What are the key messages on space heating and winter preparation of buildings in the context of the Covid-19 epidemic?

In the guidelines published in October 14, 2020, the High Council of public health (Haut Conseil de la santé publique, HCSP) recommends to maintain the heating of collective confined spaces in order to reach an appropriate temperature in regard with the occupants’ activities. Air renewal should be ensured within the rooms on a regular basis, through the supply of fresh air which should, be increased if possible.

Besides, the continuous measurement of carbon dioxide (CO₂) concentration by the means of sensors allows to assess the air quality.

The HCSP recommends the population occupancy gauge to be strictly limited to what the actual flow of fresh air input allows, while respecting physical distancing between peoples. It suggests to maintain forced-air heaters and mechanical ventilation systems in continuous operation. The HCSP recommends to check that no obstacle impedes the proper functioning of air diffusion within the rooms, and to avoid air recycling through the centralized air handling system in order to prevent the possible transfer of viral aerosols between different rooms.

The HCSP emphasizes the need to open windows for a few minutes several times a day to further increase the level of air exchange in the rooms. The HCSP points out that low humidity promotes the formation of aerosols.