Condensation on windscreen

Faults and Technical chat for the Mazda CX-3
Trewithy
Posts: 12
Joined: Wed Aug 08, 2018 3:40 pm
Location: Devon, UK.

Re: Condensation on windscreen

Post by Trewithy » Sun Nov 18, 2018 11:14 am

The moisture inside your car is actually coming from the air con system, overnight moisture inside windscreen at this time of year is not a fault.
The AC takes moisture out of the air before it comes out of the vents, the excess moisture then drains to the outside of the car. This is why you sometimes get a wet patch under the car when it is parked. The thing is not all the moisture drains away, some remains on the condenser coils. Then during the night it evaporates and rises into the car (often through the windscreen vent) where it will condensate on a cold surface i.e. the windscreen. To help prevent this it is recommended to switch off the AC for the last 10 minutes of a journey but leave the fan on to help it to dry out. When I park my car in the garage overnight I often leave the windows open an inch so the moisture can dissipate.
Last edited by Trewithy on Sun Nov 18, 2018 11:36 am, edited 1 time in total.


Strangways
Posts: 493
Joined: Mon Feb 06, 2017 10:35 pm
Location: Edenbridge Kent
Contact:

Re: Condensation on windscreen

Post by Strangways » Sun Nov 18, 2018 11:30 am

Having spent 52 years in the air conditioning industry I can confirm that House Spider is spot on!
I have suffered with this problem on all my cars and after a few experiments (using re-circ air through the a/c) I concluded I was a sweaty old sod. :D
Because of the large windscreen on the CX-3 it probably gets colder than some cars with smaller screens and therefore more condensation forms.
The only thing I can suggest is that you use a thermal windscreen cover to stop it getting so cold overnight.
CX-3 2.0 Sport Nav+ Automatic in ETERNAL BLUE
MX-5 2.0 Sport Nav Manual in SOUL RED


Strangways
Posts: 493
Joined: Mon Feb 06, 2017 10:35 pm
Location: Edenbridge Kent
Contact:

Re: Condensation on windscreen

Post by Strangways » Sun Nov 18, 2018 11:48 am

Trewithy wrote:
Sun Nov 18, 2018 11:14 am
The moisture inside your car is actually coming from the air con system, overnight moisture inside windscreen at this time of year is not a fault.
The AC takes moisture out of the air before it comes out of the vents, the excess moisture then drains to the outside of the car. This is why you sometimes get a wet patch under the car when it is parked. The thing is not all the moisture drains away, some remains on the condenser coils. Then during the night it evaporates and rises into the car (often through the windscreen vent) where it will condensate on a cold surface i.e. the windscreen. To help prevent this it is recommended to switch off the AC for the last 10 minutes of a journey but leave the fan on to help it to dry out. When I park my car in the garage overnight I often leave the windows open an inch so the moisture can dissipate.
In my opinion that is illogical. Any cold moisture is more likely to be absorbed into the 'warmer' untreated air and introduced into the cabin.
CX-3 2.0 Sport Nav+ Automatic in ETERNAL BLUE
MX-5 2.0 Sport Nav Manual in SOUL RED


SOMERS
Posts: 164
Joined: Thu Sep 06, 2018 11:20 pm

Re: Condensation on windscreen

Post by SOMERS » Sun Nov 18, 2018 4:22 pm

DaveG wrote:
Sat Nov 17, 2018 11:21 pm
Thanks Somers, but the problem isn't de fogging the screen during use which is taken care of efficiently with the air condition controls, its when the car is left unoccupied for a few hours or overnight now the temperature is dropping.
DaveG
in my vain attempt to assist you, I have determined that it is I who needs assisting ,far be it, that i would point you in the wrong direction, in the mean while , may i surgest that you go to page 5-10 and also spend time as i will do also reading through the talented comments as posted here on these pages.

Have you ever read a book starting with the last page first, my reason is i need to know where the goal post are.

Dave it takes time to undersand the finer points of the Mazda CX3 , first i had to disregard the systems in my last car.

Hint :- I sit in my car with the manual,"hands on" .

Note :- The rear window and drivers miror combination has an auto shut off after 15 minutes.

The drivers windscreen is controled by the airconditioning feature.

Type "A" & "B" are options see page 5-10

Somers CX3 soul red Auto


Trewithy
Posts: 12
Joined: Wed Aug 08, 2018 3:40 pm
Location: Devon, UK.

