Date: Fri, 29 Jan 1999 12:20:19 -0000
From: Dave Edge
Subject: [imps] Re: Heated Rear Screen
Hi all,
I thought it was time to put this thread to bed. I do not recommend the stick on rear screen heaters. I was satisfied with the results on the first day, then each subsequent day a bit more peeled off until I parked it on a sideways slope and it all fell off from one side. I screwed it up and threw it in the bin.
I have now sealed the leaks in the back and stopped the window misting most of the time. I figured if the problem carries on I will rig up a blower for the rear window. This would be far simpler.
Tim, you mentioned a hairdryer that could be used as a screen heater, where can you get these from.
Date: Fri, 29 Jan 1999 12:30:18 +0000
From: "Andrew W. MacFadyen"
Subject: [imps] Re: Heated Rear Screen
Maplin sell a blower/heater kit I think it is on a special price until the end of this month.
Andy M
From: Impmann@aol.com
Date: Fri, 29 Jan 1999 07:52:56 EST
Subject: [imps] Re: Heated Rear Screen
Hi Dave,
The hairdryer thing... not sure that was me. You used to be able to get travel hairdryers for caravans that were low voltage, but whether that would work or not remains to be seen.
Also, there are under screen heaters similar to those used in the Rally Coopers etc, these are just like a little bar heater.
You could also try upgrading your present heater blower to one from a Fiat 126 (the water cooled one), these are manically powerful! You'll probably find that it'll clear the back screen too!!!
From: Mark Norman
Date: Fri, 29 Jan 1999 14:06:09 -0000
Subject: [imps] Re: Heated Rear Screen
Hairdriers was me. (factual if not gramatical!). I have seen a pair of car/camping hairdriers used as demisters. This was in a Beetle based kit car (a Nova, no relation to the Vauxhall ones), where it was not really possible to get hot air to the front of the car. Each was glued into position under the demister grille and behind the dashboard. I think they were fairly effective - could have been better, but useful nevertheless. I have seen them for sale in camping shops.
I wonder if you need heat for a rear window demister - how about just a fan to blow air onto it? Apparently some Citroen's use long cylindrical fans for their heaters - one of these might fit quite neatly under the rear window.
From: Impmann@aol.com
Date: Fri, 29 Jan 1999 09:50:05 EST
Subject: [imps] Re: Rear demisting
Hi Mark,
I think that you would need heat, otherwise the steam will not vapourise.
Interesting about Citroen blower fans.....I'm looking at alternatives to the pathetic Imp one. Any idea which models???
Cheers,
Tim
From: Mark Norman
Date: Fri, 29 Jan 1999 15:11:25 -0000
Subject: [imps] Re: Rear demisting
Afraid that's all I know. I haven't even seen one, they were described to me. From my understanding of them, the fan is in a long cylindrical casing which (possibly) reaches across the width of the car. The air is blown out from a 'chute' in the side of the casing. Don't know where it sucks from. I guess it would be an older Citroen. I don't know how well it would work as a replacement for the front Imp fan, the bloke who told me about them was suggesting it for fitting under the rear window to demist that.
I think you could clear the mist off a window without heat, though you might have to blow the air at it harder than you would have to with heat. Perhaps someone could try experimenting in a modern car with a powerful fan.
Minor coincidence: the Nova used an Imp fan for interior air in its original design.
To: imps@onelist.com
Date: Fri, 29 Jan 1999 16:08:04 -0000
From: Dave Edge
Subject: [imps] Re: Rear demisting
You do not need warm air to demist at all. Warm air can hold more water vapour but cold air will still hold some with agitation over water. Believe it or not ice can even be removed by blowing cold (dry) air at it. A process known as sublimation allows the ice to transform straight to water vapour missing out the liquid phase. Cold air would be fine for demisting.
Incidentally on the subject of imp fans, the heater that I had in my car originally was excellent. I removed the heater matrix before fitting and cleaned it out. I since put that heater matrix in the front box and Tim gave me a new matrix, the fan is now pathetic. I didn't clean out the matrix - much less airflow, either that or the housing (cardboard) is less efficient than the metal one I had originally.
Where can I get a high pressure air line to blow through the matrix the wrong way. Would a garage airline be enough? I'll let you all know if this is a goer.
Date: Fri, 29 Jan 1999 16:51:13 +0000
From: Andrew W. MacFadyen
Subject: [imps] Re: Rear demisting
The air dosen't need to be warm but must above 0°C not easy on a frosty morning when the air temperature is below zero.
Andy M
From: Mark Norman
Date: Fri, 29 Jan 1999 18:16:52 -0000
Subject: [imps] Re: Rear demisting
you don't have an airlock do you? I got one after removing & refittong the matrix without draining the system. I fixed it by disconnecting the top heater hose & pouring water into it from a jug until water came out of the matrix pipe where the hose was connected to, then reconnecting the two quick!
Date: Fri, 29 Jan 1999 16:55:51 +0000
From: Andrew W. MacFadyen
Subject: [imps] Re: Heated Rear Screen
I checked out the Maplin demister blower it is Maplin part no NA19V it has just been introduced at £14.99 it looks quite neat.
http://www.maplin.co.uk