A recent episode of the ASHRAE podcast titled ‘Ventilation in Theory vs. Ventilation in Practice’, featured ASHRAE members Megan McNulty and Andy Persily, two seasoned professionals in the field of mechanical engineering and ventilation. This is part two of a five-part series.
The evolution of ASHRAE Standard 62.1
This is part two of a five-part series. Image supplied by Freepik
McNulty shifts the conversation to the pivotal period in the early ’90s, specifically addressing the significant changes introduced in the 1989 version of ASHRAE standard 62.1. Persily acknowledges that the energy crisis of the time heavily influenced the standard, leading to a shift in focus. The committee was directed to craft the standard in mandatory and enforceable language, a departure from the previous versions that often-used terms like “should” instead of “must” or “shall.”
The 1989 version marked a departure from the ’80s, a decade that may not have been the pinnacle of ventilation in buildings. The revised approach sought to create clear, enforceable requirements, eliminating ambiguous language and ensuring that compliance could be easily integrated into building codes.
Persily and McNulty delve into the consequences of this shift, highlighting the unintended consequence that the standard, once an aspiration to surpass, became the minimum legal requirement for buildings. Despite its initial intent as a baseline, over time, the codes evolved into the target to meet rather than exceed.
The conversation takes an insightful turn as McNulty and Persily discuss the changing perception of ventilation, particularly in the wake of the Covid-19 pandemic. She notes a heightened awareness of indoor air quality and the necessity of continuous ventilation. The duo explores resistance to change, with Persily emphasising the importance of educating clients on the capabilities of their systems and the potential for improvement.
McNulty notes the challenges faced in advocating for better filtration and increased ventilation rates. Building operators may initially resist change, citing technical limitations or cost concerns. However, she emphasises the importance of understanding each building’s unique system, dispelling misconceptions, and finding the right balance between energy efficiency and optimal indoor air quality.
It becomes evident that the world of ventilation is dynamic and multifaceted. McNulty and Persily’s experiences highlight the ongoing efforts to balance energy efficiency with the imperative of providing superior indoor air quality. The conversation serves as a reminder that every building and its ventilation system is unique, requiring a tailored approach to meet the ever-evolving standards and the expectations of occupants.
Ventilation surprises: a daycare mix-up
Persily shares a story from a building walkthrough involving a daycare centre and an adjacent office space. The two spaces shared the same outdoor air intake – a setup designed to serve both units efficiently. However, during a baseline assessment, Persily noticed a peculiar discrepancy in temperature. Instead of outdoor air reaching both spaces, the daycare air was inadvertently being supplied to the office. This revelation prompted questions about the duration of this mix-up and highlighted the importance of baseline assessments in ensuring proper ventilation functionality.
Continued in part three…
Source
Live webinar on ASHRAE website.
