Misty screen

[samoilis1970]

Hi all, my wife's C30 1.6 petrol has lots of condensation inside front screen, I have checked for wet carpets and leaks but I can't find any, the car hasn't got a sun roof. Any ideas?? Many thanks ☺️

[Welton]

No-one normally agrees with me on this but don't use the air con in cold weather, when the car is parked up there is basically a very wet evaporator (heat exchanger) and an equally wet condense catch tray underneath it. This moisture then condenses out onto the windscreen above it.

People then say "hey but when I switch on the a/c the screen clears really quick" yes it does but the moisture stays in the climate control unit and therefore the interior.

In my experience you're best to have a completely dry interior in winter and use heating only. The incoming air is dry anyway once heated as all the airbourne moisture is laying on the ground as dew or ice.

[samoilis1970]

Originally Posted by Welton

No-one normally agrees with me on this but don't use the air con in cold weather, when the car is parked up there is basically a very wet evaporator (heat exchanger) and an equally wet condense catch tray underneath it. This moisture then condenses out onto the windscreen above it.

People then say "hey but when I switch on the a/c the screen clears really quick" yes it does but the moisture stays in the climate control unit and therefore the interior.

In my experience you're best to have a completely dry interior in winter and use heating only. The incoming air is dry anyway once heated as all the airbourne moisture is laying on the ground as dew or ice.

Hi Welton and thank you for you advice, it's actually make sense what you said!! I will try your method for the new few days and see how it goes. Many thanks ☺️

[LizardOfBodom]

Welton - that is defo a less-common advice, I must admit (that is the polite way of saying I totally disagree :P) but hey - if it works for you thats great!
As for OP question - Pollen filter if neglected can defo make the condensation unbareable so I would recommend checking this and/or the air intake side (like under the bonnet vents) that may clog with wet leafs etc...
if both sides are 100% spot on then unless you have something wet inside of the car, like carpets, underroof carpet or something, I have no idea.

[Petey80]

I'm not sure what Volvo's blower motors and re-circulation valve/motors are like, but if the re-circulation valve is stuck closed and not letting any fresh air in [and circulating cabin air] the windscreen and other windows will mist up.

This happened with my previous car as the re-circ motor broke and was stuck shut, re-circulating the moist cabin air. I managed to get it open and then cut the wire so it no longer moved. No more misty windows.

But of course, misty windscreen can also be due to moisture in the car somewhere.

[ITSv40]

Originally Posted by samoilis1970

Hi all, my wife's C30 1.6 petrol has lots of condensation inside front screen, I have checked for wet carpets and leaks but I can't find any, the car hasn't got a sun roof. Any ideas?? Many thanks ☺️

Have you double checked the drivers side front carpet is not wet/damp underneath. The vent pipe for the a/c/heater is on the drivers side of the 'transmission' tunnel just in front of where your left foot rest when driving. The tube can get blocked/come adrift and the condensate from the a/c will sit on the floor pan instead of draining underneath the car. Volvo produced a modified design of pipe to overcome the problem. You will have to remove the front carpet to check and the top of the carpet may feel dry, but underneath could be wet.

If the a/c matrix tray is swimming in water as Welton suggests - the drain tube is blocked and needs clearing. There should not be any amount of standing water sloshing around.

[StatusRed]

Originally Posted by Welton

No-one normally agrees with me on this but don't use the air con in cold weather, when the car is parked up there is basically a very wet evaporator (heat exchanger) and an equally wet condense catch tray underneath it. This moisture then condenses out onto the windscreen above it.

People then say "hey but when I switch on the a/c the screen clears really quick" yes it does but the moisture stays in the climate control unit and therefore the interior.

In my experience you're best to have a completely dry interior in winter and use heating only. The incoming air is dry anyway once heated as all the airbourne moisture is laying on the ground as dew or ice.

I only ever turn it on for 30 seconds to demist the windows during winter, and maybe on a longer run I'd have it on for 10 minutes to satisfy the myth that it needs to be on for about 10 minutes a week to lubricate the seals.

[samoilis1970]

Originally Posted by ITSv40

Have you double checked the drivers side front carpet is not wet/damp underneath. The vent pipe for the a/c/heater is on the drivers side of the 'transmission' tunnel just in front of where your left foot rest when driving. The tube can get blocked/come adrift and the condensate from the a/c will sit on the floor pan instead of draining underneath the car. Volvo produced a modified design of pipe to overcome the problem. You will have to remove the front carpet to check and the top of the carpet may feel dry, but underneath could be wet.

If the a/c matrix tray is swimming in water as Welton suggests - the drain tube is blocked and needs clearing. There should not be any amount of standing water sloshing around.

Hi its v40 I have checked everything above all dry no wet carpets nothing, I think I will change the pollen filter and see what happens

[ITSv40]

Originally Posted by samoilis1970

Hi its v40 I have checked everything above all dry no wet carpets nothing, I think I will change the pollen filter and see what happens

I hear what you say, but I would still check under the carpet. My son has a V50 and soon after he bought it removed the carpets to generally clean them. The carpets were bone dry on the top, but the drivers side of the car was swimming in water and the foam underlay was saturated. The drain tube was the culprit and when he went to Volvo the parts chappie said, 'oh yes, we sell a lot of these, but the modified design is much better'.

[samoilis1970]

Originally Posted by ITSv40

I hear what you say, but I would still check under the carpet. My son has a V50 and soon after he bought it removed the carpets to generally clean them. The carpets were bone dry on the top, but the drivers side of the car was swimming in water and the foam underlay was saturated. The drain tube was the culprit and when he went to Volvo the parts chappie said, 'oh yes, we sell a lot of these, but the modified design is much better'.

Thank you ITS v40 will strip the carpet the weekend and see how it is under there 😎