Fogging up?

[Devoniageoff]

My new (fabulous!) MG4 Trophy keeps fogging up! The recirculation setting is set
to outside air but unless the fan is on no air appears to be coming in. Is it always necessary to have fan on (?battery drain?) Or shouldn't the forward motion of the car let air in? Any thoughts anyone? Many thanks!

 

[Rolfe]

That's weird. I have experienced almost no fogging up, even when driving in heavy rain last week. I had started the journey with recirculated air but when I got a bit of fogging I switched to outside air and it stopped.

I remember a couple of weeks ago I switched the heating on when the evening was chilly, and the windscreen immediately began to fog, but I then switched on the windscreen demist and it cleared almost immediately. That was all with recirculating air too.

I've had two passengers in the car on several occasions and not noticed fogging. In fact I'm seeing less fogging than I did with my previous car. So no, I don't think this is normal for the MG4.

 

[Rolfe]

Wait a minute, do you have the air vents open?

 

[bowfer]

That’s what aircon is for, demisting as well as cooling.
Switch the aircon on

 

[Rolfe]

It's not necessary. I drove a long way last week without the aircon (or heating) on, and it didn't fog up most of the time.

 

[Ian Key]

The fan will use very little battery. In the aircon settings I have the air set to outside air and if you select the small cog icon you can set the fan speed when auto is selected. I've changed mine to low.

 

[Rolfe]

That's true, but the OP seems to be experiencing excessive fogging and there has to be some reason for it.

 

[Ian Key]

A lot of factors can cause misting up apart from the lack of air circulation.
If the weather is warmish and dry it might be worth opening the windows while it's on the drive and letting it have a good air.
Might be worth checking if the carpets are dry. Could be a leak around the door/window seals.
Did the OP have a protective treatment applied inside that hasn't totally finished drying out?
Is the car only doing short journeys so the car isn't getting aired?
Is the car frequently or recently washed which can also cause misting up.

 

[JDMB]

I’ve noticed quite a bit of fogging if the aircon isn’t on, although initially my front middle vents weren’t open, but it has been warm and wet down here so maybe a combination of factors at play for me.

 

[Devoniageoff]

Wait a minute, do you have the air vents open?

Hi, yes air vents open, but no air flow without the fan on? Is that normal do you think? In an ICE car you'd normally get some ventilation from the forward motion of the car.

 

[tsedge]

That could be for aerodynamics.

AC will dramatically reduce fogging because it dehumidifies the air, however, you shouldn't need AC in summer so if there is excessive fogging with the fan on and AC off, it suggests damp may be getting in somewhere.

 

[Devoniageoff]

That could be for aerodynamics.

AC will dramatically reduce fogging because it dehumidifies the air, however, you shouldn't need AC in summer so if there is excessive fogging with the fan on and AC off, it suggests damp may be getting in somewhere.

Thank you. I also just realised (duh) that there's obviously no radiator grill so no outside air being needed!

 

[bowfer]

I’ve noticed quite a bit of fogging if the aircon isn’t on, although initially my front middle vents weren’t open, but it has been warm and wet down here so maybe a combination of factors at play for me.

Lots of cars are like this now.
I just put it down to the fact they’re better built/insulated and your soggy breath isn’t finding a way out.
I’ll never fathom people switching aircon off and on all the time.
It’s literally a 24/7 thing, no need to ever switch it off.
Renault even default the aircon to on in their cars, you have to request off.

 

[siteguru]

AC always stays on for me ... it needs to be on to lubricate parts in the AC system anyway, otherwise they'll eventually dry up and cause leaks.

 

[PeteC]

I also get fogging after a while if I turn aircon off. It first affects the side windows. I usually leave aircon on.

 

[Eber]

Mine really fogs up quite heavily, too. Someone mentioned in another thread that it could be due to the transport by ship (humid port areas and whatnot). Here it is parked charging next to my i3. Both cars have been standing outside for about one day, it hasn't been raining, ground is dry. The MG4 fogs up completely when temperature or humidity changes.

I have to drive with A/C on all the time (what I'd be doing anyway).

 

[bowfer]

Mine really fogs up quite heavily, too. Someone mentioned in another thread that it could be due to the transport by ship (humid port areas and whatnot). Here it's parked charging next to my i3. Both cars have been standing outside for about one day, it hasn't been raining, ground is dry. The MG4 fogs up completely when temperature or humidity changes.

I have to drive with A/C on all the time (what I'd e doing anyway).

Ooh, that does seem a bit much..
Definitely no damp anywhere?
Under the boot floor (someone mentioned leaky tailgate seals last weeks)

 

[tsedge]

I leave my AC on year round and just toggle the overall air system on/off or crack open a window in summer. I don't think AC itself uses that much unless it is dramatically cooling.

@siteguru is right that AC needs to be used regularly for the system to stay in good health, that's been true for many years and predates EVs.

Mine really fogs up quite heavily, too. Someone mentioned in another thread that it could be due to the transport by ship (humid port areas and whatnot). Here it's parked charging next to my i3. Both cars have been standing outside for about one day, it hasn't been raining, ground is dry. The MG4 fogs up completely when temperature or humidity changes.

I have to drive with A/C on all the time (what I'd e doing anyway).

Could be because the air vents close when the MG4 is off?

 

[JDMB]

I leave my AC on year round and just toggle the overall air system on/off or crack open a window in summer. I don't think AC itself uses that much unless it is dramatically cooling.

@siteguru is right that AC needs to be used regularly for the system to stay in good health, that's been true for many years and predates EVs.

I noticed the estimated range on the small screen dropped by about 10-15 miles (can’t fully remember) when I toggled it on this morning. Not too much in the scheme of things, and it is just an estimate anyway.

 

[tsedge]

I noticed the estimated range on the small screen dropped by about 10-15 miles (can’t fully remember) when I toggled it on this morning. Not too much in the scheme of things, and it is just an estimate anyway.

It will drop more when you first put it on as that's the higher load but when the temperature is achieved it will most likely use less - so you will get some of that back.

I have no doubt it does reduce range a bit, but I haven't noticed a large effect.