Originally posted by illusion
ummmm YES YOU DO NEED YOUR AIR CONDITIONING ON
Do some research before you tell people misinformation.
Heating and air conditioning are two separate systems. The A/C system removes excess moisture from the air producing cool dry air, that mixes with the heated air and then mixes with the inside air and reduces the overall moisture in your interior. Also make sure to not have your car on recirculate, the outside air is also more than likely less humid than inside. Your windows fog up because your body produces moisture, as does your breath. Since the inside is cooler than the outside the moisture is attracted to the cooler surface(the windows) and condenses from vapor to droplets. Having dry air will pull the water back off of the windows.
In cars with automatic climate control when you press the defrost button, the A/C will automatically come on, there's a reason it does.
If you really want to defrost your car fast, turn your A/C on as cold as it can go, your windows will defrost WAY fast, since you are equalizing the temperatures, and drying the air out.
If turning the A/C on does no good, then something is wrong with your A/C system, more than likely the air dryer.
No you don't only time I ever had the A/C on was when in the middle of a drive my windows started fogging up and I had to get control of it, if you have your heat set right you won't need A/C.
Either way works, so get off your high horse of yours being the only way it can be done :goodjob: