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BREATHE EASY VENTILATION AND HEALTHCARE DESIGN By Paul Ninomura J ust like the right dose of medicine can improve health, proper ventilation is an integral part of patients' wellbeing in healthcare facilities. The newly revised ASHRAE Standard 170-2013, Ventilation of Health Care Facilities, has recently been published. This standard provides the minimum requirements for the design of ventilation systems to provide environmental control for comfort, as well as infection and odor control. The standard was written by ASHRAE and the American Society for Healthcare Engineering and is one of a family of documents that offers guidance, regulation and mandates to designers of healthcare facilities. When the standard was first published in 2008, it was the first American National Standards Institute standard to specifically address ventilation in healthcare facilities. The standard is available for adoption by various authorities for healthcare facility construction such as city, state and federal governments. It has been adopted by private national organizations such as the International Mechanical Code and has been inc incorporated into the Facility Guideline Ins Institute's "Guidelines for Design and Co Construction of Health Care Facilities." Ventilation systems and designs fo healthcare facilities are intended for to provide a comfortable environment fo patients, healthcare workers and for v visitors while diluting, capturing and e exhausting airborne contaminants including potentially infectious airborne agents. Without high-quality ventilation in healthcare facilities, patients, healthcare workers and visitors can www.mcdmag.com become exposed to contaminants through normal respiration of particles in the air. Poorly ventilated healthcare facilities may increase the concentration of airborne contaminants including fungi or mold, which may cause allergic responses in even healthy workers and occupants. Some patients are profoundly immune-suppressed for prolonged periods and, if exposed, are highly susceptible to infection from fungi. For all these reasons, and considering the various occupancies and patient populations, great care must be taken in the design of healthcare ventilation systems. Standard 170-2013 is being republished in response to rapidly changing industry practices, both in healthcare and building design. The standard has been in constant maintenance since 2008 and the past five years have provided an opportunity to review and further improve it. The revised standard features updates, changes and clarifications dealing with humidity, ducted returns, recirculating room units and duct lining, to name just a few refinements. One trend that almost all classes of buildings have seen on the rise lately has been energy efficiency. Provisions for the application of energy recovery are now specifically addressed in 170-2013. However, as the standard stipulates, if energy recovery systems are utilized, the systems cannot allow for any cross-contamination of exhaust air back to the supply airstream. Run-around coils are just one example of a system that is permitted. Due perhaps as a reflection of the slow economy recently, the standard also addresses some issues that may reduce costs to build and operate healthcare facilities. Standard 170 allows relative humidities as low as 20 percent for some rooms. This may result in smaller capacity of humidification equipment, lower operating costs and reduced maintenance costs. The standard permits some use of plenum returns in outpatient facilities, which in turn may result in lower construction and operating costs. Additionally, some hospitals are interested in utilizing displacement ventilation to reduce operating costs. The standard addresses the application of displacement ventilation within patient rooms. In some sense, designers of healthcare facilities, and those who dedicate their time to publish standards such as 170, must follow the same creed as healthcare professionals: to first do no harm. Standard 170-2013 is a refinement with improved clarity over the original standard and helps to provide a healthy environment for all. Paul Ninomura, P.E., ASHRAE-certified healthcare facilities design professional, is a mechanical engineer at the Indian Health Service, Seattle, Wash. He is chair of the ASHRAE Standard 170 Committee and is a revision committee member for the FGI "Guidelines for Design and Construction of Hospitals and Outpatient Facilities-2014." November/December 2013 | Medical Construction & Design 53