Skip navigation

Controls: The Most Straightforward Path to Energy Efficiency

I just finished reading yet another report that concludes improving energy efficiency is the most viable building energy resource available today. Readers of HPAC Engineering, however, know that the most straightforward path to improving building energy efficiency is to improve the building control systems. This has been our mantra for more than a decade now, but we’ve seen surprisingly little change, even while the underlying digital technologies have experienced remarkable advances. So, it may be helpful to reflect upon why progress has been so slow in our industry’s digital control applications—and, more importantly, what we can do to improve it.

In the last decade, great advances have been made in technologies for digital systems and in technologies that enable designers to create more efficient building envelopes and spaces. The result is an opportunity for a paradigm shift in the fundamental concept of creating comfortable indoor environments. For more than a century, the principle behind indoor comfort has been focused on conditioning the building. Now, that principle can (and must) change to focus building energy systems on the occupants: to keep them comfortable whenever and wherever they are in the building. Advanced technologies enable this fundamental shift. And if these technologies are applied effectively, building energy use can drop to a fraction of what is now required. But achieving the full benefits of such a shift also requires fundamental changes in how we design, implement, and operate building control systems.

Currently, most building controls still incorporate only a single-space temperature sensor to serve multiple offices and/or workstations. Lighting control usually is independent of the thermal control system. These crude and outdated means of occupant area control need to change dramatically if we are to realize the building energy-performance opportunities newer technologies offer. And there’s more. Building control systems need to be updated with much improved point and database-management features to fully monitor and control each occupant area and still be cost-effective. And they need more robust control logic that can incorporate self-configuration, self-setup, self-tuning, and automatic fault-detection/response functions. Of course, such control programs no longer can be generated by mechanical design engineers who cannot hope to incorporate the multitude of factors required for each control decision. And the control programs cannot continue to be uniquely programmed for nearly every building or system to which such advanced control is applied.

Changing from how most building controls are designed, implemented, and operated today to how they could and should be developed is a daunting task, but one that will capture enormous value by saving what would otherwise have to be invested in building new power plants, paying higher electric bills, and eventually cleaning up the environmental damage that may otherwise take place. I think nearly everyone close to the building controls industry shares some recognition of this opportunity and the hurdles that stand in the way of achieving it. There are many good ideas for viable solutions. There is likely no magic bullet; the needed change will take time and talent. But it’s time to start discussing what building systems and controls could become and to consider good ideas now being developed. I want to help kick off this newsletter with a commitment to help realize such a future. In my contributions, I will discuss both technologies and processes that I believe may help achieve this more efficient future. I invite your thoughts, comments, and good ideas.


Principal of The Hartman Co., an HVAC engineering and technology-development firm, Thomas Hartman, PE, is an internationally recognized expert in the field of advanced high-performance building-operation strategies. His accomplishments include development of Hartman Loop, an integrated approach to chiller-plant control that dramatically improves operating efficiencies as plant load decreases; Terminal Regulated Air Volume, a network-based, variable-air-volume control technology that coordinates central-fan-airflow and supply-air-temperature control with actual zone requirements; the Dynamic Control family of software strategies and algorithms, which were among the first to employ integrated strategies to take advantage of microprocessor-based control systems; and the Hartman Energy Valuation System, one of the first hourly building-energy simulation programs. He can be reached at 254-793-0120 or [email protected]

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.