Leaving car engine running

System

Richard53 wrote: »

That's what aircon is for, not just for hot summer days.

Assuming your car has aircon. One of my cars is a convertable. It doesn't seal enough to stop condensation, it has no aircon. What do I do?

BeenThroughItAll

Tarambor wrote: »

Assuming your car has aircon. One of my cars is a convertable. It doesn't seal enough to stop condensation, it has no aircon. What do I do?

Have a new roof fitted.

Richard53

wongataa wrote: »

But if the temperature is below 4-5°C then the aircon will not turn on in cars even if the light turns on when you press the button. So if it is cold the aircon status is irrelevant as it won't help.

It will dry the air whatever the temperature, which is why it helps to stop misting.

Tarambor wrote: »

Assuming your car has aircon. One of my cars is a convertable. It doesn't seal enough to stop condensation, it has no aircon. What do I do?

MX-5? Mine too. Funnily enough, there are enough gaps to let draughts and rain in, but not enough to let condensation out. The only way to stop it misting in weather like this is to drive with the roof down (as I saw a guy doing today in 2 deg C).

wongataa

Richard53 wrote: »

It will dry the air whatever the temperature, which is why it helps to stop misting.

Not if the temperature is below the limit for the air-con to turn on. Air-con not on = no air drying. If the air-con is not on how can it still dry the air?

I have seen this myself in my car which has air-con. If the air-con is not on for any reason (too cold or not switched on) then you can get misting of the windows as the incoming air is not being dried.

nickcc

Would prefer someone to run their car so as their windows were clear before driving off and killing some innocent.

Johno100

nickcc wrote: »

Would prefer someone to run their car so as their windows were clear before driving off and killing some innocent.

Yes, but think of the planet! I'm sure that poor innocent and their nearest and dearest would understand it would be for the greater good.:grouphug:

reeac

wongataa wrote: »

Not if the temperature is below the limit for the air-con to turn on. Air-con not on = no air drying. If the air-con is not on how can it still dry the air?

I have seen this myself in my car which has air-con. If the air-con is not on for any reason (too cold or not switched on) then you can get misting of the windows as the incoming air is not being dried.

wongataa wrote: »

But if the temperature is below 4-5°C then the aircon will not turn on in cars even if the light turns on when you press the button. So if it is cold the aircon status is irrelevant as it won't help.

If you use the air on all the time then it will keep the car interior dry and minimise interior condensation on cold mornings.

Richard53

wongataa wrote: »

Not if the temperature is below the limit for the air-con to turn on. Air-con not on = no air drying. If the air-con is not on how can it still dry the air?

I have seen this myself in my car which has air-con. If the air-con is not on for any reason (too cold or not switched on) then you can get misting of the windows as the incoming air is not being dried.

The compressor on my last car used to run whatever the outside temperature (although I can't say I stood there with a thermometer to check exactly) and the windows demisted in seconds even when it was sub-zero. I assumed that this meant the aircon was running, but perhaps I imagined it.

IamNotAllowedToUseMyName

Richard53 wrote: »

The compressor on my last car used to run whatever the outside temperature (although I can't say I stood there with a thermometer to check exactly) and the windows demisted in seconds even when it was sub-zero. I assumed that this meant the aircon was running, but perhaps I imagined it.

If it was running it wasn't doing anything much. Air below about 4c simply doesn't contain any significant moisture for the aircon to remove, hence some companies save fuel by not allowing the compressor to run. More likely it had some instant heating system?

Richard53

IanMSpencer wrote: »

If it was running it wasn't doing anything much. Air below about 4c simply doesn't contain any significant moisture for the aircon to remove, hence some companies save fuel by not allowing the compressor to run. More likely it had some instant heating system?

I don't think so. It was only a bread-and-butter Mondeo. I used to leave the A/C on auto, so it ran 24/7/52 as it was designed to.


Whether it was doing anything or not, it was brilliant at demisting the screen. It's something you don't really appreciate until you don't have it. My current Land Rover is still misted up after 20 miles No A/C plus leaky door seals.