Using AC to demist windows

The Dreamer

Well what can I say? I have a picture in my head of a French designer pulling on his 'Gitane' - shrugging his shoulders and saying, with just a hint of smile, 'pour le rosbif, c'est bon'

gibbsy

Not only does AC make for a more comfortable car, summer and winter, it is also an important safety feature keeping the windows clear of moisture which is a brilliant aid to visibility.

car-man

There's a job that had to be done back in the day on the Citroen Xantia...the clutch cable pivot (some idiot made it plastic) which used to break off...to fit a new one you had to remove the clutch pedal, held on by a single bolt which was fitted from the heater side (obviously in open space on the left hand drive models)...You can't get the bolt out because of the heater so you have to saw the head off...imagine lying with your back on the door sill, head under the dash cutting off a bolt head...it hurt!!
Some French designer must have had a real good laugh about that!!"

car-man

Great news
Yes, a clogged pollen filter can cause smells, that's why I said replace it before using the AC bomb.

Another problem caused by a blocked pollen filter is the car constantly steaming up!
They can also cause loss of power to the heater blower and also heater motor failure!

Thankfully I don't have to worry about fitting pollen filters anymore now that I've retired
Almost 50 years working on cars is enough to drive anyone crazy!
I only have family cars to maintain now!

chrisgeary

Common wisdom seems to be to run AC all year round, but the problems with that, for me at least, are:
a) that the evaporator is always moist.
b) come winter time below 3-4c the compressor will stop running anyway.

a) That constant moisture is why it eventually starts to smell as its a breeding ground for bacteria. Provided it has been dried out, not using AC will NOT cause it to create bacteria and the musty smells associated with it. It's the same with home AC as well. Annual maintenance at the end of the warmer months is needed to keep things healthy because it isn't practical to dry out the indoor unit every day.

b) When the compressor stops in winter because its too cold, all that moisture on the evaporator starts to evaporate and because the glass is very cold, condensation forms and its almost impossible to remove without wiping by hand, even with the heater on full blast. Eventually, the heater will deal with it but its pretty inconvenient if you're on a busy road somewhere and suddenly your car mists up.

After a few decades on the road and not using AC full time (but still using it every few weeks to maintain the seals), I've never had AC fail due to perished seals, never had to "bomb" clean it and my windows never mist up during wet weather.

@Ste7en : the reason why you can't use AC as a short term demisting fix is because the moisture you're removing condenses on the evaporator. You then turn off the AC and that moisture evaporates back into the car. Either you choose to run AC full time to keep humidity under control noting the caveats above or you choose to run AC as little as possible so the evaporator is always dry anyway. Enough air circulation in the car will prevent misting 95% of the time provided you're not permanently recycling air.

The Dreamer

I would say so - I only used to help out in a mates garage, in Lincolnshire, in the eighties - I was known as the world's oldest 'mechanic's apprentice'! I was doing it in between various exams I was taking at the time; I had no money, and in return, Pete, my mate, kept my car on the road - despite my best efforts to write the thing off. (3 engines and two gearboxes from the scrappy - when you could do that sort of thing)!

Skinning your hands in the freezing cold, and the cuts then filled with muck and grease, can never be called fun - though we did have some laughs! So less than a year in a garage, and despite it being highly satisfying, fixing things, it convinced me that as soon as I could afford it, I'd hand over the keys to someone else - with a 'fix it please', and suck up the bill!

But having said that - the easier jobs, where a limited skill DIY'er can save a few bob, I still enjoy - I'm not about to go crawling around under a car on stands on a wet driveway, but a bit of fiddling here and there, I can cope with!

PS Got my lad to swap out the pollen filter and set off the 'bomb' - his first bit of car maintenance!

Jamie

I'm not surprised at all actually. I've owned loads of Japanese cars and haven't found any annoying design details present on RHD models. Japan is a RHD country don't forget and very thoughtful engineers.

Some of the Japanese cars I've owned have even had the stalks for indicators on the correct side for RHD, although sadly that's getting rarer.

The Dreamer

Indeed. I was hopeful - but after Car-man said the Mazda’s he’s worked on were different to the YouTube vid I’d linked to, I was a little concerned that our Honda might be the same - thankfully not!

Simba

and hence why i have a brand new PF still waiting to be installed 3 months after purchase

Cliff

If you are using the A/C the air should be on circulate to dehumidify quickly. If you switch the A/C off then switch to intake fresh air. If you leave on circulate it will quickly steam up again.