Why good ventilation is important?
If there is not enough ventilation in a building, the concentration of aerosols builds up. They can float in the air for a very long time. (source)
Investigate the direction of the airflow
When people breathe air, it gets sucked off with mechanical ventilation in a certain place. If people sit in the stream of contaminated air, they’ll get everything along. (source). Not sure about the airflow stream in your building? Blow bubbles at your desk! Scientists are actually blowing helium filled bubbles to determine the airflow direction (source).
Avoid recirculation of used air
Some HVAC (Heating, ventilation, and air conditioning) -systems circulate warm air back in the building. This causes the unwanted effect of contaminated air flowing back into the rooms. The settings can be adjusted to avoid this, although this is more power-consuming. (learn more)
Monitoring air quality
With sensors, one can measure the air quality and identify risky areas like travel junctions. But one can also identify high occupancy moments or highly popular spaces across the weeks. With a Particulate Matter sensor, one can measure indoor air quality based on the number and size of particulate matter in the air at any given time. With a CO2-sensor, one can monitor air quality continuously based on CO2 levels.
Portable air purifiers
Portable Air purifiers can reduce viruses or bacteria present in the air flowing through the device. They achieve this by blocking viruses and bacteria (for example using filters) and/or killing them (for example using UV-C) (source).
Tips to improve the ventilation:
- Open outdoor air dampers beyond minimum settings to reduce or eliminate HVAC air recirculation.
- Open windows and doors, when weather conditions allow, to increase outdoor airflow.
- Use fans to increase the effectiveness of open windows but think about airflow and correct settings (read more)
- Ensure ventilation systems operate properly
- Rebalance or adjust HVAC systems to increase total airflow
- Turn off any demand-controlled ventilation (DCV) controls that reduce air supply based on occupancy or temperature
- Improve central air filtration
- Inspect functionality of the ventilation fans
- Use portable high-efficiency particulate air (HEPA) fan/filtration systems to enhance air cleaning
- Install UVGI-systems to reduce exposure of COVID (source)
Managing people to reduce the spread of the Coronavirus in the building
Why managing people is important?
First, people are the ones who spread Coronavirus. But secondly, people are also important in using the ventilation system properly.
Educate in the proper use of the ventilation system
A functioning ventilation system is one thing, however, having people use it properly is another. There are differences between ventilation systems and how people suppose to use them (like opening doors or not). Educate the building users to ensure proper ventilation.
Using booking systems where people can reserve desks or rooms prevents overcrowdedness and a high chance of contamination between people. Furthermore, the data gives also an indication of the crowdedness of the office and specific spaces.
Monitoring occupancy is the best way to understand how many people there are in the building, where they cluster, and when they leave. Together this gives valuable information about the potential spread of the Coronavirus. One could monitor occupancy with Workplace Observation Studies or by using sensors that have their own benefit. Booking systems give an indication of occupancy but the actual occupancy deviates quite often from the actual occupancy. In one study, we analysed the differences for one university and the booking system showed an occupancy of 39,1%, while the actual occupancy turned out to be 14,1%, which is less than half. A visualisation of the data is shown below.
Figure 2. booking behaviour vs. actual occupancy (source: Measuremen Portal)
Why assets are important
Next to people and ventilation, assets, such as desks, chairs, hand sanitising stations, and signing can nudge and remind people to use their workplace safely which reduces the risk of the spread of the Coronavirus.
Hand sanitising stations
Placing hand sanitisers with paper towels in the office at visible places will improve hand hygiene and reduce the spread of the Coronavirus.
Regular cleaning of desks at the end of the day or at the end of use can reduce the spread of the Coronavirus. The preferred measure depends on your own workplace policy. When you employ flex working, keep in mind the risks of device sharing (next section).
Reduce device sharing
Device sharing imposes a larger risk of the spread of the Coronavirus, which is thus advised to be limited.
Across narrow paths in the building, where safe distance can’t be ensured, it’s smart to apply routing. Signs like traffic indications can be used and placed e.g. 1,5 meters apart to nudge keeping safe distance learn more.
Touching doors, trash cans, sanitisers, and faucets are easy ways for the virus to spread. By operating them with gestures, speech, or proximity through sensor-equipped devices, one can avoid contagion.
Avoid overcrowding in rooms and open areas by removing chairs or desks. If this is not possible, one can also use signs, tape, or ribbons to prevent the use of chairs or desks. Tip: think of a positive way of framing that avoids the annoyance of the users.
Last but not least, signing can be used to avoid the spreading of the coronavirus through surfaces and deposition of the virus. Although many interventions (like wearing a mask) have become regular practices now, reminding your building users about hygiene and risks can make it improve adherence and might reduce their mental strain instead of reminding themselves. One could use signs, markings, or use (digital) communication to ensure practices like:
- Wearing masks when walking through the building
- Keeping proper distancing
- Stimulate hand sanitising
- Washing hands regularly and effectively
- Cleaning devices and desks
- Doing the “Vampire” cough – coughing into elbow or handkerchief
- Stimulate working remotely when people have a cold or feel ill
- Use ventilation system effectively