HISTORY Cooling It

Happy Birthday to You, CCl2Fl2.

Freon is 50 years old. To the list of those inventions and discoveries which forever altered human history -the printing press, the football, gunpowder, color television – we must add the chemical compound Freon. We owe a very special vote of thanks to Freon this year for enabling us to withstand those endless servings of refried air during the hottest summer in Dallas history.

Freon makes life possible in Dallas. Freon allows disco dancing to be considered a rational alternative to lying in the hammock. Freon makes the unthinkable thinkable. We can go shopping for heavy woolen clothes in July without worrying that we’ve been trapped in some alien time warp. So, what is Freon?

Freon, or more accurately Freon 12, is a trademark name, owned by E.I. du Pont de Nemours, for a gas known as dichlorodifluoromethane (pronounced dye-kloro-dye-floro-meth-ane).

Freon’s raison d’être is to keep you and your Chablis coolly isolated from the corpuscle-cooking effects of our pizzaoven environment, Freon is a refrigerant, sometimes gas, sometimes liquid, which is pumped through the arteries of your air conditioner and refrigerator. As it goes through its unending compression-expansion cycle, it cools thing

How it works is based on a simple principle. As a gas is compressed, it will get hotter; as it expands it gets cooler. Your air conditioner has two sets of coils, one inside and one outside the house. As the Freon moves through the inside coils it is a cool gas of around 40°F. A fan blows air across these cold coils, chilling the air and circulating it through your house.

As the Freon leaves the inside coils it goes through a compressor which squishes the cool gas and makes it a hot gas of around 110°F. Next, this hot gas moves through the outside tubular coils where the air cools the gas down a little bit turning it into a liquid which is still fairly hot.

This hot Freon liquid is pumped through a tiny hole and as it comes out into a larger tube it expands to a gas again. As it expands it rapidly cools down to around 40°F. The cold Freon gas circulates through the inside coils where a fan blows air across them, chilling the air and circulating it through your house. It works beautifully. Be thankful.

Freon wasn’t discovered until 1930 in Dayton, Ohio, by Thomas Midgley, Jr., a mechanical engineer turned chemist. Midgley was the kind of guy who was as close to his fold-out copy of the periodic table of elements as Karl Maiden is to his famous name credit card.

It was Midgley’s close observation of this periodic table which had made possible his earlier discovery of tetraethly lead, the antiknock gasoline additive. He was then working at the Dayton Engineering Laboratory – Delco – for young Charles Kettering, the whiz who later became head of General Motors. When Kettering moved to GM to head their new research lab he took Midgley along with him. Kettering said, “Tom Midgley is my best discovery.”

The Frigidaire division of GM needed a safe, cheap refrigerant for their line of mechanical refrigerators. Some previous refrigerants, like ammonia, had caused nausea when they leaked from their coiled confines. Methyl chloride, another refrigerant, was sweet-smelling in a subtle sort of way, but it had the unfortunate side effect of killing people in their sleep.

Refrigerator sales were slumping, and so were the customers. Kettering told Midgley that Frigidaire needed a new refrigerant gas. It had to be col-orless, odorless, non-toxic, non-flammable, and cheap. Midgley went away with his periodic table. He realized that to meet all of Kettering’s requirements the new compound would have to contain fluorine. He came back in three days with dichlorodifluoromethane – Freon.

The good researcher never says, “It won’t work; it can’t be done.” Instead, he says, “How can we overcome this difficulty, solve this problem, and move ahead?” Tom Midgley had always exhibited the traits of a good researcher-versatility and action.

For example, Midgley had faced a problem caused by his tetraethyl lead gasoline additive. It reduced engine knock but it also left behind an obnoxious goo which damaged spark plugs and valves. He had to find something else to add to the gasoline to get rid of the goo.

He discovered that the addition of a bromine compound would do the trick. But there wasn’t enough bromine available in the entire world. Next, he had to invent a system for extracting bromine from sea water to assure an adequate supply of bromine to make the compound to remove the goo caused by the additive that reduced engine knock. It is from such activity that fortunes are made.

