Skip to main content

Traveling Safely In a Shared Vehicle During COVID-19 - Be Certain You Know What the Recirculation Button Does

The air recirculation button is important to your safety whenever you travel. When sharing a vehicle with others its proper use can be critical.

When traveling in a vehicle with others you share the air they breathe. And not just the air they breathe in. You also share the air they breathe out. A typical vehicle has a capacity of about 100 cubic feet of airspace inside. Each time you breathe in or out, you take in or put out about 0.2 cubic feet of air. 100 breaths equal about 20 cubic feet of air volume. That takes about five minutes on average. If you are in a car with four other people, you collectively breathe in and out the entire volume of air inside the vehicle in just 100 breaths or in about five minutes. With centers for Disease Control experts saying that it is possible to spread the COVID-19 virus via respiratory droplets within six feet of another person, the inside of a vehicle is a confined space you really don't want to be in with others if at all possible. But if you must, know this:

Recirculation button imageHow Air Inside A Vehicle Circulates
The air in the car is only static if you enable the recirculation function of the heating and ventilation system. That button prevents the free flow of air from the front of your vehicle, or from the dash area, back. Every vehicle has outlets in the rear quarter panels that allow air out. That makes sense if you think about it. Air can only come in if it can also flow out. When you enable the recirculation button on the dash, it tells the car to shut the intake. That then means that the majority of the air inside the vehicle is static instead of being refreshed by flowing in the front and then out the rear.

Why The Recirc Button Matters
The recirculation button works very effectively. You know this is true because when you accidentally leave it on, the windows fog up. That fog is moisture from your breath. You are breathing out vapor and droplets that stay in the air, accumulate, and raise the humidity. The cool glass causes it to condense and make the film you see as "fog."

Make Sure Recirculation Is OFF
Be sure you keep the recirc button off. If you have any doubts as to how it works, simply read your owners' manual. Manuals for every modern vehicle can be found online. How soon should you do this?. You have the rest of your life.

Tips For Keeping Air Fresh Inside a Vehicle
If there are only two people in the front of a vehicle it makes good sense to crack the rear windows an inch. This will improve the flow of air out of the vehicle. Turn the fan up to the loudest setting you can tolerate. If you are driving slowly, roll all the windows down.

Good luck in the weeks and months ahead. Be well.

The author is not a doctor. John Goreham is a life-long car nut and recovering engineer. John's focus areas are technology, safety, and green vehicles. In the 1990s, he was part of a team that built a solar-electric vehicle from scratch. His was the role of battery thermal control designer. For 20 years he applied his engineering and sales talents in the high tech world and published numerous articles in technical journals such as Chemical Processing Magazine. In 2008 he retired from that career and dedicated himself to chasing his dream of being an auto writer. In addition to Torque News, John's work has appeared in print in dozens of American newspapers and he provides reviews to many vehicle shopping sites. You can follow John on Twitter, and view his credentials at Linkedin.