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Winter demisting

Posted: Wed Jan 12, 2022 9:34 am
by DTEG
Anyone got any tips for demisting in cold weather, with basic (not climate-control) air-con? I am suspecting that VAG haven't improved the logic of their basic air-con since the time of our old (2003) SEAT Ibiza that by design didn't work under a certain temperature (4°C if I remember rightly), rendering it more or less useless in winter for demisting. Couple that with the reduced efficiency of modern air-con since the best refrigerants were banned, and that the windscreen vents just don't seem as powerful as accustomed, it makes for slow starts on winter mornings compared with our previous cars.

Re: Winter demisting

Posted: Wed Jan 12, 2022 4:17 pm
by old man
This might speed things up a little.
The A/C in previous car I owned struggled to cope on a hot summers day and eventually cut out. One piece of advice I received if it happened again, was to switch the air to recirculation and use the air in the car rather than pulling in hot air from outside. That made sense to, although I never needed to try it after that.
I wondered after reading your question if that might also work in cold weather, so you'd be using air in the car rather than drawing in colder air from outside.
I've just been out in my car, which was quite misted up when I got in. The misting was taking a while to clear and then I remembered the recirculation tip, so I turned it on. The windows did start to clear more quickly after that, but it could just have been because the air from the heater was warming up. Worth a try though and I don't know any other way to speed things up.

Re: Winter demisting

Posted: Wed Jan 12, 2022 6:51 pm
by DTEG
Will give that a try next time. Recirculation isn't available when on windscreen vents, but I think they blow a bit on other settings too, so may still be useful.

This afternoon, with ambient temperature more like 6°C, the air con did the job in seconds.

Re: Winter demisting

Posted: Thu Jan 13, 2022 9:09 am
by Lofty
Recirculation will work for a while as it’s using the warmer air inside the car than the ambient temperature outside the car but this while shortly add to the misting inside the car (the handbook will warn of this). I remember being told by a chief engineer from a well known manufacturer that the air con on cars (in the summer) will only have the ability to lower the temperature a certain number of degrees, sorry I can’t remember the exact figures.
Having had numerous company cars over many years, I avoid using a/c to help demisting the car like the plague as I always found it contributed to the problem the following morning making it much worse.
When purchasing my Kamiq I made a point of specifying a heated front screen (recommendations from friends) & it’s money well spent. I’ve not needed to use de-icer or scrape the screen at all & I can pull off my drive in about 2 mins. Whilst not totally clearing the inside it makes a major contribution.
There’s plenty of tips on utube on product to smear on the inside of windows that stop misting plus there’s plenty of products on Halfords shelves making this claim.

Re: Winter demisting

Posted: Thu Jan 13, 2022 10:07 am
by DTEG
The recirculation didn't make any obvious difference, and yes I was a little wary having seen the warning in the manual also. Had to have the vent set to screen+feet for it to engage at all, but think it must still be basing aircon deployment on outside temperature. Will investigate anti-mist products (hopefully not carcinogenic ones like those being pushed for spectacles misting up with facemasks!) but in the meantime have nabbed a nice microfibre towel from my cleaning kit that seems fairly effective. Thanks for all your advice!

Re: Winter demisting

Posted: Thu Jan 13, 2022 2:35 pm
by old man
. Recirculation isn't available when on windscreen vents,
I see what you mean, I hadn't realised that.
I had to go out this morning whilst the car was still iced up. I think that's only the second time in over 7 years since retirement that I've had to scrape my windows. Anyway, I started the car and put the windscreen blower on whilst I scraped the outside and by the time I was ready to drive away all windows except the rear hatch were clear. This was a pleasant surprise as all the windows were steaming up inside when I parked the car yesterday afternoon.
I've never really understood why some cars mist up badly inside overnight and others are much better.

A question; should there be a tell tale light on the dash when the heated door mirrors are on ?

Re: Winter demisting

Posted: Thu Jan 13, 2022 2:52 pm
by DTEG
I just get too depressed at seeing the low single-figures MPG when I've been defrosting with the engine on! Had wondered the same about the heated mirrors, but as far as I know it's a pretty small power draw and auto-disengages after a few minutes anyway. Did you know, according to some official spec thing, the Kamiq has simple regenerative braking? Obviously not in a true hybrid sense, but apparently helps charge the battery alongside the alternator, so less reason than ever to worry about the power drain from some of the more new-fangled gismos.

Re: Winter demisting

Posted: Thu Jan 13, 2022 3:49 pm
by old man
[quotehe Kamiq has simple regenerative braking? Obviously not in a true hybrid sense, but apparently helps charge the battery alongside the alternator][/quote]

I wasn't aware the Kamiq had it, but my last car (Kodiaq) did. As I understand it, and this came up during Covid where many of us were hardly using our cars, if you go out for a drive and barely use the brakes, then the battery doesn't charge up to full capacity as it would with just an alternator, because the system ensures that the battery has space left to take on a charge from the brakes.
This would partly explain why batteries were going flat quicker than normal.
This could be absolute tosh, but it's what I was led to understand.

Re: Winter demisting

Posted: Thu Jan 13, 2022 4:39 pm
by DTEG
And the sensitive electronics really don't like that battery being anything less than nominal voltage! Especially those (like the cruise control, if left switched on, which is not recommended in the manual but for other reasons) that self diagnose at ignition when the voltage drops even more...

Re: Winter demisting

Posted: Mon Jan 17, 2022 7:27 am
by Lofty
Just watched a utube video on how to stop windows on the car misting up, wipe over with shaving foam.
Worth a try ?