On April 3, REHVA updated its COVID-19 guidance document with the following revisions and additions:

• Latest information on the airborne transmission and implications to HVAC systems was added;
• Ventilation continuous operation guidelines were updated to be explicit;
• SARS-CoV-2 stability data at different temperatures and relative humidity was added;
• Heat recovery equipment guidance was revised including the recommendation of inspection;
• Guidance for room level circulation units was complemented;
• HVAC maintenance personnel protection recommendation was added;
• A summary of 14 points of practical measures for building services operation was added.

On the COVID-19 guidance webpage REHVA published also an updated collected bibliography, a Frequently Asked Questions section as well as the available translations of the documents.