An affordable air quality tool for meeting planners

air quality tool meter CO2
The COVID-19 pandemic has devastated the in-person meeting industry. Though it took too long to recognize that COVID-19 spreads via air transmission, we finally have effective procedures (vaccine mandates, masking, air quality standards, and social distancing) to reduce infection risk at in-person meetings. Now, meeting planners can add an affordable air quality tool to their site visits.

How can you determine air quality at a prospective venue?

Look around the room at an in-person event and you’ll see if masking and social distancing are taking place. We can implement vaccination mandates using third party vendors such as, CLEAR Health Pass, Safe Expo, and others. But how can we determine the air quality at a prospective venue?

Currently, we don’t know how to detect airborne COVID-19 viruses. (This is likely to be true for a long time. We still have no test for airborne tuberculosis bacterium (TB) transmission two centuries after identifying TB as a distinct disease.)

Luckily, under conditions I’ll outline below, we can obtain useful information about a venue’s air quality by using a device that measures a proxy for air pollution: carbon dioxide (CO₂).

People breathe in air, typically containing about 0.04% CO₂. They breathe out a mixture of gases containing about 4 – 5 % CO₂. People with COVID-19 co-exhale respiratory aerosols containing the SARS-CoV-2 virus.

If an occupied building space has effective ventilation, the occupants’ excess exhaled CO₂ is quickly diluted with fresh air, and the CO₂ level in the air remains close to normal values. Measuring the level of CO₂ in the air can, therefore, tell us whether effective ventilation is present or not.

Here are the generally accepted standards for CO₂ levels:

~400 parts per million (ppm) – Normal outdoor air level.
400 ~ 1000 ppm – Typical value level indoors with good ventilation.
1,000 ppm – the OSHA/ASHRAE recommended maximum level in a closed room.
> 1,200 ppm – Poor air quality – requires ventilation to the room.
2,000 ppm – This level of CO2 typically produces a significant increase in drowsiness, tiredness, headaches, lower levels of concentration, and an increased likelihood of spreading respiratory viruses.

Until recently, meters that measure CO₂ levels in the air cost hundreds of dollars. (Some models with especially accurate sensors or the capability to measure other air pollutants still do.) But today we can buy an affordable air quality tool — a hand-held CO₂ meter for under $100. The one I just purchased (illustrated above) cost $80, and there’s a wide variety to choose from (for example, from here or here).

My 3.27″ (diameter) x 1.26″ (depth) meter measures CO₂ levels from 0 – 5,000 ppm. It can run on standby for 18 hours, supports USB charging, and includes a battery level indicator and temperature and humidity readings. While its specifications omit accuracy, inexpensive CO₂ meters are typically reliable within ±100 ppm. This is good enough to provide a decent estimate of the air quality in an enclosed space.

My unit shows a concentration of ~350 ppm CO₂ outside my rural Vermont home, which was built tightly. In my home office, the level increases to about 450 ppm, and rises to about 525 ppm if I’m sitting next to the unit for a while. Slightly cracking open a window quickly brings down the reading.

I haven’t had time to explore other buildings yet, but am looking forward to seeing what I find out when I do.

Is a CO₂ a proxy for indoor air quality in occupied spaces?

Can measuring CO₂ levels give us a useful indication of indoor air quality?

The answer is a qualified yes. It depends!

First of all, we need to measure CO₂ levels in occupied spaces. A meeting planner doing a site visit should take CO₂ readings in occupied meeting rooms, restaurants, hotel lobbies, etc. Taking measurements in empty spaces will only show high readings if the building ventilation system is grossly inadequate (with CO₂ infiltrating from other areas.) Also bear in mind that increasing the number of occupants in a space increases the likelihood that an infectious person will be present and the number of people possibly infected. Doubling occupancy can thus cause a four-fold increase in risk of transmitting COVID-19.

Second, there are sources of CO₂ that are not related to human exhalation but will increase meter readings. A common source is combustion emissions such as gas stoves, which can significantly increase CO₂ levels. Pets can also increase CO₂ levels, though animals are unlikely to be sources of the COVID-19 virus. Such sources will cause increased levels of CO₂ without increasing the incidence of COVID-19 transmission.

Finally, air treatment options, such as MERV 13 or better filtering, or possibly ultraviolet-C radiation, may reduce the prevalence of active COVID-19 aerosols. When venues employ these mitigation strategies, CO₂ levels will not be decreased. Of course, if a venue has deployed these preventative measures, they will surely inform you about them when asked!

Due to these factors, you shouldn’t rely solely on measurements of CO₂ levels to determine whether a space is ventilated enough to mitigate transmission risk.

However, a simple CO₂ meter like the one I now own can be an effective air quality tool, providing valuable information to anyone who wants to investigate the air quality of occupied spaces at venues, hotels and properties, restaurants, and other meeting locales. I’ll be bringing mine when I travel, and I encourage you to do this as well!

