I don’t like to go outside on the really smoky days and today is one of those really smoky days. Here’s the AirNow monitor:

So it got me to thinking, how much air do we breathe every day?

I took a number from HowStuffWorks to get an estimate. They use 11,000 Liters per person per day. The American Lung Association says 2,000 gallons per person per day. That converts to 7571 Liters. I expect there will be a lot of variation in this estimate.

I found I could easily mostly fill a 4-gallon trash bag exhaling normally in one minute. The bag was not at capacity as I had my hand holding a twist in the top few inches, so I estimated the amount with a little geometry. The full part of the bag was a weird, pointy, oblong shape, so I imagined it as a right circular cylinder. I set 12 inches as the average height, 4 inches as the average radius, and used the formula Area = πr²h and got 603 cubic inches. A gallon is 231 cubic inches, so that’s about 2.6 gallons.

If I breathe air at a rate of 2.6 gallons per minute that’s 156 gallons per hour or 3744 gallons per day. That’s over 14,000 Liters. I guess I’m a “heavy breather”!

I don’t think much of my estimate, but I note that it aligns with the other estimates so I will assume their estimates are reasonable. I suspect I would breathe at about half the rate when I sleep, so my 14,000 Liters would then be closer to 10,000 Liters.

So how big is 10,000 Liters? Is 2600 gallons easier to visualize? How about 350 cubic feet?

The cube root of 350 is about seven (7 x 7 x 7 = 343). Imagine a box 7 feet on a side: height, length, and width all about seven feet. That’s how much air you need every day.

Another way to imagine it is in cubic yards, which is about thirteen. Our local garden supply outfit can deliver 10 cubic yards of rock in one load with their ten-wheeler dump truck. Those concrete mixers you see hold about 8 cubic yards.

So if you want to know how much air you need each day, it is at least one truckload!