At Forgotten Hill, we are suppressing the transmission of the Coronavirus by not only following the procedures recommended by Health Authorities, but also by sterilizing each room with powerful UV-C lamps (shown at right) between guests ‘stays. The remote-controlled UV-C lamp we use is designed to produce ozone and sterilize 40 m² in 1 hour of operation. Our rooms, including bathroom and entrance are 30.25 m².
We leave the UV-C lamp on for 1 hour when no one is in the room, and when the room has been cleaned and prepped. Effectively, when a guest enters the room, it’s sterile. The UV-C lamp destroys all bacteria and viruses directly in its irradiation zone; the ozone gas generated by the UV-C lamp destroys everything not eliminated by UV by penetrating everywhere air is present.
That ozone purification process takes longer than the UV-C radiation and is the reason we leave the UV-C lamp working for a full hour. When finished, the sterilization process is followed by opening the windows and sliding door of the room for 30 minutes to eliminate the ozone.
In addition, we have also acquired a compact handheld UV-C lamp (shown at left) that can be used to sterilize, in 20 seconds, specific items like room keys, credit card machine, doorknobs, etc. This UV-C lamp does not produce ozone. Finally, we have surgical masks available should guests need one.
It is highly likely that these types of sterilization processes are going to remain after the current pandemic ends. Global warming is bound to have unintended side effects such as the release of long-frozen viruses, as well as other microbes for which we’re unlikely to have immunity
The use of UV-C light, along with Ozone, make it possible to completely sterilize a space such as a guest room and adjoining bathroom.
The UV-C wavelength lies at the far end of the Ultraviolet spectrum, between 100 and 280 nanometres (nm). We, humans and animals, can perceive UV-C as a weak bluish light, but the most effective of the UV-C wavelength falls outside our perception, as shown on the chart at left. Still, even that weak bluish light we can see can be dangerous. UV-C lamps can cause injuries to skin and eyes. So, the use of UV-C lamp use must be closely controlled.
The germicidal action of UV-C is maximized at 265 nm with reductions on either side, as can be seen in the graph on the right. Most UV-C lamps have their main emission at, or close to, 254 nm where their action on DNA and RNA is 85% of the peak value. As a result, this type of UV-C lamp is extremely effective at breaking down the molecular structure of micro-organisms whether bacteria or virus, preventing them from replicating and causing disease.
UV-C lamps are used to sterilize operating theatres, drinking water, and foods. But UV-C is “line-of-sight” and cannot reach into nooks and crannies. Ozone (O3) can and is just as effective.
Ozone is a naturally occurring, but unstable, gas that can destroy bacteria and viruses. Ozone is that odor you smell when there is a thunderstorm. UV-C generates ozone at the 185 nm part of the its spectrum, often called UV-C Vacuum, by breaking the oxygen molecule (O2) and splitting it into two oxygen atoms. These two atoms, in turn, immediately recombine with other oxygen molecule creating Ozone (O3) which has three oxygen atoms.
On a final note, not all UV-C lamps can produce ozone. Most UV-C lamps have glass that has been chemically “doped” to exclude the 185 nm wavelength. Only UV-C lamps equipped with tubes that are not doped are able to generate ozone, making their sterilization more effective.