Ventilation optimization: The key to decarbonizing public buildings

Public agencies are among those taking aggressive steps to decarbonize their buildings in an effort to reach the shared goal of net zero CO2 emissions by 2050—the level we need to hit if we are to avoid the threshold of 1.5 degrees Celsius above pre-industrial levels. A growing number of cities are implementing carbon reduction goals and public mandates to disclose energy and carbon emissions in buildings, and several are even including penalties for those that fail to act. To reduce carbon emissions and meet these aggressive goals, public agencies are rolling out infrastructure plans to build smarter, cleaner and more sustainable buildings while also addressing existing buildings that may be negatively contributing and/or extremely out of current day standards.

One of the most impactful, yet largely untapped areas, is ventilation optimization. Not only does optimizing ventilation with centralized demand control ventilation (DCV) create a healthier space for occupants, but it is also arguably one of the best ways to meet sustainability goals relating to the built environment. With DCV, air is continuously monitored using a variety of healthy building parameters—when the air is clean ventilation rates are reduced and when any indoor air quality (IAQ) event is sensed ventilation rates are ramped up. The impact is exponential and must be tackled first to yield maximum impact. Tackling ventilation dramatically drives down both heating/ventilation/air conditioning (HVAC) energy use and direct carbon use (gas heat and reheat) emissions.

Start with the big energy culprits and work down

Buildings that house offices typically have systems that can represent up to 30 percent of total energy use. If those buildings have laboratories, this rate increases to 60-70 percent. In a typical lab, centralized DCV can reduce HVAC costs by 40-60 percent and with an average reduction of around 750 metric tons of carbon dioxide equivalent. In addition, the average payback is less than three years. As a first step, public agencies should identify those buildings that are typically the most energy and carbon intensive, bringing ventilation optimization to those spaces before other areas. As a bonus, optimizing ventilation with DCV also creates safer, healthier and more productive spaces for all occupants.

Public buildings, such as K-12 schools, municipal office buildings or libraries, can also employ the same philosophy of using ventilation optimization to reach sustainability goals. In schools, for example, DCV compliments designs using dedicated outside air systems, VRF/VRV and chilled beams, allowing equipment to be smaller and reducing baseline energy requirements to achieve any net zero energy or carbon goals. Not to mention the simultaneous benefit of healthier IAQ for students and staff, which is especially important in the age of COVID or future airborne viruses.

Energy efficiency first

Using this type of “energy efficiency first” strategy and implementing ventilation optimization before other carbon reduction measures reduces the capital cost of those future measures—a $1 million investment in airflow optimization can reduce the cost of electrification by 4-5X. This reduction in thermal requirements is especially important when investing in heat pumps and electric boilers.

Ventilation analytics to measure energy consumption

Data analytics are also a critical piece of managing energy use and maximizing savings. Energy dashboards, for example, let building owners quickly identify which areas across the entire building portfolio are consuming the most HVAC-related energy. By providing data that goes all the way down to the room level, these dashboards help building owners identify the root cause of an issue to ensure maximum energy savings, as well as meet and sustain efficiency and sustainability goals.

Energy dashboards are entering the market just as public agencies are pushing for net zero goals. At the same time, there are carbon penalties looming in several cities that would impose fines and other penalties for buildings that fail to reduce carbon emissions to stated levels. Any building owners seeking to comply with new regulations will benefit from using an energy dashboard for reporting purposes. Dashboards allow for tracking and maintaining ventilation-savings opportunities through features that might include the following:

• Graphs showing normalized energy savings by room;
• Ability to graph attributes from all buildings in a single chart, allowing owners to view the top opportunities for energy savings and prioritize the most readily achievable; and
• “Dollar-per-square-foot” metrics, providing total estimated energy savings.

Building owners will want the ability to track progress, but they will also benefit from identifying problem areas and getting help with root cause analysis. In the future of intelligent buildings, advanced AI and cutting-edge ventilation optimization solutions provide those features.

The time is now

With so many new energy regulations on the immediate horizon, public agencies need to tackle this environmental challenge, and deliver on decarbonization goals. Never has it been so important to advance our capability to meet this growing need. For public agencies, this means the time for ventilation optimization is now. The climate crisis is perhaps the biggest challenge we will face in our lifetime. Public agencies can be part of the solution, while delivering healthier and safer spaces for the occupants that utilize these facilities.

Dan Diehl is the CEO and president of Aircuity, He has more than 25 years of industry expertise across a wide variety of vertical markets and disciplines in commercial and light industrial building markets. Prior to Aircuity, Diehl led business development at Lutron Electronics, was a partner for six years with Synergy, and spent 11 years at Johnson Controls Inc. Diehl earned a BS degree in Mechanical Engineering from the University of Maryland and has an MBA from Villanova University.