Just read a great little article from Fine Homebuilding Online. It has harsh things to say about the insulative value of foil lined bubble wrap. While awesome as a reflective barrier in your windows, not so much as insulation. http://www.greenbuildingadvisor.com/...ilding-eletter

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George ><>
2005 5.4L E250 RB50 4x4 SMB
2000 4Runner Limited 4WD

But God demonstrates his own love for us in this: While we were still sinners, Christ died for us. Romans 5:8

Thank you for posting!

I still have a full roll of foil faced bubble wrap insulation I bought over 10 years ago.

I just never could convince myself about its worthiness to get around installing it.

Yes, I want something over my windows, especially in the Summer, but the flimsy bubble wrap nature always seemed like a pain for installation storage.

Is there a very thin rigid radiant barrier without bubbles which I could cut to fit then store on the inside ceiling when not it use?

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2002 E350 ext.; 160K; 7.3L; 4R100 (w/4x4 deep pan & filter); 4x4 conv. w/2007 F250/F350 coil frnt axle (oppos. dual Bilstein press. shocks cured DW) diff chg from 3.55 to 3.73 (bad!); BW1356 t.c. (bad!); LT265/70R17/E Michelin LTX M/S2; Engel MT60 Combi Fridge-Freezer; 4 BP 380J pv panels; Auragen 5kw AC gen. in top alt. position; Webasto Dual-Top; Voyager top. 1995 5.8L EB Bronco, bone stock.

Here's a material that I attempted to get purchased via a Group Buy here on the forum. The Group Buy didn't go anywhere, but I'm still very happy with Heat Shield. After we sold out SMB and included the Heat Shields along with it, we bought a full set for our Excursion.

viewtopic.php?f=13&t=6280&hilit=+group


Herb

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SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.

It seems to me too many have confused the very name of this material as having R values at least equal too other known and accepted insulation products.

It was never intended to be anything more than a radiant barrier against surfaces such as metal roofs or walls like found in buildings. Used in conjunction
with bat or foam planks its highly effective for its stated purpose.

I've installed this my self and it works just as promised, reducing inner skin temperature by as much as 20* with direct sunlight on one side. It works as promised, at least in my instances.

Well, I'm not an engineer but I've used this stuff in 104 degree and 20 degree temps and it is effective. Technically, scientifically I can't tell you how effective. In the heat it meant that I actually could cool the van. In the cold it meant that I only had to run my little cube ceramic heater for 40 minutes at 0430. The rest of the time body heat was sufficient. I have it cut to press fit in the front and back windows and it just rolls up in the SMB installed windows. Of course I also have a large piece for the windshield. Besides insulation/radiant barrier work it also provides much better privacy than the screens. I agree that you should refer to this product as a radiant barrier and not insulation. It's great for the windows but not sufficient as your primary insulation though I'm sure it would be helpful if used as the first layer against the van skin followed by bats or rigid foam.

Exactly---I do the same, great minds think alike!

I use a high quality inner solar shield bought through an eBay seller, example here: http://www.ebay.com/itm/CUSTOM-Fit-S...item3ccde6b09b. These roll up very compactly, stay in great shape even after a few years of daily use. For a mere $35 or so you've
got privacy out the ying-yang and they fit pretty much perfectly too!

HTH

Looks to be the same stuff that I bought as Heat Shield.
https://www.heatshieldstore.com/#custom-fit-div


Herb

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SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.

Herb, it looks like in addition to the typical windshield, Heatshield also makes side and rear panels too:

https://www.heatshieldstore.com/sun_sha ... /e350/2002

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2002 E350 ext.; 160K; 7.3L; 4R100 (w/4x4 deep pan & filter); 4x4 conv. w/2007 F250/F350 coil frnt axle (oppos. dual Bilstein press. shocks cured DW) diff chg from 3.55 to 3.73 (bad!); BW1356 t.c. (bad!); LT265/70R17/E Michelin LTX M/S2; Engel MT60 Combi Fridge-Freezer; 4 BP 380J pv panels; Auragen 5kw AC gen. in top alt. position; Webasto Dual-Top; Voyager top. 1995 5.8L EB Bronco, bone stock.

Had the Heat Shields for the windshield and front door windows of our SMB, and have the full set for our Excursion (8 shades in all). Love them, though eventually some of the suction cups can pull off. Last time I had an issue, Heat Shield sent me new suction cups and some reinforcing tabs for free. Great customer service. Website isn't that great, and doesn't necessarily show all the options they have available, so it's best to call.


Herb

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SMB-less as of 02/04/2012. Our savings account is richer, but our adventures are poorer.

My 2 cents....

Not questioning whether it has worked for you, but the valid question being addressed by the article is why is it effective. Almost anything can reduce heat transfer right? Whether putting on an old sweat shirt or covering up with newspaper or plastic trash bag can make a lot of difference to how comfortable we feel, and they don't have reflective surface. Corrugated cardboard works well as long as it stays dry, unfortunately making it a favorite of some homeless.

Anyway, the reflective outer layer does not affect heat transfer by either conduction or convection. Not directly anyway. A radiant surface only affects radiant heat flow which is usually a very very small number in most applications. And that's what the article is correctly critical of. Reflective surfaces can play a major part when heat is flowing between two bodies at vastly different temperatures, and also when conduction and convection have already been reduced to next to nothing. The first example is solar radiation because the sun and things on Earth are at very different temperatures. A radiant barrier between the sun and our skin will prevent heat to reach us. But so would any opaque item. It doesn't always have to reflect it. Sometimes absorbing the heat is good enough to stop heat flow.

A vacuum thermos bottle is a great example of when reflective is very important. That's because the vacuum stops both conduction and convection, so radiant heat flow is the main path to make our coffee get cold. Stainless vacuum mugs are usually polished inside to reduce heat flow. And in old days the glass thermos had a mirror finish to do the same.

Bottom line is that technical data can be misused very easily for advertising reasons. And sadly it often is. It all comes down to the specific use. The same product could go from very useful to almost worthless in different applications. And in house construction the article claims more of the latter.