Businesses urged to improve indoor ventilation to reduce Covid-19 risk

Wee (bottom right) stressing a point while Dr Su (top left), Dr Ooi (top right) and Billy (bottom left) listen on.

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By Adrian Lim

KUCHING, Sept 14: Businesses are encouraged to improve the ventilation on their premises in order to reduce the risk of Covid-19 transmission through aerosols.

As Covid-19 transmission especially the Delta variant which can be transmitted through aerosols is more dangerous and spread faster, Universiti Malaysia Sarawak (Unimas) Department of Community Medicine and Public Health Professor Dr Anselm Su Ting highlighted that businesses and industries are required to improve the ventilation on their premises as an additional measure to control the spread of the coronavirus.


Dr Su pointed out that business communities need to take into account ventilation control in order to further reduce the risk of Covid-19 transmission through aerosols.

“If one can improve the ventilation of the indoor environment, then one can further drive the aerosol away from the person and reduce the risk of transmission.

“However, in most workplaces, the air-conditioning and mechanical ventilation (ACMV) system usually does not expel air to outdoors. They will circulate the air through the filter system.

“It is very important to prevent airborne infection indoors through various methods such as modifying the air flow to encourage air exchange and if possible adding in a filtration system,” he said during a dialogue session on standard operating procedures (SOPs) for ventilation improvement at malls or eateries organised by Kuching South City Council (MBKS) for business operators via Zoom today.

Dr Su noted that a centralised air-conditioning system is better compared to a split air-conditioning system as it has an outdoor air damper and return air damper which release air from indoors when they are opened.

He pointed out that by shutting the return air damper and opening the outdoor air damper of a centralised air-conditioning system, there will be clean and fresh air circulating continuously.

As for premises using split air-conditioning systems, he suggested opening windows to allow fresh air from outdoors to enter, whilst at the same time switching on the air-conditioner to cool the air in the indoor environment.

Dr Su explained that the principle is to dilute the air and encourage air exchange in an indoor environment.

Adding on, Dr Su explained that this principle was taken into consideration while drafting the SOPs for improving the ventilation for non-residential buildings in Sarawak together with the Ministry of Local Government and Housing (MLGH).

“Basically, the principle of this SOP is to do whatever we can at a minimal cost to dilute the air and to exchange the contaminated air with fresh or clean air as frequently as possible, “ he added.

Dr Su said the SOPs on ventilation improvement for non-residential buildings was developed based on space configuration as it is not possible to draft the SOPs based on topography or the usage of the building.

The SOPs encompass enclosed buildings with centralised air-conditioning systems, enclosed buildings with openable windows and split air-conditioning systems, enclosed buildings with openable windows and without air-conditioning systems, and enclosed buildings without windows or open windows not possible.

Apart from that, Dr Su said the SOPs were designed to include spaces like kitchens, toilets and shower rooms within a building.

He also noted that business owners could further improve indoor air quality at their premises by installing portable air cleaners.

On the usage of hand dryers in toilets and kitchens within a building, Dr Su said it is not encouraged at the moment as hand dryer will generate lots of aerosols through high speed air currents in an indoor environment.

He added it is much more hygienic to use disposable towels or paper towels to wipe hands dry before throwing it into a rubbish bin.

Dr Su added shopping malls here should discourage shoppers from using hand dryers in the toilets as many foreign countries did without hand dryers.

In the meantime, he said non-pharmaceutical public health intervention measures such as social distancing and wearing face masks still apply in workplaces to reduce the risk of Covid-19 infection.

Among those who attended the dialogue session were MBKS mayor Dato Wee Hong Seng, Sibu Municipal Council (SMC) chairman Clarence Ting, MBKS councillors, Sarawak General Hospital senior consultant paediatrician Dr Ooi MH, MLGH chief environmental health officer Billy Sujang and representatives from restaurants, coffee shops, eateries, shopping malls and cinemas.

Wee pointed out that MLGH should release guidelines as soon as possible to facilitate businesses in implementing SOPs.

Billy also explained the details of the SOP including minimum requirements, ways to improve air filtration and options that businesses can implement to generate clean and fresh air within an enclosed environment within a building. — DayakDaily