Electric Heaters...?

[Tomcat]

Morning All,

Now I've done a search and can't find anything specific about this (although that may be down to the wording I'm using) but what I am after is any knowledge or experience from the collective about 12v heaters for the car.

I have a temporary issue with one of my cars that could be solved by buying a heater/fan that you plug into the 12v socket, to defrost/demist the screen, I have looked on Amazon and while there are plenty to choose from, the reviews are poor.

I remember years ago reading something about this on here but I can't remember what the conclusion was or indeed if there were actually any good ones you could buy!

Anyone??

Cheers

J

[Captain Colonial]

Would a better and cheaper option be to purchase the defog-demist spray divers use inside their face masks?

I know many of them simply spit into the face masks and rub it over the glass, but even Roy Hattersley might struggle to do a whole Westfield screen!

[Welly Jen]

I think the problem with electric car heaters is that they just can't supply the same amount of heat that a conventional one plumbed in to the engine cooling circuit can. They are hundreds of watts, rather than thousands. To supply the same sort of power electrically would overload the alternator. Think of a one bar domestic electric fire, 1KW. That would be 71 amps at 14V. Too much for most alternators, especially since they have to run the engine electrics, lights, screen demist, etc etc at the same time. The amount of waste heat from the engine is many KW. The issue with that is more getting rid of it, as the many cooling problem posts on this forum show! Diverting some of it to heat the car interior is simple.

Jenny

(Corrected amps for watts. Doh!)

[FILFAN]

Would a better and cheaper option be to purchase the defog-demist spray divers use inside their face masks?

I know many of them simply spit into the face masks and rub it over the glass, but even Roy Hattersley might struggle to do a whole Westfield screen!

washing up liquid also does a good job. just a couple of small drops to a cloth then polish the glass with it

[Tomcat]

Thanks guys, it was a thought! Mainly the issue is that the heater matrix on the lads Pug has sprung a leak so we had to bypass it, I want him to be able to clear the screen at least till we can get the dash out and fit a new matrix, its getting cold and icy so its not much fun!

I would have been prepared to spend some money on a temporary solution, if it would have worked, but no point if not!

J

[TAFKARM]

I had a similar problem when my mx5 heater packed up in the worst winter on record (probably). I bought a 12v heater, it was useless.

[Norman Verona]

When I bought my car there was a switch with the HRW symbol. Confused the hell out of me until I realised it was the heated FRONT screen.

[Meakin]

When I bought my car there was a switch with the HRW symbol. Confused the hell out of me until I realised it was the heated FRONT screen.

Did it only work when you were reversing?

[User0083]

I use rain-x, rain-x screen wash and rain-x anti fog.

Hardly need wipers, never use them above 50mph, except in extreme downpours! Then screen will must up when I first get in, especially if I'm damp from rain or sweating from gym. But clears extremely quickly with std heater or driving off (only if in car park and clear).

[FILFAN]

I use rain-x, rain-x screen wash and rain-x anti fog.

Hardly need wipers, never use them above 50mph, except in extreme downpours! Then screen will must up when I first get in, especially if I'm damp from rain or sweating from gym. But clears extremely quickly with std heater or driving off (only if in car park and clear).

You have been branded

The stuff does smell nice though

[Norman Verona]

I only had my screen on for a few years. I remember well going to Manchester Airport to fly to Germany for a meeting. It was a cool crisp morning with clear skies. Flying back it was peeing down at Manchester. Coming over the Snake I had rain on the outside of the screen, rain on the inside of the screen and rain on my glasses. Couldn't see a thing! Had to pull over wherever I could to wipe all three surfaces.

[User0083]

You have been branded

The stuff does smell nice though

I used them in the Mini Cooper... 1968 Cooper S! Found them good. Used other brands and nothing seemed to work as well. Use them on helmets, work very well and used them on every vehicle since. When I run out you can really notice the difference.

[User0083]

I only had my screen on for a few years. I remember well going to Manchester Airport to fly to Germany for a meeting. It was a cool crisp morning with clear skies. Flying back it was peeing down at Manchester. Coming over the Snake I had rain on the outside of the screen, rain on the inside of the screen and rain on my glasses. Couldn't see a thing! Had to pull over wherever I could to wipe all three surfaces.

Been caught in a couple of showers that usually happen with the door on and if it's heavy traffic on a motorway with very wet roads the spray off a lorry gets sucked in on the corners and screen wash bubbles come in through bottom corners of windscreen. Not had it bad enough to have to stop yet. But not far off it.

[blankczechbook]

some tin tops have an electric heater which helps the window clearing in cold starts.. only kicks in the the battery is in good nick and the alt has spare capacity.

our s-max has it and a heated screen.. which is handy cause the diesel engine takes ages to get hot unless driven up a big hill :-D

it isn't too powerful when compared to a proper hot water heater but does help.

i used to have a rag in the westie for interior window wiping.. when the rain was very bad the rag could be used to soak up water in the footwells and then wrung out ( again and again :-) )