Energy Efficiency as a Tool for Decarbonization

By Luke Carothers

Governments around the world are introducing legislation to move towards net-zero carbon emissions by the Year 2050.  In light of this, the AEC industry is capitalizing on previous work and pushing the conversation forward through the ever-growing number of net-zero carbon projects.  One of the biggest hurdles in the way of the AEC industry’s push towards decarbonization is energy consumption.  Experts estimate that nearly one third of all energy consumption is wasted.  This has serious implications for net-zero carbon goals, placing strain on clean energy systems and moving us further away from those goals.

Within the built environment, one of the biggest areas of energy inefficiency is providing indoor air quality for buildings. Dan Diehl is the CEO of Aircuity, which is a 20-year leader in reducing carbon emissions and creating healthier indoor environments. Diehl began his career in the built environment in 1990, working out of college as a mechanical engineer. His career has spanned many different areas of the built environment, such as working on new construction projects, energy retrofitting, and performance contracting work. Diehl also spent nearly a decade working in lighting and lighting efficiency.  Sensing that ventilation optimization was the next big opportunity to tackle in the built environment, Diehl began working at Aircuity, and has been there for the past 14 years.  

Although Aircuity was founded in 2000 as an indoor air quality monitoring company, their technology was brought to market in 2007, meaning that the company was just starting out when Diehl joined in 2008. Diehl joined the Aircuity team just as their current installed platform was being launched, helping the product enter the market for the first time.  Introducing the concept of demand control ventilation required shifting from the previous way of doing things, which involved setting “prescriptive or fixed” air change rates in labs and other critical environments.  

The process of setting these prescriptive or fixed air change rates in critical environments incurs a “huge energy penalty”, according to Diehl. Bringing in air from the outside using large fans, conditioning it, heating or cooling it, and/or dehumidifying it is an incredibly energy intensive process. This is only amplified when talking about critical environments such as labs and research facilities that require 7 to 15 times the cost of energy use and intensity compared to an office building. For Diehl and Aircuity, these clear examples were the entry point into the larger market, and now, 14 years later, their client list spans the globe from U.S.-based projects at the University of California, Irvine, Takeda Pharmaceuticals, Northwestern University, Eli Lilly and Google, along with lab projects abroad in Southern Australia to the Great Mosque of Mecca.  

With the looming crisis of climate change, decarbonization has been a frequent topic of discussion.  Likewise, the COVID-19 pandemic has brought indoor air quality to the forefront of building design.  Diehl believes Aircuity sits at the nexus these two major areas of concern for the AEC industry: decarbonization and indoor air quality.   There has been much talk in recent years about how the industry can achieve decarbonization goals, and this is evidenced by the growing number of net zero projects being announced. While the process of decarbonization may seem intuitive to some, Diehl emphasizes that it must begin with focusing on energy efficiency. Before engineers begin thinking about how and where to install elements such as solar panels, it is necessary to work to minimize how much energy the building needs to function.  Understanding the “road map” forward to achieving decarbonization goals requires a thoughtful planned strategy and execution, and it starts with an “efficiency first” mindset.  HVAC is the next frontier for improvement.  Ventilation management is the largest and easiest area for immediate improvement using proven technology and strategies that deliver reliable ROIs with many other soft benefits.  Diehl believes that the impact of such systems as solar panels will be greater after determining their lowest necessary output. This places a greater emphasis on making systems such as air ventilation more efficient. 

As more projects push for net zero designation, the focus on starting from an energy efficiency perspective only strengthens our push for decarbonization as energy technologies continue to develop. Diehl describes this approach as “wringing all the waste out of [the building]” so that systems such as solar panels, microgrids, and clean energy systems can be implemented to the fullest degree. For example, a building that has removed these inefficiencies can make use of multiple systems working in tandem with something like solar panels providing the base power and a microgrid to support it through peaks in usage. 

The pressure to build these net-zero projects comes largely from a series of incentives and punishments, which DiIehl describes as “carrots and sticks.” In places like New York City, Boston, and California, penalties are being incurred on projects for their carbon usage and energy efficiency through actions such as taxes and fines. On the other hand, many utility companies are introducing utility incentive programs that provide rebates for these more efficient projects. Diehl notes that in places like New York, up to 70 or 80 percent of projects are funded through such rebates because the utility companies realize the usefulness of reducing overall usage.  

As the push for decarbonization continues, the mindset of placing energy efficiency first provides a clear path for expanding our efforts. This mindset not only leads to better building practices, but it also gives incentive to governments and utility companies to continue investing in these more sustainable projects. 

Luke Carothers is the Editor for Civil + Structural Engineer Media. If you want us to cover your project or want to feature your own article, he can be reached at lcarothers@zweiggroup.com.