Eric Knight of Evacuator System Responds to Greensboro Air Quality Issue

This afternoon, after news broke that swimming star Caeleb Dressel was hospitalized with breathing issues due to poor air quality, we had a chance to speak with Eric Knight, who is one of the designers of the new Paddock Evacuator brand HVAC system that the Greensboro Aquatic Center installed in anticipation of this week’s Winter Junior National Championships.

A bit of background on Knight, so that we all understand where he’s coming from. At the 2012 Olympic Trials, Knight was a professional swimmer, training at SwimMAC Carolina, and competing for a spot on the Olympic team. That’s where I first met him. He was also on SwimMAC’s American Record-setting 200 yard medley relay last week at Winter Nationals in Knoxville.

Knight is also an asthmatic, a problem that he says developed from just the same kinds of conditions that some swimmers are experiencing this week at the Greensboro Aquatic Center. The point is, while Knight does have a vested interest in his systems working as an employee of the company that installed them, this is also a personal matter. It’s one that he has felt the effects of, it’s a problem that he says is not a new problem, and it’s one that Evacuator has made their mission to fix.

The Backstory

“First of all,” Knight said when I called him, “I want to emphasize one thing: the owners of the Greensboro Aquatic Center have done everything within their power to fix this problem. I take the blame for the issues with air quality that some swimmers are experiencing at GAC, and we are doing everything we can to fix them.”

“The number of swimmers we’ve seen in this pool,” estimated at about 1,300 according to Knight, “has apparently passed some kind of threshold, and with some of the design challenges and other challenges we’ve seen specific to this week, the system hasn’t been able to handle the load. And I take 100% of the responsibility. As far as I know, the owners of GAC are the first major pool to ever try and do something about the air quality issues. There’s air quality issues at every big meet, but the GAC owners hired us to fix that problem.”

The Technology

The reason Evacuator’s system is unique, as explained by Knight, and why GAC brought their services in, is that it does not recirculate air.

Traditional HVAC systems remove 10-20% of the air, according to Knight, removed from the ceiling of the natatorium, and the rest ‘rains’ back down upon the facility: usually the spectators at the top.

“The heaviest air is at the bottom,” Knight said. Evacuators work on the principle that this low, heavy air has the most chloramines. “That’s why the swimmers start coughing first, then the coaches, then the lifeguards, because they’re higher up. Eventually, there’s so many chloramines in the pool that they have to go somewhere, and so they start to rise. The more swimmers in the water, and the more splashing, the more chloramines that will be released from the water.”

Chloramines are the byproduct of the chlorine in the water fighting the biological materials (urine, sweat, etc.) coming off of the swimmers. In other words: they’re the effect of the chlorine doing its job.

So the Evacuator system sucks the air out from just above the surface of the water, and exhausts it all. There’s no recirculation of chloramine-heavy air, like a traditional system. That’s what’s new about the Evacuator systems, which debuted in early 2010 at the Jenks facility in Oklahoma.

The Leadup to Today’s Tipping Point

“Last week, we ran a meet at the GAC, and the air was immaculate,” Knight said. “That’s not my bias, I was getting messages from coaches. The system was working when there were about 900 kids.”

When the Evacuator team arrived, however, for Winter Juniors, they found a large curtain hanging behind the awards stand that was blocking a significant amount of airflow (the same kind of curtain USA Swimming uses at many large meets).

“What we do is all about airflow,” Knight said.

So first the curtain was removed, which Knight said solved a lot of the problems.

“But then there’s a banner,” he continued, “running along the far side of the pool, with sponsor names on it. That was causing more problems, because again it was blocking the airflow.”

What’s happened, Knight said, and what has been supported by several commenters on our site, is that there’s pockets, or “deadzones.”

One deadzone is behind the platforms. Another is along the far side of the pool, opposite the spectators, where the banner is blocking the air flow, and where the Bolles swimmers were sitting, as were several other swimmers with severe complications (more reports have come out that Dressel was not the only swimmer hospitalized.)

“In front of the platforms is great, on the side where the spectators are sitting is great. There’s a deadzone behind that banner where the bleachers are.”

The Immediate Solutions

As soon as the tipping-point on this problem was hit this morning, Evacuator took emergency action. Here’s what they say they’re doing to help clear the problem.

  1. They’ve raised the banner (seen in the picture above) by 3 inches. The banner isn’t going to go away, because it’s sponsors of the meet, but by raising the banner, they’re hoping to improve air circulation.
  2. Evacuator has brought in its emergency, portable system to start sucking out air from the deadzone immediately. Knight says that this is typically a system they use for demonstrations, but it is being repurposed as an emergency answer to this problem.
The image above, sent to us by Knight, shows that the banner in the 'dead zone' on one side of the pool has been lifted, which hopefully will alleviate some of the problems had by swimmers like Dressel.

The image above, sent to us by Knight, shows that the banner in the ‘dead zone’ on one side of the pool has been lifted, which hopefully will alleviate some of the problems had by swimmers like Dressel.

The Takeaways

Knight says that the company has learned a lot about what they do. “We put this system in after-the-fact,” Knight said, “so we had to fit the system to the facility. We are confident that in new facilities our systems work great. Jenks is a great example of that. But in those situations we have full flexibility, and that’s not something that will always be afforded to us.”

A photo showing just how crowded the pools are in Greensboro.

A photo showing just how crowded the pools are in Greensboro.

“We also weren’t aware of how big of an impact all of the signage that major meets like this have would affect the air flow. Anybody who’s been here will tell you that the air, overall, is better. This is a big improvement over where it was. I was at Masters Nationals, and I couldn’t walk from one end of the pool to the other without coughing up a lung.”

“It’s a combination of those challenges, along with something we’ve learned about big meets. I don’t think we realized the amount of chloramines that could be kicked up with this many swimmers in a pool. I counted over 120 in a 6 lane pool this morning. It seems we’ve hit a tipping point at a meet of this size, and it’s something we need to take into consideration when working with future pools that might host meets of this enormous nature. I’m not sure we can do anything permanently to make a meet of this size perfect. I don’t think we can, I don’t think anyone can, but we’re going to keep trying.”

Knight signed off with a reiteration of how seriously they’re taking the matter, how concerned they are about the health of the athletes and coaches, and a commitment to do everything possible to fix the situation in Greensboro.

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Maybe I was immune, but when Masters Nationals were held there in 2012 with approaching 2,000 swimmers and the pool in use all day long, I don’t recall anyone complaining about air quality. It’s obviously a problem and I’ve experienced it at pools before, but my n of 1 experience at GAC was superb. Did something change between then and now?

patrick, i too was in attendance (and if i remember correctly talked to someone in your family during that meet) for usms nationals and thought the air quality was great. i thought the air quality was better than it was at most of the large meets i had been to in the past 3 or 4 years, and at most of those meets i was coaching and not swimming. typically the swimmers notice the air quality more than coaches. i also wonder why/how it is so much worse at this meet about 18 months later

My eyes have been irritated in the facility since I arrived on Wednesday. I feel the air quality has been some of the worst I have seen in 30 years of coaching.

Kudos to Eric for a quick and thorough response.

If that banner is causing an issue, it needs to come down- end of story.

And coaches and athletes need to chat and do their part in not making it worse… stop peeing in the pool!

About Braden Keith

Braden Keith

Braden Keith is the Editor-in-Chief and a co-founder of He first got his feet wet by building The Swimmers' Circle beginning in January 2010, and now comes to SwimSwam to use that experience and help build a new leader in the sport of swimming. Aside from his life on the InterWet, …

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