[xsb00st]

Originally Posted by Saosin17

water at 32 degrees fahrenheit will become a solid ice... for a surface of any body of water noamtter what size (puddle) the surface temp of that body needs to only be 37 degrees to begin the process from liquid to solid

I have just been schooled! (As I crawl back into my little hole)

[alexk_e90]

Originally Posted by LEDZEP

I've modded mine with blow dryers in front of the front tires. When the snowflake sensor comes on, the blow dryers fire up and thaw the road in front of me.

LOL. Damn that is funny.... Got a part # for that?!?!?

[shuzmaker]

Does anyone know if the "Ding" is going to be "DING DINGING" every time I get in the car when it is less than 37F? It is getting a little annoying especially when it's going to be this weather for a while in North East.

[abc]

is this feature mentioned in the manual anywhere.

[JamieA]

Originally Posted by bbq

A breeze cannot 'chill' the water any lower than the ambient temperature since wind chill factor only affect things that produce heat (i.e. human, animal, etc). A breeze only *feel* colder to a human due to the more rapid heat loss.

If a breeze could chill the water to a lower temperature, it would chill the temperature senor in the same manner so there wouldn't be a need for the extra margin......

Well then all those evaporative airconditioners mustn't work then. And blowing air over hot food doesn't cool it?

The process works because of heat transfer, it isn't things that produce heat, but have heat, and unless something is at 0 deg K, or -273 deg C it has heat to loose.

Water likes to soak up heat to evaporate, in the process cooling whatever is left behind.

[brad4221x]

Originally Posted by shuzmaker

Does anyone know if the "Ding" is going to be "DING DINGING" every time I get in the car when it is less than 37F? It is getting a little annoying especially when it's going to be this weather for a while in North East.

I'm with you on that especially if it been 20 degees for 3 straight weeks. Plus, I feel I'm inteli...intelleg...intelligent enough to know when to watch out for ice.

[LEDZEP]

Originally Posted by JamieA

Well then all those evaporative airconditioners mustn't work then. And blowing air over hot food doesn't cool it?

The process works because of heat transfer, it isn't things that produce heat, but have heat, and unless something is at 0 deg K, or -273 deg C it has heat to loose.

Water likes to soak up heat to evaporate, in the process cooling whatever is left behind.

Yep. As usual, Jamie is right. I know I personally experience much more shrinkage on a windy day!

[ABR]

Originally Posted by bbq

A breeze cannot 'chill' the water any lower than the ambient temperature since wind chill factor only affect things that produce heat (i.e. human, animal, etc). A breeze only *feel* colder to a human due to the more rapid heat loss.

..

Wind can accelerate water evaporation, which will lead to lower temperature of the water.

[ABR]

Ops, JamieA was first. Damn it.

[Airboy]

Originally Posted by JamieA

Well then all those evaporative airconditioners mustn't work then. And blowing air over hot food doesn't cool it?

The process works because of heat transfer, it isn't things that produce heat, but have heat, and unless something is at 0 deg K, or -273 deg C it has heat to loose.

Water likes to soak up heat to evaporate, in the process cooling whatever is left behind.

He did say "cannot 'chill' the water any lower than ambient temperature". If the object is already at ambient temperature, how is moving air going to 'cool' it, when there is no temperature difference?

[34Three]

must be your first BMW?

This has been around for ages...had it on a 1993 E36 coupe...it always gives you a scare first time of the season!

ha ha

Man they were ahead of their time with this 13 years ago.

[ek9hatch00]

that sound does annoy me every morning now...i personally dont like it

[bbq]

Originally Posted by JamieA

Well then all those evaporative airconditioners mustn't work then. And blowing air over hot food doesn't cool it?

Do evaporative air conditioners work on a pool of standing water? Blowing air helps *accelerate* the cooling, but does it cool food any lower than the ambiet temperature?

Originally Posted by JamieA

The process works because of heat transfer, it isn't things that produce heat, but have heat, and unless something is at 0 deg K, or -273 deg C it has heat to loose.

Heat only transfers from a hot (relatively) body to a cold body unless you apply energy to force the movement. I dont think a pool of water can transfer any heat to its surrounding air (moving or not) on its own to create a different in temperature.

Originally Posted by JamieA

Water likes to soak up heat to evaporate, in the process cooling whatever is left behind.

Again water can only soak up heat from things that has a higher temperature since heat naturally flow from a hot body to a cold body. Hence why sane people don't pour boiling water on others to 'cool' someone down just because hot water evaporate much faster......

[ABR]

It was awhile I studied physics... But from what I remember -- process of evaporation (changing from liquid to vapor condition) consumes energy. There no heat transfer between wind and water. Wind just takes vapors away making easirer for next layer of moleculars to leave liquid's surface.

[ON325i]

Originally Posted by ek9hatch00

that sound does annoy me every morning now...i personally dont like it

if it annoys u, that means it worked already

[BMW0]

dinging in Italy too.

[espo]

Originally Posted by bbq

Do evaporative air conditioners work on a pool of standing water? Blowing air helps *accelerate* the cooling, but does it cool food any lower than the ambiet temperature?

Heat only transfers from a hot (relatively) body to a cold body unless you apply energy to force the movement. I dont think a pool of water can transfer any heat to its surrounding air (moving or not) on its own to create a different in temperature.

Again water can only soak up heat from things that has a higher temperature since heat naturally flow from a hot body to a cold body. Hence why sane people don't pour boiling water on others to 'cool' someone down just because hot water evaporate much faster......

Actually..... No. Water CAN be cooled to a lower temperature than the surrounding "dry bulb" air temperature (this is the temperature that most thermometers read). It can not be cooled below the "wet bulb" temperature. The difference between the 2 is related to the relative humidity of the air. The process of cooling water is both a heat AND mass transfer process in which there is both sensible heat transfer from the air to the body of water as well as a latent heat effect from the water evaporting. There is always a driving force for the water to evaporate into the air unless the relative humidty is 100% (i.e. the air is saturated). The lowest temperature that the water can achieve (as well as the mico thin layer of air right above it) is refered to as the "wet bulb" temperature as is always lower then the dry bulb and slightly higher than the dew point of the air.

This is the process by which industrial cooling towers (as well as evaporative cooling systems) work. They blow ambient air over a falling stream of water to cool the water down to the "wet bulb" temperature. Normally it is possible to cool water down to 70F when the ambient temperature is upwards of 90F....

So in short yes ice can form on the roads when the outside temperature is above 32F!! BTW I have a PhD in chemical engineering and if you are really interested I can send you a few references that explain this in more depth that I can go into here :rocks:

[ABR]

espo89, thanks for the post.

[ON325i]

Although I read your short explanation a few times, I'm still having trouble understanding... i gues that is why i'm not in Chem Eng , haha

thanks so much for the informkation espo89

[BMW0]

What else can we expect from this wonderful snowflake? Well its doing great! Every morning hearing the charm reminds me of the road condition, and its time to drive safe once again~

[DannyDeez]

How loud and long is the ding? I cant stand beeping noises, they drive me crazy. My car gives me the snowflake symbol too but its quiet.

[webcoll]

Personally I can't see why anyone would get so excited about a snowflake indicator! It dings.............so what!!

Most new cars these days have them in one form or another.......certainly in Europe.