The year of 2020 brought forward a global pandemic that changed the way we live, work and interact.
At home, we found ourselves crafting wellness-promoting spaces and in the workplace we started to realize that a comfortable and healthy environment meant more than just good lighting or access to an in-building gym.
Now, as a result of the pandemic, indoor air quality (IAQ) is more important than ever. Defined as the conditions occupants experience within a building, particularly those related to health and wellbeing, comfort and productivity, IAQ is no doubt a focus for companies as they review return to the workplace initiatives. Although there are no technologies commercially available today that can directly measure viruses in buildings in either the air or on physical surfaces in real-time, there is still plenty that can be done to reduce transmission risk, including continuous monitoring. Before we explore why this strategy is the necessary first step in fighting airborne spread of COVID-19, let’s explore the different ways the novel coronavirus is transmitted.
COVID-19 Routes of Transmission
The three main modes of COVID-19 transmission are: contact transmission, respiratory transmission and airborne transmission. While contact transmission was the first route to be officially identified, as time went on and we learned more about the virus causing COVID-19, public health organizations like the CDC started to recognize the coronavirus as a “respiratory virus” and as such, revealed that it is mainly transmitted between people through "respiratory droplets" when symptomatic people sneeze or cough.
And just as we began to think that we had some answers for COVID-19 transmission routes, reports of airborne transmission became more and more substantial. Multiple studies, including a study published in the New England Journal of Medicine found that virus particles that were aerosolized could remain viable for up to 3 hours, making airborne transmission not only possible but also potentially more harmful than other routes of transmission.
Role of IAQ in Preventing Airborne Transmission
Now you may be wondering: how does this all relate to indoor air quality? The answer lies in the conditions that are known to exacerbate airborne transmission — one of the most widespread and dangerous routes of COVID-19 transmission. These conditions are:
- Enclosed spaces with potential infection
- Prolonged exposure to respiratory particles
- Inadequate ventilation or air handling
- Spaces with relative humidity lower than 30 percent
- Particulate matter levels above 10g/m3
If it’s not already obvious, what they all have in common is good air quality (or lack thereof) — which makes all the difference when it comes to COVID-19 airborne transmission risk. The results of recent studies underscore the importance of continuing to enforce air quality strategies to protect human health both during and after the COVID-19 crisis.
Challenging the Recommended IAQ Strategies
Now that we can distinguish between the different modes of COVID-19 transmission and know that our indoor spaces need the utmost protection against airborne spread of the SARS-CoV-2 virus, let’s explore and challenge some of the prevention strategies identified by ASHRAE.
ASHRAE’s first recommendation is 100% fresh air supplied via window ventilation or via air handling units, whether that means keeping windows open at all times or opening all the dampers for your air handling unit to reduce the CO2 levels and provide as much fresh air as possible. The main concern related to this strategy is that high ventilation inevitably results in high consumption and an energy penalty as it takes more to cool or heat the air to the right temperature, and equipment would need to be sized to accommodate higher demand.
ASHRAE’s second recommendation is filtering outdoor air with HVAC filters to be able to decrease the amount of indoor pollution and create a virus-averse environment. Recommended filter grade is MERV-13 and higher, however, public spaces like schools, universities, offices tend to have air handling units that can at best handle MERV-11 grade filters. The recommended MERV-13 grade filter is too restrictive for the spaces that are most in-need and can significantly reduce the lifetime of an HVAC system.
Some of the current examples of HVAC retrofit solutions include: bipolar ionization, UV lights, and HEPA filter units. With so many options available, it can be an overwhelming task to identify the pros and cons of each solution and select the one that makes most sense for the unique problem your building is facing. And once a choice is made, the issue of quantifying the results and proving that the implemented solution has succeeded persists.
Continuous Monitoring for a Data Driven Strategy
With these strategies in mind, how do you determine the right strategy for your building?
When it comes to any important decision, it is crucial to gather as much information as possible to be able to gain a deep understanding of the issue at hand and make an informed decision. In this case, making an informed decision lies in the ability to understand your building’s indoor environment with the help of data before assuming what problem your building is facing and spending your budget on a solution that is not the right fit for you.
This is where continuous air quality monitoring comes handy. By taking consistent measurements of important IAQ parameters such as PM2.5, TVOCs, and CO2, you’re establishing a healthy IAQ baseline that can be used as a reference point to make effective decisions that improve the indoor environment. Furthermore, continuous monitoring helps collect a more complete set of data that represents the true air quality in your space and identify problematic areas that could be missed by doing spot checks exclusively.
Air quality monitoring devices, like the Sensedge Mini, can gather this crucial information on your building’s environment in real-time, present the findings on a unified platform for further analysis and answer questions like “Where can ventilation be increased?”, “What spaces will need a retrofit solution?”, or “Can we increase filters class in our HVAC system?” to allow you to make informed, data driven decisions.
As experts in our field, we know that implementing air quality monitoring comes with its own set of challenges. Click below to watch our webinar on this topic and find out about the common pitfalls or blind spots you may experience as a building owner and facility manager when first implementing your IAQ monitoring strategy, and learn about the specific examples and actionable recommendations to avoid these mistakes.