heating in new construction.

The health and monetary savings from increased clean air will be substantial. In addition to eliminating a potent source of greenhouse gas emissions and methane leakage, these new Bay Area standards will avoid an estimated $890 million per year in health impacts due to reduced air pollution exposure and prevent an estimated 85 premature deaths, according to the Bay Area Air Quality Management District.

These efforts are also an important part of what I call “the perfect storm” pushing our nation to an efficient, all-electric, heat pump powered 21st century. The three forces coming together to drive these important changes are:

1. Local electrification and air quality mandates (like this important Bay Area standard) that are phasing out fossil fuel combusting appliances.
2. Federal standards that phase out inefficient electric resistance heating (for water heaters, new draft standards are set to be released soon and should take effect by 2029).
3. Incentives from the Inflation Reduction Act that will make heat pumps more affordable through tax credits and rebates.

And we need to accelerate all these efforts, as the IPCC recently released the frightening final portion of its 6th assessment report calling for countries to phase out coal oil and gas in order to “defuse the climate time-bomb.” The Bay Area is doing its part to phase out gas combustion in homes, leading the way to a healthier climate and cleaner air.

Featured photo by Call Me Fred on Unsplash