One of the most positive revelations of quarantine 2020 was the scientific confirmation of the version that ultraviolet radiation, which has long been used in medicine for the purpose of disinfection, is effective for inactivating SARS-CoV-2. The introduction of advanced UV‑C systems allows to abandon such a toxic measure as the treatment of surfaces and premises with chemicals. Prevention is necessary, because the WHO warned that the virus is constantly mutating. We talk about the technology in detail with examples of implemented projects from the company Signify (ex-Philips Lighting).
Light heals and kills
"Ultraviolet history" begins in 1800. The English optician and astronomer William Herschel, studying the solar spectrum and experimenting with a glass prism, discovered that beyond the red border of scattered sunlight there is an invisible zone in which objects are heated. Herschel called this heat energy infrared rays and assumed that there is something on the other side of the rainbow — beyond the violet color — too. Literally immediately after the publication of this scientific work, the German physicist Johann Wilhelm Ritter described electromagnetic radiation beyond the limits of the violet part of the spectrum as "ultraviolet rays".
For the next two centuries, scientists studied the influence of ultraviolet light on living matter — the human body and microorganisms. Ultraviolet normalizes biological processes, positively affects the development of the skeleton, is a regulator of circadian rhythms, provoking the production of melatonin. But it can be dangerous, and for microorganisms it is simply murderous. It all depends on the length of the light wave.
Modern solariums use lamps that generate radiation with a wavelength of 315 to 400 nm, for medical purposes — for phototherapy — in a narrow range from 280 to 315 nm. And short-wave ultraviolet radiation from 180 to 280 nm is indispensable for disinfection, denoted by the abbreviation UV‑C. Ultraviolet with a wavelength below 230 nm when interacting with oxygen in the air generates ozone — a strong oxidizer that is dangerous to health. At the same time, radiation with a wavelength of 263 nm has the maximum disinfecting properties. If the lamp in the room smells of ozone during operation, this is a clear indicator that it is operating in a range that is not optimal for disinfection.
Recent history of UV‑C
If disinfection with the help of ultraviolet light is a more than two-century history, why was it that in the first months of the COVID-19 pandemic, everyone was recommended to use sanitizers, but there was almost no information about ultraviolet light? The use of UV-C as a weapon to combat the COVID-19 pandemic was preceded by scientific research. It was important for scientists to understand exactly how the SARS-CoV-2 virus reacts to ultraviolet radiation, what dose is critical, what is the optimal distance from the source to the target, and how much time is needed for the effect.
Tests conducted in the spring and summer of 2020 by scientists at the National Laboratory of New Infectious Diseases (NEIDL) at Boston University showed that UV-C light of a certain power literally destroys the DNA and RNA of SARS-CoV-2. As experimental samples, the scientists used bactericidal lamps Signify (ex-Philips Lighting), a leader in the field of lighting equipment. The laboratory staff treated the surfaces on which the virus was located with different doses of UV-C radiation produced by Philips TUV lamps. Laboratory tests have shown that UV-C lamps inactivate 99% of SARS-CoV-2 viruses on the surface within 6 seconds.
Dozens of medical clinics around the world are strengthening security measures, equipping spaces with UV‑C installations for the inactivation of SARS-CoV-2 viruses. Image source: Signify
"The results of our tests show that the viruses were completely inactivated: in a matter of seconds, we could no longer detect a single virus," Dr. Anthony Griffiths, associate professor of microbiology at Boston University School of Medicine, announced this good news publicly on June 16, 2020. The full scientific report is publicly available.
After receiving such positive research results, there was a surge of activity in the market of ultraviolet devices. So, Signify announced the purchase of Germicidal Lamps & Applications (GLA). This Dutch company specialized in the production of ceiling devices for air disinfection and has accumulated a lot of experience in UV-C disinfection. The infusion of GLA into the composition of the industry giant made it possible to combine the companies' developments and bring production to a new level of capacity. As a result, innovative and effective devices from Signify appeared on the market, capable of providing significant help in the fight against the spread of the pandemic.
Later, Boston University's findings were confirmed at the Innovative Bioanalysis Laboratory in Costa Mesa (California, USA) and at the Warsaw Institute of Biotechnology of the Food and Agricultural Industry. Dozens of countries have officially approved the use of Signify light fixtures for preventive measures aimed at combating the pandemic. Recommendations on the use of ultraviolet radiation for disinfection can also be read on the website of the Public Health Center of the Ministry of Health of Ukraine.
