ADR 15 - Demisting of Windscreen

**TooF** · 05-03-2007, 05:55 PM

a number of the newer euro vehicles use a small 12v heater in the internal blower system so tat you get warm air frm the moment youstart the car without having to wait for the coolant to warm up... thought about adapting one of these units ?

**wagonist** · 05-03-2007, 06:12 PM

Again, though, you've spoken about 2 race cars, not something you can get normally road registered (& no, rally cars are not "normally" road registered like other vehicles).

I like the 12v heater thing built in though. Would be very handy in Europe where it could take a while to warm up the "coolant"

**styler** · 06-03-2007, 10:12 PM

hey i have looked into replacing the heater box in my rolla with 2 electric heaters mounted under the dash blowing up through the existing demister vents. should connect up with a short fabricated adapter and some wiring. will be much lighter, problem free and work instantly on cold days when there is bad misting up.

only thing im trying to work out is if it will be sufficent enough, apparently the water heater boxes put out a load more heating power than an electric one but i think 2 electric ones may do. i will find out shortly when i put them in lol...

**stumpygt4** · 06-03-2007, 10:39 PM

Well for competition cars it states in the cams manual that you may remove the original demister, but must retain an electronic demisting device. This year they added “must not impede the driver’s vision in any manner"

I am going to buy one from http://rallynuts.com/motorsport/, they have a blower for around $90 or so. Its cheeper than having a heated windscreen for $1000.

Cheers
Jeff

**Billzilla** · 06-03-2007, 10:54 PM

<useless triva>

A lot of cars in hot places like Malaysia, Indonesia, etc, are not fitted from the factory with heater boxes. There's no hot or warm air selection available on the panel.
I've got a photo of one somewhere, I just can't find it sorry

</useless triva>

**Billzilla** · 06-03-2007, 11:05 PM

Found it!

**wagonist** · 06-03-2007, 11:09 PM

Might be interested in looking into these heaters. Looking at buying a car where they had to sacrifice the A/C (which sits underneath the heater box) to fit a trans tunnel in. If I can make the heater samller, I just might be able to fit the A/C core back in

Also might have to find the picture of a car's dash in Euro where they didn't have a "cold" setting, nor A/C

**roadsailing** · 06-03-2007, 11:19 PM

Wodner how i missed this thread...

anyway, i work for an OEM automotive air conditioning company and until recently the only ADR we had to comply to was ADR 15.

to be honest, i'm not sure what rule there is now, i think it is something like "you should probably be able to demist the front windscreen"

car companies have their own specicications that cover defrost/defog/demist, so new cars will always have something for seeing out the front window.

A/C actually works a lot better than a heater to defog the windscreen, as the "dry" air coming out of the vents "sucks up" the moisture off the windscreen and clears it. hot air has to heat up the windscreen to the point the moisture will evaporate, but you need a heater for de-ice etc.

Bill, we do a few A/C only kits for SE asia (no heater) and we do/have done heater only kits for other parts of the world.

best way to clear your windscreen is with dry air (fresh not recirc) A/C on and the heater on.

having said that, i think the 12 volt hairdriers are a great idea and you could plumb them in to your existing demist vents without too much trouble, also you can buy electric elements designed specifically for heating air, we use them in diesel cars as they don;t produce much heat. they are pissweak compared to a normal heater core, but would help get the job done.

as for me, i will always run a heater, as its otherwise wasted energy and i know how bitter a car can get without a heater, after re-installing my ECU into my car i decided to leave the blower off to save some time, then drove to benalla with freezing air blowing in through a hole i couldn;t block off, it sucked!

hope that helps in some way, i might look into the whole ADR15 thing a bit more