23 replies to this topic

[Ethel]

Okay no probs cheers , Ive noticed when I change from car to screen the heater flap dosnt seal very well and Ive noticed when I cover the gaps with my hands that the air coming from the vents is much more powerful and efficient any body got any ideas on how to seal it better and stop air leaking around the flap ?

It's not a great design, it might be more effective to add a  flap to stop the air exiting from the heater. If you're crafty you might manage to make the heater flap open it...

 

Inner flaps seals against the matrix. Outer flap is larger and seals against a frame between the screen and car vents. The inner flap pushes the outer flap open as it's set from screen to car. A spring could return it - or gravity and magnetic rubber (e.g. fridge door) to hold it shut.

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It you need more airflow up the demister tubes, then replacing the foam on the flapper door with a slightly oversized piece can make a big difference.

My foam was shot when I was servicing my heater core, and I realized that all you need is about 1/8"-1/4" extra overlap to help snug up against the sides of the heater chassis and then less air will escape to your feet and instead it go up the demister tubes.

If you use a pretty loose cell foam it will deform and squish well and will not cause the flapper to be too stiff in its movement.

Perished foam:  OldFoam.jpg   38.54K   2 downloads

New foam:  NewFoam.jpg   30.71K   3 downloads

[James1997]

Cheer guys will have to take it apart and do this thanks for the help :)

[Ethel]

That's a good idea,

 

I was thinking of some sort of wiper seal for the flap edges, but couldn't see how it'd cope with flipping directions as you open or close the flap. Perhaps polythene closed cell foam (used as for packaging hard discs etc.) would be more durable, or felt the sliding edges with self adhesive velcro?

[noeman]

I came across this thread and found it very helpful as I too have very feeble screen demisters.
I gavered it must of been the foam on my heater flap has deteriorated as when it's on screen it's still blowing around my feet.
I've took my heater out to check and yes the foam had perished.
Looking at James potter's post to over hang new foam, would you also advise over hang the bottom of the flap too as this where most of the hot air escapes. Also what thickness foam?
I was looking at this
Look at this on eBay http://www.ebay.co.uk/itm/254114536238

[Pops_Guild]

I’ve been thinking about this.

Most modern cars use AC to instantly demist the windscreen. I have a JDM Mini so have the addition of air con and have been looking at whether it might be possible to add the air stream from the AC duct to the regular demist pipes. Physically there’s enough space just need find the right connectors so I can have a go. Will need to modify the AC duct too, so I have a spare to play with

You reckon it’d work?

[Bobbins]

I reckon it's worth a try, was thinking the same with my JDM. The vents are in the top centre of the dash so has to be viable to tap off them and route into the demist ducting even if it's a permanently open link. You go first :)

Edited by Bobbins, 12 February 2019 - 06:52 AM.

[Pops_Guild]

Yeah, would be permanent but it don’t think it will matter, when you want it demist should just stick the AC on.

I’m nearing the end of the restoration of mine, I’ll get it done and MOT’d then I’ll have a play later ?

[Bobbins]

Webasto do a 60mm diverter valve, eBay item no. 331450693874.

Attached Files

•  8C7A5DA7-F7C3-4E16-8FBC-E3FD1E02E9AA.jpeg   97.27K   3 downloads

Edited by Bobbins, 12 February 2019 - 07:06 AM.