Germicidal UV

The Building and Grounds Committee has been thinking about ways to make the building safer during this time of plague.  The advice we hear most often is improve the ventilation.  The Commons is not well ventilated. The blowers only work to add heat, they don’t bring in fresh air and they don’t supply much air flow.

We decided to try installing short wavelength ultraviolet lamps above the ceiling fans.  This is light commonly referred to as UV-C.  We set the fans for up-draft so that air is pulled away from people and into the UV illuminated space near the ceiling where viruses will be inactivated.  The lamps are shaded so that no one will suffer sunburn or eye damage.

So far, we have installed one lamp.  It is wired to the fan so that it comes on whenever the fan is on.  We will wait a bit to see if the UV causes any problems.  Eventually we plan to install two lamps on each fan.  We can do all four fans for about $400.

We included a photo of the one lamp we installed.  A small portion of the light is in the visible range, so you can see a blue glow that shows that the lamp is on.  If one can see the blue glow reflected from the surroundings, could one also see the reflections of the UV?  We checked with a UV meter, and it’s okay.

Ventilation in the new section of the building is better.  Air is pulled out through vents near the ceiling, passed through filters and returned via floor vents.  We will investigate to see if we can add UV lamps in the ducts.

Think about layers of protection from Coronavirus.  Each layer has holes in it, so we need to pile up several layers to increase our safety.

To learn more about germicidal UV, search for: IES Committee Report CR-2-20

—Steve Ferguson, Board President

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