Gulf Construction Online - Optimum air quality ‘vital to hygienic interiors’

Healthy Buildings

Optimum air quality ‘vital to hygienic interiors’

01 August 2020

Al Salem Johnson Controls (York), a leader in the heating, ventilation and air-conditioning (HVAC) Industry, recommends several important precautionary measures to help tackle the Covid-19 pandemic such as providing air-handling units with high-quality, efficient filtration systems that can filter out viral particles of all sizes.

“The outbreak of Covid-19 has raised concerns about the virus’ airborne transmission, calling for an urgent re-evaluation of ventilation systems inside closed spaces in order to ensure superior indoor air quality (IAQ),” says Engineer Rabie Makki, Product Manager for Airside at Al Salem Johnson Controls (York).

These measures help to reduce its transmission, especially with the possibility of viruses travelling through the air at a higher rate in closed spaces, and with viral particles travelling across surfaces, if the air flow is higher than the required limit, Makki says, pointing out that the indoor air quality can be maintained through a number of basic measures. These include effective filtration and purification of air entering the building through the HVAC systems; and setting temperature and humidity at specified levels.

Makki says the best way to ensure that virus particles do not hover or linger in common enclosed spaces is to increase its rate of ventilation and air circulation, and to ensure the methods of expelling the particles outside the building.

“International air quality standards – including those of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (Ashrae 62.1) – recommend that air should be regularly changed and circulated in rooms every hour depending on the size of the room, its use, the number of occupants and other factors.

“For example, the air inside smoking rooms needs to be changed 15 to 20 times per hour, laboratories six to 12 times, warehouses three to 10 times, offices six to eight times, office buildings’ dining rooms seven to eight times, meeting rooms eight to 12 times, and parking in building basement 15-30 times,” he says.

Al Salem Johnson Controls (York) recommends that companies should carry out periodic preventive maintenance check-ups, and increase their frequency during the pandemic.

Furthermore, the company suggests cleaning and sterilising the air ducts, water ducts, filters and other components, and switching off and restarting the system from time to time, while ensuring optimum humidity levels inside the units, to combat the spread of viral particles, moulds and bacteria inside them.

Makki calls upon project owners, consultants and contractors to consider several factors when designing new buildings and facilities. The HVAC equipment should meet the buildings’ requirements, taking into account the required levels of fresh air, and to increase the ventilation whenever required.

Humidity levels inside the building should not be less than 40 per cent or exceed 60 per cent in order to prevent the growth of mould and of pollutants that will affect health, he adds.