Team-BHP - Unclear Glass during Rain

Hi,
I have owned an ALTO LXI a week back and i had to drive the car in the rain during night, a couple of times. Most of the time, i use to have my AC ON. During the rain, a white layer forms in the outside of the glass which makes difficult for me to see through the glasses.
It is definitely not inside, since i used the defroster during the rain.

Infact, the white layer forms inbetween the wipping cycle of the wiper and makes it difficult for me to see through.

Please help me in understanding what would be the reason for the glass getting unclear during rain@ night.

ALso, let me know what i need to do, to avoid such problems in future.

Regards,
Vinod

This is a very irritating problem during rains, when putting the A/c on makes the windows misty (since the glass becomes colder than the outside temp). As a result, side-vision is seriously hampered.

Any solutions?

mvk... this is a known phenomenon. its just the reverse of the regular fogging from inside. Basically the fogging happens due to the temperature difference on the two sides of the glass depending on which side is warmer. So the fog can very well happen from outside as well. In fact it does happen with everyone some time or the other. The best solution I have found is to switch off the AC (yes, switch it off) and roll down the window if possible. Essentially try to neutralize the temperature difference between the two surfaces.

Quote:

Originally Posted by Zappo (Post 502824)

The best solution I have found is to switch off the AC (yes, switch it off) and roll down the window if possible. Essentially try to neutralize the temperature difference between the two surfaces.

Or just keep the AC on.

I think the best results are achived when we roll down our windows a litle, so that water does not come inside but the temparture in and out become same, to remove the white layer formed on teh glass. I have done this number of time and it works.

Vinod you need to let us know exactly what you meant! Defogger or Demister?

As Rudra and Zappo said, the best way to avoid this is to either keep the ac running or roll down the windows to neutralize the temp. I don't know how effective is the use of those sprays which claim to cut the formation of mist on the windscreen. In Shillong we have this problem quite often and I have realised that the best way to avoid is to keep the ac on. I cannot keep the windows down as the rain enters the cabin and I don't have a rain visor installed.

MVK,

This is a common occurance - a semi-permanent film on the outside of the glass during rain even if the defogger/demister in on. I experienced it on my MLR drive and the damn layer wouldnt go away even with wash-wipe cycle from the wiper/downing all windows.

The solution I adopted - Sunsilk shampoo sacthets emptied, properly lathered across the windscreen by hand, and rinsed/dried with large tissue papers. Worked like a charm.

I know exactly what you are talking about vinod. Happens a lot here near the coast. It is basically because the AC cools the glass to a temperature far lower than the outside temperature. The humid air in our coastal area's means that the moisture condenses on the outside of the windscreen, side and rear glass. Think of the moisture that forms on the outside surface on a glass of cold water. it's the same principle.

There is not much you can do really, but you could try to minimise its occurrence by:
- directing the draft away from the windows
- controlling the temperature of the AC
- on the side windows, you can simply wind them down and up again to get rid of the moisture on the outside.
- For the rear windscreen, use the defogger.

Quote:

Originally Posted by SumitB (Post 502815)

He probably means the defogger

Quote:

Originally Posted by Rudra Sen (Post 502811)

What is this defroster? :confused:

Quote:

Originally Posted by msdivy (Post 502827)

Did he mean demister?

Defogger: An electric or hot air device to remove the fog or ice from both the inside and outside of the windshield, backlight (i.e., rear window) or even mirrors. Some are designed to remove fog from the side windows.

Defroster: The apparatus (either a fan connected to the heating system or electrical wires imbedded in the glass) which removes frost or fog from a window.

Demister: A British term for a defogger or defroster

Source: Dictionary of Automotive Terms Abbreviations