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REHVA published its first COVID-19 guidance mid-March 2020. After two updates (April and August), the fourth version is focusing on how to reopen and safely use buildings after the lockdown, providing advice on specific components, buildings/space types, and suggesting mitigation measures.

The REHVA guidance summarises advice on the operation and use of building service systems during an epidemic of a coronavirus disease. The current (4.1) version of the guidance was published on 15 April 2021 and overwrites all previous ones. Further updates are expected in the upcoming months as more academic data becomes available.

Principal updates compared to the previous version (4.0)

  • The operation of mechanical ventilation systems in commercial buildings 1 hour before and after building usage time is enough if the building would be ventilated with 3 volumes of outdoor air at that time.
  • Recommendation to change the CO2 setpoint to 550 ppm in demand-controlled ventilation systems, in order to maintain the operation at nominal speed.
  • In the heat recovery sections of the HVAC systems, plate heat exchangers and enthalpy plate exchangers with permeable membranes do not contribute to the virus transmission.




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Other Guidance documents

Technology Specific Guidance

  • UVGI disinfection technology (a brief overview), [TK] – This document aims to explain the specific terms used in the UV technology field, the reasons why UVGI is used for virus inactivation, mentioning briefly the main features of UV-C lamps. It presents the UVGI device typology, providing also some general, practical rules and limitations for safe usage.

  • Criteria for room air cleaners for particulate matter  - This document recommends criteria that would enable a safer and more effective operation of portable air cleaners and purifiers. The most important parameters envisaged are: noise, energy efficiency, clean air delivery rate (CADR), placement, service and maintenance, operation and generation of pollutants.

  • Limiting internal air leakages across the rotary heat exchanger - This specific guidance includes some precautionary measures to reduce internal air leakage in ventilation systems and prevent the transmission of the virus through particles suspended in the air.

Building/room Specific Guidance 

  • School buildings – The purpose of this guidance is to provide summarised advice on the operation and use of building services in schools, in on-technical language, targeting school principals, teachers and facility mangers. Updated version is online!
  • Download the Infographic here - [EN, RO]

  • Ventilation in patient rooms - This guidance provides reccomendations for ventilation of patient rooms. Patient rooms are divided into 3 different categories: normal areas/patient rooms; temporary areas/wards for patients with infectious diseases; isolation rooms with airborne infections.

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