Studies have shown that in poorly ventilated and/or crowded settings, the virus that causes Covid-19 can linger in the air for long periods and cause infections. This is especially true in indoor areas like offices, restaurants, religious centres and educational institutions that are air-conditioned but not equipped with a good ventilation system.

The Malaysian health ministry has provided guidelines on improving ventilation in healthcare settings, many of which can be applied to air-conditioned residential or commercial spaces. Here are the key points:

1. Open the windows

Let fresh air enter by opening windows or sliding doors to create cross ventilation. Keep them open for as long as possible. By doing so, the likelihood of the virus lingering in the air is lowered.

For rooms with single-sided ventilation – that is, an opening in just one wall – fresh air flows in and stale air goes out on the same side.

Having the openings on adjacent or opposite walls provides better ventilation as it allows cross ventilation to occur. This causes pressure differences between one side of the room and the other.

Air is drawn into the room on the high-pressure windward side and drawn out on the low-pressure leeward side.

There are, however, limitations. The department of occupational safety and health cautions against opening windows situated near neighbouring houses to reduce the amount of shared air.

And in high-rise apartments, look out for windows that open into shared corridors or face other units. Also, avoid spending time on balconies that are in close proximity to neighbouring units.

2. Switch on the fan

To improve air circulation, switch on the fan. If there is only one stand, floor or table fan available, direct it in the same direction of natural airflow.

If several fans are available, use one to push the air outwards by letting it face an open window or door. But do not direct the fan directly at people seated next to each other, to avoid airborne transmission of particles.

3. Invest in an air purifier

If you cannot improve ventilation, the next best thing is to invest in an air purifier. A commonly used floor or standalone air purifier with a high-efficiency particulate air (Hepa) filter would effectively remove contaminants and airborne particles.

4. Install an exhaust fan

A powerful exhaust fan adds ventilation to areas with limited openings, drawing out stale indoor air and reducing the risk of the virus remaining in an enclosed area.

It is also a good idea to install an exhaust fan in shared spaces like the bathroom and pantry.

What are the chances?

The likelihood of contracting Covid-19 would depend on how long one is exposed to the virus, as well as the viral load. Since infections are more likely to occur in air-conditioned spaces with poor circulation, good ventilation is essential to allow fresh air to flow in and stale air to exit.

However, ventilation alone is not enough if one is in close contact with an infected person. Hence, existing guidelines such as wearing a mask, washing your hands frequently and practising physical distancing remain essential.

This article originally appeared on Recommend.my – Malaysia’s #1 Home Improvement Services Platform. Recommend.my offers a safer and more convenient way to hire the best home improvement and home maintenance professionals. From flooring to interior design to air-conditioner servicing, get access to thousands of the best local contractors and professionals at your fingertips.