While any plan for cleaning and disinfecting campus spaces should include a range of overlapping actions, UV disinfection is worth considering as part of your broader strategy.

What are UV rays and how do they disinfect?

Ultraviolet rays are light waves that fall between the range of visible light and X-rays. Within the broader UV category are three main types of ultraviolet light: UV-A, UV-B, and UV-C waves.

In the most basic terms, UV-A and B are longer waves than UV-C, and shorter UV waves are more effective for disinfection. UV-C’s shorter wavelength allows it to penetrate much smaller things – for example, the cell membranes of a virus.

UV disinfection isn’t new, of course – it’s been in use in various capacities for more than 100 years, most commonly as a water purifier. It has, however, received more attention from facility services teams since the pandemic began.

Does UV disinfection kill Coronavirus?

The short answer is, it depends. UV-A and B have shown little to no effect on the virus that causes COVID-19. UV-C, on the other hand, has potential.

With enough time and intensity, UV-C can penetrate Coronavirus. The rays either neutralize the virus particles completely or destroy the parts that allow for reproduction. Without the ability to replicate, virus particles die off in short order.

And while UV technology companies aren’t claiming – yet – that UV-C reliably, effectively kills the virus, ongoing research shows promise in the technology.

In fact, researchers showed decades ago the effectiveness of UV-C light in reducing the spread of diseases including influenza and measles. Today, facility services teams often use UV-C lights to disinfect HVAC coils inside ductwork, which can foster bacteria and mold if not properly maintained.

So why can UV-C units consistently disinfect HVAC coils, but show inconsistent results with Coronavirus?

HVAC coils are stationary, so they’re constantly exposed. Airborne particles, on the other hand, pass through the rays briefly, so there’s a shorter opportunity to neutralize them.

The main factors that affect neutralization of Coronavirus include:

  • Air recirculation rates
  • Intensity of the UV light
  • Dwell time
  • Concentration of particles in the air

As research progresses, we remain hopeful that the technology will be refined to fully neutralize Coronavirus.

Are UV rays safe?

Yes, when used to disinfect nonporous surfaces, air, or water. However, overexposure to ultraviolet light can harm us – so keep in mind that UV lamps should not be used to disinfect skin.

The UV-C units we’re discussing today are safe. Here’s why: They’re installed inside HVAC ductwork, so only the inside of the duct is exposed to the rays.

Other advantages include:

  • minimal environmental impact
  • no residue on surfaces
  • affordability
  • the opportunity to integrate UV disinfection lights into existing structures

Remember, UV disinfection may become a valuable part of your overall Campus Readiness strategy, but it’s just one step in slowing the spread of COVID-19. Consider all your options, including intensified cleaning and disinfecting plans, use of masks and other PPE, social distancing markers, upgrades to outdoor space, and electrostatic spray technology.

Most of all, make sure you choose a reliable facility services partner – one you trust and enjoy working with.

Whether you’re open now, taking a winter break, or moving forward on a “wait and see” basis, our HES team is always ready to help you refine your Campus Readiness plan.