Motoring Discussion > Keeping side windows clear	Miscellaneous
Thread Author: SteelSpark	Replies: 50

Sun 28 Nov 10 08:45   Keeping side windows clear - SteelSpark

I had a ongoing battle with my side windows steaming up this morning. I had to keep opening them to clear them, but they didn't stay clear for long. I tried having the heating on full blast for a while but that didn't help, and neither did having it switched off. A few times I just had to open my side window at junctions. Any advice on how best to keep them clear this time of the year? Reply to this message | Report message

Sun 28 Nov 10 08:53   Keeping side windows clear - Dog

Haven't you got aircon comrade SS. Reply to this message | Report message

Sun 28 Nov 10 08:56   Keeping side windows clear - Clk Sec

Perhaps it wasn't switched on. I've made that mistake myself. Reply to this message | Report message

Sun 28 Nov 10 09:14   Keeping side windows clear - Old Navy

Aircon does not work below about +5C. Have you swithed to "recirc"? That will steam up the car. Last edited by: Old Navy on Sun 28 Nov 10 at 09:15 Reply to this message | Report message

Sun 28 Nov 10 13:16   Keeping side windows clear - VxFan

>> Aircon does not work below about +5C. But I think the dehumidifying function of it still does. I leave my AC (well Climate control) on all year round and if there is any mist on the inside it soon clears no matter how cold it is outside. Reply to this message | Report message

Sun 28 Nov 10 13:17   Keeping side windows clear - Runfer D'Hills

Agreed Dave. Reply to this message | Report message

Sun 28 Nov 10 13:34   Keeping side windows clear - Iffy

...Agreed Dave... Agreed Humph and Dave. Aircon dries the air at any temperature. On Fords, and I'm sure many others, the aircon switches on automatically when you go for max demist. Reply to this message | Report message

Sun 28 Nov 10 13:44   Keeping side windows clear - Old Navy

>> >> Aircon does not work below about +5C. >> >> But I think the dehumidifying function of it still does. I leave my AC (well >> Climate control) on all year round and if there is any mist on the inside >> it soon clears no matter how cold it is outside. >> Aircon only dehumidifies if it is switched on, and is actually operating. I leave mine "on" all the year round as well but I think you will find that the aircon shuts itself off, (although it indicates on) to stop the system freezing internally and causing damage. The user manuals of several of my cars have stated this. Last edited by: Old Navy on Sun 28 Nov 10 at 13:47 Reply to this message | Report message

Sun 28 Nov 10 13:53   Keeping side windows clear - Zero

>> I leave mine "on" all the year round as well but I think you will >> find that the aircon shuts itself off, (although it indicates on) to stop the system >> freezing internally and causing damage. The user manuals of several of my cars have stated >> this. >> I think it just shuts off the pump, but all the rest of the system (like the condenser and dryer airflow) all stays the same. I have certainly found "aircon on" at temps below 5c produces dryer air and demists better. Last edited by: Zero on Sun 28 Nov 10 at 13:54 Reply to this message | Report message

Sun 28 Nov 10 13:56   Keeping side windows clear - Clk Sec

I keep my aircon switched on all the time and it seems to be fully operational regardless of the weather conditions. Never get misted up windows. Reply to this message | Report message

Sun 28 Nov 10 13:58   Keeping side windows clear - Old Navy

>> I think it just shuts off the pump, but all the rest of the system >> (like the condenser and dryer airflow) all stays the same. I have certainly found "aircon >> on" at temps below 5c produces dryer air and demists better. >> Please could you explain how an aircon system works with its pump off, It a bit like saying a fridge will work when it is unplugged. The system shuts down to stop the evaporator, (the bit in the heater that cools and dehumidifies the air), freezing solid. Reply to this message | Report message

Sun 28 Nov 10 14:01   Keeping side windows clear - Zero

>> Please could you explain how an aircon system works with its pump off, It a >> bit like saying a fridge will work when it is unplugged. I didnt say the Aircon worked, I said the airflow was the same. If you turn your aircon OFF flaps redirect the air away from the normal Aircon path Reply to this message | Report message

Sun 28 Nov 10 14:03   Keeping side windows clear - Old Navy

Stop digging Z. :-) Reply to this message | Report message

Sun 28 Nov 10 14:07   Keeping side windows clear - Zero

>> Stop digging Z. :-) Is it my fault you don't understand? Reply to this message | Report message

