# Windscreen insulation Internal or external?



## Pat-H (Oct 30, 2009)

Picking up an AutoSleeper Pollensa on the Peugeot Boxer Chassis and looking at insulation for the screen and front doors.
I see there are internal and external solutions.
What are peoples thoughts on the benefits either way?
Condensation and water is obviously an issue and I imagine an internal solution will help but may still generate condensation.
An external solution may work better.
External solution is more prone to wind disturbance and theft.

Thanks


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## Ken38 (Mar 24, 2009)

Having a good internal blind I would vote solidly for EXTERNAL!!  

I am trying to justify ordering a new high quality external. They seem much better at minimising condensation and clearing the windscreen for an early morning start is a pain!


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## duxdeluxe (Sep 2, 2007)

External solution for me. No condensation and it is secured via the locked doors, so anyone thieving it would have to cut the screen off, rather limiting its future usefulness. Personally, until you mentioned it, I never thought of theft except that it prevents anyone from seeing anything inside and a dull metallic grey thing doesn't really excite many people so inclined to look elsewhere

hope that helps

Edit - as per Ken - 100%

Also what age is the Pollensa? I will shortly have an external screen for the older model (X244) Ducato/Peugot if you're interested. PM me if you are. Cheers


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## wakk44 (Jun 15, 2006)

If you are bothered about condensation then external screens are the way to go.They are more efficient and have better insulating properties.

I don't think theft is an issue as the front doors trap the screen on either side.Wind can make them flap a bit but we have never had any real problem in that regard.

Internal screens are not as efficient and you will get condensation on the inside of the windscreen in the morning.However if wild camping they are better for a quick getaway if necessary.

We have a set of both and use them according to the situation. :wink:


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## Grizzly (May 9, 2005)

Good morning Pat;

If you are looking to insulate against cold then external insulation- a thick padded silvered windscreen cover is the answer. This keeps heat in and prevents condensation forming on the inside of the windscreen. We have never had internal condensation form, however cold outside, when we have had the external screen in place. We have noticed those with internal screens having to dry the dashboard and windscreen.

You can buy external screens that have a let-down section so you can keep it in place over your cab side doors all day but let down the front so you can see through the windscreen. You can also buy long-line ones to give your engine some degree of protection.

Theft does not seem to be a problem- at least, I've not seen anyone report a theft on this forum in all the years I've been a member. They do fit securely trapped in the cab doors.

If you are looking to insulate against heat then either internal or external are effective though, again, external has the edge as the windscreen itself does not become hot.

We've just come back from Spain and Portugal and were there from early January. As a compromise we took our summer-weight external screen- a sort of thin, silvered mesh cover- with us rather than the bulkier winter screen cover. On the coldest nights- down to -12 deg C- we tucked a couple of silvered car windscreen covers between the external screen and the windscreen ( outside the van) and were pleased at how effective they were at preventing condensation and keeping us warmer.

G


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## bubble63 (Sep 30, 2009)

hi
had all options, just call silver screens in Yorkshire and order external with privacy net.

does what it says on the box

recommend 

neill, Cambridge


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## sallytrafic (Jan 17, 2006)

The only time I don't use my external ones is when I don't want to look as if I'm permanently camped when wild camping. I then use curtains or my internal screens depending upon the season.

The ones for my Ford Transit are the snuggest fitting I have seen and have a feature that limits the flapping on the sides. 

(Its a long strip of velcro that goes from the front lower corner of the cover hooks around the bottom front of each door and back up to the bottom side of the ext cover on to a mating strip of velcro. Depending upon the angle you bring it up, it alters the tension along the bottom sides of the cover)

When I'm on my main computer I'll add a sketch.


