Hogeschool van Amsterdam

A-Z Students International Sports, Management and Business (ISMB)

Ventilation in the AUAS buildings

What is de AUAS doing to prevent the spread of the coronavirus in our buildings via virus particles in the air (aerosols)?

Recirculation of indoor air

A bit of background information will be provided first.

Two aspects play a part in ventilation with regard to the coronavirus:

  1. the recirculation of indoor air without bringing in fresh air from outside;
  2. tiny particles known as aerosols.

RIVM distinguishes between recirculation from room to room (where the air travels a longer distance) and recirculation over a short distance running directly from person to person. For example, mobile air-conditioning units and table fans are not recommended, as they cause an airflow from one person directly to another.

Central recirculation

At an earlier stage, the decision was already made for the AUAS buildings to switch off the central recirculation of the air treatment system at the building level. However, there are also buildings with recirculation at the room level. Combined with good ventilation and the proper extraction of the air, this situation does not pose a risk. (Good ventilation involves the supply of sufficient clean air from outside in accordance with the current rules and regulations.) Aerosols (particles that may contain the virus) are sufficiently removed when good ventilation is present and do not pose an additional risk in this case. This situation has been mapped in each room. If a system indeed presents a risk, it has been switched off.

Changes to ventilation system

The ventilation systems are continuously assessed against the lates guidelines of the RIVM. If new insights are gained into the possible spread of the coronavirus via ventilation systems, this information may prompt us to change the ventilation system.

Rooms that do not comply with the guidelines

Some rooms do not comply with the RIVM guidelines. If so, the use of the room has been adapted. For example, the room is taken out of use or can only be used by one person. This information is always displayed outside the room.

Does the ventilation in my building comply with the RIVM guidelines?

Again, a bit of background information will be provided first.

Ventilation is the constant renewal of the air (24 hours a day). The outside air always replaces part or all of the inside air that is polluted by moisture, gases and possible pathogens. Ventilation can be achieved via natural (e.g. grilles or gaps) or mechanical ventilation (ventilation systems).

Overview of ventilation per AUAS building:

Almost all the AUAS buildings (BPH, TTH, KSH, KMH, WBH, MLH, DMH, FMB) are equipped with ventilation. These ventilation systems comply with the RIVM guidelines. We assess whether there is sufficient ventilation for each room. Adjustments will be made where necessary.

Mechanical ventilation

If there is mechanical ventilation, opening doors is not required.

Some rooms have partial recirculation for the purpose of climate control (cold air, for example). This system is still on where it is safe to use, combined with a ventilation system that supplies fresh air from outside. Recirculation has been switched off or restricted where it is not safe. As a result, it might get warmer or colder than usual at a location. In other words, temperature is not an indication of ventilation. All the locations have been examined, whether they are offices or teaching locations. It is indicated at the entrance to each room how many people can be present in a room if the supply of fresh outside air is limited. This number is usually much lower than required for ventilation purposes due to the need for a distance of 1.5 metres. If you stick to this maximum, the room will be properly ventilated and does not pose any risk.

Natural ventilation

If a room can only be ventilated naturally, this is indicated near the door.

Almost all the rooms in the Leeuwenburg Building have good ventilation. The system works partly with recirculation from the room itself. As extraction takes place at the top of the room, small particles that may contain viruses are removed to a sufficient extent. This situation was assessed by a senior safety expert and found to be safe. Ventilation and air supply comply with the RIVM guidelines. As a result of the low occupancy in our buildings, the standard for working and teaching environments is met.

A number of rooms cannot be used, as their air supply comes from the adjacent room. This fact is indicated outside the room itself.

In the NTH, mechanical ventilation takes place in all rooms. In some rooms the maximum number of people for the room is restricted. This information is always displayed outside the room.

A frequently asked question is whether you can use a table fan. If you are alone in a room, that's no problem. If you are with more people, you have to assess whether the airflow does not go from one to the other. For that reason, RIVM gives a negative advice in the latter case.

Questions on ventilation in general or in a specific room of a building?

If you would like to learn further details of ventilation and climate, contact servicedesk-fs@hva.nl.

14 September 2021