If your office does not have a mechanical ventilation system to provide fresh air, you should now open all windows and doors as often as possible.
And air conditioning should be reduced or turned off when that happens, said three government agencies in an updated set of guidelines on improving building ventilation and air quality to prevent the spread of Covid -19.
The new directive comes as Singapore sees an increase in coronavirus cases in the community, with 21 locally transmitted cases reported yesterday.
In the five-page document, published jointly by the Building and Construction Authority, the National Environment Agency and the Ministry of Health, authorities noted that Covid-19 can be spread by viral aerosols in closed, poorly ventilated environments.
“It is therefore essential to mitigate this risk by improving ventilation and air quality in indoor environments,” they said.
The guidelines define the actions that building owners and facility managers should take in three types of contexts.
For air-conditioned spaces with mechanical ventilation – such as office buildings and shopping centers – managers should ensure that ventilation systems are in good working order and maximize the supply of outside air.
Air should be purged at least once a day before building occupancy and indoor air recirculation should be reduced. To expel indoor air, exhaust fans must also be running at full capacity in areas such as toilets.
Spaces without mechanical ventilation – such as retail stores – should have their doors and windows open as often as possible, and operators should consider installing window-mounted exhaust fans.
In confined spaces, where the risk of disease transmission is high, portable air purifiers with high efficiency filters can be considered as an interim measure. These spaces include dental clinics or premises where Covid-19 patients may be present.
For naturally ventilated spaces such as cafes and dormitories, operators should keep windows and doors open at all times, with outward facing fans installed to increase air exchange. They should check other systems – including water seals in the sanitary system – to make sure there are no unwanted air leaks into occupied spaces.
These measures should not exist in isolation, authorities said. High contact points should be disinfected regularly and building occupants should always observe safe distance measures and wear masks.
Public buses and trains are well ventilated, according to a study conducted last year by the Agency for Science, Technology and Research.
The study found that air in trains is exchanged every six minutes through ventilation systems and as doors open and close at each station. On buses, fresh air enters when the doors open and close. Buses are also ventilated at interchanges when their doors are left open.
“Ventilation systems, combined with intensified cleaning and disinfection regimes – along with commuters ‘adherence to the strict discipline of wearing effective masks and not talking – will minimize commuters’ exposure to the virus,” the authorities said.