Signify CEO Eric Rondola made a public statement: "Given the potential of the technology to help fight the coronavirus, Signify will not keep the technology for exclusive use, but will make it available to other companies."
Three main tasks
So, as part of the strategy to combat the COVID-19 pandemic, bactericidal ultraviolet lamps have three main tasks:
- disinfection of surfaces;
- deactivation of the virus in the air;
- disinfection of small and large objects.
Use of Philips UV‑C disinfection bars for disinfection of public spaces of various types. Image source: Signify
Laboratory tests have shown that UV-C lamps inactivate 99% of SARS-CoV-2 viruses on the surface within 6 seconds
Universal mobile cart from the Philips UV–C line for disinfecting premises. Image source: Signify
Today, the Signify range already includes devices for the complete solution of the first two problems, and partially for the third. So, Signify suggests using cameras with built-in UV-C light to disinfect objects. They can be installed at train stations and airports — in storage rooms to disinfect luggage, as well as in offices and institutions in order to disinfect badges, keys, phones, bags, laptops in a matter of seconds. In clothing stores, ultraviolet cameras or stands are ideal for disinfecting items that have been returned from fitting rooms. In short, such boxes will be appropriate almost everywhere.
Offices, shops, pharmacies, schools
In order to clearly explain how UV‑C systems work in rooms, we can cite several already implemented cases as examples.
Forte Partners, a large Romanian company specializing in urban planning, engineering and architectural design, became the first Signify client to install ceiling-mounted UV‑C systems to disinfect the upper layers of the air in its headquarters in Bucharest - in open spaces and in meeting rooms . It is logical that architects should be pioneers in the application and testing of such innovations, since their experience is used in the future when designing objects.
Philips UV‑C ceiling lamps are primarily convenient because they can be used in rooms with people around the clock. The natural movement of air in rooms occurs from the bottom up. At the level of the ceiling, the air streams are irradiated with ultraviolet radiation, which is harmful to viruses, and come down purified. Since the light is not directed downward, but parallel to the ceiling, people can safely stay in the disinfected space. Philips lamps emit ultraviolet with a wavelength of 253,7 nm, which ensures the maximum level of disinfection and the absence of by-product ozone production.
"Thanks to natural ventilation in the room, air disinfected in the upper layers circulates and is cleaned with maximum efficiency. Therefore, we see it as an ideal application for our offices and second residential buildings," said Stephen Burke, Director of Construction at Forte Partners.
Use of Philips UV‑C installations for disinfection of the upper air layers in the offices of Forte Partners. Bucharest, Romania. Image source: Signify
In February 2021, the Signify company announced the successful implementation of a pilot project in the pharmaceutical industry: 40 Philips UV‑C ceiling lamps, which are safe for humans but destroy the coronavirus, have already been installed in 280 branches of the Slovak pharmacy chain dm.
The example of Slovak pharmacists was followed by the managers of the largest Polish retail chain Społem, which unites more than 3 thousand stores "It is important for us that Philips UV‑C disinfection devices reduce the risk of infection of customers and Społem employees in stores. This increases safety and does not cause discomfort. We believe that investing in disinfection with the help of Philips UV-C devices confirms the authority of our brand, especially in such a difficult situation as the coronavirus pandemic," says Agnieszka Derlecka, president of the Społem chain of stores.
Philips UV‑C ceiling lamps are convenient in that they can be used safely in rooms with people present at any time of the day
In Społem, they did not limit themselves to the installation of ceiling air disinfection systems in all their stores, but decided to use additional UV‑C emitters to disinfect surfaces, which are automatically activated at night, when supermarkets are empty, and treat racks and counters with ultraviolet light.
Even more powerful three-stage protection was chosen by the management of the network of OPTIMAX ophthalmology clinics in Malaysia. Even at the peak of the pandemic, the country's government did not close vital medical institutions, demanding that the administrators strengthen safety measures as much as possible. In order to minimize the risk of infection for patients and staff, OPTIMAX equipped clinics not only with stationary ceiling bactericidal systems and rails, but also with mobile disinfection carts that can be used in any space in the absence of people. Different models of trolleys are focused on the coverage area from 20 to 36 square meters. m, they are convenient for sterilization of operating and laboratory rooms. All stationary and autonomous bactericidal devices are integrated with an intelligent control system, thanks to which the responsible employee can control their operation in real time and remotely.
