The tendencies that were beginning to be implemented in new designs for healthy offices were accelerated by COVID-19, and work spaces have had to be adapted to go back to work following the guidelines of the World Health Organization (WHO).

According to the WHO, city dwellers spend between 80% and 90% of their time in enclosed environments. In these enclosed spaces (offices, schools, hospitals, malls, etc.), bacteria, viruses, dust mites, particles and environmental tobacco smoke coexist, which could alter the quality of the air indoors and have harmful effects on human health.

It is very important to have a suitable climate control system that provides proper ventilation to ensure that any viruses in microdroplets or suspended particles do not affect other users, and to minimize the risk of infection.

Factors that determine air quality

The U.S. Environmental Protection Agency has identified several factors that determine air quality in offices:

• Ventilation systems and the recirculation of air, heating and air conditioning.
• Use of air filtering devices which eliminate harmful pollutants.

Investment in these factors will improve worker wellbeing and productivity. For example, higher levels of CO2 affect people's ability to concentrate, use information and make decisions.

What factors influence the air inside an office?

• Physical factors like relative humidity, air speed, temperature and noise.
• Chemical factors like carbon dioxide (indicating insufficient air renewal indoors) or different pathogenic agents (viruses and bacteria).
• Factors related to building maintenance tasks, cleaning, refurbishment or remodeling.
• The activities performed by the building's occupants.

The government has published a series of recommendations on how to use climate control systems, with a special emphasis on the importance of air renewal at a minimum of 12.5 liters per second (l/s) per occupant, which is the rate that the Regulation on Thermal Installations in Buildings assigns to good-quality air.

To reach this rate, ventilation has to increase and/or occupancy of spaces has to decrease.

Among the recommendations listed, we can highlight:

• Whenever possible, work with outdoor air and minimize recirculation.
• Ventilate at least 2 hours before entering the building, and leave a lower flow 2 hours after closing the building.
• Reinforce the maintenance of climate control systems, and keep ventilation systems on over the weekend with a minimum flow to allow the rooms to air out.

To see all the measures, you can download the manual of recommendations published by the Ministry for the Ecological Transition.

Opening offices will mean adapting workspaces and gradually going back to the new normal with the goal of minimizing risks and applying the measures that can guarantee the health of both workers and customers.