More information on the relationship between CO₂ levels and COVID-19 exposure

If you’d like to learn more about the relationship between CO₂ levels and COVID-19 exposure risk, here are some useful references:

And here are some less technical media articles on CO₂ meters:

Venue ventilation for COVID-19

venue ventilation COVID-19 Attention, meeting planners! Safe meeting venue ventilation for COVID-19 is critical. As we start thinking about returning to in-person events, it’s crucial to check that venues are upgrading their HVAC systems to handle potentially virus-infused air.

There has been little public discussion on this important topic. In this post, I’ll explain why questions about venues’ HVAC safety should be at the top of your site visit checklist.

Before we start, I need to make clear I’m not an HVAC engineer. My (perhaps) relevant background is an ancient Ph.D. in high-energy particle physics, and two years spent exploring ventilation systems—specifically air-to-air heat exchangers—when I owned a solar manufacturing company in the 1980s.


Since the pandemic began, the science on COVID-19 transmission has evolved rapidly. Because early theories turned out to be inaccurate, current preventative measures are frequently misdirected. So I’ve included a short history of theories of COVID-19 transmission that shed light on the reasons we’ve underestimated the importance of ventilation in creating safe environments for indoor events.

Next, I’ve outlined what current research indicates venues and properties should be doing.

Finally, I’ve aired my concerns about how well venues and properties are responding to the safety concerns I’ve introduced.

Read the rest of this entry »

No, I do not hate in-person meetings

hate in-person meetings I’d like to be clear that I don’t hate in-person meetings, despite what some have been posting recently on a Facebook group for meeting professionals:

“Often wondered why so many on this feed hate live events.”

“It is my opinion that this group does not support any in-person meetings or gatherings of any kind…”

” I am sad to see so many industry giants verbally destroying our industry – apparently with glee.”

Let’s explore what’s causing opinions and feelings like this in the meeting industry.

The tension in the meeting industry

As I’ve said before, the pandemic’s impact on lives and businesses has been devastating, especially for the meeting industry. COVID-19 has virtually eliminated in-person meetings: our industry’s bread and butter. Many meeting professionals have lost their jobs, and are understandably desperate for our industry to recover. We are all looking for ways for in-person meetings to return.

Unfortunately, I and many others believe there is a strong case to make against currently holding in-person meetings. Ethically, despite the massive personal and financial consequences, we should not be submitting people to often-unadvertised, dangerous, and life-threatening conditions so we can go back to work.

I’ve been posting bits and pieces of the case against currently holding in-person meetings on various online platforms, and decided it was time to bring everything together in one (long for me) post. I hope many meeting industry professionals will read this and respond. As always, all points of view are welcome, especially those that can share how to mitigate any of the following concerns.

The strong case against holding in-person meetings right now

Here are four important reasons why I think we shouldn’t be holding “large” in-person meetings right now. (Obviously, “large” is a moving target. Checking Georgia Tech’s COVID-19 Event Risk Assessment Planning Tool as I write this, a national US event with 500 people is extremely likely (>95%) to have one or more COVID-19 positive individuals present.)

1) Posted safety protocols are not followed

Seven months ago, I explained why, in my opinion, in-person meetings do not make sense in a COVID-19 environment. I assumed that in-person meetings could, in principle, be held safely if everyone:

  • meticulously observed social distancing and masking;
  • could safely travel to and from events;
  • be housed safely; move around event venues while safely maintaining social distancing; and
  • eat and drink safely.

Even if one could meet these difficult conditions, I questioned the value of such in-person meetings. Why? Because meetings are fundamentally about connection around relevant content. And it’s impossible to connect well with people wearing face masks who are six or more feet apart!

In addition, there’s ample evidence that some people won’t follow declared safety protocols. Since I wrote that post, we have heard reports and seen examples of in-person meetings where attendees and staff are not reliably social distancing, and/or aren’t wearing masks properly or at all.

Orlando, Florida, OCCC Together Again Expo, July 2020

This is most likely to happen during socials and meals, where masks have to be temporarily removed. It’s understandably hard for attendees to resist our lifetime habit of moving close to socialize.

2) We perform hygiene theater—but please don’t ask us about our ventilation systems

Many venues trumpet their comprehensive COVID-19 cleaning protocols. Extensive cleaning was prudent during the early pandemic months, when we didn’t know much about how the virus spread. But we now know that extensive cleaning is hygiene theater (1, 2); the primary transmission vector for COVID-19 is airborne.

A recent editorial in the leading scientific journal Nature begins: “Catching the virus from surfaces is rare” and goes on to say “efforts to prevent spread should focus on improving ventilation or installing rigorously tested air purifiers”.

I haven’t heard of any venues that have publicly explained how their ventilation systems minimize or eliminate the chance of airborne COVID-19 transmission!

Why? Because it’s a complicated, and potentially incredibly expensive issue to safely mitigate. And venues are reluctant or unable to do the custom engineering and, perhaps, costly upgrades necessary to ensure that the air everyone breaths onsite is HEPA filtered fast enough to keep any COVID positive attendee shedding at a safe level.

