WHO COVID-19 Guidelines for Air conditioning

World Health organization(WHO)

COVID-19 Guidelines in Air conditioning

What is vantilation and how can it prevent COVID-19 from spreading?

Ventilation involves introducing clean air into a space while removing stale air, in order to maintain or improve air quality. Ventilation can be achieved naturally (e.g. by opening a window) or by installing a mechanical system.

The spread of COVID-19 occurs most often when an infected person is in close or direct contact with another person. The risk of the spread of the virus is higher in crowded and poorly ventilated spaces where people spend long periods of time together in close proximity. Improving indoor ventilation can reduce the risk of the virus spreading indoors.

Ventilation is not a standalone measure and it should be implemented as part of a comprehensive package of measures, such as physical distancing, wearing a mask, frequent hand cleaning, and coughing or sneezing into a bent elbow. Each of these is important to protect you against COVID-19 infection

How do I naturally Vantilated a room?

When you are inside with other people, open windows or doors whenever possible. For instance, try to get a cross breeze so that air coming in from one window moves across the room and exits from another window. 

Can I use Air conditioning or other vantilation systems?

Heating, ventilation and air-conditioning (HVAC) systems are used to maintain indoor air temperature and humidity at healthy and comfortable levels. A well-maintained and operated system can reduce the spread of COVID-19 in indoor spaces by increasing the rate of air change, reducing air recirculation and increasing the amount of outdoor air coming in. Settings that recirculate the air should not be used. HVAC systems should always be regularly inspected, maintained, and cleaned.

How can improve heating and air conditioning at home?

Non-ducted heating and air conditioning units that recirculate air, such as fan-coil or split units, should be assessed, maintained and cleaned according to manufacturer recommendations. Assess the unit’s filter and consider replacing the existing filter with MERV14/F8 or the highest compatible filter with the filter rack, in collaboration with an HVAC professional. The units and filters should be periodically cleaned and maintained according to manufacturer recommendations.

Since January 2020, WHO has provided recommendation on ventilation in COVID-19 guidance. Early in the pandemic, WHO established the WHO Environment and Engineering Control Expert Advisory Panel (ECAP) for COVID-19 to review available scientific evidence and practices and update recommendations on environment and engineering controls. This multidisciplinary network brings together technical experts from various fields, such as infection control specialists, engineers, architects, aerobiologists and environmental experts.

What is WHO doing to address vantilation in the context of COVID-19?

In June 2020, WHO contributed to guidance on ventilation and air-conditioning systems in the context of COVID-19, available here. WHO works closely with the World Meteorological Organization Joint Office for Climate and Health and the United States National Oceanic and Atmospheric Administration (NOAA) through the Global Heat Health Information Network to develop and update this guidance.

In February 2021, WHO published a roadmap to improve ventilation.