Proper ventilation allows detainees to breathe normally, evacuates humidity from their cells and gets rid of bad odours. It is important that inmates are able to open the windows. In hot climates, ventilation can be greatly improved with air conditioning or the installation of electric fans. If, on the other hand, the cells or dormitories are too cold and are poorly insulated, detainees may have to block the windows, thereby preventing the entry of fresh air and natural light. Windows should not be fitted with totally opaque glass so that the prisoners are able to see outside from their cells/dormitories. Similarly, windows should not be placed high up above eye level.
Ventilation must be adequate both in detainees’ living quarters and in all places where they spend time, such as in the workshops or the canteen. Proper kitchen ventilation is particularly important to ensure the hygiene of served meals and food preservation. The prison infirmary should benefit from the same conditions to ensure hygiene standards and to protect medical supplies. The showers must be well ventilated to allow the evacuation of moisture and prevent the transmission of certain diseases, especially skin disorders. Adequate ventilation helps reduce the risk of the transmission of tuberculosis.
The climate is obviously a crucial factor in the management of the ventilation system. The authorities should do everything necessary to ensure both a medium temperature and good air circulation inside the prison. Poor ventilation, combined with a hot and humid climate and overcrowding, is damaging to the health of detainees.
It is also important that spaces reserved for people coming from outside, such as meeting areas for family and lawyer visits, are well ventilated and have sufficient light. Areas allocated for staff, checkpoints, locker rooms and offices should benefit from similar conditions.
Good ventilation can be assured through the inflow of fresh air or through air conditioning, or through a combination thereof. Access to outside air should always be possible. According to the ICRC, a practical way of calculating ventilation in places of detention is to determine the ratio of the size of windows or other openings to the area of the floor. To renew the air in a satisfactory manner, the following two requirements must be fulfilled:
• the size of the openings must be no less than one tenth of the floor area;
• available air space must be no less than 3.5 m3 per person.
Compliance with these requirements is especially important if the detainees are not able to spend long periods in the open air every day. At a minimum, detainees should be able to spend at least one hour a day in the fresh air outdoors.