Reflectix insulation

[Tom Trostel]

Reflectix is an flexible plastic insulation product. It looks like bubble wrap with a layer of silver mylar attached. Sunshades for car windshields are made of the same material. It's sold in rolls by Home Depot and Lowe's. Some pop-up and hybrid owners use it to insulate their bunk ends and vinyl areas. So I copied their idea to help make my trailer more comfortable. I cut 4 pieces of Reflectix to cover the inside of the vinyl that connects the two parts of the roof of my trailer. The two longer pieces are 100" X 14" and the other two are 48" X 14". They are held in place by friction. When not in use they are rolled up and stored under the benches. I think most Compact Jr, Compact II, and Trails West Campster owners could benefit from the same mod. I find it helps a great deal with keeping in heat in the winter and ac in the hot months. I also plan to cut pieces to match the windows of my trailer. These would be held in place with Velcro at the corners. Would be less for insulation and more for privacy and keeping out sunlight.

I've posted this mod before and am redoing it to help rebuild the archives.
Tom Trostel

http://albums.photo.epson.com/j/ViewPhoto?...0373&p=70829465

[John & Sandy M]

The stuff is used in the Scamp and, I think, the Casita. According to the Scamp literature the double layer is R15 (beats me how they arived at that) but...it works very well in our Scamp preventing solar heat build-up in the summer. Little experience in the cold tho.

[Kurt & Ann K.]

There is no sign of it's use by the factory on my 2000 Casita.
A very similar product (if not the same) is available from auto parts stores. It is meant for sound reduction and used under the hood, on firewalls, between the door skin and upholstered panel, and under the trunk lid too name just a few. I used it to line the aluminum diamond-plate enclosure for the generator on Nuestra Casita's tongue. 3M General Trim Adhesive (Part No. 08088) could be used to glue it to foam panels to make even more efficient insulation. For window use, it could be simply tucked behind the blinds (our blinds have velcro strips which prevent them swinging while underway).
For our purpose, we used 3M Super Trim Adhesive yellow (Part No. 08090) because of it's heat resistance.
[/U]Kurt[U] & Ann K.

[pjanits]

I slid this stuff as far up between the walls of my Burro as I could, and lined the closets and cabinets and floor bins with it.
It seems a little warmer so far, but too soon to tell. It's quieter anyway.
My Burro had no insulation.

[Pete Dumbleton]

I believe Casita relies on the foam backing on the carpet as additional insulation, rather than Reflectix.

Scamp is apparently less than forthcoming about the R15 value of Reflectix -- At some time in the past, I was reading some Reflectix literature and it said something like "can bring a standard house wall up to R15" or words to that general effect -- I doubt that the Reflectix alone is more than R3-5.

That said, however, I can attest that if one leaves one's Scamp parked in the sun all day, it will hld the heat inside for a looong time at nite before it cools down, which is why I always try to park in shade or where I can put a tarp over a line between a couple of trees.

Found a Link and on a masonry basement wall with a 1" space it has R-3.30 and with a 2" space it is R-4.24. In an attic, as a reflective barrier, they make this statement:

"What about R-values? Reflectix® performs as a radiant barrier in this use rather than as an insulation. Therefore, we make no R-value claims for this application."

[Bill Abbay]

In a past life, I was hired to evaluate the claims made by Reflectix by a building supply retailer. In the process, I found that most of what they claim is a gross extrapolation from very favorable test conditions. While it's true that reflective air film(s) (the basic effect behind the product) can procuce good effective R-values, the average real world application of the product won't. The State of California has a very technically competent Energy Commission that has denied Reflectix's claims in virtually every area, to the point that, as far as I know, it isn't certified for any application in new or remodel construction. And that includes the assemblies listed in the Reflectix brochure that Pete has listed the link to.

Of course, this doesn't preclude them from continuing to claim almost anything in their Point of Sale displays or brochures.

As Pete points out, above, because it takes an air space adjacent to Reflectix to achieve any useful R-value, it's use in our trailers may not deliver as much as we would hope. On the other hand, there is some benefit to the product. In an otherwise uninsulated trailer, applying something with an R-3 or so R-value to an R-2 wall might make a noticeable difference. While the reduction in heat loss may be modest, the reduction or elimination of condensation, for example, might make it all worth it.

