Summer in Minnesota is special because we have so much to do outdoors. There are towering forests for camping, lakes for swimming and boating, hills for biking and hiking. 

The only downside: The heat and humidity can make it feel like you’re trying to breathe through a wet sweater. In the doggiest dog days of summer, air conditioning is more than a luxury—it’s nearly a necessity.

As a tribute to the invention that helps us keep our cool when the weather heats up, here are nine facts and busted myths about air conditioning.

Fact: A Founding Father helped invent air conditioning

Is there nothing Benjamin Franklin couldn’t do? In addition to inventing bifocals and experimenting with electricity, Franklin helped explore the science of cooling through evaporation of volatile liquids like alcohol and ether. He was able to cool a thermometer to 7 degrees Fahrenheit on a 64 degree day!

Myth: Fans and swamp coolers work just as well as air conditioning

While sitting in front of a fan can make you feel cooler, it’s not actually lowering the temperature in the room. The coolness comes from evaporating sweat on your skin. In fact, a fan’s motor can increase the ambient temperature!

Swamp coolers work in dry climates, as they add humidity to the air and then cool through evaporation. In a humid environment like a Minnesota July, they don’t stand a chance.

Fact: Minneapolis is the birthplace of in-home air conditioning

Nope, not Phoenix or Las Vegas: The first AC unit was installed in the home of Charles Gilbert Gates in 1914. The massive machine (6x7x20 feet) may not even have seen use, however—Gates died shortly before it was installed. Minneapolis historians estimate it would cost at least $1,500 a month to cool a mansion as large as Gates’ today, and that’s using equipment that’s at least 60% more efficient than it was in the 1910s.

Myth: Crank the thermostat down for faster cooling

I know, it’s hard to wait for relief when your house heats up. It’s only natural to turn down the temperature as far as it will go. But the truth is that your AC can only cool the air so fast, regardless of what the temperature setting is. Turning the temp down will just mean your house will eventually get too cold for comfort.

Fact: Summer vacation is a relic of pre-AC days

For the most part, summer vacation as we know it is the result of unbearable heat during summer months. Without air conditioning, school buildings were so hot, and so uncomfortable, that they implemented summer break to give students and teachers relief from the heat. And for the sake of kids everywhere — we’re glad the tradition of summer vacation stuck around, even though it’s no longer needed.

Myth: Air conditioning can be bad for your health

This is one of those stubborn urban legends that refuses to fade away. Sitting in an air-conditioned room won’t affect your respiratory health, cause a fever or chill, or make you develop a cold. However, if your vents and ducts aren’t clean, or your filters need changing, the air quality could exacerbate allergies.

Fact: Air conditioning saves lives

AC does more than just keep you comfortable. It can help keep you alive, too! Prior to modern air conditioning, the chances of folks dying from heat stroke or exhaustion were quite high. But, research has found that the chance of dying on hot days has fallen 80% over the last 50 years — which correlates with the rise in access to A/C.

Myth: You should keep your AC fan constantly running

It may seem logical to keep air circulating when the AC unit isn’t actively cooling. But running the fan nonstop can let moisture back into your house, affecting your humidity levels and how cool your house feels. It’s better to let your thermostat do the regulating—select “auto” so that the fan only runs when the cooling system is actively engaged

Fact: AC is more affordable than ever

In the early days of air conditioning, an AC unit might have cost as much as your house. In today’s dollars, they went for between $120,000 and $600,000! Thankfully, modern AC units are far more reasonable to install—between $500-$10,000 depending on the unit and installation. And they’re far more efficient than the 1910s models, of course.

Fake or Fact? Now You Know!

Were you familiar with any of these air conditioning myths and facts? From the early days of electric fans to modern, central air conditioning systems, A/C has come a long way.

Learn more about air conditioning with our guide to the many types of air conditioners and how to choose the best one for your home.