What is Air? How Do We Define It?

Air is everywhere. In our homes, in our offices, in our car, in our lungs. Everywhere you go on this blue planet we call Earth there must be air, or otherwise you won’t be conscious for very long!! 75% of all air is found in the troposphere, the lowest layer within Earth’s atmosphere (UCAR Center for Science Education 2020).

So what exactly is this “air” we may often take for granted? Gases, water vapor, aerosols, and a variety of chemicals combine to form what we know to be “air”. According to NASA, air is made up of approximately 78% nitrogen and 21% oxygen. Small amounts of other gases are also present such as carbon dioxide, neon, and hydrogen.

Aerosols such as dust and pollen are picked up naturally by the wind along with pollutants such as soot, smoke, and exhaust from vehicles and power plants. You may be familiar with the term “smog”, which refers to the point where aerosols in the air combine in a high enough concentration to begin reducing visibility. When this occurs, it can become difficult for both plants and animals to breathe.

All livings things require air in order to live. The process of respiration is necessary for all living organisms to produce energy. During this process, the air is breathed in and the oxygen is used to fuel metabolic reactions and releases carbon dioxide as waste. The process is similar in plants, where oxygen is used in conjunction with sugars produced during photosynthesis to produce energy for plant growth.  

Also contained in air is water vapor. Depending on where you live, you may be familiar with the unpleasant “muggy” feeling that comes along with a hot summer day. Relative humidity is a measurement of the water vapor content in the air. Typically expressed as a percentage, a high relative humidity indicates that the air is saturated. Low relative humidity occurs during winter when the temperature of the air doesn’t permit it to hold much water vapor (this time of the year is also ripe for problems associated with static).

The volume of air can also change due to a variety of factors. At higher altitudes, the air pressure is less leading to a lesser concentration of molecules in the air. For those that follow the NFL, you may have heard about the difficulties NFL players experience when traveling to play at Mile High Stadium in Denver, CO. This is due to the difference in altitude impacting the density of the air and thus the concentration of oxygen molecules. With less oxygen molecules in each breath that is taken, it’s easier to feel “winded” or out of breath and any physical exertion becomes much more difficult.

The volume of air is also intentionally compressed (by way of an air compressor) to generate a viable utility used across many different industries. Often taken for granted, the costs associated with the generation of compressed air make it an expensive utility. Here at EXAIR, we want to make sure you get the most out of your compressed air by offering a range of products designed to help you use it efficiently. Reach out to an Application Engineer today to discuss your options for implementing an Intelligent Compressed Air Solution.

Tyler Daniel

Application Engineer

E-mail: TylerDaniel@EXAIR.com

Twitter: @EXAIR_TD

Center for Science Education. What’s In the Air? | Center for Science Education. (n.d.). Retrieved April 6, 2022, from https://scied.ucar.edu/learning-zone/air-quality/whats-in-the-air

Photo courtesy of Randy Wick via Flickr Creative Commons Attribution 2.0 Generic License

Leave a Reply