[Brian B-P]

I agree with Bill that the application in our trailers is unlike the intended application, and is unlikely to be very effective as general wall insulation. Aside from the reflective properties, the material is bunch of bubbles, and thus must be somewhat effective as insulation to limit heat loss by conduction. I do not see how it could possibly be as effective as a foam intended for insulation, and those materials typically achieve no more than R5 per inch, so I doubt that a couple layers of Reflectix would be as good as even R3, but I'm only guessing.

I think this material is used on molded trailer walls primarily because it is a somewhat flexible sheet, while other insulation materials are either too rigid to fit to the curved trailer walls (such as polystyrene foam), or not capable of holding together as a surface covering (such as fiberglass batting). The mechanical properties also make it workable for the window shade and removable panel applications that Tom described.

I have not yet had the opportunity to see the internal construction of a Bigfoot trailer, but as I understand their literature, they use expanded polystyrene foam board, with an insulation value of R8:

Originally posted by http://www.bigfootrv.com/traveltrailers/features.htm
1 1/2" high density EPS insulation (R8)

Since Bigfoot seems to be the only current molded fiberglass trailer maker which claims any suitability for winter operation, their choice seems particularly relevant.

While it is a motorhome - not a trailer - the EarthRoamer body construction is molded fiberglass and it, like the Bigfoot , uses foam for insulation and is intended for cold-weather use. By the way, I think one of their bodies on a suitable frame would make a very interesting molded fiberglass travel trailer.

Again, mechanical properties are important, and ability to be rolled up makes it particularly suitable for Tom's application, where the stiff foam insulation would not work.

[Bill Abbay]

Brian,
Haven't been inside the walls yet, but you can see inside the roof here, just scroll down.

[Jackie]

other insulation materials are either too rigid to fit to the curved trailer walls (such as polystyrene foam)

Brian - See my posts under mods - Begin the Begin - where I used the polypropylene - rated at R12 in this application.

[Pete Dumbleton]

Bill, off the insulation topic, but below is a photo of Nevin Lescher's door holder solution -- the strut stays attached -- when the door is closed, the strut keeps it closed and when open, it stays that way. I've lost the narrative that Nevin had with it as he had to do some critical measurements to match an exactly correct strut for both the open and closed positions.

[Brian B-P]

... See my posts under mods - Begin the Begin - where I used the polypropylene - rated at R12 in this application.

Thanks for the pointer, Jackie - I had not yet had a chance to look at your very interesting and well illustrated posts.

The Microfoil looks like a potentially good alternative to both Ensolite and Reflectix, depending on specific application requirements. Just like Reflectix, the Microfoil will have much lower effective insulation value without the air gap, so I certainly wouldn't expect it to work as R12, but I would guess it would be better than the same thickness of Reflectix.

Jackie, was your R12 value intended to refer to Tom's application, or the wall lining application of your Ensolite replacement?

[Jackie]

The following is from the Microfoil website. I hope it answers your question, as I understand it.

"The microfoil insulation has a stand alone r-value of 14.4. When you start
to incorporate a trapped airspace with the material, you can really increase
your r-value. On the average 1" of trapped air space has about a r-4 value,
for each additional inch added to the trapped airspace the r-value increases
4 fold, from 1 to 6 inches of trapped air, after 6" you will get diminishing
returns. For instance 14.4 + (6" of trapped air x 4) your r-value would be
38.4 (roof downward). In a horizontal wall application the r-value would
equate to 10.2 + ( 3" of trapped air x4) your r-value will be r-22.2. You
have to under stand the insulation is a directional material. In different
applications you have a directional r-value. Plus you have to count the
trapped airspace to get a over all total. "

[Brian B-P]

That's the description which I read from the Microfoil site, but I am suspicious of the "stand alone" value: I think they are assuming it is not in contact with other materials on both the warm and cold sides, but has at least some space on the foil side, for the reflective effect to take place. I can't image any 1/4" thick foam has a resistance to thermal conduction of R14.4; for that thickness R1 to R2 is believeable. If this material were really that effective, it would be R57.6 per inch, and it could just be used in two to four 1/4" layers to handle any wall or attic requirement instead of arranging for air spaces.

