Nov 21 2015
Chicago Public Schools Superintendent Forest Claypool continues to talk about budget issues with respect to repairing the dangerous condition of the heating, ventilating and air condition systems (HVAC) systems in the Chicago Public Schools. Yet, while he was talking about what caused the carbon monoxide poisoning at Prussing Elementary School, two more teachers got poisoned on Friday, November 20, 2015 at Shields Elementary School, 4250 S. Rockwell St. in the Brighton Park neighborhood. Click here for more on Shields Elementary carbon monoxide poisoning.
Both major incidents involved someone failing to either open or close a door. Human error results in exposure to potentially fatal gas, dangerous gas that can destroy the life of someone who is fortunate not to die from the exposure. The reason human error is central to these two incidents is that the Chicago Public Schools have antiquated systems for air handling that require engineers on site all of the time. Those engineers must be trained in very specific procedures, which if not followed, can result in carbon monoxide leaks.
Carbon monoxide is an invisible, odorless gas that can kill and disable. Without carbon monoxide detectors in places they can be heard if they go off, people may die.
How can something as simple as forgetting to open or close a door cause so much mayhem? It has to do with fire’s need for oxygen and what happens when two systems clash for the available fresh air. In most, if not all of the Chicago Public Schools, heat is primarily provided by burning natural gas. In an older school such as Prussing Elementary School, that heat gets to the classroom through a boiler system. Boilers are big and generate great heat and lots of exhaust.
Natural gas is a clean fuel and when it has enough oxygen, the chemical reaction is essentially turning the carbon based fuel into carbon dioxide, CO2. CO2 is a harmless gas to humans – it is what we exhale when we breath. But when there is not enough oxygen, boilers and hot water heaters produce the deadly gas, carbon monoxide, CO, with only one oxygen atom in the molecule. That was the first problem at Prussing Elementary School, the boiler, for some reason wasn’t burning efficiently and producing far too much carbon monoxide.
The other problem at Prussing was that something was sucking exhaust back down the chimney and into the school. That something was the air handler for the school. While more than 100 feet away from the boilers, that air handler was like a large vacuum cleaner, competing for oxygen with the boilers and pulling exhaust back into the boiler room. There is nothing in the design of either system to prevent this from happening, except two doors.
The first is the “fire door” into the boiler room, which must be kept closed. Typically, people think of fire doors to keep a fire inside that room. But the fire doors also keep the boiler rooms air supply from being sucked somewhere else. At Prussing, this life protecting fire door was in decay and even if closed, wouldn’t have provided even a semblance of being air tight.
The other culprit door at Prussing Elementary School was the door that was to be kept open as part of air handling unit. The purpose of this door was to provide fresh air to the air handling system so that the air handling system wasn’t stealing air from the boilers. This door was closed instead of open.
Thus, here is what happened. The boilers were running, needing lots of oxygen in order to safely convert natural gas into heat and CO2. The air handlers were running, needing air to circulate in the school. The door to the boiler room wasn’t sealing the boiler room from the rest of the school. The doors to the outside for the air handling system weren’t open, so the air handler was sucking air from wherever it could find it, including the boiler room. That suction not only starved the boilers for enough oxygen, creating carbon monoxide, but also pulled the exhaust gases from the chimney, back into the boiler room. Because no fire door sealed the room, that carbon monoxide was sucked out of the boiler room and into the air handler system. Once there, the air handler circulated the carbon monoxide throughout the school.
The fix the Chicago Public Schools has provided to this system is focused on making the old boiler run more efficiently. But other than replacing the decrepit fire door into the boiler system, they have done nothing to truly solve this problem. If that fire door should be left open again and the doors for the air handler system left closed again, the same thing could happen.
There are repeated calls to replace the $500,000 boilers in this school. While they may very well be due for replacement, brand new boilers could have the same problem if the fresh air requirements of combustion (and air handlers) are not addressed. Both systems should have their own dedicated air and that dedicated air should be piped directly to the systems. Yes, that would require some reengineering and some very big PVC piping. But it would not require a million dollars in new boilers.
While I am not an engineer and I suspect that something a bit more sturdier than this PVC piping shown here might be required, http://www.homedepot.com/p/Advanced-Drainage-Systems-8-in-x-20-ft-Polyethylene-and-Cerex-Drain-Pipe-8710020/100147652 this pipe costs $66 at home depot. It is 8″ by 20 feet. Two of such pipes dedicated to the air handler, would eliminate the need for leaving a door open on the air handler. I am sure that the Chicago Public Schools could find a way to spend $10,000 on the installation of such a system at Prussing Elementary School, but it wouldn’t cost a million dollars. A more elaborate and expensive system would also assure that the boilers were running on their own dedicated fresh air.
Yes, these systems would have to be engineered by a real engineer, not a lawyer experienced in carbon monoxide poisoning. But you want to guess how much the Chicago Public Schools is going to spend just on engineers to defend their actions in the Prussing litigation? More is my guess. Well you would correctly point out that there are a lot of schools in the Chicago Public School system. True, but hundreds of thousands of lives are at stake. And at the rate the Chicago Public Schools is going, lots more litigation.
In the meantime, those who risk their lives in the Chicago Public Schools should get the protection of carbon monoxide detectors. But those detectors are not likely to be sensitive enough to detect levels that can sicken people over time, not immediately like happened in these last two incidents. For more on how sensitive a carbon monoxide detector should be, click here.
Carbon monoxide happens because fires need oxygen to breath. People need oxygen to breath. Lets deal with the oxygen needs for the fire to assure that the people are breathing oxygen, not carbon monoxide.