IAQ Improvements for Existing Buildings

Honestly, where do I even begin? I was asked to keep this relatively brief, but considering my past involvement in crafting two white papers with BuildingGreen (Considerations for Continuous Air Quality Monitoring and So, You Have Some IAQ Monitors. Now What?), countless hours discussing indoor air quality (IAQ) on my YouTube channel, and five years of volunteering with the USGBC on the LEED EQ TAG — this will be a challenge because in a lot of ways I live and breathe this topic (pun intended). The above examples have ingrained the importance of IAQ deeply in my professional life and personal interests (case in point, if you ask my kids what my job is, they’d tell you I’m an engineer and I “do air quality”).  

The importance of IAQ was also catapulted into the global consciousness by the health crises of 2020 (see ASHRAE Standard 241 and resources like BranchPattern’s FIRE tool). While these events have broadened the general public’s interest in the quality of indoor environments, my engagement with IAQ has long been a passion, stemming from my background in mechanical engineering. This includes a detailed focus on ventilation calculations and an understanding of how outdoor ambient air quality impacts the indoor environments—critical knowledge governed by standards like ASHRAE 62.1 (which is often misunderstood and/or misapplied in new construction).

It’s crucial to recognize that a building starts aging from day one of occupancy. Oftentimes also the best laid plans for energy and health go out the window – though usually not literally because too few commercial buildings in the U.S. actually have operable windows… but I digress. The phases of design, construction, and operations each present opportunities to influence IAQ, yet they also come with risks for inadvertently compromising the quality of our indoor air. Despite these challenges, we’ve seen a significant increase in tools and technologies aimed at understanding IAQ and its impacts on our health and wellness. These innovations, although still early in their development in terms of precise measurement and control capabilities, mark a pivotal advancement towards managing air quality in real-time.

Considering existing buildings are often already established or restricted compared to strategies we’d utilize in new buildings, here’s a quick play by play of how to improve and enhance IAQ in Existing Buildings:

1. Talk to an Expert: The first step in addressing IAQ is to consult with an expert specifically versed in the nuances of indoor air quality. This expert should extend beyond your typical go-to mechanical engineer or technician and be knowledgeable about the latest in IAQ standards and innovations PLUS have a working knowledge of HVAC and ventilation system design and operation. Did you know there’s an Indoor Air Quality Association (IAQA) and credentials for RESET Professionals focused on Air? Those are good places to find expertise. Also, utilizing partners with working knowledge of existing building services like LEED O+M, Energy Auditing, and Retrocommissioning can go a long way to improving IAQ without sacrificing energy and operational carbon performance. ‍
2. Understand your Air: Assessing IAQ requires a holistic view. This includes evaluating both the outdoor air that enters the building (ventilation air) and identifying potential sources of pollutants inside. Understanding these factors is essential for effectively managing indoor air. This step should incorporate a thorough review of building materials, operational chemicals, and ongoing processes. These elements significantly impact the indoor air chemistry, which can fluctuate and interact in complex ways (refer to my upcoming article on the building microbiome…) For mechanically ventilated spaces, it’s also important to calculate the minimum amount of outdoor / ventilation air that should be delivered to the building – considering any renovations or functional changes that have taken place since original design. This can then be compared to operational measurements. ‍
3. Check your Systems: Check your filters and evaluate options for improving efficiency and other corrective actions. For systems with outdoor air economizers, make sure those are functional (sounds really basic, I know, so just do it). Identify and inspect openings, remove all debris or biological materials and repair physical damage to louvers and screens. Test and confirm any apparatus for proper operation (repair and replace as needed). For spaces with mechanical exhaust, test and confirm proper operation. Compare overall building air balance and check pressurization. ‍
4. Get Testing: Employ both static and dynamic testing methods. Static “point in time” testing, like those used for certifications such as LEED or WELL, provides a snapshot in time, which is crucial for benchmarking and can get more detailed with laboratory analytics. Conversely, continuous monitoring devices allow for the observation of air quality over time, revealing trends and enabling proactive management. And make sure you’re not just collecting data, but really understanding what it tells you. ‍
5. Analyze and Act: Data is only as good as the action it prompts (this is basically the whole point of the second whitepaper linked above and will probably prompt a third). It’s imperative that this data is analyzed and interpreted by someone capable of understanding its implications on building operations. This individual should ideally be integral to the building’s management team and possess a keen interest in continuously improving IAQ. Also, someone not afraid to ask tough questions. (Check out more specifics on optional actions in the current public comment language of LEEDv5 O+M credit “Indoor Air Quality Performance”, which I’m both really proud of writing, and also acknowledge that it’s very complicated so please submit your feedback when the second public comment period opens… )‍
6. Educate and Engage: Educate those within the building on how their actions can affect IAQ. I know this can be a scary undertaking, but understanding the impact of one’s behavior on the air quality can empower occupants to make changes that foster a healthier indoor environment.

By integrating these strategies into a comprehensive IAQ management plan, stakeholders can transform the approach from reactive to proactive, ensuring that buildings not only start with but maintain high standards of indoor air quality throughout their lifecycle.