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Old 31st October 2009, 13:32   #181
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Hi,

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Originally Posted by Moonraker View Post
Guys - I am facing this issue in my new fiesta and i tried to use warm air directed towards the windshield, fog started forming inside. Changed to cold air fog started forming outside.
Any help would be much appreciated
Regular AC is more than enoughto prevent fogging. You don't even have to direct the air towards the windshield.

As long as you keep the difference between the inside / outside temperature to the minimum, fogging is usually not seen.

The next time you use the AC and see fogging outside, use the temperature control / thermostat to shift from the maximum. Experiment on how much to reduce.

Hope this helps.
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Old 31st October 2009, 14:40   #182
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This thread has started long back but seems the problem still persist ?

I have been driving cars made by Maruti, Hyundai and Ford - I never has such serious problem of fogging so far. I always drive with A/C on. During heavy rains the a/c will run on minimum. Even at that stage if my co-passengers feel cold and used to ask me to switch of the A/C. Within 5 minutes of switching off the A/c,the fogging will form and then I switch on the A/c , immediately the fog used to disappear.
I used to practise this method till I reach the destination.

I never ever used to turn the A/c towards windscreen(turning the a/c towards windscreen may make fog formation quickly?). Even now I am following same system. You must control the temperature according to the situation.

Thanks
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Old 3rd November 2009, 05:00   #183
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I tried to set the temperature to the minimum setting but nothing worked and i had to use the defogger setting given in the A/c and it directs the air to the windshield. Could the front sunfilm cause this issue?
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Old 3rd November 2009, 13:54   #184
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Default Fog control

I just use the following simple steps to get rid of fog problem in cold weather or driving in rain:
- Close all the windows
- Start AC and keep the slider somewhere midway between cold-hot.
- Put the AC vent position to defrost mode where the air is diverted to windshield.
- Keep the fan speed appropriately (usually 1st or 2nd stops).
- Especially if it's foggy outside (winter - early mornings), run the wiper too (in normal mode) to get rid of fog getting formed outside.

I use this even in heavy rain situations and never had any problem with visibility.

HTH,
KK
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Old 3rd November 2009, 19:04   #185
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Hi,

Quote:
Originally Posted by Moonraker View Post
I tried to set the temperature to the minimum setting but nothing worked and i had to use the defogger setting given in the A/c and it directs the air to the windshield. Could the front sunfilm cause this issue?
Having never used front windshield sunfilm extensively (except in my Viva CRDi) I don't know whether that can cause this problem.

With the temperature in the minimum setting, you had outside fogging, that is strange.

I hope there is some help for your problem.
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Old 3rd November 2009, 20:19   #186
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Quote:
Originally Posted by trrk View Post
With the temperature in the minimum setting, you had outside fogging, that is strange.
Why strange? It is expected to worsen outside fogging because it will make glass cooler. I have mentioned many times that the idea is to keep it as hot as possible along with A/C switched ON. Also, there is no need to play inside-outside temperature "matching" game. Just keep it as hot as you can bear with A/C ON, and you will be sorted. Trust me, A/C takes care of inside fogging while hot air takes care of outside fogging.

@Moonraker, when you faced inside fogging while throwing hot air, it is very likely that A/C was switched off(?) If so, next time just try both together. I am sure it works, provided your car's A/C isn't designed to stop automatically when temp is set to hot side!

Looks like people neither search nor read the thread before posting same thing over and over again, or else they must be thinking whatever I have been posting is senseless. (So, here onwards I shall restrain myself from offering voluntary advice on this matter!)
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Old 4th November 2009, 11:08   #187
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Trivia related to the topic : Drove a W140 S Class recently. That heck of an opulent car was kitted with double-glazed glass windows (in '92 !!!). Purpose of two glass layers = Better sound insulation and windows don't fog up (thin gap between the two glass layers).

These Germans I tell ya....
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Old 4th November 2009, 12:38   #188
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Hi,

Quote:
Originally Posted by santosh.s View Post
Why strange? It is expected to worsen outside fogging because it will make glass cooler.
I had replied to moonraker ans asked him to shift from the maximum cool to minimum cool and hence I found it strange that it did not have effect.

I do hope that he undertood my intention and shifted towards the hotter side of the thermostat!
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Old 4th November 2009, 13:20   #189
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Fogging up is caused by water condensing on glass.

Use the following working principles JUDICIOUSLY to help avoid fogging, depending on cold or hot weather.

Cold glass encourages condensation: heat glass either with demister element or blower/heater. Works in cold weather, rainy or sunny.

Flow through ventilation removes moisture from car: switch from recycle mode to flow through mode. Good for hot rainy weather.

Air conditioning does exactly that, it removes heat AND moisture from car. The heat dissipates at heat exchanger, the moisture condenses on the cooling coil and is drained away. Good for hot, humid weather.

