COVID-19 ventilation and air conditioning
COVID-19 Guidance by Federation of European Heating, Ventilation and Air Conditioning Associations
As response to the coronavirus pandemic (COVID-19 or SARS-CoV-2), REHVA experts drafted a guidance document on how to operate and use building services in areas with a coronavirus outbreak to prevent the spread of COVID-19 depending on HVAC or plumbing systems related factors.
This REHVA document considers the best available evidence and knowledge to date, utilizing an ongoing Dutch literature review elaborated by dr. Francesco Franchimon, complemented by international REHVA experts as a joint effort.
Due to the ever-changing information about the disease, the document will be updated and complemented with new evidence when it becomes available. REHVA thanks the co-authors of this document for their much-appreciated contribution.
REHVA is currently updating COVID-19 guidance document. The following new recommendations are under preparation:
- Recommendation of regenerative heat exchangers (rotors) is under change, to consider the leakage and pressure difference between exhaust and supply side. The leakage via rotor, carrying over also particles, may increase from the limit of the standard of 5% to 15% if fans create higher pressure on the exhaust air side. Evidence suggest that rotors with adequate purge sector do not transfer particles, but the transfer is limited to gaseous pollutants. Because the leakage does not depend on the rotation speed, it is not needed to switch rotors off. If needed, the pressure differences can be corrected by dampers or by other arrangements.
- Additional evidence will be added to the question of relative humidity. SARS-CoV-2 stability (viability) has been tested at typical indoor temperature of 21-23 ℃ and RH of 65% with very high virus stability at this RH. Together with previous evidence on MERS-CoV it is well documented that humidification up to 65% may have very limited or no effect on stability of SARS-CoV-2 virus. Therefore, the evidence does not support that moderate humidity (RH 40-60%) will be beneficial in reducing viability of SARS-CoV-2, thus the humidification is NOT a method to reduce the transmission and spread of SARS-CoV-2.
This article first published by REHVA https://www.rehva.eu/activities/covid-19-guidance
Download REHVA’s Guidance document