National Design Standards Amended as a Result of Ventilation Research Efforts

Research Efforts Promote Addendum to ANSI/ASHRAE/ASHE Standard 170 Ventilation of Health Care Facilities

SAN FRANCISCO--(BUSINESS WIRE)-- As a lead collaborator of the Healthcare Ventilation Research Collaborative (HVRC), consulting and engineering firm Mazzetti Nash Lipsey Burch (M+NLB) announced today that research efforts for alternative ventilation strategies in health care facilities has culminated in a code change to the American Society of Heating, Refrigerating and Air Conditioning (ASHRAE) Standard 170 to allow for use of the system in hospitals.

In early 2009, M+NLB completed work on North America’s first displacement ventilation system for a patient room in an acute care hospital. The system was installed and tested in Kaiser Permanente’s Modesto, California facility to demonstrate the application and determine if displacement ventilation—which differs from conventional ventilation in placing air outlets low on side walls, rather than on the ceiling—could offer energy savings while maintaining comfort and control of airborne contaminants. Initial research conducted by the HVRC, showed that displacement ventilation has the potential to reduce energy savings by up to 30 percent, while still maintaining ventilation effectiveness.

“Displacement ventilation systems have been used in many other types of buildings, but they haven’t been used in hospitals in North America due to concern about patient safety and comfort,” said Arash Guity, M+NLB’s Chief Environmental Performance Engineer. “There is great potential with displacement ventilation to provide safety and thermal comfort while delivering significant energy savings and system designs at competitive prices to conventional ventilation systems.”

The completed research included a literature review, energy modeling, laboratory testing, numerical analysis using computational fluid dynamics (CFD), and field mock-ups. The research concluded with the confirmation of the hypothesis that displacement ventilation, at reduced airflow rates, provides the opportunity for significant energy savings while maintaining patient comfort and safety. The results were presented to the ASHRAE Standing Standard Project (SSPC) Committee 170, and approved in early 2011.

“Addendum G of ASHRAE Standard 170 expands the options engineers have to save energy in hospital while maintaining or enhancing the safety of patients and staff,” said Bob Gulick, M+NLB’s Chief Mechanical Engineer and HVRC member. “It also exemplifies how the new ASHRAE process of “continuous maintenance” allows reasonable changes to become part of the Standard more quickly than in the past.”

Key collaborators to the effort include HVRC steering committee members, Paul Marmion and Ray Pradinuk, from Stantec. The research and its efforts could not have been possible without the funding provided by Kaiser Permanente and Partners Healthcare.

About Mazzetti Nash Lipsey Burch

Founded in 1962, M+NLB is a full-service mechanical, electrical, plumbing, and technology engineering consulting and design firm, also providing value-added commissioning, equipment planning, materials and waste reduction, and environmental performance consulting services. It has offices in San Francisco, Irvine, and Sacramento, Calif.; Portland, Ore.; Nashville, Tenn.; Denver, Colo.; Baton Rouge and New Orleans, La., and Houston, Tex. It is one of the first engineering companies in the U.S. to add an environmental performance practice to its list of client services. For more information please visit


Mazzetti Nash Lipsey Burch
Manoh Tsukii, 415-364-7289
[email protected]

KEYWORDS:   United States  North America  California

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