By Tom Hartman
Among the flurry of conferences, webinars, and workshops aimed at increasing awareness and developing collaborative efforts to reduce the carbon footprint of buildings, nearly all concerned identify improving energy efficiency as a key — or even the only — near-term response that can reduce greenhouse gas emissions by the order of magnitude believed to be needed.
Unfortunately, the building industry appears to be caught in the classic conundrum of doing the same thing over and over and expecting a different outcome. Building construction and operations leaders have for decades claimed to be placing a strong focus on improving building energy utilization. And indeed, the energy efficiency of appliances, equipment, and building systems has improved. But according to the most recent U.S. Commercial Buildings Energy Consumption Survey (CEBCS) data (2012), overall commercial building energy use intensity has declined hardly a tick since the early 1990s. At one recent conference, a presenter made a compelling case that our newest buildings are among the most energy wasteful ever. How is that possible?
The building energy efficiency movement has focused on reducing energy use through individual components and subsystems. The thinking is that designers can select from a menu of potential improvements. This approach has failed to deliver the expected benefits because it doesn’t account for how changes to one element can affect others. (A simple example is energy efficient lighting upgrades that lead to increases in heating energy use.) Yet this item-by-item strategy continues to dominate. Energy audits in existing buildings and efficiency plans for new buildings continue to treat each energy consuming element separately. The result is that buildings rarely achieve their expected overall energy performance.
An Integrated, Occupant-centered Future
To reduce building energy use dramatically, we need to discard the efficiency menu approach and shift from heating and cooling entire buildings to installing more integrated, decentralized systems that support occupants’ actual use of a building. Some of the technologies that will enable this shift are still emerging. But facility executives and the providers they work with can take steps now to significantly reduce energy consumption in their new and existing commercial buildings.
Based on my review of building energy efficiency initiatives that have delivered real results, the following are proven paths to success.
- Collaborative design. To deliver a building with well-integrated efficiency measures, the architects and all engineering disciplines must engage in a collaborative analysis and design effort. That’s the only way to ensure that all systems work together in a fully integrated manner, adjusting lighting, HVAC, and other systems as outdoor and occupancy conditions change.
- Advanced controls. Effective, sophisticated, and well-supported controls are central to achieving an efficient and easily operated building, whether it’s new construction or a retrofit. Yet the current process of design, construction, commissioning, and turnover of control systems is so disjointed that it is wholly inadequate to support high-performance buildings. Controls should be at the forefront of both design and long-term operations, and controls integrators should be involved early in the design phase and throughout the building’s life cycle.
- System-level optimization. Technology that controls all HVAC or other building systems as a unit can integrate the various components, optimizing energy efficiency and alerting building operators to performance drift. To take just one example I’m familiar with: The Rockefeller Group reduced emissions at its Time-Life Building in New York City (1271 Avenue of the Americas) by nearly 3,000 tons of CO2 annually and achieved LEED-EB certification using the OptiCx platform from Optimum Energy.
- Accountable support. Build in direct lines of authority and accountability for ensuring that equipment and systems operate as expected and each building meets its overall energy use target. Monitoring and analysis technology can give operations staff the data and technical support they need to keep systems operating efficiently throughout their life cycles.
We can design, build and operate buildings much more efficiently, so it’s frustrating to continue to see disappointing outcomes. But if we in the building community incorporate these four elements into our design process to the fullest extent possible, I can say from experience that we will achieve far better results, and the buildings we work on will have the near-term positive impact we all want.
Hartman, P.E is principal of The Hartman Company, a technology development and applications firm in Georgetown, TX that works with its clients to apply emerging technologies that promise to improve building energy efficiency and enhance occupant comfort. He discovered the Equal Marginal Performance Principal on which Optimum Energy technology is based, and he serves as a consultant to Optimum Energy.