The History of IAQ and Radiation
We’ve covered how Radon is bad for your home and business. We’ve covered how IAQ is important. What about the one place where the two mix: history. The greatest development for air quality, the High Efficiency Particulate Air Filter (HEPA Filter) exists because of radioactivity and a need for workers to survive in a very, very dangerous workplace.
Working With Atoms
In the 1940s the world was at war. Numerous countries were deep into nuclear research. The US had its Manhattan Project, Germany had the Uranprojekt or Uranium Club, and Japan had Ni-Go. The problem with working on nuclear materials is that they can kill you before you’ve ever noticed. They directly emit radiation, but far more deadly is the potential to create radioactive dust and gasses. Little chunks of your nuclear material or nuclear byproducts that float in the air.
This is the same issue you face with Radon. Uranium and other nuclear materials produce something dangerous that gets into the air. The issue is a bit scarier with things like the Manhattan Project. At least in your basement you’re dealing with lesser radioactive gasses and particles. Still deadly, but at least you can’t expose a sheet of x-ray film with them.
In the lab and nuclear production facilities, this wasn’t a matter of working through allergies, though the causes were the same size. This was a matter of walking into a room, taking a breath of contaminated air, and falling over dead later that day. There had to be something that would filter the poison from the air. Get every last particle of it before it reached the workers or the outdoors.
Catching Tiny Things
The solution was a highly efficient, particulate air filter. Something that could achieve incredible levels of cleanliness with an emphasis on particles. These filters employ a number of strategies to get the job done. There are maze-like interiors, dense fibers, and other tricks to ensure nothing can be forced from one side to the other but the air and other gasses. It’s more like pushing air through a wall than it is like a filter. A solid wall of concrete probably lets more air through it than a HEPA filter.
The HEPA standard requires a filter to stop particles down to 0.3 Micrometers in any axis. That’s something less than 1/25,400th of an inch long. During the war, this meant capturing radioactive particles. Little flecks of uranium, plutonium, and their fission byproducts would be held safely in place and never get to harm the scientists or outside community.
For about a decade, the technology was classified. HEPA was only a thing if you were a government worker or worked for a company doing specialized work for the government. In the 1950s the technology was declassified and quickly spread.
For the average consumer, HEPA is how you defeat your allergies all summer long. You lock down your house and filter every inch of air coming in or out of the place. There’ll never be a single episode of allergies as long as those filters are fresh and everything is properly maintained (though a few showers may be necessary to decontaminate after outdoor excursions).
For the industrial world, HEPA brought a whole new level of manufacturing precision. The first application was radioactive particles, things poisonous to a human. What about all the other particles, poisonous to equipment? Think about it: you’re building something with measurements down to the millionths of an inch at NASA, putting a single fleck of dust on it, is going to throw off those measurements. Imagine the world of processor design, where you’re working just a step above building processors atom by atom.
This was an issue already in the 1850s. Watchmakers were having issues with pollution in the air. Tiny particles of dust and soot from early coal powered factories, among many other things, were enough to throw of the operation of their watches. Some watch companies relocated to rural regions to get some work done. A ball bearing manufacturer in World War I is said to have used air conditioning to fend off particles interfering in their precision. The cooler air was denser and likely washed the airborne pollutants to the floor, away from their equipment.
HEPA Filters enabled the first true clean-rooms. These are facilities where the air is nearly completely pure. There are no contaminants. It’s just oxygen, nitrogen, and zero particles of anything else. With heavy filtration, the dirt can be pulled out of the air, and there’s nothing to mess with manufacturing. No specks of dust to throw off measurements, machining, or get into the tiny crevices of microscopic parts.
Technology is Amazing
What was once meant to save lives is not enabling better, more precise engineering and keeping you safe from allergen induced headaches and runny noses. Sometimes if you build it, people really will come banging down the door to get it.