P31 Ventilation:Layout 1 27/04/2021 12:19 Page 31 Ventilation

Making air-conditioning units safer for Covid-19 and the new normal

It’s thought that some air-conditioning systems could be helping the coronavirus to spread through closed indoor spaces, explains Mark Kaufmann,HVAC engineer at,a London-based air-conditioning and fridge-freezer business. Here, he explains more and shares guidance on how we can work to make our air-con units safer, limiting and even virtually eliminating the spread of the virus.


wo superspreader events spring to mind. An incident in Guangzhou, China, in which an asymptomatic diner was thought to have coughed and spluttered too close to a

restaurant HVAC unit, and the notorious Diamond Princess cruise ship that had to be quarantined last February. It is thought that the ship’s interconnected air-conditioning was behind the rapid multiplication in cases. Given air-conditioning units typically operate indoors, and given that we

know Covid-19 is a highly contagious virus, capable of lingering in the air through respiratory droplets, it’s no wonder that so many scientists are ready to point their fingers at them. And so the European Federation of Heating and Ventilation Engineers

(REHVA) organisation has laid out careful guidelines on how we can all work to make our air-con units safer, limiting and even virtually eliminating the spread of the virus.

Turn your air-conditioning unit up, not down Despite the ominous message above, the solution is not a case of simply switching off or dismantling your HVAC units. In fact, it is the opposite. As REHVA suggests, we should configure our air-conditioning units so that they can better dilute or “blow away” virus particles before they can settle down on surfaces and become infectious.

Mark Kaufmann HVAC systems need to be reconfigured — if they aren’t already — to

increase the amount of air that they pull in from the outside. This outside air then needs to be distributed indoors at a quicker rate. This will ensure the air is frequently recycled, and quickly exchanged for fresh outside air.

Air-conditioning units and open windows Of course, the old fashioned form of air-conditioning — opening the windows — will also help to ensure the air in an interior space is frequently exchanged. But for obvious reasons, there are plenty of situations where simply opening the window isn’t practical. After all, open the windows on a cold winter’s day, or in a noise-polluted

(or just polluted) area and there will soon be problems. And even if you have the luxury of living or working in the most ideal

environment, in which the windows can be open all year round, a properly configured HVAC unit would still offer a much safer, better alternative.

New, even safer tech may be on the horizon The most efficient and protective air-conditioning units around come fitted with high-efficiency particulate air (HEPA) filters. They are essential in environments where safety is paramount, such as in surgical theatres and for rapid air-recycling on planes. HEPA filters literally have thousands of particle-grabbing layers that trap

everything from viruses, dust particles, to fungi. They work to such a rapid recycling frame that they completely replace a room’s air supply roughly 20-30 times an hour. And though HEPA filters are niche for now, thanks to our now germ-

sensitive world, they may soon not be. In fact, we could one day see HEPA air-con units as standard in the “new normal”. Right now the biggest issue standing in the way of this reality is not a

money one, but a technical one. At present, there is no clear way to integrate the filter technology into conventional air-conditioning units without the filter “dragging” on the air-recycling system. There are also issues with sealing the two together.

Making indoor areas safe with air-conditioning The everyday HEPA filter may still be a while off, but that doesn’t mean we can’t start tweaking, reconfiguring, or replacing our HVAC units in order to make our indoor spaces safer. But we can limit infection rate with a bit of awareness: to keep your indoor area safe from viral particles lingering in the air, quite literally blow them away with regular, circulated air, fresh from the outdoors. In short: just turn the HVAC unit up. May 2021 electrical wholesaler | 31

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