Eric Knight of Evacuator System Responds to Greensboro Air Quality Issue

  16 Braden Keith | December 13th, 2013 | Junior Nationals, National

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.

In This Story


  1. 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

  2. Dmh1026 says:

    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.

  3. Hulk Swim says:

    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!

  4. Swim Parent says:

    It’s to bad we put sponsors before our athletes! If the banners are are issue, GET THEM DOWN!

  5. BaldingEagle says:

    I bet that the air quality will be much better tonight with the fixes, and certainly after an overnight purging of the air through the Evacuator, now that banners and curtains have been altered.

    If GAC has UV bulbs in the filtration lines, that will also remove almost all of the chloramines in the water, while the Evacuator purges the air. 9-10 hours of clear water with no swimmers producing “organics” will allow the UV to destroy all forms of chloramines. Then, tomorrow, the Evacuator can stay close to even with the air issue during warm-up, and definitely catch up when the main pool is cleared for competition.

    I’d say the identification of the curtain is a major factor. The diving well is used continuously for warm-up/down. There have to be 80+ swimmers in there at all times, all creating “organics” and chloramines. Since the Evacuator is on the opposite side of the building, a cloud could be blocked into that area.

    • Dr. Harry Fish says:

      I find it deplorable that when this company’s product fails in such a high profile environment, that the president of the company is not the person that accepts the blame.

      In reviewing their site, while I do see evidence that the Chloramines exist, I do not see any scientific data that the Evacusuk works.Without that scientific data, you can’t design a system that that is adequate. It’s a vacuum plain and simple, Check out their site for yourself

  6. AZ Swim Parent says:

    My swimmer or the teammates have no complaints. Compared to the Federal Way facility, GAC’s air quality is absolutely better. I think that the GAC facility is disadvantaged by not having spectator areas on both sides of the pool which would allow for more air circulation. Maybe GAC should consider allowing opening of the window area to allow the inflow of fresh air. Anyway, this is a nice facility but probably not the right size for a major well attended event like the Jr Nationals.

  7. TMF says:

    Despite the efforts, the air quality is not safe or adequate for an event of this size or caliber. My swimmer is having significant trouble sleeping and swimming without coughing. All of these swimmers have attended countless “big meets”. How many times are athletes brought to the hospital due to poor air quality? These athletes have worked hard to reach the level of Junior’s, National’s, etc. There is a lot riding on these meets that affect their future. The problem may be improved but US Swimming needs to reconsider plans to have high level, national meets at this facility.

    • Braden Keith says:

      TMF – it’s actually not uncommon for swimmers to be hospitalized due to poor air quality at big meets. Happened at Indy this summer as well.

      That doesn’t make it acceptable, but it happens at big meets at just about every indoor facility. It’s a big problem that someone needs to do some serious work on for swimming in general if USA Swimming wants to continue to host meets of this size.

  8. ACHILLES says:

    Excellent article with good insight from the manufacturer. The biggest problem appeared to be the USA Swimming curtain, which has now been removed. The sponsor banner has been raised to promote better flow. Unless they cut down on the quantity of swimmers at these meets (split the girls and boy to different venues) or move them to an outdoor facility, problems like this will continue. USA Swimming LOVES that curtain and won’t easily get rid of it anywhere else.

  9. Please read this 2010 Gold Medal Mel post, Chlorine and Urine can Kill, Part II, as an intro to what follows, along with the additional resources sited ( Then read this follow up blog post, A Chloramine Prevention Precursor: Are You “Practicing” Healthy Swimming at Your Pool (, which I posted on Feb. 11, 2010, taking special notice of the additional embedded GMM blog post link, Chlorine and Human Secretions, THE FACTS (—-a-chloramine-prevention-precursor—-clorami.html). These posts and sited references are full of factual information on chloramine prevention and management. Please contact me at the email address listed for additional information into the best practices tried, studied and available for chloramine control.

  10. swimdad says:

    It seems that another method of water sanitization is the answer. It is my understanding that there are UV systems that use UV light in conjunction with much smaller amounts of chlorine to kill the bacteria in pool water.
    Does anyone know about this type of pool system?