Re: Condensation on windscreen

Post by Trewithy » Sun Nov 18, 2018 4:28 pm

Strangways wrote:
Sun Nov 18, 2018 11:48 am
Trewithy wrote:
Sun Nov 18, 2018 11:14 am
The moisture inside your car is actually coming from the air con system, overnight moisture inside windscreen at this time of year is not a fault.
The AC takes moisture out of the air before it comes out of the vents, the excess moisture then drains to the outside of the car. This is why you sometimes get a wet patch under the car when it is parked. The thing is not all the moisture drains away, some remains on the condenser coils. Then during the night it evaporates and rises into the car (often through the windscreen vent) where it will condensate on a cold surface i.e. the windscreen. To help prevent this it is recommended to switch off the AC for the last 10 minutes of a journey but leave the fan on to help it to dry out. When I park my car in the garage overnight I often leave the windows open an inch so the moisture can dissipate.
In my opinion that is illogical. Any cold moisture is more likely to be absorbed into the 'warmer' untreated air and introduced into the cabin.
Strangways
When you are parked overnight there is no warmer untreated air being introduced into the cabin.


Strangways
Posts: 493
Joined: Mon Feb 06, 2017 10:35 pm
Location: Edenbridge Kent
Contact:

Re: Condensation on windscreen

Post by Strangways » Sun Nov 18, 2018 4:44 pm

Trewithy wrote:
Sun Nov 18, 2018 4:28 pm
Strangways wrote:
Sun Nov 18, 2018 11:48 am
Trewithy wrote:
Sun Nov 18, 2018 11:14 am
The moisture inside your car is actually coming from the air con system, overnight moisture inside windscreen at this time of year is not a fault.
The AC takes moisture out of the air before it comes out of the vents, the excess moisture then drains to the outside of the car. This is why you sometimes get a wet patch under the car when it is parked. The thing is not all the moisture drains away, some remains on the condenser coils. Then during the night it evaporates and rises into the car (often through the windscreen vent) where it will condensate on a cold surface i.e. the windscreen. To help prevent this it is recommended to switch off the AC for the last 10 minutes of a journey but leave the fan on to help it to dry out. When I park my car in the garage overnight I often leave the windows open an inch so the moisture can dissipate.
In my opinion that is illogical. Any cold moisture is more likely to be absorbed into the 'warmer' untreated air and introduced into the cabin.
Strangways
When you are parked overnight there is no warmer untreated air being introduced into the cabin.
Sorry I didn't explain myself well. What I meant, was that when you turn off the air con moisture is no longer being removed. The fan only mode will then either bring in air which contains moisture or recirculate the moisture already there. I accept no additional moist air will be introduced, but the air in the car will still contain moisture that will condense on the windscreen if it gets cold.
CX-3 2.0 Sport Nav+ Automatic in ETERNAL BLUE
MX-5 2.0 Sport Nav Manual in SOUL RED


Trewithy
Posts: 12
Joined: Wed Aug 08, 2018 3:40 pm
Location: Devon, UK.

Re: Condensation on windscreen

Post by Trewithy » Sun Nov 18, 2018 5:14 pm

Thank you Strangways,

You are correct when you say " the air in the car will still contain moisture that will condense on the windscreen if it gets cold" and that moisture may well come from the damp condenser coils which are in the car behind the dashboard near the heater.


SOMERS
Posts: 164
Joined: Thu Sep 06, 2018 11:20 pm

Re: Condensation on windscreen

Post by SOMERS » Sun Nov 18, 2018 5:25 pm

zoylander wrote:
Sun Nov 18, 2018 9:07 am
I wonder how many forum members have garages, but do not use them for their intended purpose.

I live in a road of 17 properties, all of which have garages, and 8 of these have double garages including my own. I am one of only 3 out of the 17 who keep their cars in the garage. The rest fill them up with bikes, lawnmowers, freezers, in fact anything except cars, and on a frosty morning there they are scraping their windscreens.

The best protection anyone can give their car is a dry garage.
I have my garage jamed packed with enought equipment to build a house, and I am not joking ,circular saws ; jointers band saws,cement mixers; mowers ; scooters ;mountain bikes; generators.

Our CX3 and all my other cars used to sit out side. I usualy get 12 /14 years out of a car unless some ome sticks a Red CX3 under my nose.

