risk from air conditioning?

[spothorse]

Hi all,

I was sitting outdoors enjoying a bought drink earlier, when I noticed said establishment had big air con units expelling hot "exhaust" air outside at very high force, from a big fan like most air con units.

I know there are concerns about air conditioning and Covid indoors, but what about this situation indoors? My table was a metre or two away from the nearest fan.

I've had both doses of Covid vaccine and am otherwise fit and healthy. The reason I'm so cautious is due to living with an elderly relative.

Thanks

Sorry, the above of mine should read "...what about this situation outdoors?"

Could it have been from the kitchens?

Most good aircon systems should have filters, while those heating air will have hot elements that kill the virus (less likely it's in heat mode with a system expelling hot air outside). These both rely on regular maintenance and filter changing; also essential to prevent legionnaires disease, so regular practice. Machines that blow air about without filters can spread many viruses, though that still relies on someone infectious being near the system within the last half hour or so. So it really depends on the specific unit. That's indoors.
Outdoors, you have wind to dissipate any particles much more quickly; that lowers any indoor risk enormously, but if the fan is blowing air onto you then there is still a small risk. If it were me, I probably wouldn't sit there again because I don't like hot air, but I'd also not stress about it for one time.

@HSHorror

Could it have been from the kitchens?

Hey....not sure actually if it was from the kitchen, or air con to cool the customer area!

@MRex

Most good aircon systems should have filters, while those heating air will have hot elements that kill the virus (less likely it's in heat mode with a system expelling hot air outside). These both rely on regular maintenance and filter changing; also essential to prevent legionnaires disease, so regular practice. Machines that blow air about without filters can spread many viruses, though that still relies on someone infectious being near the system within the last half hour or so. So it really depends on the specific unit. That's indoors. Outdoors, you have wind to dissipate any particles much more quickly; that lowers any indoor risk enormously, but if the fan is blowing air onto you then there is still a small risk. If it were me, I probably wouldn't sit there again because I don't like hot air, but I'd also not stress about it for one time.

Great thanks for this. So it sounds like the risk being outdoors, was pretty low.

Anyone else have any experience/thoughts on it?

I’d agree with MRex. The risk is likely to be minimal, but if you had the option of sitting somewhere that wasn’t directly blowing on you I’d take that.

Indoors with a system that just moves around the air already inside is where the big risk is.

Thanks guys. I do wonder if the Delta variant has changed the game with regard to outdoor transmission, incl. from a high pressure source like one of those air con exhaust fans

This won’t pose a risk with most, if not all, commercial air conditioning systems. It’s not pumping air from inside, it’s the cooling system which removes the heat from the refrigerant which flows through sealed pipe work.

There is a page on the health and safety executive website about ventilation and air conditioning that you should find reassuring.

If the Aircon unit looks something like this, then it's just a heat exchanger. The air doesn't come from inside the building.