The use of Philips UV-C units for disinfection of the upper layers of the air in Społem chain stores in Slovakia. Image source: Signify
A similar strategy of a new security system was adopted in the well-known Parisian multidisciplinary clinic Avec La Clinique Vauban, and in Amsterdam, at the request of the municipality, they started installing ceiling disinfection systems in schools, preparing for the new school season.
An alternative for restaurateurs
In the spring of 2020, when the SARS-CoV-2 virus was just beginning to attack European cities, Italian architects Massimiliano and Doriana Fuksas from Studio Fuksas together with their colleagues wrote an open letter to the Italian government, in which they proposed to abandon the use of public air conditioners. They reminded that earlier these systems were spreaders of the causative agents of "legionaire's disease" and other infections. "One of the main tasks of new buildings and architectural spaces should be cleaning and disinfecting the air with the help of simple and effective sustainable systems, for example, UV lamps, capable of disinfecting any environment in a short time," the appeal said.
If in living spaces it is possible to do without an air conditioner even in hot weather, choosing effective protection from the sun as an alternative (read more in the article "How sun protection helps to solve the problems of modern architecture and construction" in volume 16 of PRAGMATIKA.MEDIA), then abandon hoods in establishments it is impossible to have a public meeting - both in the halls and in the kitchens.
One of the restaurants of the Hong Kong Tao Heung chain was recently equipped with a system of UV-C lamps that inactivates the SARS-CoV-2 virus. Image source: Signify
The Hong Kong government is currently considering tightening regulatory requirements for restaurants and cafes. It can introduce at the legislative level the equipping of all systems of centralized ventilation and heating HVAC (Heating, Ventilation, Air Conditioning) with HEPA filters of the latest generation. The restaurateurs are seriously concerned, since the global modernization of ventilation systems is a significant expense not only for redesign and installation, but also an increase in electricity consumption, because the filters create additional resistance, due to which it is necessary to increase the power of the fans.
"Upgrading the system and finishing the air ducts requires substantial additional investments and takes a lot of time," explained Vinny Yau, vice president of Tao Heung Group Limited. Equipping all restaurants operating under the Tao Heung brand with Philips UV‑C ceiling disinfection systems took just a few days. According to Vinna Yau, this method is an ideal solution for the HoReCa sphere.
Guided weapon
It is necessary to remember that ultraviolet radiation is a source of potential danger, the neglect of which can lead to serious consequences. Ultraviolet radiation can cause skin burns, damage to the cornea and lens. It is extremely important that the equipment used in public places be supplied and installed by specialists.
For example, recirculators, which are extremely common on our market — devices consisting of a UV lamp enclosed in a casing and equipped with fans — are not an effective air disinfection system, since at each moment of time a small amount of air is exposed to radiation compared to the volume of the room, and due to the use of low-quality lamps, they can also generate ozone, which is harmful to humans. On the website of the Public Health Center of Ukraine, by the way, the use of UV recirculators for air disinfection is not officially recommended due to their inefficiency.
Philips UV‑C ceiling installations for disinfection of the upper layers of the air are installed in kindergartens and schools in Amsterdam. Image source: Signify
Realizing that the pandemic will lead to an explosive demand for disinfecting equipment, in the summer of 2020 the Global Lighting Association (GLA) gathered world experts to supplement the existing international photo safety standards with new requirements. Signify has ratified the UV‑C Safety Guide published by the Global Lighting Association and applies its requirements in conjunction with other professional standards.
Safety requirements cannot be neglected in any case, especially when it comes to objects of the social sphere
To protect users from the unwanted influence of ultraviolet light, Signify supplements UV-C devices with unauthorized access blockers, timers, motion sensors, and voice warnings. For complete security, it is preferable to use an intelligent control system, similar to the topics that PRAGMATIKA.MEDIA wrote about earlier in the articles "If the sky becomes too bright. Environment of the world and friendly-lighting","Bright side of the city. Architectural enlightenment and its perspectives","Connecting city. Light on bridges».
Installation of ultraviolet disinfection systems is preceded by lighting engineering calculations and design. The task of Signify is to ensure both the efficiency of the system and its security at the same time. After the devices are installed, specialists check the correspondence of the actual parameters with the calculated ones in order to be confident in the result.
These are necessary safety requirements that cannot be neglected in any case, especially when it comes to social facilities - kindergartens, schools, hospitals, homes for the elderly, sanatoriums.
