This dependence is related to the inverse square law, according to which the intensity of light radiation is inversely proportional to the square of the distance from the radiation source. That is, the further away from the source, the weaker the light intensity. It has been determined that in order to maintain the required level of intensity per 1 m2 of area, the radiation power must be at least 1 W. So, for example, for a room of 15 m2, you need to choose an irradiator with a power of at least 15 W.

Recirculators are prohibited for use for air disinfection in healthcare and social welfare facilities by Order of the Ministry of Health of Ukraine dated May 6, 2021, due to their ineffectiveness. Let's analyze this ban... In recirculators, normal bactericidal ultraviolet light is hidden in a “box.” And therefore, its ability to disinfect the air becomes completely dependent on how the air flows through this very “box.” And this is where problems begin to arise... ​ Air is drawn from the room into the recirculator, which is usually mounted on the wall. But ask any ventilation specialist, and they will tell you that for an extractor fan to work effectively, i.e., to effectively remove any pollution from the room, it must be placed as close as possible to the source of the pollution. That is why smokers try to smoke near a window through which smoke is removed, or a kitchen hood is placed above the stove, not on the opposite wall. According to the laws of physics, an extractor hood only works at close range. For fans manufactured in China, which are commonly used in our domestic recirculators, this distance is no more than 20-30 centimeters. This fact can be easily verified with a smoke test. In other words, hanging quietly but beautifully in the corner, the recirculator cannot in any way affect the air in the room as a whole. And the microorganisms that were in the air before the recirculator was turned on will remain there after it is turned on. From an epidemiological point of view, the longer a microorganism remains in the air, the greater the risk of encountering it and becoming infected, especially in today's environment, where more and more microbes are becoming resistant. You don't have to look far—just think of tuberculosis and the situation with it in Ukraine. Therefore, when it comes to air purification, the most important aspect is how quickly this purification process takes place. In modern science, the speed of air purification, including from microbes, is usually expressed in terms of equivalent air exchange rates. The recirculator's passport usually states that it passes 50 m3 of air per hour through itself. This is often not enough to ensure even a single air exchange in a room. According to the IC TB Standard, the air exchange rate should be 6...12. This means that for a room with an area of 16...17 m2, you need at least six recirculators! Considering the price of this device, you can immediately abandon this idea. In practice, the recirculator draws through itself a volume of air that is lower than the passport value. This is because this device “chases” the air under its body, “forgetting” about the air in the room. ​ On the other hand, shielded UV irradiators are equivalent in efficiency to approximately 20 times the air exchange. ​ Given these facts, UV-BLAZE is categorically opposed to the use of recirculators and is definitely in favor of the principles of conscious use of ultraviolet light 😉

For maximum UV protection, the irradiator must operate continuously while people are present in the room. Whether it is a doctor's office, a reception area, or a school classroom, the irradiator must operate as long as people are present. When there is no one in a closed room, there is no risk of disease transmission, meaning there is no need for the UV irradiator to operate continuously. However, in wards where patients are constantly present, especially in intensive care units where air safety is critical, irradiators must operate continuously, both day and night.