Healthcare Ventilation Standards: Why More Research is Needed
Arash Guity, PE, LEED AP, CEM
Associate Principal, Mechanical-Energy Engineer
Remember that time when you experienced an unpleasant staleness in a building, any building? Perhaps you felt light-headed, maybe even disoriented?
Though invisible, good ventilation is critical in all types of buildings. It provides adequate 02 for respiration and removes contaminants (i.e. air pollutants) and C02 from the air – two things that are not only important for your health but vital for your life! And, though poor ventilation is difficult to visually detect, its presence (or lack thereof) is felt.
Now consider a critical building such as a hospital. Not only is the comfort of patients and staff of concern, but the prevention of airborne infection and the assurance of a safe environment for everyone is imperative. After all, this is a place of healing.
Ventilation for non-healthcare, commercial buildings is governed by ASHRAE Standard 62.1 Significant research supports why specific ventilation rates exist. (Again, the primary role of ventilation here is to provide adequate O2 for respiration and to remove air pollutants and contaminants.)
Ventilation standards for healthcare facilities, including hospitals, is established by ASHRAE Standard 170 in most states. Unlike 62.1, we lack sufficient evidence for aspects of the standards. The “evidence” dates back to the 1850’s with Florence Nightingale, prescribing two air changes per hour (for certain spaces). We still reference this (in part) today.
WHY the slow progress towards change?
The healthcare industry is cautious about change, which is understandable. There is an underlying fear of putting patients at greater risk or opening doors to potential litigation. These are sound fears. However, with the surging importance of sustainability and impacts of climate change, motivations are being forced to change.
Mazzetti has been highly visible, on this invisible issue… Ten years ago, we formed the Healthcare Ventilation Research Collaborative to evaluate alternative ventilation strategies for healthcare facilities. The research proved displacement ventilation greatly reduced energy consumption, improved the removal of airborne particular matter, and had an increase in ventilation effectiveness, thereby improving patient comfort.
As a result, the approach to ventilation was amended in ASHRAE 170 and adopted subsequently into code in most states. It was this research initiative that enabled displacement ventilation to become a viable option that was ultimately selected for Lucile Packard Children’s Hospital Stanford project (to be completed later this year).
Late last year, we spearheaded a proposed addendum to ASHRAE 170 that was developed by an international collaborative of epidemiologists, infection preventionists, micro-biologists, and designers. The addendum acknowledges that no single set of regulations could adequately cover all possible scenarios, but that allowing some flexibility to apply local knowledge and assess local threats would produce better outcomes.
Our hypothesis, though controversial for some, is that we frequently over-ventilate spaces. We don’t truly understand ‘why’ the standards prescribe a certain number of air changes. As a result, hospital owners (likely) are wasting energy dollars without improving indoor air quality.
What if, we could actually observe the relationship of indoor air quality and energy per varying air changes? For owners, there’s potential to save upfront costs (less ventilation needed, less HVAC equipment needed) and operating costs (less energy spend), while maintaining the health and safety of all occupants.
We have this opportunity—an opportunity to readdress ventilation in healthcare, so that we can improve indoor air quality, while eliminating wasted energy. We are participating on a research team, funded by the California Energy Commission (CEC), to generate much-needed evidence for ventilation codes in healthcare.