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## rosalan (Aug 24, 2009)

I understood that for hot sun, the internal blinds keep your van cool.
For cold weather and winter, the internal blinds keep the condensation away and the heat in.
I must be honest and say that I do not like the external screens for several reasons. 
They do not look attractive and can get dirty. 
Putting them up in bad weather (rain etc) is not a joy and they will be wet to pack away.
They are generally more expensive and I am a miser. :wink: 
Alan


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## Grizzly (May 9, 2005)

rosalan said:


> I understood that for hot sun, the internal blinds keep your van cool.


Given that, in hot sunshine, your windscreen heats up and stays hot while the sun shines, acting as a big hot radiator, I would think that the best thing you can do is prevent any sun getting to said windscreen and so preventing it heating up in the first place.

This can only be done effectively with an external blind.

An internal blind will preven some heat transmission through to the cab but not as well as an external one.

Have you tried the thinner, summer weight, external solar shields ?

http://www.silverscreens.co.uk/Solar View.html

G


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## StewartJ (Nov 20, 2009)

External 100%, very light and easily stowed, once practiced literally a couple of minutes to set up single handedly. We also have fitted Remis internals but in cooler weather condensation is horrendous.

Externals do also provide a lot of insulation .


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## Rosbotham (May 4, 2008)

As others have said, external are better. Having said that, unless it's exceptionally hot or cold, we don't use them any more now that we have a front lounge van....even with the flap down, they prevent you seeing all of the view and shut out some of the light.


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## sallytrafic (Jan 17, 2006)

rosalan said:


> I understood that for hot sun, the internal blinds keep your van cool.
> For cold weather and winter, the internal blinds keep the condensation away and the heat in.
> I must be honest and say that I do not like the external screens for several reasons.
> They do not look attractive and can get dirty.
> ...


Having both there is no comparison the external ones work the internal ones work a bit (and that is for hot or cold)

The promised sketch


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## Pat-H (Oct 30, 2009)

Thanks everyone.
Lokks like external is the best bet for us.
Looking at a few options currently.
As always the choice is buy cheap or buy very expensive or somewhere in between.......


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## Grizzly (May 9, 2005)

Pat-H said:


> As always the choice is buy cheap or buy very expensive or somewhere in between.......


We've had several external blinds - summer and winter weight- and have bought from the 2 main firms: Silver Screens and Taylormade. Both have provided excellent fast service ( 48 hours from placing order to receiving screens) and we have not had the slightest trouble with any of the screens.

I'd be happy to buy again from either or both.

http://www.silverscreens.co.uk/

http://www.taylormade-covers.co.uk/

G


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## gaz44 (May 21, 2009)

we have internal, and the condensation can be bad.
they would not be our choice but we were given ours by discover when we brought the van.
they mostly stay in the locker, we use a blanket hanging from the overcab bed for privacy.


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## Mrplodd (Mar 4, 2008)

External Silver Screens every time. Good quality that fit well. I would also recommend the mesh panel they do that fits across the windscreen and provides shade from the sun whlst allowing you to see out.

DONT buy cheaper ones, it really is a case of you get what you pay for!!


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## MEES (Apr 20, 2006)

On previous van we used internal and did get condensation.
new van has cab curtains with thick black liners and we have never used the silver screens since.
We were in -18 in Germany and we had no problems.


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## witzend (Aug 22, 2009)

*which one*

Hi all I read this and had decided to go for the external but looking thru the aires photo's hardly any vans in the pictures are using them most have internal any thoughts as to why


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## Grizzly (May 9, 2005)

*Re: which one*



witzend said:


> Hi all I read this and had decided to go for the external but looking thru the aires photo's hardly any vans in the pictures are using them most have internal any thoughts as to why


I'd hazard a guess: most aires photos are taken during spring, summer or autumn when having one on the windscreen is not so vital. If you look at the ski -aires ( can't remember what they are called) I bet they have external screens.

It might be also partly because there are some aires where the occupants are a little concerned about safety and want to be sure they can make a quick get-away if necessary....but they are few and far between.