The material does look promising for both of the applications we are discussing; I just don't think either one matches the base conditions that led to the manufacturer's "stand alone" insulation value claim.

[Bill Abbay]

Folks,

On the average 1" of trapped air space has about a r-4 value,
for each additional inch added to the trapped airspace the r-value increases
4 fold, from 1 to 6 inches of trapped air, after 6" you will get diminishing
returns.

I suppose this might fall under the heading of "don't believe everything you see on the Internet". The Microfoil site, for instance, would have us believe that [b]air ("R-4 per inch") has a better R-value than fiberglass insulation (R-3.5 or so per inch). This just ain't so.

And, unfortunately, air space diminishing returns begin at far less thicknesses than 6". The bugaboo here is thermal convection. When you have a thermal gradient across an air space, the warm/cold difference causes convection, effectively moving heat from the warm side to the cold side. This drastically reduces the effective R-value of the space. The effect actually begins at under an inch, which is why dual pane windows seldom have glass separations over 3/4". This is the reason why super high efficiency insulated glass is triple glazed..

As I mentioned before, some insulation is certainly better than nothing. And doubtless, some forms of insulation are more appropriate for a given application than others. But whether you're getting what you pay for, that is the question.

[jack maloney]

I used the polypropylene - rated at R12 in this application.

Can you source sheet polypropelene material? All I can find is electrical insulation. Thanks!

[Pete Dumbleton]

I used the polypropylene - rated at R12 in this application.

Can you source sheet polypropelene material? All I can find is electrical insulation. Thanks!

Umm, maybe too many "e"s and not enuf "y"s ??? :76 Try also "visqueen" which is what the construction trades call sheet poly.

[Brian B-P]

...Umm, maybe too many "e"s and not enuf "y"s ??? :76 Try also "visqueen" which is what the construction trades call sheet poly.

In the British Visqueen product list (all I found readily in Google), all of the products appear to be thin membranes, rather insulating foams of any thickness. They are also probably all polyethylene, rather than polypropylene. who knows, maybe there's whole different product line in the U.S.

By the way, I had never heard of "visqueen" before today - it's just called "poly" around here are far as I know.

[Bill Abbay]

By the way, I had never heard of "visqueen" before today - it's just called "poly" around here are far as I know.

Pete's just showing his ... maturity, there. Years ago, poly film, especially in the construction trades, was likely made by Visqueen. As more manufacturers got into the act, it was less likely to be, actually, "Visqueen", but the name stuck, like we call pull-up tissues "Kleenex". Not so much any more. More on Visqueen here.

Sometime you just gotta be old to know stuff.

[John & Sandy M]

In a former life I evaluated various insulated packaging for the shipment of drugs to hospitals and distribution warehouses (yes... I did drugs for many years!). Polystyrene (the stuff in inexpensive foam coolers etc.) foam has a R value of around 3 per inch and polyurethane foam about R7 (the stuff in high quality coolers and better refrigerators). The insulating quality of the polyurethane foam is due to the size of the bubbles in the foam and due to the use of freon in it's production. I found by thermocouple measurement of temp. changes in a hot box (this was aroung 55C as I recall). Urethane foam with aluminized mylar bonded to both sides performed 3-4 times better than the polysytrene foam as a packaging insulator.

As for usage in a fiberglass trailer? Probably could be done but would be expensive and difficult to use

[Brian B-P]

...Polystyrene (the stuff in inexpensive foam coolers etc.) foam has a R value of around 3 per inch and polyurethane foam about R7 (the stuff in high quality coolers and better refrigerators). The insulating quality of the polyurethane foam is due to the size of the bubbles in the foam and due to the use of freon in it's production...

Lots of good information!

The "stuff in inexpensive foam coolers" is polystyrene foam, usually molded from beads, but better polystyrene insulation such as Styrofoam® is extruded. The extruded foams have better structure, and thus higher R-values; for instance, most Styrofoam® products are R-5 per inch. And no, this isn't an ad for Dow products...

Looking for background information for this discussion, I found that there is a Insulation.org web site. Obvious, in hindsight...