How corona-safe is the campus? Five questions about ventilation in the buildings

Do all buildings comply with RIVM standards?

Yes. The RIVM requires that buildings satisfy the ventilation standards as recorded in the Building Decree. “We follow the RIVM guidelines. Of course, we also see that experts sometimes contradict each other, but we do not have that expertise in-house ourselves. All buildings on the campus comply with the 2012 Building Decree,” explained Weustink. This mainly means that the building at the time of construction or renovation met the ventilation standards that applied at that time. It is essential, however, that the type of use has not changed since. Weustink is not entirely certain whether and where changes have taken place. “It is certainly possible that the type of use has changed. A faculty or department can decide to use a meeting room as a workspace. Other ventilation standards apply even after such minor changes,” she explained. That is partly why the university is conducting additional investigations.

Is a building that complies with the Building Decree ‘coronavirus safe’?

Weustink admits that such compliance does not offer any guarantees. “RIVM doesn’t suggest that either. But as long as we continue to adhere to the 1.5-metre rule, wash hands frequently and stay home if we have symptoms, it is safe to come to the office.” Until now, 20 per cent of staff was permitted to attend the office. The university is now starting to work with what Weustink calls the dynamic capacity of a building, which is the capacity that remains after ensuring that colleagues can always stay 1.5 metres away from each other, including in the hallways, lifts and stairwells. “In some cases, this new standard results in a considerable capacity increase,” stated Weustink, but a general percentage for all buildings cannot be given. This differs per building, for instance because of the number of floors and the use of lifts. An important piece of advice is, however, to air rooms after use, for example by opening doors and windows. “We switched off the recirculation of indoor air a long time ago when it became clear that this could be of influence.” She does, however, want to emphasise that employees are still asked to work from home as far as possible.

Opening windows sounds sensible, but what should you do if the windows can’t be opened, such as in the V building, the A building and in a few other places? Or if it’s freezing cold outside?

Weustink: “First of all, there are indeed some places where windows cannot be opened. This applies to some of the workspaces in Sanders building, for instance. But because staffing levels are low, it’s possible to change workspaces. So, sit in an area where the windows do open. Doors to the corridors, emergency exits and stairwells should not be opened for long periods of time due to the air treatment system.” The additional investigation aims to demonstrate whether a building’s ventilation system is sufficient, which would mean that windows would not need to be opened anymore.

How are the additional investigations going?

“We are focusing in the first instance on the buildings that have the highest throughput of students and staff: Van der Goot building, where examinations also take place, Mandeville, Polak, Sanders and G building. The additional investigation has been completed for the Van der Goot building, but we’ll be busy for some two months with the rest,” explained Weustink. For most buildings, known data can be used to check that the ventilation systems meet the criteria. “For example, based on a space that can accommodate fifty people in accordance with the 1.5-metre regulations, we then calculate how many cubic metres of air per minute are needed for this. For the G building, for instance, we have less data, so we need to take actual measurements,” stated Weustink.

What were the results of the Van der Goot building investigations?

“In the Van der Goot building, the system can extract sufficient air from outside based on a user capacity in accordance with the 1.5-metre standard. This means that the windows do not need to be opened. However, you also need to investigate whether the building will continue to be comfortable when the outside air is cold. The investigation calculations show that the building will still be comfortable with outdoor temperatures as low as minus six degrees.” According to Weustink, the ventilation system in this building does not need modifications now to ensure safe working, studying and examinations on a limited scale.