[watchfirst9]

No lah. Depends on the person. I know most like about 25 C. I actually did a survey 3 decades ago. Why? Because I was in a meeting room where the temperature was set at 11 C. Everyone felt too cold and in the end shortened the meeting (I did wonder if someone wanted to end the meeting early and sabotage it by setting the temperature to 11C). It made me wonder what is the comfortable temperature and I asked around. I get a HUGE range of answers from 17 to 27 C. Yes, 27C. And most of them are around 25C. Very few below 22C. or Higher than 26C.

Those who wanted below 20C always wear a jacket. LOL.

Many like to set to 21 and below is perhaps due to ageing aircon.

[Sentinel]

I doubt this virus is man made especially virus is subject to temperature fluctuations.

Well, if u know, u know, if not, so be it

[Oyk]

The outside ambient temp. is around 32 degrees C, during the day, so I reckon that if the aircon. is set at 24 degrees will be suitable temp.....

No 18 degree no talk.

[Oyk]

Room temperature is 29. If you set the air con to 29, you might as well not turn on the aircon, and simply use a fan....and you breathe in healthier air .

[RiseofAsia]

Many like to set to 21 and below is perhaps due to ageing aircon.

Actually, it is lazy to service the aircon.
Once you have regularly service your aircon.
Your old aircon will be cooling even at 25 degree.

One simple way to make air con cooler is to use a brush to brush the compressor fan coil dust away(It will be even better if you spray water on the compressor fan coil, but got to do it during rainy day if you are living in HDB. Need to switch off aircon power first. Do not spray water near the compressor electrical area, just spray on the big compressor fan coil will do.