Even in high school Midgley had been a practical problem solver. He was on the baseball team. The spitball was beginning to be used by pitchers, so Midgley began looking for a substance other than spit which would give the ball the right amount of slipperiness needed for maximum curving effect. He discovered that an extract of the inner bark of the slippery elm was just the thing. Soon, even rival teams were using his extract.

But back to Freon. The widespread use of Freon, leading indirectly and inadvertently to a land boom in the Southwest, almost never happened.

Many scientists were openly skeptical of the supposed safety of fluorine compounds. Midgley decided to test his Freon on some small animals. He brewed up five small batches of the compound. The first bottle resulted in no ill effects on the test animals. But each of the other four bottles killed the animals exposed to them.

“Hmm,” Midgley thought, “darn peculiar.” He found that an impurity had sneaked into the last four bottles, creating a lethal dose of phosgene gas. It was the phosgene that killed the animals, not the Freon.

If those four contaminated bottles of Freon had been tried first on the test animals, he would have naturally suspected that it was the Freon itself which was fatal. It was just a lucky break that Midgley tried the only good bottle first.

When Midgley first presented the findings of his discovery to skeptical colleagues at a chemical society meeting he demonstrated both the non-toxic and non-flammable properties of Freon in one breath. He filled his lungs with the Freon vapor and then exhaled it gently to surround and snuff out a candle flame. The scientists cheered.

Freon went into Frigidaire refrigerators and most of the competitors’ models as well. General Motors formed a partnership with du Pont to start a separate company, Kinetic Chemicals, to manufacture and market the new compound.

With that problem behind him, Tom Midgley, who looked a bit like Dr. Bunsen Honeydew of Muppet Labs, decided that he needed to get out of the lab more often. He took up golf. He had never played the game before. Characteristically, he studied golfing books and talked with professionals about the mechanism of the swing-soon he was playing in the low 70s.

From refrigerators, Freon moved into air conditioners. In 1934, Frigidaire built a full-size model home at the Century of Progress Exposition in Chicago to demonstrate the marvels of home air conditioning. At this time there were only a handful of private residences which were completely air-conditione

Room air conditioners became increasingly popular toward the end of the Thirties. But when World War II began, Freon was drafted. Besides being a wonderful refrigerant, Freon was also a terrific aerosol propellant. It was compressed into millions of olive drab aerosol cans of insect spray. Home air conditioning went dormant until Freon became available agai

After the war, the Freon market was divided between its use as a refrigrant and its use as an aerosol propellant. Of course, no one knew back then that in the mid-Seventies Freon was going to be considered a hazard to the ozone in the stratosphere of planet Earth. What alarmed the scientists, who had slowly come to believe that everything is connected to everything else, was the realization that the depletion of stratospheric ozone could create a threat to all animal life on earth, including, of course, human

The problem is this. Ozone absorbs ultraviolet radiation. If there is less ozone, more ultraviolet gets through to us. Ultraviolet radiation can cause skin cancer. So there you are. Freon was eliminated as an aerosol propellant. The ozone was saved. Life went on.

The reason that the Freon in your air conditioner doesn’t also harm the ozone is because it doesn’t escape into the atmosphere-unless you take a fire ax to the tubing. Even if you did, the effect would be negligible unless the entire population of Dallas took fire axes to their air conditioners all at the same time. And you know that’s not going to happen, no matter how high electric bills go.

No discovery is perfect. Freon may not be good for the ozone, but it is great as a refrigerant. By continually doing its thankless job in our air conditioners, Freon keeps us sane and functioning in this life-in-the-fast-lane society.

So, happy 50th birthday, Freon! Thanks a lot. The least we can do to show our appreciation is to turn down the thermostat for a few hours, invite the gang over for a frozen daiquiri, and drink a toast in memory of Tom Midgley, the man who made it all possible.


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