G


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## rosalan (Aug 24, 2009)

In the hot sun, the internal blinds do work well. In the winter they are not so good. Just aquired an external blind, following advice from Uncle Norman. If he was wrong :evil: 
Alan


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## safariboy (May 1, 2005)

rosalan said:


> I understood that for hot sun, the internal blinds keep your van cool.
> For cold weather and winter, the internal blinds keep the condensation away and the heat in.
> I must be honest and say that I do not like the external screens for several reasons.
> They do not look attractive and can get dirty.
> ...


If anything internal blinds will make condensation worse. The glass temperature will be lower (no longer being heated from the van) and that is probably the most important thing.
Given a good bag having to pack away a wet outside cover is not really a problem.
The aluminized summer weight covers are good when there is no cloud as they reduce radiation which is the major source of heat loss. If it is just very cold they are not so good.


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## rosalan (Aug 24, 2009)

Sorry Safariboy I have already seen the error of my ways following a sharp talking to by the good Uncle Norm and added an external blind to my collection. :wink: 
Alan


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## Stanner (Aug 17, 2006)

As they are inside the glass there is no way that internal screens can keep heat out in the summer and as they are internal they just insulate the glass from the heat of the van and so increase condensation in winter.

Having used both I just cannot see any situation where internal screens are better at anything than external ones.


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## safariboy (May 1, 2005)

Stanner said:


> As they are inside the glass there is no way that internal screens can keep heat out in the summer and as they are internal they just insulate the glass from the heat of the van and so increase condensation in winter.
> 
> Having used both I just cannot see any situation where internal screens are better at anything than external ones.


I agree with your conclusion but not all your reasoning. An aluminized screen will reflect out radiation and so keep the van cooler - inside or outside. It is still better to have the reflector on the outside because of effect due to wavelength changes.


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## Stanner (Aug 17, 2006)

safariboy said:


> Stanner said:
> 
> 
> > As they are inside the glass there is no way that internal screens can keep heat out in the summer and as they are internal they just insulate the glass from the heat of the van and so increase condensation in winter.
> ...


A reflector outside the glass will reflect far, far, more than ANY reflector inside the glass, where (as you say) wavelength changes mean most of any heating effect is trapped inside the glass.

Both will result in a cooler vehicle, but stopping the heat getting in in the first place results in a cooler, cooler vehicle - Thus


> Having used both I just cannot see any situation where internal screens are better at anything than external ones.


.

They may be better than nothing, but that isn't what I said.

Internal screens have only one advantage over externals - they can be left in place when driving - but please only do that on windows that you do not need to see through.


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## Ken38 (Mar 24, 2009)

Having lived for a while with internal and now having switched to external. The external are much more effective with condensation. They are also much easier to fit and take off.

There is no argument about external insulation versus internal for the sun. External is better in theory and practice.

For heat retention on cold sunny days internal would trap more heat in the vehicle by the greenhouse effect. Light and UV are allowed through the glass and converted to infra red which cannot exit the glass so it warms it and the air inside. That is also why they are not so good in the summer keeping heat out. 

During nights it would take a lot of careful analysis to figure out. My thermodynamics theory is a long way behind me! But the glass is definitely colder with internal blinds so any damp (from breathing) air that can circulate will cause condensation. That is my practical experience.

It was interesting at the Peterborough show watching the "internals" sponging off the water to leave and the externals just driving off! Having just bought my new external it completed the argument for me.


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## witzend (Aug 22, 2009)

How about theft of external blinds I know how they fit around doors and that they'd be damaged removing them etc but they would still be usable with some repair Has anyone had any stolen?


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## cabby (May 14, 2005)

I feel safe in saying tyhat theft of external blinds is not what one hears of. they would have to cutit off the vehicle around the doors and roll it up and walk away, all infull view of anyone around, now that I would say is deterrant enough.
External are better to insulate from cold, when wet you can roll them up and place them in the shower to drip dry. :lol: along with the shirts.

however if you do a lot of wild camping then the see through external ones might be your best bet.

cabby


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