However, many of us are more often engaged in more prosaic pursuits that result in steamed up car windows; just this morning I drove home with two very wet and panting dogs after a wonderful walk in wet woodlands. Additionally there has been; bringing the children home form swimming on rainy Saturday mornings, lugging several bags of wet washing to the launderette after the washing machine had broken down, and driving home from Snowdonia with a dripping tent after packing it up in the rain, exacerbated by the wet sleeping bag that my daughter had thrown up on the night before. I expect that police officers on a stake-out in an unmarked car, in January, with a flask of tea may also experience difficulties but as advanced drivers they will of course know the solution.
So how do we ?standard drivers? deal with the problem?
The basic principle is that you need to replace the moist air in the car with dry air, and direct that dry air (either warm or cold) onto the windscreen. The faster the air flow the quicker the de-mist.
Where does the moisture come from?
Moist air comes from various sources, wet things like; washing, tents and hair; breathing things like people and dogs; and condensing things like cold car windows and your air conditioning system. Dealing with these situations calls for the appropriate use of the car's interior temperature controls.
The age and specification of your car will dictate which controls you have available to tackle misted windows. Most drivers are familiar with the heated rear window control, and how it works, however, dealing with de-misting in the front can be confusing. There are usually several dials, sliders or buttons associated with the control of; the temperature, the direction, and the speed, of the air flow. When used in combination they can either alleviate the problem of misted windows or create it!
Beware the Re-circulate air control!
At our auto reconditioning business, we find that customers who complain of fogging problems in their cars are often in the habit of leaving the ?re-circulate air? control turned on. When on, this control prevents unpleasant air coming in from the outside like; diesel fumes, bonfire smoke, or burger van aromas, which is of course a good thing, but if you have it on all the time, especially when the interior air is already moist, then all you are doing is re-circulating the same damp air. This will of course get progressively worse as you puff and pant whilst stretching across to scrub the window with a bit of grubby Kleenex, so keep it turned off as default.
Use your car's air conditioning effectively.
This whole scenario is exacerbated if you are running your air conditioning, in combination with the re-circulate air control. This will cause even faster fogging of your windows. Air conditioning systems use a refrigeration process like a domestic fridge, and just as a fridge condenses water as a part of the cooling process and dribbles it onto your kitchen floor, so your air conditioning produces water that can evaporate again into the cabin air of your car. This is prevented if you draw fresh air into your car, in other words turn ?re-circulate air? off, whilst running your air con.
We actually recommend that you do run your air conditioning periodically all year round, as it will keep the system in good order and slow down the build up of bacteria which causes odour.
One last tip? clean windows demist far quicker than dirty windows, so why not take advantage of the moisture on them next time they are steamed up and give them a wipe with a good quality microfibre cloth. I recommend keeping one in the car as they are useful for all sorts of things.