(1) Disinfect the indoor air. The maximum radiation output is in still air at an ambient temperature of 20°C. When the air temperature is high or low, it will affect the heat exchange between the surface of the ultraviolet tube light tube and the air, and then affect the temperature field inside the lamp tube, reducing the radiation output. The air contains water vapor. Since water molecules can absorb ultraviolet rays, when the air humidity is high, the penetration of ultraviolet rays will be weakened and the disinfection effect will be reduced. When the humidity is 70%, 80%, and 90%, in order to achieve the same effect, the radiation intensity needs to be increased by 50%, 80%, and 90% respectively.
(2) Disinfect the air in the air duct. When the air temperature is 24°C, the flow velocity is 0.472m/s, and the relative humidity is in the range of 35%-85%, the radiation intensity of the UV lamp is inversely proportional to the air moisture content. Therefore, the power of the UV lamp should be increased when the humidity is high. Air temperature and humidity affect the radiant output of UV lamps.
(1) For indoor UV sterilization lamp tube hanging irradiation method. The increase of air flow rate will strengthen the mixing of indoor air, increase the opportunity of microbial particles in the lower part of the room to be brought into the upper space, and improve the sterilization rate; but at the same time, when the air flow rate is too large, the residence time of microbial particles in the effective range of ultraviolet radiation will be shortened, and the sterilization rate will be reduced.
(2) For the central air-conditioning duct internal irradiation method. An increase in air flow rate will enhance the cooling effect of the UV lamp, reduce the internal temperature of the UV lamp tube, and reduce the radiation output.
Reference ballasts have a stable voltage/current ratio at rated frequency and are relatively insensitive to changes in temperature, current and surrounding magnetic fields. The monitoring found that the use of different ballasts has a great influence on the radiation intensity of ultraviolet tube lights. Therefore, in daily supervision, infection control personnel should strengthen the guidance on the correct use of ultraviolet tube lights in departments, and reduce the influence of factors such as ballasts on the effect of ultraviolet disinfection.
The results of a study showed that for terminal disinfection of high-risk wards, the use of standard chemical methods plus ultraviolet light disinfection can significantly reduce the probability of infection with multidrug-resistant bacteria and Clostridium difficile in patients re-entering the ward.
In the initial ozone output rate: the initial ozone output rate of the non-ozone lamp should be lower than 0.05g/(kW·h). The initial ozone output rate of the ozone lamp should not be lower than 80% of the nominal value. The use of ultraviolet tube lights needs to pay attention to safety. If ozone residue or leakage exceeds a certain concentration, it will cause harm to the human body. Excessive exposure to ultraviolet rays will cause cataracts, skin cancer, etc., so pay attention to ventilation after disinfection.