Scenario from hell: fully occupied car in cold rainy weather. Heater warms cold wet air from inlet vent, mixes it with the breath fogging caused by passengers who obstruct the outlet vents with their bodies. Open the windows a crack and suffer a little cold and wet. At least your windscreen will be cleared by the heat from the blower, you'll drive better and youíll get home quicker!
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Old 4th November 2009, 13:47   #190
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[quote=santosh.s;1564052]Why strange? It is expected to worsen outside fogging because it will make glass cooler.
@Moonraker, when you faced inside fogging while throwing hot air, it is very likely that A/C was switched off(?) ]

Hi Santosh;

I got few points but I need clarification on some.
Please correct me if I am wrong in what I understood.

1) I need to turn ON the AC and move the temperature selector to hot (red)area
2) Need to set fresh Air mode on( recirculating off)
3) Direct the air to windscreen

correct?

Now my question
1) AC in my car gets switched off as soon I move it to hot (red)area. What I need to do in this scenario?

2) While cleaning the outside of glass through wiper after every stroke a thin film of moisture is formed which obstructs view. What has to be done in this case

and please don't stop posting comments. Your comments are very helpful.
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Old 4th November 2009, 15:29   #191
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Quote:
Originally Posted by sparkguy View Post
1) I need to turn ON the AC and move the temperature selector to hot (red)area
2) Need to set fresh Air mode on( recirculating off)
3) Direct the air to windscreen

correct?
Me thinks that point 1 is very important. If it is followed, points 2 and 3 are not that important. 2 is not really required as long as A/C is ON, it will dehumidify air inside cabin in both modes (at least it is true for my car). 3 will make glass warming more effective and faster, but if you are blowing cold air, it will also be more efficient in it's adverse effect of making the glass cooler!

Quote:
1) AC in my car gets switched off as soon I move it to hot (red)area. What I need to do in this scenario?
Bad luck, I thought some old cars had such a design. Which car do you use? (from your id it seems to be a spark, which isn't really an old model). If you don't mind time and efforts to be spent you can do some reverse engineering and try to override this functionality (at your own risk). Or else you can alternately use hot air and A/C mode depending upon whether it is external or internal fogging, respectively. Make sure to use A/C for just enough time to clear internal fogging, overuse may cool down glass temp. If that turns out to be tough, then other ways (less preferred in my opinion) like using fresh air mode or opening windows a bit (which will also allow some rainwater to enter into cabin!). Experiment with these options yourself.

Quote:
2) While cleaning the outside of glass through wiper after every stroke a thin film of moisture is formed which obstructs view. What has to be done in this case
This is actually the main topic of this thread, but I guess no definitive answer yet. There are multiple suggestions given by people, from various cleaning or other solutions to be applied to changing wiper blades. I have changed my OEM blades (had crossed their lifespan anyway) to Bosch ones. They seem to be performing better (not leaving behind an opaque layer).

Last edited by santosh.s : 4th November 2009 at 15:31.
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Old 4th November 2009, 18:28   #192
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Hi,

Quote:
Originally Posted by sparkguy View Post
1) I need to turn ON the AC and move the temperature selector to hot (red)area
Now my question
1) AC in my car gets switched off as soon I move it to hot (red)area. What I need to do in this scenario?
It is more like a trial and error method.

Move the temperature selector towards the hot side gradually. If you go into the 'hot' area, the compressor may stop. The ideal point would be the junction of the blue / red area or if it has a white in between, the centre of the white area or near the white / red junction.



See the knob in my City. The Spark arrangement seems to be similar from what I can see in the images over the net.

Fresh air mode and directing air to windshield is not actually needed.

Last edited by trrk : 4th November 2009 at 18:32.
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Old 4th November 2009, 21:33   #193
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weird. My nissan quest turn the AC automatically on as soon as the air is directed to windscreen, to prevent fogging.
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Old 4th November 2009, 22:45   #194
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Hi Rajendra,

Please use the fresh air mode when you are using ac with rains outside and keep atleast one window down by a couple of inches.This should solve your problem.

If it does not then visit to your nearest MUL workshop and ask them to do the following:

1)Check the ac grill temp with thermometer while maintaining engine rpm at 2000.

2)when the ac grill temp. reaches 3-4degrees centrigade the ac compressor should cut off to avoid fogging from outside.If it does not cut off then just check the min. temp attained.Anything below 2.5 - 3degrees will cause fogging of the windscreen.

3)During this test maintain the ac fan knob at lowest position.

4)Check the quantity of ac gas(ref manufacturer specs.though for swift i think it should be around 400units)

If the ac compressor does not cut off as required then ask the technician to replace the thermistor / fin sensor with a new one.This should definitely solve your problem.

Do let me know if the problem is not solved.

Shantanu!!!!


Quote:
Originally Posted by raja748 View Post
Dear Friends,

I have a SWIFT-VXI.Last monday it started raining heavily in the evening.
=====================
Please help me...

Regards,

Rajendra
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Old 5th June 2011, 11:42   #195
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Default Re: Foggy/Misty windshield-urgent help required

Hey as far as i understand, What the AC does is control the moisture. This is what reduces the misting inside the cockpit. The temperature u set on the ac does not really matter.

1. If misting has already occurred only then hot temperature is reqd. (All aircraft do it, am a pilot i know this!!!)
2. Reference, ever seen the excess water thrown out during humid weather by all Airconditioner (Humidity aka moisture control).
3. For misting outside, good wipers can resolve the issue completely.
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