Sun 28 Nov 10 13:57   Keeping side windows clear - idle_chatterer

>> >> Aircon does not work below about +5C. >> >> But I think the dehumidifying function of it still does. I leave my AC (well >> Climate control) on all year round and if there is any mist on the inside >> it soon clears no matter how cold it is outside. >> I'm sorry to say but that it doesn't dehumidify below 4 or 5 DegC - it can't, it is thermodynamically impossible. The dehumidification (is that a word?) is a by-product of cooling the air, colder air can hold less moisture so it condenses on the aircon condenser-matrix. If the incoming air is cooler than the matrix can achieve (i.e. less than about 4 DegC) then it won't be cooled and moisture won't condense. I have to admit that some of my cars with CC have been better than others when the aircon was left on and the temperature fluctuated around 4DegC level, although I tended to switch the aircon out for the time that ambient temperatures did this to avoid all the steaming up and dank smells. I apologise for the pseudo science lesson tone of this post...... Also a fridge or freezer installed in an unheated shed or garage might stop working if the ambient temperature drops too low, it uses the same technology after all. Reply to this message | Report message

Sun 28 Nov 10 14:04   Keeping side windows clear - Zero

>> I'm sorry to say but that it doesn't dehumidify below 4 or 5 DegC - >> it can't, it is thermodynamically impossible. The dehumidification (is that a word?) is a by-product >> of cooling the air, colder air can hold less moisture so it condenses on the >> aircon condenser-matrix. If the incoming air is cooler than the matrix can achieve (i.e. less >> than about 4 DegC) then it won't be cooled and moisture won't condense. The matrix could still disipate heat from the ambient air, even if its not chilled by the pump. Reply to this message | Report message

Sun 28 Nov 10 14:12   Keeping side windows clear - idle_chatterer

>> >> The matrix could still disipate heat from the ambient air, even if its not chilled >> by the pump. >> Yes, you are right, it could and will. I would admit that I have long since forgotten the details of specific heat capacities and such like but I'd guess that the effect would be quite small (although not inconsequential) against the volume of air passing the matrix ? Reply to this message | Report message

Sun 28 Nov 10 14:17   Keeping side windows clear - Iffy

...I have to admit that some of my cars with CC have been better than others when the aircon was left on and the temperature fluctuated around 4DegC level... Perhaps sending the lukewarm air on a longer journey through the aircon system allowed more moisture to condense on the inside of the pipes and ducts, even though the aircon was not working. Reply to this message | Report message

Sun 28 Nov 10 15:38   Keeping side windows clear - Suppose

>> But I think the dehumidifying function of it still does. I leave my AC (well >> Climate control) on all year round and if there is any mist on the inside >> it soon clears no matter how cold it is outside. >> As Old Navy and others have said, it seems against the laws of physics and thermodynamics that your climate control is off yet dehumidifying function is still working "no matter how cold it is outside". Anyone care to explain the physics of how that might work? Reply to this message | Report message

Sun 28 Nov 10 15:57   Keeping side windows clear - Stuartli

As far as I'm aware, if the outside temperature is lower than four or five degrees Celsius, an aircon system cuts out if you try to turn the direction control fully to windscreen demist - the reason is that it prevents the windows almost immediately misting up and reducing visibility to zero. Always been the case with my cars and there's a reference in the manuals in the air conditioning system section. Reply to this message | Report message

Sun 28 Nov 10 16:02   Keeping side windows clear - Zero

Nothing to do with where the air is directed. It wont work below 4 or 5 wherever the air is directed. Reply to this message | Report message

Sun 28 Nov 10 16:18   Keeping side windows clear - Stuartli

>> Nothing to do with where the air is directed. It wont work below 4 or 5 wherever the air is directed.>> I don't make it up as I go along.....:-) The air con works as expected in its normal position (feet and partial windscreen) but, as soon as I turn the direction control towards screen demist in Recirculate mode and it reaches about 10 o'clock on the dial, it shuts off if the outside temperature is too low. Happened on my previous cars as well. The manual also states that if the air cooling system cannot be switched on, "it may be for the following reasons:" which include "the outside temperature is lower than approximately +5 degrees C (+41 degrees F). Reply to this message | Report message

