Why do some cars fog up more than others?

Question

I drive a '99 Toyota Camry, and it fogs up very quickly in relativity mild weather. I've had to use the defogger on the windscreen all day, every day for months. I can't use the heater much at all without all the windows fogging up.

My Dad drives an '04 Holden Commodore. He can have the heater on really high, and it NEVER fogs up. He's only ever had to use the defogger a few times.

There's been no difference with the products used on the cars (ie, neither are treated with anything to stop them fogging up).

...Why?

Answer 1

if your car has a passenger compartment air filter (aka pollen/allergy filter) you may need to change  it, its usually contained under the engine in the bulk head and should be changed yearly

Answer 2

Check to see if you are loosing coolant / water in radiator, if you are then you will probably got a leak in the heater core which is in the heater box, this would cause windows to fog.

To quickly get rid of fog switch the air con on when using the heater, air con will get rid of moisture which is fog.....

hope ths helps...

Answer 3

My car fogs up really bad within seconds of turning the heater on. Aircon normally removes the fog unless its really cold (around freezing point). Car also tends to fog up quickly if its raining outside.

Answer 4

It's a matter of humidity level within the car. People breathe out water vapour, water vapour is in the air, and often, cars leak water and have wet interior linings or underlay on the floor, you name it. When the heater goes on,  it circulates this moist air, it hits the glass which is cold and condenses over it. Eventually the heat will overcome this, but the most effective way is to use the aircon, as it removes moisture from the air. In winter with my car, for example, I find I use the aircon constantly, this is the only way to effectively clear the fogging from the windows and keep them clear. Especially with more people in it than just me!

Answer 5

Here's a great tip!  Take a bar of just a little wet soap and rub it on your windows then wipe off with paper towels.  A great defog tip.  I use it in my bathroom so my mirror dosn't fog up.

My old car was hopeless at defogging too so I used this method.

Answer 6

All depends on how cold it is outside and how warm and wet your breath is.If it suddenly gets cold outside and it's warm an humid inside the cabin the wind screen will fog up quickly .So be sure to know where your air conditioner,demister and fan controls are so you don't run off the road when attending to the fog. These things typically happen when it first starts to rain,you can go into a skid. Sometimes helps to carry a paper towel or rag under the seat. Take care.

Answer 7

it depends on where the vents are & how well the system works

I noticed that if I put the heat setting right in the middle it seems to defog the best