DOE Issues Preliminary Determination on ASHRAE 90.1-2019

On April 21, 2021, DOE issued a preliminary determination that Standard 90.1-2019 will achieve greater energy efficiency in buildings subject to the code. DOE estimates national savings in commercial buildings of approximately:

  • 4.7 percent site energy savings
  • 4.3 percent source energy savings
  • 4.3 percent energy cost savings
  • 4.2 percent carbon emissions

If the DOE makes a final affirmative determination, and it likely will, states will have two years to certify that they have reviewed the provisions of their commercial building code regarding energy efficiency, and, as necessary, updated their codes to meet or exceed the updated edition of Standard 90.1.

Since 1992, 42 U.S.C. 6833 has required the DOE to evaluate new versions of ASHRAE 90.1 or its successor to determine if adopting the new version as a nationwide minimum standard would improve energy efficiency in commercial buildings. If it does, “each State shall, not later than 2 years after the date of the publication of such determination, certify that it has reviewed and updated the provisions of its commercial building code regarding energy efficiency in accordance with the revised standard for which such determination was made. Such certification shall include a demonstration that the provisions of such State’s commercial building code regarding energy efficiency meet or exceed such revised standard.”

LPDs, As Low As We Should Go

ASHRAE has released a series of changes to Standard 90.1 in preparation for the 2016 update.  Among those changes is the further tightening of LPDs (click here) in all space and building types.  In my opinion, these changes should be rejected by the lighting community.

Rather than provide tight, but reasonable, limitations on the power consumption of lighting systems, the LPDs proposed in the revision of Table 9.5.1 are so low that they clearly favor LED technology almost to the exclusion of all others.  They also strongly imply that energy efficiency is the most important criteria of a lighting system, regardless of the application.  Neither of these positions is appropriate for this document or the organizations that develop and maintain it.

The proposed LPDs are nearly impossible to meet by lighting designers who wish to exercise their best judgement, or meet client requirements, by selecting project appropriate sources of light other than LED.  In some cases this imposes an avoidable financial burden on the owner.  For example, LED luminaires with a combination of high output and smooth dimming to zero (such as those required for theatres, cinemas, houses of worship, etc.) are substantially more expensive than halogen alternatives, and may require more expensive control systems as well.  Clients requiring excellent color rendering (such as high end retail, art schools, museums, and health care facilities) are also compelled to purchase premium priced LED fixtures.

The only way that these low LPDs (and the even lower LPDs we assume will be proposed in the future) make sense is if they are paired with hours of usage to arrive at a time weighted limitations.  Even then, the LPDs should be high enough to permit designers and owners a choice in the technology that they use for a given application.  The proposed LPDs come very close to eliminating that choice.

I’m not saying that all buildings should be illuminated with incandescent light, or that LPDs should be abolished. I am saying, however, that the ever tightening of LPDs cannot go on forever, and that we have reached a tipping point where these limitations are having unjustifiable impacts on designs and budgets.  In my opinion, LPDs should not be further reduced for the foreseeable future.

DOE Updates Energy Conservation Requirements

On September 26, 2014 the U.S. Department of Energy issued a determination that ANSI/ASHRAE/IES Standard 90.1-2013 would achieve greater energy efficiency in buildings subject to the code than the 2010 version.  The DOE analyses determined that the energy savings would be:

  • 8.7% energy cost savings
  • 8.5% source energy savings
  • 7.6% site energy savings

As a result, all states are now required to certify that they have reviewed the provisions of their commercial building code regarding energy efficiency and, if necessary, updated their codes to meet or exceed the 2013 edition of Standard 90.1.   States must submit certification of compliance by September 26, 2016 or explain why they cannot comply.

Why is this happening?    The DOE is required by the Energy Conservation and Production Act (42 USC 6833) to review each new edition of ANSI/ASHRAE/IES Standard 90.1, and issue a determination as to whether the updated edition will improve energy efficiency in commercial buildings.  If the determination is that the new version will improve energy efficiency, that standard becomes the new nationwide minimum requirement.  States aren’t required to adopt Standard 90.1, but whatever standard they develop or adopt must be at least as stringent as Standard 90.1.

Some of the changes in the new standard are:

  • Lumen Power Densities (LPDs) for most building and space types are reduced by approximately 10% from the 2010 version.
  • More stringent requirements for lighting controls
  • A new table format for determining LPDs and control requirements in individual spaces

The DOE website contains additional information, including PDFs of the analyses they conducted.

