On the Journey to Net Zero: A Holistic Approach to Safely Achieving Two Air Changes Per Hour
Gordon Sharp, Aircuity, Inc.
As we strive to build more and more energy-efficient laboratories whether to achieve net zero buildings, campuses, or only to significantly reduce energy expenses, the most impactful approach for many laboratories is to significantly reduce the volume of airflow moving through the building. The challenge is how to do this safely and cost-effectively in the face of multiple laboratory building requirements related to fume hoods, thermal loads, and dilution ventilation.
In the last few years there have been new design approaches that have been discussed at Labs21 including demand based control of air changes and hydronic cooling approaches such as chilled beams. Furthermore, in the last year, the major laboratory standards of NFPA 45 and ANSI/AHIA Z9.5 have also changed, and now provide for significantly reduced fume hood minimum flow rates down to about 40 percent of what was previously recommended.
Although these and other concepts have been discussed individually, what has been lacking is a unified or holistic discussion of how these three changes to the traditional laboratory design paradigm can be used together to create a whole that is greater than the sum of the parts. The ultimate goal and resultant prize is safely achieving a minimum air change rate of about two ACH for a broad range of laboratories for both day and night operation, significantly reducing both energy and possibly capital costs as well.
This goal can be reached by using these three design changes to, in turn, address each of the above three room airflow requirements. For example, the airflow requirements for cooling can be reduced with hydronic cooling for laboratories with at least moderate to high thermal loads. For laboratories with at least moderate hood densities, the fume hood exhaust requirements can be reduced with VAV hoods operating down to or near the new minimum fume hood flow requirement. Finally, the dilution ventilation requirements can be safely reduced with demand based controls for air change rates.
This presentation will present several different system design approaches for combining hydronic cooling, demand based laboratory controls, and the new fume hood minimum recommendations together and assess their pros, cons, and success at safely attaining a two ACH flow for a wide majority of laboratories for night and even potentially daytime operation. Case studies of these approaches will be provided, including use in some net zero laboratory buildings. Finally, baseline system comparisons including traditional VAV systems and the use of heat recovery will also be presented.
Biography:
Gordon Sharp is the chairman of Aircuity, Inc., and has more than 25 years of wide-ranging entrepreneurial experience and more than 25 U.S. patents in the fields of energy efficiency and laboratory controls. As founder, former president, and CEO of Phoenix Controls, he led the development of this world leader in laboratory airflow controls that was acquired by Honeywell in 1998. In 2000, Mr. Sharp founded Aircuity, which was spun out of Honeywell and is a smart airside efficiency company providing building owners with sustained energy savings through its intelligent measurement solutions.
Mr. Sharp is a graduate of MIT with bachelor’s and master’s degrees in electrical engineering. He is a member of the ANSI Z9.5 Laboratory Ventilation Committee and a member of the board of directors of the International Institute for Sustainable Laboratories, the nonprofit foundation that officially cosponsors and operates the Labs21 conference. Mr. Sharp is also on the board of advisors of the MIT-Fraunhofer Center for Sustainable Energy Systems and has testified before Congress on the topics of climate change and energy efficiency.