Adequate ventilation of indoor spaces where people have removed masks for eating or drinking is barely mentioned in governmental gathering requirements (like this one, dated March 3, 2021, from the State of Nevada). These guidelines assume that whatever ventilation existed pre-COVID is adequate under the circumstances, as long as all parties are socially distanced. We know from research that there are locales — e.g. dining rooms with low ceilings or inadequate ventilation — where this is not a safe practice, since it’s possible for COVID droplets to travel far further than 6 feet.

In case you are interested, current recommendations are for MERV 13 filtering throughout the venue. Does your venue offer this?

P.S. I expect there are venues that have done this work. Do you know of venues that have done the engineering to certify a measurable level of safe air on their premises? If so, please share in the comments! We should know about these conscientious organizations.

3) Inadequate or no pre-, during-, or post- COVID testing, and contact tracing

Shockingly, many in-person meetings now taking place require no pretesting of staff or attendees. (News flash: Checking someone’s forehead temperature when they enter a venue will not detect anyone who is infectious for the two days before symptoms appear, or who is asymptomatic.)

Even if everyone in the venue is tested daily, the widely used quick tests are simply too unreliable. From Nature again:

“Deeks says that a December trial at the University of Birmingham is an example of how rapid tests can miss infections. More than 7,000 symptom-free students there took an Innova test; only 2 tested positive. But when the university researchers rechecked 10% of the negative samples using PCR, they found another 6 infected students. Scaling that up across all the samples, the test probably missed 60 infected students.”
—Nature, February 9, 2021, Rapid coronavirus tests: a guide for the perplexed

Finally, I find it upsetting that venues like the OCCC keep claiming that they are #MeetingSafely when they are doing no post event follow-up! If an attendee contracts COVID-19 at the event, returns home, and infects grandma, how would the OCCC ever know?! Under the circumstances, I think it’s misleading, dangerous, and unethical for such a venue to publicly claim that they are providing an #MeetingSafely environment.
hate in-person meetings

4) We’re meeting safe—but you can’t sue us if we’re not

In fact, some in-person meetings quietly acknowledge that they may not be providing a “safe” environment. One meeting venue held an in-person meeting that required waivers that forever bind attendees and their family members, and “heirs, assigns and personal representatives” not to sue if they contract COVID-19.

“I voluntarily assume full responsibility for any risks of loss or personal injury, including serious illness, injury or death, that may be sustained by me or by others who come into contact with me, as a result of my presence in the Facilities, whether caused by the negligence of the AKC or OCCC or otherwise … I UNDERSTAND THIS IS A RELEASE OF LIABILITY AND AGREE THAT IT IS VALID FOREVER. It is my express intent that this Waiver binds; (i) the members of my family and spouse, if I am alive, and (ii) my heirs, assigns and personal representatives, if I am deceased.”
—Extract from the Orlando, Florida, OCCC American Kennel Club National Championship Dog Show, December, 2020, Waiver

I’m not sure how you can bind people to a contract who may not even know they are a party to it. But, hey, I’m not a lawyer…

So, can we safely and ethically hold in-person meetings right now?

For the reasons shared above, I don’t believe we can safely and ethically hold in-person meetings right now. Consequently, it’s alarming that many venues, and some meeting planners, are promoting in-person meetings in the near future.

Do I hate in-person meetings?

By now it should be clear that I stand with meeting professionals like Cathi Lundgren, who posted the following in our Facebook group discussions:

“I’m not going to be silent when someone holds a meeting in a ballroom with a 100+ people and no masking or social distancing…I own a global meetings company—and we haven’t worked since March but no matter how much I want to get back at it I’m not going to condone behaviors that are not positive for the overall health of our industry.”
Cathi Lundgren, CMP, CAE

And here’s how I replied to the first Facebook commenter quoted at the top of this post:

“For goodness sake. I LOVE in-person events. It’s been heartbreaking for me, like everyone, to have not attended one for a year now. But that doesn’t mean I am going to risk stakeholder, staff, and attendee lives by uncritically supporting in-person meetings that are, sadly, according to current science, still dangerous to attend. When in-person meetings are safe to attend once more — and that day can’t come soon enough — you bet I’ll be designing, facilitating, and attending them.”

I hope it’s clear that I, and those meeting professionals who are pointing out valid safety and ethical concerns, don’t hate in-person meetings. Realistically, the future of in-person meetings remains uncertain, even with the amazing progress in developing and administering effective vaccines. More mutant COVID-19 strains that are resistant to or evade current vaccines, transmit more effectively, or have more deadly effects are possible. Any such developments could delay or fundamentally change our current hopes that maintaining transmission prevention plus mass vaccination will bring the pandemic under control.

I’m cautiously optimistic. But, right now, there are still too many unknowns for me to recommend clients to commit resources to future large 100% in-person events. Hub-and-spoke format hybrid meetings look like a safer bet. Regardless, everyone in the meeting industry hopes that it will be safe to hold in-person meetings real soon.

In the meantime, please don’t attack those of us in the industry who point out safety and ethical issues and consequences of prematurely scheduling in-person meetings. We want them back too! We all miss them.