A Problem Too Small to See

At Sandia National Laboratories in New Mexico, the parts kept getting smaller. By 1959, engineers were building tiny mechanical components for the nation's nuclear weapons program, and something kept ruining them. Not a design flaw. Not a bad batch of metal. Dust.

Specks too small to notice were landing on delicate parts and causing defects. The lab already used "cleanrooms," but they weren't very clean. When Sandia tested one of the best cleanrooms of that era, it still averaged more than one million particles in every cubic foot of air. Sandia compares that to the air in a typical college classroom or busy office today.

The problem was how the air moved. Those rooms blew filtered air in, but it tumbled and swirled once it got inside. The turbulence kept stirring dust back up instead of carrying it away. And the workers themselves were a constant source of new particles. Later research found a single person sheds around a million biological particles into the air every hour.

A Sandia physicist named Willis Whitfield was asked to help. He was about to fix the problem with a sketch that took him a few minutes.

"Let the Air Be the Janitor"

In 1960, on an airplane, Whitfield drew his idea. His son later said the sketch took only a few minutes. Whitfield's own version was even simpler: "Five minutes, I just did the obvious thing."

The obvious thing was this. Stop fighting the air. Instead, make all of it move in one smooth, steady direction, like a slow river, so it sweeps particles away from the work and out of the room before they can settle. Whitfield described it as letting the air be the janitor.

His first prototype was a small room, about 10 by 6 feet. Air passed through high-efficiency filters that caught 99.97% of particles 0.3 microns and larger, then moved through the room so steadily that it replaced all the air roughly 10 times a minute. It moved at just over 1 mile per hour, slow enough that workers barely noticed it. Later designs sent the air straight down over the work, out through a grated floor, through more filters, and back around again.

"We Thought They Were Broken"

When the team switched on the dust counters in the new room, the readings dropped to nearly zero. Whitfield later remembered the moment in a 1993 interview: "We thought they were broken."

They weren't. Measurements showed about 750 particles per cubic foot, compared with more than a million in one of the best conventional cleanrooms. Whitfield's room was more than 1,000 times cleaner than anything else in use.

The numbers were so good that people didn't believe them. Some manufacturers accused him of running a hoax, and at meetings, colleagues had to vouch for his credibility. But the results held up. When Whitfield presented his "ultra-cleanroom" in 1962, TIME magazine nicknamed him "Mr. Clean," and one of his supervisors put it simply: "The cleanest air in the world is what we have."

From Microchips to Operating Rooms

Industry jumped on the idea. RCA and General Motors were early adopters. Within a few years, Sandia says, roughly $50 billion worth of cleanrooms had been sold. The design made it possible to build ever-smaller electronics, and eventually the microchips inside every phone and computer. As one Sandia director later put it, "Little did he know his invention would enable the semiconductor industry, and thereby enable all modern electronics."

It also moved into medicine. Bataan Memorial Methodist Hospital in Albuquerque became the first to use the design in operating rooms. MD Anderson Cancer Center built 22 cleanrooms to protect leukemia patients, whose immune systems couldn't fight off the germs in ordinary air. Whitfield went on to work with NASA on keeping spacecraft sterile. Today his design is still used in surgery and recovery rooms, and in making vaccines, medicines, and medical devices.

Most Buildings Still Live in 1959

Here's the surprising part. Sandia compares the dirty "best" cleanroom of the 1950s to the air in a typical college classroom or busy office. In other words, the room you're sitting in right now may have air about as clean as the room Whitfield was trying to escape.

That's not because we can't do better. We clearly can. We've engineered chip factories and operating rooms down to almost nothing. We just never applied that thinking to the places where most people spend most of their lives: offices, schools, clinics, and homes.

Letting the Air Do the Job, Again

Every building with central HVAC already has a river of air moving through it, from room to ductwork and back again. ViroZap puts that moving air to work. It's the first FDA-cleared, Class II medical device engineered for in-duct air disinfection, developed by Dr. D. Yogi Goswami, a USF Distinguished University Professor and Florida Inventors Hall of Fame member.

He Did the Obvious Thing

Willis Whitfield died in 2012 at age 92. Sandia's director said his impact was "immense; even immeasurable." Every phone, laptop, and modern operating room carries a little of that five-minute sketch.

His lesson was simple enough to draw on an airplane. Air is always moving. You can let it stir things up, or you can put it to work.

The air in your building is already moving. Make it do something useful.