Sun 28 Nov 10 16:24   Keeping side windows clear - Zero

>> >> Nothing to do with where the air is directed. It wont work below 4 >> or 5 wherever the air is directed.>> >> >> I don't make it up as I go along.....:-) >> >> The air con works as expected in its normal position (feet and partial windscreen) but, >> as soon as I turn the direction control towards screen demist in Recirculate mode and >> it reaches about 10 o'clock on the dial, it shuts off if the outside temperature >> is too low. >> >> Happened on my previous cars as well. >> >> The manual also states that if the air cooling system cannot be switched on, "it >> may be for the following reasons:" which include "the outside temperature is lower than approximately >> +5 degrees C (+41 degrees F). The manual states nothing about the screen now does it. None of my VWs cut out the aircon when directed to the screen. It has nothing to do with directing the air at the screen - I know you are not making it up, merely mistaken. Reply to this message | Report message

Sun 28 Nov 10 09:20   Keeping side windows clear - Victorbox

I'd start checking carpets and under carpet sound insulation for damp and the seats as well if you have a sunroof. A sodden and choked pollen filter is another culprit. Reply to this message | Report message

Sun 28 Nov 10 13:42   Keeping side windows clear - Robin O'Reliant

>> A sodden and choked pollen filter is another culprit. >> I had terrible trouble with misting windows on my Astra when I fist got it and ordered a new pollen filter online, suspecting that to be the problem. When I got it I found there was nothing to replace, a previous owner had dumped the thing and ran without one. I fitted it anyway and have not had a problem since which seems strange, but so what, it worked. Reply to this message | Report message

Sun 28 Nov 10 10:01   Keeping side windows clear - Notdoctorchris

If you have aircon then check out when the cabin filter was replaced and look at it to see how mucky it is. I've found a blocked filter can cause a lot of misting up. Reply to this message | Report message

Sun 28 Nov 10 10:05   Keeping side windows clear - R.P.

Pound to a penny it's a pollen filter - first place to look for me. Reply to this message | Report message

Sun 28 Nov 10 10:11   Keeping side windows clear - hobby

That should keep him occupied for an hour or two! :-) Reply to this message | Report message

Sun 28 Nov 10 10:16   Keeping side windows clear - R.P.

www.puravent.co.uk/filters/index.php Site we normally link to. Reply to this message | Report message

Sun 28 Nov 10 10:41   Keeping side windows clear - L'escargot

If you have face vents at the outside of the fascia then direct them outwards towards the side windows; close any other face vents; set the heater air distribution control to face vents; set the heater to maximum temperature and maximum airflow. It works for me. I find that using aircon in cold weather is a mixed blessing. It dries the incoming air when it's on, but when you switch it off any residual moisture in the aircon unit comes back into the car and makes the misting problem worse until the residual moisture has dried out. Incidentally, when it's frosty the outside air is already dryer than usual because the moisture has precipitated out as frost. Reply to this message | Report message

Sun 28 Nov 10 11:08   Keeping side windows clear - Zero

Pollen filter if its got one is where I would go first too. What car is it? does it have side window demisters? ,most do. Reply to this message | Report message

Sun 28 Nov 10 11:25   Keeping side windows clear - L'escargot

>> I had a ongoing battle with my side windows steaming up this morning. Did you bring snow/water on your shoes and clothes into the car? Reply to this message | Report message

Sun 28 Nov 10 11:33   Keeping side windows clear - -

Could be the filter, but i'd have thought the screen would be misting up too unless SS is using the quickclear. It sounds like cool or no air is being fed to side windows for some reason. It pays to keep the windows very clean though, much more reluctant to mist inside and out. Last edited by: gordonbennet on Sun 28 Nov 10 at 11:34 Reply to this message | Report message

Sun 28 Nov 10 13:23   Keeping side windows clear - RattleandSmoke

I had this problem when I used to drive my dads Fiesta. I checked the pollen filter and I am not joking it had not been replaced since the car was made in 1996. It was the most horrible thing I have ever removed from a car, replaced it cured the problem. Reply to this message | Report message

Sun 28 Nov 10 13:29   Keeping side windows clear - R.P.