The reason , I live in country with a very hot , salty, humid cilimate , you can see the salt coming off the ocean having the car inside will cause the body work to rust out. i do have a carcover for the sun protection.
On many ocasions I spray the car off with plain water only and blow dry with a wet vac, the under body is loaded with a rust prevension product ,there is wax where most people would not think of applying it ,I had the car 6 months before putting it on the road to prep it and treat every exposed area.

B.T.W. the read doors and "C" post collect sand

Garages : The biger the garage the more you can put in it , boys and girls, don't forget that attic, the welcoming committee out side, there are two geese ,welcome aboard !

P.H.D. Piled. Higher. and Deeper. I have tools in there that go back over 60 years and my neighbours need me, you got to love them.

Somers CX3 Soul Red Auto


SOMERS
Posts: 164
Joined: Thu Sep 06, 2018 11:20 pm

Re: Condensation on windscreen

Post by SOMERS » Sun Nov 18, 2018 5:33 pm

SOMERS wrote:
Sun Nov 18, 2018 5:25 pm
zoylander wrote:
Sun Nov 18, 2018 9:07 am
I wonder how many forum members have garages, but do not use them for their intended purpose.

I live in a road of 17 properties, all of which have garages, and 8 of these have double garages including my own. I am one of only 3 out of the 17 who keep their cars in the garage. The rest fill them up with bikes, lawnmowers, freezers, in fact anything except cars, and on a frosty morning there they are scraping their windscreens.

The best protection anyone can give their car is a dry garage.
I have my garage jamed packed with enought equipment to build a house, and I am not joking ,circular saws ; jointers band saws,cement mixers; mowers ; scooters ;mountain bikes; generators.

Our CX3 and all my other cars used to sit out side. I usualy get 12 /14 years out of a car unless some one sticks a Red CX3 under my nose.

The reason , I live in country with a very hot , salty, humid cilimate , you can see the salt coming off the ocean having the car inside will cause the body work to rust out. i do have a carcover for the sun protection.
On many ocasions I spray the car off with plain water only and blow dry with a wet vac, the under body is loaded with a rust prevension product ,there is wax where most people would not think of applying it ,I had the car 6 months before putting it on the road to prep it and treat every exposed area.

B.T.W. the read doors and "C" post collect sand

Garages : The biger the garage the more you can put in it , boys and girls, don't forget that attic, the welcoming committee out side, there are two geese ,welcome aboard !

P.H.D. Piled. Higher. and Deeper. I have tools in there that go back over 60 years and my neighbours need me, you got to love them.

Somers CX3 Soul Red Auto


SOMERS
Posts: 164
Joined: Thu Sep 06, 2018 11:20 pm

Re: Condensation on windscreen

Post by SOMERS » Sun Nov 18, 2018 5:35 pm

SOMERS wrote:
Sun Nov 18, 2018 5:33 pm
SOMERS wrote:
Sun Nov 18, 2018 5:25 pm
zoylander wrote:
Sun Nov 18, 2018 9:07 am
I wonder how many forum members have garages, but do not use them for their intended purpose.

I live in a road of 17 properties, all of which have garages, and 8 of these have double garages including my own. I am one of only 3 out of the 17 who keep their cars in the garage. The rest fill them up with bikes, lawnmowers, freezers, in fact anything except cars, and on a frosty morning there they are scraping their windscreens.

The best protection anyone can give their car is a dry garage.
I have my garage jamed packed with enought equipment to build a house, and I am not joking ,circular saws ; jointers band saws,cement mixers; mowers ; scooters ;mountain bikes; generators.

Our CX3 and all my other cars used to sit out side. I usualy get 12 /14 years out of a car unless some one sticks a Red CX3 under my nose.

The reason , I live in country with a very hot , salty, humid cilimate , you can see the salt coming off the ocean having the car inside will cause the body work to rust out. i do have a carcover for the sun protection.
On many ocasions I spray the car off with plain water only and blow dry with a wet vac, the under body is loaded with a rust prevension product ,there is wax where most people would not think of applying it ,I had the car 6 months before putting it on the road to prep it and treat every exposed area.

B.T.W. the rear doors and "C" post collect sand.

Garages : The biger the garage the more you can put in it , boys and girls, don't forget that attic, the welcoming committee out side, there are two geese ,welcome aboard !

P.H.D. Piled. Higher. and Deeper. I have tools in there that go back over 60 years and my neighbours need me, you got to love them.

Somers CX3 Soul Red Auto


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