What is the employer's responsibility?
Employers have a special responsibility to their employees in this regard. Workplace safety is more important than ever in this era of the Corona pandemic. Companies need to consider how social distan-cing works in offices, how to keep aerosols low in offices, meeting rooms and canteens, and thus how to guarantee good air quality. Returning to the workplace must not mean a relapse to skyrocketing infection rates.

How is the quality of indoor air measured?
It is no longer sufficient to intuitively regulate the air supply, temperature and humidity. First, the values for temperature, humidity, Co2 and TVOC (Total Volatile Organic Compounds) must be continuously recorded and stored as raw data. At the same time, the environmental variables such as fresh air supply, heat supply, number of people in the measurement area and outside temperature must be measured and stored.

How is the air quality calculated?
The Co2 load in ppm is evaluated according to the following table.

RATING INDEX CO2 PPM MEANING

Excellent	1	0 - 400	The indoor air is as fresh as the outdoor air
Good	2	400 - 1000	The indoor air quality is at a safe level
Moderate	3	1000 - 1500	The indoor air quality has reached noticeable levels
Poor	4	1500 - 2000	Indoor air quality has reached worrisome levels
Very poor	5	2000 - 5000	The air quality inside has reached unacceptable levels
Severe	6	5000 and above	The indoor air quality has exceeded the maximum workplace concentration values concentration values

 

The total of all mobile organic particles is indexed according to the TVOC rating.

TVOC RATING	INDEX
Excellent	0 - 50
Good	51 - 100
Moderate	101 - 150
Poor	151 - 200
Very poor	201 - 300
Severe	301 - 500

 

The relative humidity at normal indoor temperatures of approx. 21 Grand is ideally at 50-70%.
Only when all limits are met can the workplace be classified as Safe. This forms the basis for bringing employees back into the office.

Which influencing factors have to be considered?
Co2 and TVOC levels increase rapidly when there are many people in a small room with little or no fresh air. This often happens in meeting rooms without outside windows.

What is the solution to improve this situation?
First, the data must be collected and made visible to the employees. In a second phase, the room air can be proactively regulated on the basis of the long-term data collected. In this way, the limit value exceedances can be minimized.

By using combined IoT sensors, the measured values can be collected cost-effectively:

• Air Quality Sensor for temperature, humidity, Co2, VOC and IAQ (Indoor Air Quality).
• People counting sensor
• Supply air sensor

Depending on the sensor, this data can be displayed directly or visualized in real time on a dashboard for the entire office area.
Due to the long-term storage of the data, calculation models can later be created using Big Data Analytics, which allow the air quality to be regulated at an early stage based on forecasts such as weather and occupancy.

Bruno Frommenwiler, Head of Business Development, Bix Bytes Solutions AG