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windscreen and demisting rules
Murphy - 20/2/12 at 09:46 PM

Hi,

I am in the process of figuring out wipers and roof scenario but have heard that I would need a demister/heater.

Is this true?

If so how basic can it be. Will the ceramic style by 12V sucker mount one do or will I have to do the ducts and cut the scuttle etc?

Thanks ,
John

T66 - 20/2/12 at 10:03 PM

Caravan 12v hair dryers apparently.....

Murphy - 20/2/12 at 10:10 PM

Surely a handheld hairdryer when driving carries the same penalty as a mobile?

sorry, wasn't sure what the reply meant.

Can I use the basic to get by Mr. Grumpy MOT?

adithorp - 20/2/12 at 10:40 PM

Yes you need "effective" demisting. Either hot air or heated screen... and yes, 12v ceramic heaters will do. You'll need 2 though to cover the whole screen. Thats how mine past SVA with them mounted delow (and through) the dash, pointing vertically up onto the screen. The caravan hairdryer thing is done the same way or monted remotely and ducted to the screen.

I'll try and find pictures...

quote:
Originally posted by Murphy
Can I use the basic to get by Mr. Grumpy MOT?


Not required for MOT though, just IVA.

[Edited on 20/2/12 by adithorp]

Murphy - 20/2/12 at 11:06 PM

Thanks. So for my MOT I would not require heaters to demist?

adithorp - 20/2/12 at 11:39 PM

No.

In reality they're no use anyway in a kit. Most of what get's on the inside of the screen is rain coming around the side and a blower won't clear that; Squeegee works best then. The only time I've had condensation was entering warn tunnels in the alps on cold damp days; Then the screen misted instantly and a squeegee was used again. I've no side windows though so might be different with full weather gear but I'd still go for a good squeegee.

Murphy - 20/2/12 at 11:51 PM

Great! That really helps keep simple for me. I'm sure I will have enough problems getting wipers and the like fitting and working.

Thanks

loggyboy - 21/2/12 at 12:46 AM

Do IVA without the screen, add it after.

britishtrident - 21/2/12 at 09:23 AM

The word "roof" in the original post rings alarm bells, I think something more powerful might be needed if you want the car to be usable.

Murphy - 21/2/12 at 09:57 AM

A vinyl roof for getting caught in the usual 4 seasons in one day. Will the small 12v ceramic style heater suffice?

adithorp - 21/2/12 at 10:27 AM

You can see my heaters poking through the dash top here...



If your talking about a bikini/bimbi/half-hood like the ones SoftBitsForSevens do (mines similar) then you should be ok with a squeegee. As said most of what gets on the screen is fine spray that whips around the screen onto the inside. The ceramic heater will help but not cure the problem.
With a full hood, doors, plus damp, sweaty driver and passenger then condensation will be more than any electric heater will cope with.