It was the most horrible thing I have ever removed from a car Rattle I can't believe that and you having been a student and all ! Reply to this message | Report message

Sun 28 Nov 10 14:34   Keeping side windows clear - Stuartli

The best way to speed up demisting is to ensure that the inside windows are as spotlessly clean as possible (not easy at this time of the year), to prevent a film building up on the surface which allows condensation to build up. Reply to this message | Report message

Sun 28 Nov 10 14:35   Keeping side windows clear - Stuartli

>>It was the most horrible thing I have ever removed from a car>> I've said that occasionally about some of my passengers...:-) Reply to this message | Report message

Sun 28 Nov 10 15:11   Keeping side windows clear - RattleandSmoke

Is that before you after you have murdered them? Reply to this message | Report message

Sun 28 Nov 10 15:57   Keeping side windows clear - Stuartli

>> Is that before you after you have murdered them?>> No:-) But I've sometimes wanted to..... Reply to this message | Report message

Sun 28 Nov 10 16:07   Keeping side windows clear - RattleandSmoke

I know the feeling and I don't even have a mother in law. Reply to this message | Report message

Sun 28 Nov 10 16:12   Keeping side windows clear - Old Navy

>> I know the feeling and I don't even have a mother in law. >> Yet. Reply to this message | Report message

Sun 28 Nov 10 16:36   Keeping side windows clear - Clk Sec

>> I know the feeling and I don't even have a mother in law. Actually, there are some very good one's around. Don't settle for second best. Reply to this message | Report message

Sun 28 Nov 10 16:37   Keeping side windows clear - Bellboy

try wearing a gimp mask for the first few miles hth....... Reply to this message | Report message

Sun 28 Nov 10 16:47   Keeping side windows clear - BiggerBadderDave

"Actually, there are some very good one's around" The dead ones presumably Reply to this message | Report message

Sun 28 Nov 10 16:48   Keeping side windows clear - Iffy

...The dead ones presumably... Looking forward to your usual Christmas? Reply to this message | Report message

Sun 28 Nov 10 16:53   Keeping side windows clear - BiggerBadderDave

"Looking forward to your usual Christmas?" A fortunate change in circumstance. Wife's sister has bought a large house in the next street and is about to drop a sprog. So for this year at least, we'll be staying in Warsaw and the blubber-in-law will be staying at their house. Happy times. Reply to this message | Report message

Sun 28 Nov 10 16:56   Keeping side windows clear - Iffy

...Wife's sister has bought a large house in the next street..the blubber-in-law will be staying at their house... 'Dangerously near,' as Fletcher once said to McKay in Porridge when referring to the proximity of Sunderland to Scotland. Reply to this message | Report message

Sun 28 Nov 10 17:13   Keeping side windows clear - BiggerBadderDave

It's a Polish thing I suppose. The couple opposite live next door to her parents. The sister of the woman next door lives further down the road. And at least another three that I know of have immediate family on the street. My sister lives in Stalybridge which is still dangerously near for me. Actually I don't mind them being so close, although it's my wife that was dealt all the pretty genes, her sister got a great bum. Reply to this message | Report message

Mon 29 Nov 10 13:18   Keeping side windows clear - FotheringtonTomas

Don't breathe so heavily. Switch the heater out of "recirculate" mode. Dry out the inside of the car if you'got it wet, or have wet stuff in it. Put the heater on "full blast" but not on the hottest setting - more air will be circulated. Leave the windows on all the time, and wear a jersey. Reply to this message | Report message

Tue 30 Nov 10 17:31   Keeping side windows clear - SteelSpark

Thanks for all the advice guys, much appreciated. It turns out that I didn't have the A/C on (I hadn't realised that you could have the heater on but not the A/C). I did direct the vents onto the windows and turned off the re-circulate. There seemed to be an improvement, but I probably haven't driven far enough for a proper test. I'll see how it goes over the next few days. It is much colder here and some snow has arrived. Reply to this message | Report message

Wed 1 Dec 10 00:04   Keeping side windows clear - Dave_

Aircon working in freezing temperatures... "Close Door" buttons in lifts... *bangs head against wall* SS - You'll likely find that the moisture condensing on your windows stems from a lack of airflow in that direction plus a damp coat and cold weather... The ventilation system in your Mondeo (yours is a Mondeo isn't it?) is more or less the same as in my Escort. For quickest demisting I shut off the centre two vents, open the vents at either end of the dashboard and point them fully up and fully towards the window. I set the fan on full speed, the stratification to the picture of a windscreen, and the heat up to full hot. This will demist the windscreen and front door windows in a couple of minutes and keep them clear. Your feet will get cold though... Reply to this message | Report message