Great promise
Since the pandemic that the world is facing is global, protracted and recurring, further transformation of devices, including designer ones, is inevitable. If they become a familiar part of any interior, then the aesthetic requirements for models will also increase, there will be (already there!) a demand for expanding the assortment.
Mask, camouflage the equipment, or, on the contrary, emphasize its presence? After all, the interior of any space - whether it is a lobby of a residential complex, an apartment or a waiting room at an airport - must subconsciously create a sense of security in people. Only then will they feel comfortable. This aspect, in particular, was discussed within the framework of the panel discussion "In search of the "new black"" organized by PRAGMATIKA.MEDIA in March 2021. What to expect from interior design of public spaces in 2021." The pandemic pushes to change and the emergence of new typologies of public places.
The use of Philips UV‑C installations for disinfection of the upper layers of the air in the rooms of the RB Leipzig football club, at the Red Bull Arena stadium. Leipzig, Germany. Image source: Signify
"I think this is an extremely important and promising topic that affects each of us. For example, in schools and kindergartens, classes are divided now, but for this it is necessary to arrange breaks and take children out in an organized manner. And this is a waste of time and certain organizational difficulties. It is necessary to introduce more modern solutions," says architect Olga Chernova. According to Alexander Popov, co-founder of the archimatika architectural bureau, the question of the future of centralized ventilation and air-conditioning systems is no less acute: "It is important to clarify the prospects - how effective are UV‑C systems for cleaning air flows in working air conditioning units? Will they be able to inactivate the virus, if you take into account that the air in the room will circulate at a higher speed than with natural convection? This is important for us as designers. And as for users — also."
The director of Signify Ukraine, Aleksey Shershen, considers it quite natural that specialists from related industries have similar questions, because despite the fact that ultraviolet disinfection has been used since the last century, modern complex UV solutions are considered innovative.
The use of Philips UV‑C units for disinfection of the upper layers of the air at the stadium and campus of the PSV football club. Eindhoven, Netherlands. Image source: Signify
"If the building has a centralized forced ventilation system, increasing the speed of air circulation will not have a significant effect on the effectiveness of air disinfection with our UV‑C installation, if the frequency of air exchange is within the norms determined by SanPyN (for offices).
The idea of integrating UV‑C devices directly into a centralized air conditioning system is not the most successful option for symbiosis. Reasons: the high cost of implementing such a system, the need to develop new project documentation, increasing the complexity of service and requirements for the qualification of service personnel. Separately placed devices give more flexibility, because they can be placed exactly where disinfection is really needed, and not bear the costs of processing the entire volume of air circulating in the building," explains Alexey Shershen.
Since the maximum effectiveness of UV disinfection against viruses and bacteria has already been proven, it makes sense to compare the cost of operating UV‑C systems and systems with air filtration using "strengthened" HEPA filters.
Bactericidal UV‑C systems successfully suppress most known pathogens, for example, seasonal influenza viruses
"This question is best left to specialists who know the price of similar filters and their service life. Philips UV-C lamps, for example, have a useful life of 15 hours — that's more than 000 years of continuous operation and 1.5–4 years of operation under standard office conditions.
What is really important to understand and be aware of are the risks associated with the danger of UV radiation. The calculation and installation of the systems should be performed only by professionals", — Aleksey Shershen once again focuses attention on safety.
Every month, more and more companies and institutions decide on the need for additional investments in security dictated by the pandemic. The use of new equipment strategies will allow developers and business representatives to reduce the risks associated with the possibility of a recurrence of pandemics. And also get a competitive advantage in the market, compared to the subject who ignored the lessons of the past.
Use of Philips UV‑C installations for disinfection of the upper air layers in the offices of Forte Partners. Bucharest, Romania. Image source: Signify
However, it is also important that the bactericidal UV‑C systems equally successfully suppress the majority of known pathogens, for example, seasonal influenza viruses, respiratory infections, etc. Therefore, the expediency of their use is just as justified as the fire protection systems that are currently in use is not in doubt.
"If governments and city officials manage to learn from the coronavirus pandemic, our cities will become much more comfortable," says David Barnes, an adjunct professor of history and sociology at the School of Arts and Sciences at the University of Pennsylvania. Earlier, the fear of a new outbreak of cholera in 1858 forced the London authorities to lay a centralized sewer line, and the reforms of Baron Haussmann gave Paris not only water supply and sewage, but also large parks - "light cities". Just as it happened before, when the world faced global epidemics, the COVID-19 pandemic pushed us to a new civilizational leap, radically changing the requirements for safety.