  11. The Evacuator System is currently installed at the Mt. View Aquatic Center in Marietta, GA. It’s been in place and working since October 2012. Mt. View has a 50 meter competition pool and a 25 yd. x 6 lane instructional pool. There are 3 USA Swimming Teams that practice using the 21 x 25 yard lanes in the 50 meter pool. This pool has a very low profile roof, so the air volume above the pool is very limited. The pool opened in 2000 and faced terrible air quality issues from the beginning. Many approaches were tried to resolve chloramine issues.

    Additional exhausts fans and upsizing the fresh air intakes was the first adjustment. The issues lessened a little, but still the air during heavy loads (practices and meets) was poor at best. With the new approach in 2004 of using UV light systems in the 100% flow in the pool return lines, the chlorimes all but disappeared from the pool water and the air quality improved. But, again during heavily loaded swim meets and practices doors were opened and additional fans were placed on the deck to freshen the air, which helped the situation, but poor air quality remained.

    In 2010 Don Baker, Paddock Industry’s President contacted me about relatively a new Paddock Evacuator system. We studied the product and visited one of the first installations in Rock Hill SC. Cobb County, GA approved funding the installation of 5 Evacuator bench systems at Mt. View and after installation in the fall of 2012 we have not had a air qualitiy issue.

    Eric Knight is correct, the key is having your air flow not being disrupted during meets and practices. The Paddock Evacuator system has been installed at another Cobb County Aquatic Center which is an indoor water park and the chloramine issue there have been resolved. The third Cobb County aquatic center is on schedule for another Evacuator to be installed at West Cobb Aquatic Center next month. This pool is a multipurpose recreational pool that is heavily used.

    In summary, as the Aquatic Manager for Cobb County and as a private Aquatic Consultant, I advise my administrators and my other agency clients to include this equipment in new aquatic center construction projects and retrofit bench Evacuators in existing facilities that had air equality issues.

  12. concerned parent says:

    My daughter swam at this facility last spring and had to stop during her swim to be treated by EMS (i cannot even describe the burns on her face). Part of the problem is that the air is trapped and cannot get out of the four walls of the pool (the water sits much below the gutters and gets trapped). The 6 inches above the surface is wall, which is blocking the air from getting out. I get that the signs are part of the problem, but the air has to be able to get our of the actual pool. Additionally, with all of the organic matter (let’s think about how many swimmers swim at y nats, never mind at juniors, and that is a whole lot of chlorimines/trichlorimines – byproducts. Chlorine cannot break down urine! It does seem that this facility is doing everything it can to fix the problem, but the problem, to an extent, is out of their hands. Lower the chlorine levels (I liken it to sunscreen – 50spf is no more protection that 80spf), because the higher the chlorine levels, and the more organic matter in the pool, the great your byproducts Add a whole lot of fans to get the chlorimine/trichlormines moving so it does not sit right where the swimmers are breathing, and maybe, just maybe there will be some relief. And to all those fans sitting in the spectator area who come out with burning eyes and sinus issues, that is not the smell of chlorine, that is chlorimine. Maybe we need to start at the top where the regulations about chemical usage is determined.

    • Canadian B says:

      My understanding is that chloramines (the pool smell) indoors increase drastically when chlorine levels are to low. A drop in pH will also quickly spike chloramine smell into the air space. Perhaps before large meets, the free chlorine target should be increased, not lowered as you suggested. This and perhaps other action might compensate for the anticipated spike in bather load. 2ppm may be better than 1.2ppm for these events. I’d like to see best practices from indoor pools that have solved this dilemma.
      Was there a change at the pool when operators try to save on the very expensive cost of running a pool? Note, UV systems allow safe operation at even lower typical free chlorine levels. However this makes operation riskier when shock loading the pool with hundreds of unwashed 🙁 sweaty kids. When that many bathers enter the water at once, it makes it that much riskier to indoor air quality at meets. The volume of the pool water and the chemical addition / measuring systems are not set up to account for such major changes in loading. Ground level air removal and the so-so method of increasing in water level air mixing help, but avoiding generation is better.
      The Europeans have gone to ozone treatment with a large aging pool volume, and avoid chlorine – there may be a compromise that will let our kids swim just as healthy as when we were kids.

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About Braden Keith

Braden Keith

The most common question asked about Braden Keith is "when does he sleep?" That's because Braden has, in two years in the game, become one of the most prolific writers in swimming at a level that has earned him the nickname "the machine" in some circles. He first got his feet …

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