I have Accord 2008 LX-S Coupe
once i saw there was white smoke comming out from my AC.

i turned it off and try to turn it on again after 10 mins, and still the same
then i tried it next time and after that i never seen it back again.

anybody knows what was it?and why this thing happened?

 

I will guess this is condensed water (like a cloud).

 

Yess it is like clouds,
do i need to worry about it ? or is this common in cars ?

 

White smoke is a small fog from moisture. It occurs when the evaporator freezes solid and is usually accompanied by poor/no cooling.

If you're getting OK cooling, it may be very humid outside conditions and fresh air intake selected. Going to recirculate should improve cooling and reduce condensation.

good luck

 

son's old prelude happened when I was riding w/ him.

the air wasn't cooled anymore after that day - so sudden white cloudy air resulted from a sudden big leak of A/C system freon,
that supercooled the blower air as freon escaped AC system and expanded greatly into the non-pressurized blower vent system (atmosphere).

This is my take on what happened to this '86 prelude AC system failure

 

Yeah, a leak is one possibility.

But it seems a lot more likely that it's just water vapor condensing by the cool AC. Exactly the same as the "steam" that rises from ice on a humid day, or from dry-ice on any normal day. Was it a very humid day? Has the AC system been OK since?