Some Thoughts on Climate Change

The climate related news lately has been pretty bleak.  The news includes:

  • Separate studies by NASA and the University of Washington both find that the Western Antarctic ice sheet is collapsing into the sea.  At this point the melting is unstoppable and could raise global sea levels by 4 feet.  To put this into perspective, the average elevation of Miami is 6 feet above sea level.
  • The Carbon Tracker Initiative has estimated that 60% to 80% of our coal, oil, and gas reserves are “unburnable” if we are to limit global warming to a somewhat manageable 2°C.
  • According to NOAA, CO2 levels measured at Mauna Loa, Hawaii have risen by 24% in just the past 56 years.

Which naturally had me asking what I can do as a citizen and as a lighting professional.  My initial thought was, “Not nearly enough to make a difference.”  But, once I recovered my balance I realized that things aren’t as gloomy as they seem.  Yes, we still have a long way to go in order to maintain a livable planet.  This includes that fact that some industries are going to fade away, be legislated away, or be forced to adapt to new circumstances.  The economic impact of that doesn’t worry me too much for several reasons.  First, the IPCC finds that the sooner we act the easier the transition will be, and that the cost of addressing climate change would result in an average annual reduction in economic growth of a mere 0.06% for the rest of this century.  Second, those industries that become obsolete will be replaced by new industries.  Imagine the jobs that would be created if every flat roof in every city were to be outfitted with solar panels.

We also need the Republican Party to join the real world.  When 97% of the world’s climate scientists in industry, government, and research institutions agree that climate change is happening and that the cause is man-made only a fool would join with the remaining three percent.  When someone like Marco Rubio says that he’s not convinced, he doesn’t mean that he’s reviewed the research history and, because of his deep expertise in this field, finds the conclusions lacking.  He means that some of his biggest donors are companies and individuals who rely on fossil fuels for their wealth and that rather than adapt they are going to deny.  Fortunately, although only 25% of Tea Party Republicans believe that there is evidence for climate change, 84% of Democrats and 67% of all American adults do believe the scientists.

On the positive side, our profession has accomplished quite a bit. For example, the maximum lighting power density (LPD) allowed under ASHRAE 90.1for an open office was 1.9 w/sf in 1986, 1.3 w/sf in 1999, and .98 w/sf in 2010.  And, our clients are asking for more.  Here are the number of LEED certified buildings 2000 – 2012.

Source:  U.S. Green Building Council
Source: U.S. Green Building Council


That last number is 4,605 projects in 2012, when 41% of all nonresidential buildings starts were green, as compared to 2% of all nonresidential building starts in 2005.  Better than that, Net Zero buildings are a reality, and as the design and construction industries adapt we’re going to see more of them. Other organizations are working on this, too.  For example, already has commitments from a number of U.S. cities and property owners representing about 100,000,000 square feet of real estate to dramatically reduce fossil fuel consumption and greenhouse gas emissions.

So designers and builders have begun, and we’re moving with increasing speed toward reducing the effect of the built environment on climate change.  But there’s more to do, including convincing those who oppose action that a planned transition is achievable, affordable, sustainable, and in the best interest of the entire planet.

Energy Code Update

Yesterday the DOE issued a Notice of Preliminary Determination that ANSI/ASHRAE/IES Standard 90.1-2013 would achieve greater energy efficiency in buildings subject to the code than its predecessor, 90.1-2010. The preliminary analysis estimates national  energy savings of approximately 8.5% for commercial building energy consumption.

The evaluation of every new version of ASHRAE 90.1 is required by law.  Now that the DOE has determined the level of energy savings the analysis is available for public review.  A docket has also been established to accept public comments.  Feedback is requested by June 16, 2014.

If this determination is finalized, States would be required to certify within two years that they have reviewed the provisions of their commercial building code regarding energy efficiency and updated their codes to meet or exceed Standard 90.1-2013.  More information is available on the DOE website.

As much as I kick and scream about being strangled by tight LPDs, the recent climate related news, from the collapsing ice sheets in the Western Antarctic to atmospheric CO2 concentrations that are higher than ever recorded,  has given me a reason to embrace adoption of 90.1-2013.  I’ll have more to say on that soon.