Hepa filters

Air bio-contamination control in hospital environment by UV-C rays and HEPA filters in HVAC systems

The contamination of air-handling units is a widespread phenomenon in buildings with air-conditioning systems, including hospitals. The germicide capacity of UV-C rays is known and, in the air-conditioning apparatuses, the UV-C lamps are generally located inside the air ducts. Aim of the paper is to evaluate the effectiveness of UV-C lamps when they are differently placed, i.e. in a position to directly irradiate the HEPA filters surface. We built ad hoc experimental air-conditioning systems, with HEPA filters and UV-C lamps in the two described positions.

Regarding “Understanding the ‘Scope’ of the Problem: Why Laparoscopy Is Considered Safe during the COVID-19 Pandemic”

SARS-CoV-2 range in size from 0.06 to 0.125 μm, falling squarely within the particle-size range that HEPA filters capture with extraordinary efficiency: 0.01 micron and above. It is incorrect to state that HEPA filters are not able to catch particles below 0.3 micron, like SARS-CoV-2 virus.

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