Dewpoint

I had an unusual experience travelling home yesterday evening. It was still quite warm so I had the aircon on in the car, but the windscreen was slowly misting up. I increased the fan speed which only made it worse . . . until I realised the misting was on the outside, caused by a combination of the high air temperature and humidity and the chilling of the 'screen by the air conditioning. A burst of warm air from the heater dispersed it quickly, but it's something I have never before experienced in 50 years of driving. Maybe I never had such an efficient air conditioning unit before

Not really model engineering but perhaps a good illustration of the 'dewpoint' effect which causes rust on machines and has been discussed on the forum many times.

Just illustrates how humid the weather is currently, it’s certainly very oppressive here in Sussex, we had a thunderstorm last night but it didn’t clear the air much. Dave W

Reminds me of an overnight coach trip I did many years ago from Brisbane to Sydney. The aircon was so cold that all the windows on the coach were covered with condensation on the outside and it was more than just 'mist', it was running down onto the body panels. And that was at 2AM on a Saturday in September! Australia can have hot humid nights even in early spring.

I get that practically every morning, living on a tiny island the air is inevitably humid almost all year round especially the summer months. Before driving off ac on, wipers on heater on blower and demist max and wait for the coolant temperature to raise!

I get that practically every morning, living on a tiny island the air is inevitably humid almost all year round especially the summer months. Before driving off ac on, wipers on heater on blower and demist max and wait for the coolant temperature to raise!