People breathe up to 15,000 liters of air in and out every day. Yet few people give much thought to the quality of the air they breathe. Partic­u­larly indoors, where we spend more than 90 percent of our time on average, values such as temper­a­ture, humidity, and PM2.5 (fine dust with an aero­dy­namic diam­eter smaller than 2.5 microm­e­ters) are crucial for well-being and health in addi­tion to CO₂ content. These vari­ables have been shown to have a direct impact on the prob­a­bility of viral infec­tions such as influenza, SARS-CoV-1 or SARS-CoV-2. The RESET Viral Index provides real-time infor­ma­tion about these prob­a­bli­ties.

For the under­lying formula, RESET researchers first eval­u­ated more than 100 studies on air quality and infec­tion poten­tial and clas­si­fied them into four key para­me­ters that influ­ence infec­tion risk: virus surviv­ability, host immune system health, dosage (amount over time), and trans­mis­sion rate/infection. They then inves­ti­gated how these para­me­ters could be mapped with measured values to make them applic­able to building oper­a­tions and venti­lation systems.

Rela­tive measured values for temper­a­ture and humidity are incor­po­rated into the “virus surviv­ability” and “host immune system health” para­me­ters. They are highly inter­de­pen­dent: warm and humid air increases virus surviv­ability, for example, while dry air makes it more diffi­cult for the body to remove viruses via the mucous membranes and increases the risk of infec­tion.

The “PM2.5 impact” measures the number of suspended parti­cles in the air: the higher the concen­tra­tion of PM2.5, the higher the risk of infec­tion. The “dosage” para­meter is based on the CO₂ value and reflects the occu­pa­tion level of a room with people and thus the risk of becoming infected. On average, about 1,000 viruses have to be inhaled before infec­tion occurs  if the room is full of people talking and breathing, the risk increases.

Reli­able results depend on reli­able data  which is why temper­a­ture, humidity, CO₂ and PM2.5 levels are contin­u­ously measured by sensors. The index uses a number to provide infor­ma­tion about air quality and the risk of infec­tion. A value of 100 percent means that indoor air quality is optimal and the risk of infec­tion is minimal, while 1 percent indi­cates very poor air and a very high risk of infec­tion. So users are not only informed in real time, but can also take appro­priate action to close poten­tial “safety gaps” in venti­lation systems. 

Addi­tional product infor­ma­tion can be found here: