It’s estimated that Americans spend about 90% of their time indoors, so indoor air quality matters so much precisely because indoor air is most of what we breathe all day. Good circulation, periodically cleaning your ducts, and opening the windows when the weather is good can all help, but there’s one other tool you can air quality toolbox: ultraviolet (UV) light. Specifically UV-C, the same kind of UV light that medical teams use to disinfect equipment. But let’s back up.
What is UV light?
On a basic level, all light is electromagnetic radiation and the colors are just different wavelengths of that radiation. The color violet is at the lower end of that spectrum. The name “ultraviolet” does not mean that UV light is a really deep shade of purple, but rather that it’s “beyond” violet, with a shorter wavelength and therefore outside of the spectrum of visible light. We can’t see UV light itself, though it’s easy to forget that because most sources of UV light also emit visible light at the same time.
Before we go on, we want to take a moment to remind you that UV light in big enough doses is dangerous. It causes sunburn and skin cancer, it’s what sunblock is made to protect against, and if you look at it too much you can get a nasty eye condition called photokeratitis. Most things that kill germs – heat, chemicals – can kill people too if you up the dosage, so don’t plan to use UV light to sanitize your hands.
Anyway, UV has just the right frequency and energy to break apart the molecular bonds in the DNA of bacteria, viruses, and other germs, triggering rapid deterioration and preventing them from posing a threat to humans. The disinfectant power of UV-C has been known to the scientific community since the 1870s, and in addition to sterilizing medical instruments, it has also been used to purify water since the early 20th century.
In recent years it has also been harnessed for purifying indoor air. By forcing the air in an HVAC system through some kind of chamber filled with UV-C light, we can radically cut down on the number of airborne germs and bacteria that make you and your family sick. There are a few more complications, such as a physical filter to catch and later remove the dead microbes, but the long and the short of it is that the UV light chamber is where germs go to die.
UV air purifiers come in a wide range of prices depending on their capacity, and some are meant to stand alone while others need to be installed by a professional.
Remember that while air purification can help cut down on germs in the air it can’t do anything about germs not in the air, and therefore is not a substitute for handwashing, disinfecting surfaces, and other precautions people are taking in the pandemic.